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* Merge tag 'powerpc-4.13-5' of ↵Linus Torvalds2017-08-04
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Fixes for recently merged code: - a fix for the _PAGE_DEVMAP support, which was breaking KVM on Power9 radix - avoid a (harmless) lockdep warning in the early SMP code - return failure for some uses of dma_set_mask() rather than falling back to 32-bits - fix stack setup in watchdog soft_nmi_common() to use emergency stack - fix of_irq_to_resource() error check in of_fsl_spi_probe() Two fixes going to stable: - fix saving of Transactional Memory SPRs in core dump - fix __check_irq_replay missing decrementer interrupt And two misc: - fix 64-bit boot wrapper build with non-biarch compiler - work around a POWER9 PMU hang after state-loss idle Thanks to: Alistair Popple, Aneesh Kumar K.V, Cyril Bur, Gustavo Romero, Jose Ricardo Ziviani, Laurent Vivier, Nicholas Piggin, Oliver O'Halloran, Sergei Shtylyov, Suraj Jitindar Singh, Thomas Gleixner" * tag 'powerpc-4.13-5' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64: Fix __check_irq_replay missing decrementer interrupt powerpc/perf: POWER9 PMU stops after idle workaround powerpc/83xx/mpc832x_rdb: fix of_irq_to_resource() error check powerpc/64s: Fix stack setup in watchdog soft_nmi_common() powerpc/powernv/pci: Return failure for some uses of dma_set_mask() powerpc/boot: Fix 64-bit boot wrapper build with non-biarch compiler powerpc/smp: Call smp_ops->setup_cpu() directly on the boot CPU powerpc/tm: Fix saving of TM SPRs in core dump powerpc/mm: Fix pmd/pte_devmap() on non-leaf entries
| * Merge tag 'v4.13-rc1' into fixesMichael Ellerman2017-07-31
| |\ | | | | | | | | | | | | | | | | | | | | | The fixes branch is based off a random pre-rc1 commit, because we had some fixes that needed to go in before rc1 was released. However we now need to fix some code that went in after that point, but before rc1, so merge rc1 to get that code into fixes so we can fix it!
| * | powerpc/mm: Fix pmd/pte_devmap() on non-leaf entriesOliver O'Halloran2017-07-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The Radix MMU translation tree as defined in ISA v3.0 contains two different types of entry, directories and leaves. Leaves are identified by _PAGE_PTE being set. The formats of the two entries are different, with the directory entries containing no spare bits for use by software. In particular the bit we use for _PAGE_DEVMAP is not reserved for software, and is part of the NLB (Next Level Base) field, essentially the address of the next level in the tree. Note that the Linux pte_t is not == _PAGE_PTE. A huge page pmd entry (or devmap!) is also a leaf and so has _PAGE_PTE set, even though we use a pmd_t for it in Linux. The fix is to ensure that the pmd/pte_devmap() confirm they are looking at a leaf entry (_PAGE_PTE) as well as checking _PAGE_DEVMAP. Fixes: ebd31197931d ("powerpc/mm: Add devmap support for ppc64") Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Tested-by: Laurent Vivier <lvivier@redhat.com> Tested-by: Jose Ricardo Ziviani <joserz@linux.vnet.ibm.com> Reviewed-by: Suraj Jitindar Singh <sjitindarsingh@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> [mpe: Add a comment in the code and flesh out change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | Merge tag 'powerpc-4.13-4' of ↵Linus Torvalds2017-07-28
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "The highlight is Ben's patch to work around a host killing bug when running KVM guests with the Radix MMU on Power9. See the long change log of that commit for more detail. And then three fairly minor fixes: - fix of_node_put() underflow during reconfig remove, using old DLPAR tools. - fix recently introduced ld version check with 64-bit LE-only toolchain. - free the subpage_prot_table correctly, avoiding a memory leak. Thanks to: Aneesh Kumar K.V, Benjamin Herrenschmidt, Laurent Vivier" * tag 'powerpc-4.13-4' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm/hash: Free the subpage_prot_table correctly powerpc/Makefile: Fix ld version check with 64-bit LE-only toolchain powerpc/pseries: Fix of_node_put() underflow during reconfig remove powerpc/mm/radix: Workaround prefetch issue with KVM
| * | powerpc/mm/radix: Workaround prefetch issue with KVMBenjamin Herrenschmidt2017-07-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's a somewhat architectural issue with Radix MMU and KVM. When coming out of a guest with AIL (Alternate Interrupt Location, ie, MMU enabled), we start executing hypervisor code with the PID register still containing whatever the guest has been using. The problem is that the CPU can (and will) then start prefetching or speculatively load from whatever host context has that same PID (if any), thus bringing translations for that context into the TLB, which Linux doesn't know about. This can cause stale translations and subsequent crashes. Fixing this in a way that is neither racy nor a huge performance impact is difficult. We could just make the host invalidations always use broadcast forms but that would hurt single threaded programs for example. We chose to fix it instead by partitioning the PID space between guest and host. This is possible because today Linux only use 19 out of the 20 bits of PID space, so existing guests will work if we make the host use the top half of the 20 bits space. We additionally add support for a property to indicate to Linux the size of the PID register which will be useful if we eventually have processors with a larger PID space available. There is still an issue with malicious guests purposefully setting the PID register to a value in the hosts PID range. Hopefully future HW can prevent that, but in the meantime, we handle it with a pair of kludges: - On the way out of a guest, before we clear the current VCPU in the PACA, we check the PID and if it's outside of the permitted range we flush the TLB for that PID. - When context switching, if the mm is "new" on that CPU (the corresponding bit was set for the first time in the mm cpumask), we check if any sibling thread is in KVM (has a non-NULL VCPU pointer in the PACA). If that is the case, we also flush the PID for that CPU (core). This second part is needed to handle the case where a process is migrated (or starts a new pthread) on a sibling thread of the CPU coming out of KVM, as there's a window where stale translations can exist before we detect it and flush them out. A future optimization could be added by keeping track of whether the PID has ever been used and avoid doing that for completely fresh PIDs. We could similarily mark PIDs that have been the subject of a global invalidation as "fresh". But for now this will do. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [mpe: Rework the asm to build with CONFIG_PPC_RADIX_MMU=n, drop unneeded include of kvm_book3s_asm.h] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | Merge tag 'powerpc-4.13-3' of ↵Linus Torvalds2017-07-21
|\| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "A handful of fixes, mostly for new code: - some reworking of the new STRICT_KERNEL_RWX support to make sure we also remove executable permission from __init memory before it's freed. - a fix to some recent optimisations to the hypercall entry where we were clobbering r12, this was breaking nested guests (PR KVM). - a fix for the recent patch to opal_configure_cores(). This could break booting on bare metal Power8 boxes if the kernel was built without CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG. - .. and finally a workaround for spurious PMU interrupts on Power9 DD2. Thanks to: Nicholas Piggin, Anton Blanchard, Balbir Singh" * tag 'powerpc-4.13-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=y powerpc/mm/hash: Refactor hash__mark_rodata_ro() powerpc/mm/radix: Refactor radix__mark_rodata_ro() powerpc/64s: Fix hypercall entry clobbering r12 input powerpc/perf: Avoid spurious PMU interrupts after idle powerpc/powernv: Fix boot on Power8 bare metal due to opal_configure_cores()
| * | powerpc/mm: Mark __init memory no-execute when STRICT_KERNEL_RWX=yMichael Ellerman2017-07-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently even with STRICT_KERNEL_RWX we leave the __init text marked executable after init, which is bad. Add a hook to mark it NX (no-execute) before we free it, and implement it for radix and hash. Note that we use __init_end as the end address, not _einittext, because overlaps_kernel_text() uses __init_end, because there are additional executable sections other than .init.text between __init_begin and __init_end. Tested on radix and hash with: 0:mon> p $__init_begin *** 400 exception occurred Fixes: 1e0fc9d1eb2b ("powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs") Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds2017-07-21
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull core fixes from Ingo Molnar: "A fix to WARN_ON_ONCE() done by modules, plus a MAINTAINERS update" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: debug: Fix WARN_ON_ONCE() for modules MAINTAINERS: Update the PTRACE entry
| * | debug: Fix WARN_ON_ONCE() for modulesJosh Poimboeuf2017-07-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Mike Galbraith reported a situation where a WARN_ON_ONCE() call in DRM code turned into an oops. As it turns out, WARN_ON_ONCE() seems to be completely broken when called from a module. The bug was introduced with the following commit: 19d436268dde ("debug: Add _ONCE() logic to report_bug()") That commit changed WARN_ON_ONCE() to move its 'once' logic into the bug trap handler. It requires a writable bug table so that the BUGFLAG_DONE bit can be written to the flags to indicate the first warning has occurred. The bug table was made writable for vmlinux, which relies on vmlinux.lds.S and vmlinux.lds.h for laying out the sections. However, it wasn't made writable for modules, which rely on the ELF section header flags. Reported-by: Mike Galbraith <efault@gmx.de> Tested-by: Masami Hiramatsu <mhiramat@kernel.org> Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: 19d436268dde ("debug: Add _ONCE() logic to report_bug()") Link: http://lkml.kernel.org/r/a53b04235a65478dd9afc51f5b329fdc65c84364.1500095401.git.jpoimboe@redhat.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'work.uaccess-unaligned' of ↵Linus Torvalds2017-07-15
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull uacess-unaligned removal from Al Viro: "That stuff had just one user, and an exotic one, at that - binfmt_flat on arm and m68k" * 'work.uaccess-unaligned' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kill {__,}{get,put}_user_unaligned() binfmt_flat: flat_{get,put}_addr_from_rp() should be able to fail
| * | | kill {__,}{get,put}_user_unaligned()Al Viro2017-07-03
| | | | | | | | | | | | | | | | | | | | | | | | no users left Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | | | Merge tag 'powerpc-4.13-2' of ↵Linus Torvalds2017-07-14
|\ \ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc fixes from Michael Ellerman: "Nothing that really stands out, just a bunch of fixes that have come in in the last couple of weeks. None of these are actually fixes for code that is new in 4.13. It's roughly half older bugs, with fixes going to stable, and half fixes/updates for Power9. Thanks to: Aneesh Kumar K.V, Anton Blanchard, Balbir Singh, Benjamin Herrenschmidt, Madhavan Srinivasan, Michael Neuling, Nicholas Piggin, Oliver O'Halloran" * tag 'powerpc-4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/64: Fix atomic64_inc_not_zero() to return an int powerpc: Fix emulation of mfocrf in emulate_step() powerpc: Fix emulation of mcrf in emulate_step() powerpc/perf: Add POWER9 alternate PM_RUN_CYC and PM_RUN_INST_CMPL events powerpc/perf: Fix SDAR_MODE value for continous sampling on Power9 powerpc/asm: Mark cr0 as clobbered in mftb() powerpc/powernv: Fix local TLB flush for boot and MCE on POWER9 powerpc/mm/radix: Synchronize updates to the process table powerpc/mm/radix: Properly clear process table entry powerpc/powernv: Tell OPAL about our MMU mode on POWER9 powerpc/kexec: Fix radix to hash kexec due to IAMR/AMOR
| * | | powerpc/64: Fix atomic64_inc_not_zero() to return an intMichael Ellerman2017-07-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Although it's not documented anywhere, there is an expectation that atomic64_inc_not_zero() returns a result which fits in an int. This is the behaviour implemented on all arches except powerpc. This has caused at least one bug in practice, in the percpu-refcount code, where the long result from our atomic64_inc_not_zero() was truncated to an int leading to lost references and stuck systems. That was worked around in that code in commit 966d2b04e070 ("percpu-refcount: fix reference leak during percpu-atomic transition"). To the best of my grepping abilities there are no other callers in-tree which truncate the value, but we should fix it anyway. Because the breakage is subtle and potentially very harmful I'm also tagging it for stable. Code generation is largely unaffected because in most cases the callers are just using the result for a test anyway. In particular the case of fget() that was mentioned in commit a6cf7ed5119f ("powerpc/atomic: Implement atomic*_inc_not_zero") generates exactly the same code. Fixes: a6cf7ed5119f ("powerpc/atomic: Implement atomic*_inc_not_zero") Cc: stable@vger.kernel.org # v3.4 Noticed-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | powerpc/asm: Mark cr0 as clobbered in mftb()Oliver O'Halloran2017-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The workaround for the CELL timebase bug does not correctly mark cr0 as being clobbered. This means GCC doesn't know that the asm block changes cr0 and might leave the result of an unrelated comparison in cr0 across the block, which we then trash, leading to basically random behaviour. Fixes: 859deea949c3 ("[POWERPC] Cell timebase bug workaround") Cc: stable@vger.kernel.org # v2.6.19+ Signed-off-by: Oliver O'Halloran <oohall@gmail.com> [mpe: Tweak change log and flag for stable] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | powerpc/powernv: Tell OPAL about our MMU mode on POWER9Benjamin Herrenschmidt2017-07-10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | That will allow OPAL to configure the CPU in an optimal way. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: Michael Neuling <mikey@neuling.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
* | | | mm, tree wide: replace __GFP_REPEAT by __GFP_RETRY_MAYFAIL with more useful ↵Michal Hocko2017-07-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | semantic __GFP_REPEAT was designed to allow retry-but-eventually-fail semantic to the page allocator. This has been true but only for allocations requests larger than PAGE_ALLOC_COSTLY_ORDER. It has been always ignored for smaller sizes. This is a bit unfortunate because there is no way to express the same semantic for those requests and they are considered too important to fail so they might end up looping in the page allocator for ever, similarly to GFP_NOFAIL requests. Now that the whole tree has been cleaned up and accidental or misled usage of __GFP_REPEAT flag has been removed for !costly requests we can give the original flag a better name and more importantly a more useful semantic. Let's rename it to __GFP_RETRY_MAYFAIL which tells the user that the allocator would try really hard but there is no promise of a success. This will work independent of the order and overrides the default allocator behavior. Page allocator users have several levels of guarantee vs. cost options (take GFP_KERNEL as an example) - GFP_KERNEL & ~__GFP_RECLAIM - optimistic allocation without _any_ attempt to free memory at all. The most light weight mode which even doesn't kick the background reclaim. Should be used carefully because it might deplete the memory and the next user might hit the more aggressive reclaim - GFP_KERNEL & ~__GFP_DIRECT_RECLAIM (or GFP_NOWAIT)- optimistic allocation without any attempt to free memory from the current context but can wake kswapd to reclaim memory if the zone is below the low watermark. Can be used from either atomic contexts or when the request is a performance optimization and there is another fallback for a slow path. - (GFP_KERNEL|__GFP_HIGH) & ~__GFP_DIRECT_RECLAIM (aka GFP_ATOMIC) - non sleeping allocation with an expensive fallback so it can access some portion of memory reserves. Usually used from interrupt/bh context with an expensive slow path fallback. - GFP_KERNEL - both background and direct reclaim are allowed and the _default_ page allocator behavior is used. That means that !costly allocation requests are basically nofail but there is no guarantee of that behavior so failures have to be checked properly by callers (e.g. OOM killer victim is allowed to fail currently). - GFP_KERNEL | __GFP_NORETRY - overrides the default allocator behavior and all allocation requests fail early rather than cause disruptive reclaim (one round of reclaim in this implementation). The OOM killer is not invoked. - GFP_KERNEL | __GFP_RETRY_MAYFAIL - overrides the default allocator behavior and all allocation requests try really hard. The request will fail if the reclaim cannot make any progress. The OOM killer won't be triggered. - GFP_KERNEL | __GFP_NOFAIL - overrides the default allocator behavior and all allocation requests will loop endlessly until they succeed. This might be really dangerous especially for larger orders. Existing users of __GFP_REPEAT are changed to __GFP_RETRY_MAYFAIL because they already had their semantic. No new users are added. __alloc_pages_slowpath is changed to bail out for __GFP_RETRY_MAYFAIL if there is no progress and we have already passed the OOM point. This means that all the reclaim opportunities have been exhausted except the most disruptive one (the OOM killer) and a user defined fallback behavior is more sensible than keep retrying in the page allocator. [akpm@linux-foundation.org: fix arch/sparc/kernel/mdesc.c] [mhocko@suse.com: semantic fix] Link: http://lkml.kernel.org/r/20170626123847.GM11534@dhcp22.suse.cz [mhocko@kernel.org: address other thing spotted by Vlastimil] Link: http://lkml.kernel.org/r/20170626124233.GN11534@dhcp22.suse.cz Link: http://lkml.kernel.org/r/20170623085345.11304-3-mhocko@kernel.org Signed-off-by: Michal Hocko <mhocko@suse.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alex Belits <alex.belits@cavium.com> Cc: Chris Wilson <chris@chris-wilson.co.uk> Cc: Christoph Hellwig <hch@infradead.org> Cc: Darrick J. Wong <darrick.wong@oracle.com> Cc: David Daney <david.daney@cavium.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: NeilBrown <neilb@suse.com> Cc: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | powerpc/64s: implement arch-specific hardlockup watchdogNicholas Piggin2017-07-12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Implement an arch-speicfic watchdog rather than use the perf-based hardlockup detector. The new watchdog takes the soft-NMI directly, rather than going through perf. Perf interrupts are to be made maskable in future, so that would prevent the perf detector from working in those regions. Additionally, implement a SMP based detector where all CPUs watch one another by pinging a shared cpumask. This is because powerpc Book3S does not have a true periodic local NMI, but some platforms do implement a true NMI IPI. If a CPU is stuck with interrupts hard disabled, the soft-NMI watchdog does not work, but the SMP watchdog will. Even on platforms without a true NMI IPI to get a good trace from the stuck CPU, other CPUs will notice the lockup sufficiently to report it and panic. [npiggin@gmail.com: honor watchdog disable at boot/hotplug] Link: http://lkml.kernel.org/r/20170621001346.5bb337c9@roar.ozlabs.ibm.com [npiggin@gmail.com: fix false positive warning at CPU unplug] Link: http://lkml.kernel.org/r/20170630080740.20766-1-npiggin@gmail.com [akpm@linux-foundation.org: coding-style fixes] Link: http://lkml.kernel.org/r/20170616065715.18390-6-npiggin@gmail.com Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Don Zickus <dzickus@redhat.com> Tested-by: Babu Moger <babu.moger@oracle.com> [sparc] Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | powerpc: move ELF_ET_DYN_BASE to 4GB / 4MBKees Cook2017-07-10
|/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that explicitly executed loaders are loaded in the mmap region, we have more freedom to decide where we position PIE binaries in the address space to avoid possible collisions with mmap or stack regions. For 64-bit, align to 4GB to allow runtimes to use the entire 32-bit address space for 32-bit pointers. On 32-bit use 4MB, which is the traditional x86 minimum load location, likely to avoid historically requiring a 4MB page table entry when only a portion of the first 4MB would be used (since the NULL address is avoided). Link: http://lkml.kernel.org/r/1498154792-49952-4-git-send-email-keescook@chromium.org Signed-off-by: Kees Cook <keescook@chromium.org> Tested-by: Michael Ellerman <mpe@ellerman.id.au> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: Russell King <linux@armlinux.org.uk> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: James Hogan <james.hogan@imgtec.com> Cc: Pratyush Anand <panand@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | Merge tag 'powerpc-4.13-1' of ↵Linus Torvalds2017-07-07
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux Pull powerpc updates from Michael Ellerman: "Highlights include: - Support for STRICT_KERNEL_RWX on 64-bit server CPUs. - Platform support for FSP2 (476fpe) board - Enable ZONE_DEVICE on 64-bit server CPUs. - Generic & powerpc spin loop primitives to optimise busy waiting - Convert VDSO update function to use new update_vsyscall() interface - Optimisations to hypercall/syscall/context-switch paths - Improvements to the CPU idle code on Power8 and Power9. As well as many other fixes and improvements. Thanks to: Akshay Adiga, Andrew Donnellan, Andrew Jeffery, Anshuman Khandual, Anton Blanchard, Balbir Singh, Benjamin Herrenschmidt, Christophe Leroy, Christophe Lombard, Colin Ian King, Dan Carpenter, Gautham R. Shenoy, Hari Bathini, Ian Munsie, Ivan Mikhaylov, Javier Martinez Canillas, Madhavan Srinivasan, Masahiro Yamada, Matt Brown, Michael Neuling, Michal Suchanek, Murilo Opsfelder Araujo, Naveen N. Rao, Nicholas Piggin, Oliver O'Halloran, Paul Mackerras, Pavel Machek, Russell Currey, Santosh Sivaraj, Stephen Rothwell, Thiago Jung Bauermann, Yang Li" * tag 'powerpc-4.13-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (158 commits) powerpc/Kconfig: Enable STRICT_KERNEL_RWX for some configs powerpc/mm/radix: Implement STRICT_RWX/mark_rodata_ro() for Radix powerpc/mm/hash: Implement mark_rodata_ro() for hash powerpc/vmlinux.lds: Align __init_begin to 16M powerpc/lib/code-patching: Use alternate map for patch_instruction() powerpc/xmon: Add patch_instruction() support for xmon powerpc/kprobes/optprobes: Use patch_instruction() powerpc/kprobes: Move kprobes over to patch_instruction() powerpc/mm/radix: Fix execute permissions for interrupt_vectors powerpc/pseries: Fix passing of pp0 in updatepp() and updateboltedpp() powerpc/64s: Blacklist rtas entry/exit from kprobes powerpc/64s: Blacklist functions invoked on a trap powerpc/64s: Un-blacklist system_call() from kprobes powerpc/64s: Move system_call() symbol to just after setting MSR_EE powerpc/64s: Blacklist system_call() and system_call_common() from kprobes powerpc/64s: Convert .L__replay_interrupt_return to a local label powerpc64/elfv1: Only dereference function descriptor for non-text symbols cxl: Export library to support IBM XSL powerpc/dts: Use #include "..." to include local DT powerpc/perf/hv-24x7: Aggregate result elements on POWER9 SMT8 ...
| * | | powerpc/mm/hash: Implement mark_rodata_ro() for hashBalbir Singh2017-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With hash we update the bolted pte to mark it read-only. We rely on the MMU_FTR_KERNEL_RO to generate the correct permissions for read-only text. The radix implementation just prints a warning in this implementation Signed-off-by: Balbir Singh <bsingharora@gmail.com> [mpe: Make the warning louder when we don't have MMU_FTR_KERNEL_RO] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | powerpc64/elfv1: Only dereference function descriptor for non-text symbolsNaveen N. Rao2017-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, we assume that the function pointer we receive in ppc_function_entry() points to a function descriptor. However, this is not always the case. In particular, assembly symbols without the right annotation do not have an associated function descriptor. Some of these symbols are added to the kprobe blacklist using _ASM_NOKPROBE_SYMBOL(). When such addresses are subsequently processed through arch_deref_entry_point() in populate_kprobe_blacklist(), we see the below errors during bootup: [ 0.663963] Failed to find blacklist at 7d9b02a648029b6c [ 0.663970] Failed to find blacklist at a14d03d0394a0001 [ 0.663972] Failed to find blacklist at 7d5302a6f94d0388 [ 0.663973] Failed to find blacklist at 48027d11e8610178 [ 0.663974] Failed to find blacklist at f8010070f8410080 [ 0.663976] Failed to find blacklist at 386100704801f89d [ 0.663977] Failed to find blacklist at 7d5302a6f94d00b0 Fix this by checking if the function pointer we receive in ppc_function_entry() already points to kernel text. If so, we just return it as is. If not, we assume that this is a function descriptor and proceed to dereference it. Suggested-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | cxl: Export library to support IBM XSLChristophe Lombard2017-07-03
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch exports a in-kernel 'library' API which can be called by other drivers to help interacting with an IBM XSL on a POWER9 system. The XSL (Translation Service Layer) is a stripped down version of the PSL (Power Service Layer) used in some cards such as the Mellanox CX5. Like the PSL, it implements the CAIA architecture, but has a number of differences, mostly in it's implementation dependent registers. The XSL also uses a special DMA cxl mode, which uses a slightly different init sequence for the CAPP and PHB. Signed-off-by: Andrew Donnellan <andrew.donnellan@au1.ibm.com> Signed-off-by: Christophe Lombard <clombard@linux.vnet.ibm.com> Acked-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | Merge branch 'fixes' into nextMichael Ellerman2017-07-03
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | Merge our fixes branch, a few of them are tripping people up while working on top of next, and we also have a dependency between the CXL fixes and new CXL code we want to merge into next.
| * | | | powerpc/mm: Add devmap support for ppc64Oliver O'Halloran2017-07-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support for the devmap bit on PTEs and PMDs for PPC64 Book3S. This is used to differentiate device backed memory from transparent huge pages since they are handled in more or less the same manner by the core mm code. Cc: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Oliver O'Halloran <oohall@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc: use spin loop primitives in some functionsNicholas Piggin2017-07-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the different spin loop primitives in some simple powerpc spin loops, including those which will spin as a common case. This will help to test the spin loop primitives before more conversions are done. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Add some includes of <linux/processor.h>] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64: implement spin loop primitivesNicholas Piggin2017-07-02
| | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/fadump: avoid holes in boot memory area when fadump is registeredHari Bathini2017-06-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | To register fadump, boot memory area - the size of low memory chunk that is required for a kernel to boot successfully when booted with restricted memory, is assumed to have no holes. But this memory area is currently not protected from hot-remove operations. So, fadump could fail to re-register after a memory hot-remove operation, if memory is removed from boot memory area. To avoid this, ensure that memory from boot memory area is not hot-removed when fadump is registered. Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com> Reviewed-by: Mahesh J Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/powernv/pci: Add support for PHB4 diagnosticsRussell Currey2017-06-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | As with P7IOC and PHB3, add kernel-side support for decoding and printing diagnostic data for PHB4. Signed-off-by: Russell Currey <ruscur@russell.cc> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/mm: Trace tlbie(l) instructionsBalbir Singh2017-06-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a trace point for tlbie(l) (Translation Lookaside Buffer Invalidate Entry (Local)) instructions. The tlbie instruction has changed over the years, so not all versions accept the same operands. Use the ISA v3 field operands because they are the most verbose, we may change them in future. Example output: qemu-system-ppc-5371 [016] 1412.369519: tlbie: tlbie with lpid 0, local 1, rb=67bd8900174c11c1, rs=0, ric=0 prs=0 r=0 Signed-off-by: Balbir Singh <bsingharora@gmail.com> [mpe: Add some missing trace_tlbie()s, reword change log] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s/paca: EX_CTR is not used with RELOCATABLE=n, remove itNicholas Piggin2017-06-20
| | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s/paca: EX_R3 can be merged with EX_DARNicholas Piggin2017-06-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | EX_R3 is used only for a small section of the bad stack handler. Merge it with EX_DAR. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s/paca: EX_LR can be merged with EX_DARNicholas Piggin2017-06-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | EX_LR is used only for a small section of the SLB miss handler. Merge it with EX_DAR. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s/paca: EX_SRR0 is unused, remove itNicholas Piggin2017-06-20
| | | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s: Add EX_SIZE definition for paca exception save areasNicholas Piggin2017-06-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Rather than open-coding it 4 times. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Move __ASSEMBLY__ guards into head-64.h where they're really needed] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s/idle: Branch to handler with virtual mode offsetNicholas Piggin2017-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Have the system reset idle wakeup handlers branched to in real mode with the 0xc... kernel address applied. This allows simplifications of avoiding rfid when switching to virtual mode in the wakeup handler. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s: msgclr when handling doorbell exceptions from system resetNicholas Piggin2017-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | msgsnd doorbell exceptions are cleared when the doorbell interrupt is taken. However if a doorbell exception causes a system reset interrupt wake from power saving state, the message is not cleared. Processing the doorbell from the system reset interrupt requires msgclr to avoid taking the exception again. Testing this plus the previous wakup direct patch gives: original wakeup direct msgclr Different threads, same core: 315k/s 264k/s 345k/s Different cores: 235k/s 242k/s 242k/s Net speedup is +10% for same core, and +3% for different core. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s/idle: Process interrupts from system reset wakeupNicholas Piggin2017-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When the CPU wakes from low power state, it begins at the system reset interrupt with the exception that caused the wakeup encoded in SRR1. Today, powernv idle wakeup ignores the wakeup reason (except a special case for HMI), and the regular interrupt corresponding to the exception will fire after the idle wakeup exits. Change this to replay the interrupt from the idle wakeup before interrupts are hard-enabled. Test on POWER8 of context_switch selftests benchmark with polling idle disabled (e.g., always nap, giving cross-CPU IPIs) gives the following results: original wakeup direct Different threads, same core: 315k/s 264k/s Different cores: 235k/s 242k/s There is a slowdown for doorbell IPI (same core) case because system reset wakeup does not clear the message and the doorbell interrupt fires again needlessly. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s/idle: Move soft interrupt mask logic into C codeNicholas Piggin2017-06-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This simplifies the asm and fixes irq-off tracing over sleep instructions. Also move powersave_nap check for POWER8 into C code, and move PSSCR register value calculation for POWER9 into C. Reviewed-by: Gautham R. Shenoy <ego@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s: Avoid cpabort in context switch when possibleNicholas Piggin2017-06-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ISA v3.0B copy-paste facility only requires cpabort when switching to a process that has foreign real addresses mapped (direct access to accelerators), to clear a potential copy buffer filled by a previous thread. There is no accelerator driver implemented yet, so cpabort can be removed. It can be be re-added when a driver is implemented. POWER9 DD1 requires the copy buffer to always be cleared on context switch, but if accelerators are not in use, then an unpaired copy from a dummy region is sufficient to clear data out of the copy buffer. This increases context switch performance by about 5% on POWER9. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64: Drop explicit hwsync in context switchNicholas Piggin2017-06-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The sync (aka. hwsync, aka. heavyweight sync) in the context switch code to prevent MMIO access being reordered from the point of view of a single process if it gets migrated to a different CPU is not required because there is an hwsync performed earlier in the context switch path. Comment this so it's clear enough if anything changes on the scheduler or the powerpc sides. Remove the hwsync from _switch. This improves context switch performance by 2-3% on POWER8. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64s: Machine check handle ifetch from foreign real address for POWER9Nicholas Piggin2017-06-06
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The i-side 0111b machine check, which is "Instruction Fetch to foreign address space", was missed by 7b9f71f974 ("powerpc/64s: POWER9 machine check handler"). The POWER9 processor core considers host real addresses with a nonzero value in RA(8:12) as foreign address space, accessible only by the copy and paste instructions. The copy and paste instruction pair can be used to invoke the Nest accelerators via the Virtual Accelerator Switchboard (VAS). It is an error for any regular load/store or ifetch to go to a foreign addresses. When relocation is on, this causes an MMU exception. When relocation is off, a machine check exception. It is possible to trigger this machine check by branching to a foreign address with MSR[IR]=0. Fixes: 7b9f71f974a1 ("powerpc/64s: POWER9 machine check handler") Reported-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/mm: Rename map_page() to map_kernel_page() on 32-bitChristophe Leroy2017-06-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These two functions implement the same semantics, so unify their naming so we can share code that calls them. The longer name is more descriptive so use it. Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Acked-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/mm/book(e)(3s)/32: Add page table accountingBalbir Singh2017-06-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add support in pte_alloc_one() and pgd_alloc() by passing __GFP_ACCOUNT in the flags Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/mm/book(e)(3s)/64: Add page table accountingBalbir Singh2017-06-05
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce a helper pgtable_gfp_flags() which just returns the current gfp flags and adds __GFP_ACCOUNT to account for page table allocation. The generic helper is added to include/asm/pgalloc.h and has two variants - WARNING ugly bits ahead 1. If the header is included from a module, no check for mm == &init_mm is done, since init_mm is not exported 2. For kernel includes, the check is done and required see (3e79ec7 arch: x86: charge page tables to kmemcg) The fundamental assumption is that no module should be doing pgd/pud/pmd and pte alloc's on behalf of init_mm directly. NOTE: This adds an overhead to pmd/pud/pgd allocations similar to x86. The other alternative was to implement pmd_alloc_kernel/pud_alloc_kernel and pgd_alloc_kernel with their offset variants. For 4k page size, pte_alloc_one no longer calls pte_alloc_one_kernel. Signed-off-by: Balbir Singh <bsingharora@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/fadump: Set an upper limit for boot memory sizeHari Bathini2017-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | By default, 5% of system RAM is reserved for preserving boot memory. Alternatively, a user can specify the amount of memory to reserve. See Documentation/powerpc/firmware-assisted-dump.txt for details. In addition to the memory reserved for preserving boot memory, some more memory is reserved, to save HPTE region, CPU state data and ELF core headers. Memory Reservation during first kernel looks like below: Low memory Top of memory 0 boot memory size | | | |<--Reserved dump area -->| V V | Permanent Reservation V +-----------+----------/ /----------+---+----+-----------+----+ | | |CPU|HPTE| DUMP |ELF | +-----------+----------/ /----------+---+----+-----------+----+ | ^ | | \ / ------------------------------------------- Boot memory content gets transferred to reserved area by firmware at the time of crash This implicitly means that the sum of the sizes of boot memory, CPU state data, HPTE region, DUMP preserving area and ELF core headers can't be greater than the total memory size. But currently, a user is allowed to specify any value as boot memory size. So, the above rule is violated when a boot memory size around 50% of the total available memory is specified. As the kernel is not handling this currently, it may lead to undefined behavior. Fix it by setting an upper limit for boot memory size to 25% of the total available memory. Also, instead of using memblock_end_of_DRAM(), which doesn't take the holes, if any, in the memory layout into account, use memblock_phys_mem_size() to calculate the percentage of total available memory. Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc: Remove __ilog2()s and use generic onesChristophe Leroy2017-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the __ilog2() function as defined in arch/powerpc/include/asm/bitops.h, GCC will not optimise the code in case of constant parameter. The generic ilog2() function in include/linux/log2.h is written to handle the case of the constant parameter. This patch discards the three __ilog2() functions and defines __ilog2() as ilog2() For non constant calls, the generated code is doing the same: int test__ilog2(unsigned long x) { return __ilog2(x); } int test__ilog2_u32(u32 n) { return __ilog2_u32(n); } int test__ilog2_u64(u64 n) { return __ilog2_u64(n); } On PPC32 before the patch: 00000000 <test__ilog2>: 0: 7c 63 00 34 cntlzw r3,r3 4: 20 63 00 1f subfic r3,r3,31 8: 4e 80 00 20 blr 0000000c <test__ilog2_u32>: c: 7c 63 00 34 cntlzw r3,r3 10: 20 63 00 1f subfic r3,r3,31 14: 4e 80 00 20 blr On PPC32 after the patch: 00000000 <test__ilog2>: 0: 7c 63 00 34 cntlzw r3,r3 4: 20 63 00 1f subfic r3,r3,31 8: 4e 80 00 20 blr 0000000c <test__ilog2_u32>: c: 7c 63 00 34 cntlzw r3,r3 10: 20 63 00 1f subfic r3,r3,31 14: 4e 80 00 20 blr On PPC64 before the patch: 0000000000000000 <.test__ilog2>: 0: 7c 63 00 74 cntlzd r3,r3 4: 20 63 00 3f subfic r3,r3,63 8: 7c 63 07 b4 extsw r3,r3 c: 4e 80 00 20 blr 0000000000000010 <.test__ilog2_u32>: 10: 7c 63 00 34 cntlzw r3,r3 14: 20 63 00 1f subfic r3,r3,31 18: 7c 63 07 b4 extsw r3,r3 1c: 4e 80 00 20 blr 0000000000000020 <.test__ilog2_u64>: 20: 7c 63 00 74 cntlzd r3,r3 24: 20 63 00 3f subfic r3,r3,63 28: 7c 63 07 b4 extsw r3,r3 2c: 4e 80 00 20 blr On PPC64 after the patch: 0000000000000000 <.test__ilog2>: 0: 7c 63 00 74 cntlzd r3,r3 4: 20 63 00 3f subfic r3,r3,63 8: 7c 63 07 b4 extsw r3,r3 c: 4e 80 00 20 blr 0000000000000010 <.test__ilog2_u32>: 10: 7c 63 00 34 cntlzw r3,r3 14: 20 63 00 1f subfic r3,r3,31 18: 7c 63 07 b4 extsw r3,r3 1c: 4e 80 00 20 blr 0000000000000020 <.test__ilog2_u64>: 20: 7c 63 00 74 cntlzd r3,r3 24: 20 63 00 3f subfic r3,r3,63 28: 7c 63 07 b4 extsw r3,r3 2c: 4e 80 00 20 blr Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc: Replace ffz() by equivalent generic functionChristophe Leroy2017-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the ffz() function as defined in arch/powerpc/include/asm/bitops.h GCC will not optimise the code in case of constant parameter. This patch replaces ffz() by the generic function. The generic ffz(x) expects to never be called with ~x == 0 as written in the comment in include/asm-generic/bitops/ffz.h The only user of ffz() within arch/powerpc/ is platforms/512x/mpc5121_ads_cpld.c, which checks if x is not 0xff For non constant calls, the generated code is doing the same: unsigned long testffz(unsigned long x) { return ffz(x); } On PPC32, before the patch: 00000018 <testffz>: 18: 7c 63 18 f9 not. r3,r3 1c: 40 82 00 0c bne 28 <testffz+0x10> 20: 38 60 00 20 li r3,32 24: 4e 80 00 20 blr 28: 7d 23 00 d0 neg r9,r3 2c: 7d 23 18 38 and r3,r9,r3 30: 7c 63 00 34 cntlzw r3,r3 34: 20 63 00 1f subfic r3,r3,31 38: 4e 80 00 20 blr On PPC32, after the patch: 00000018 <testffz>: 18: 39 23 00 01 addi r9,r3,1 1c: 7d 23 18 78 andc r3,r9,r3 20: 7c 63 00 34 cntlzw r3,r3 24: 20 63 00 1f subfic r3,r3,31 28: 4e 80 00 20 blr On PPC64, before the patch: 0000000000000030 <.testffz>: 30: 7c 60 18 f9 not. r0,r3 34: 38 60 00 40 li r3,64 38: 4d 82 00 20 beqlr 3c: 7c 60 00 d0 neg r3,r0 40: 7c 63 00 38 and r3,r3,r0 44: 7c 63 00 74 cntlzd r3,r3 48: 20 63 00 3f subfic r3,r3,63 4c: 7c 63 07 b4 extsw r3,r3 50: 4e 80 00 20 blr On PPC64, after the patch: 0000000000000030 <.testffz>: 30: 38 03 00 01 addi r0,r3,1 34: 7c 03 18 78 andc r3,r0,r3 38: 7c 63 00 74 cntlzd r3,r3 3c: 20 63 00 3f subfic r3,r3,63 40: 4e 80 00 20 blr Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc: Use builtin functions for fls()/__fls()/fls64()Christophe Leroy2017-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the fls() functions as defined in arch/powerpc/include/asm/bitops.h GCC will not optimise the code in case of constant parameter. This patch replaces __fls() by the builtin function, and modifies fls() and fls64() to use builtins instead of inline assembly For non constant calls, the generated code is doing the same: int testfls(unsigned int x) { return fls(x); } unsigned long test__fls(unsigned long x) { return __fls(x); } int testfls64(__u64 x) { return fls64(x); } On PPC32, before the patch: 00000064 <testfls>: 64: 7c 63 00 34 cntlzw r3,r3 68: 20 63 00 20 subfic r3,r3,32 6c: 4e 80 00 20 blr 00000070 <test__fls>: 70: 7c 63 00 34 cntlzw r3,r3 74: 20 63 00 1f subfic r3,r3,31 78: 4e 80 00 20 blr 0000007c <testfls64>: 7c: 2c 03 00 00 cmpwi r3,0 80: 40 82 00 10 bne 90 <testfls64+0x14> 84: 7c 83 00 34 cntlzw r3,r4 88: 20 63 00 20 subfic r3,r3,32 8c: 4e 80 00 20 blr 90: 7c 63 00 34 cntlzw r3,r3 94: 20 63 00 40 subfic r3,r3,64 98: 4e 80 00 20 blr On PPC32, after the patch: 00000054 <testfls>: 54: 7c 63 00 34 cntlzw r3,r3 58: 20 63 00 20 subfic r3,r3,32 5c: 4e 80 00 20 blr 00000060 <test__fls>: 60: 7c 63 00 34 cntlzw r3,r3 64: 20 63 00 1f subfic r3,r3,31 68: 4e 80 00 20 blr 0000006c <testfls64>: 6c: 2c 03 00 00 cmpwi r3,0 70: 41 82 00 10 beq 80 <testfls64+0x14> 74: 7c 63 00 34 cntlzw r3,r3 78: 20 63 00 40 subfic r3,r3,64 7c: 4e 80 00 20 blr 80: 7c 83 00 34 cntlzw r3,r4 84: 20 63 00 40 subfic r3,r3,32 88: 4e 80 00 20 blr On PPC64, before the patch: 00000000000000a0 <.testfls>: a0: 7c 63 00 34 cntlzw r3,r3 a4: 20 63 00 20 subfic r3,r3,32 a8: 7c 63 07 b4 extsw r3,r3 ac: 4e 80 00 20 blr 00000000000000b0 <.test__fls>: b0: 7c 63 00 74 cntlzd r3,r3 b4: 20 63 00 3f subfic r3,r3,63 b8: 7c 63 07 b4 extsw r3,r3 bc: 4e 80 00 20 blr 00000000000000c0 <.testfls64>: c0: 7c 63 00 74 cntlzd r3,r3 c4: 20 63 00 40 subfic r3,r3,64 c8: 7c 63 07 b4 extsw r3,r3 cc: 4e 80 00 20 blr On PPC64, after the patch: 0000000000000090 <.testfls>: 90: 7c 63 00 34 cntlzw r3,r3 94: 20 63 00 20 subfic r3,r3,32 98: 7c 63 07 b4 extsw r3,r3 9c: 4e 80 00 20 blr 00000000000000a0 <.test__fls>: a0: 7c 63 00 74 cntlzd r3,r3 a4: 20 63 00 3f subfic r3,r3,63 a8: 4e 80 00 20 blr ac: 60 00 00 00 nop 00000000000000b0 <.testfls64>: b0: 7c 63 00 74 cntlzd r3,r3 b4: 20 63 00 40 subfic r3,r3,64 b8: 7c 63 07 b4 extsw r3,r3 bc: 4e 80 00 20 blr Those builtins have been in GCC since at least 3.4.6 (see https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Other-Builtins.html ) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc: Discard ffs()/__ffs() function and use builtin functions insteadChristophe Leroy2017-06-02
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | With the ffs() function as defined in arch/powerpc/include/asm/bitops.h GCC will not optimise the code in case of constant parameter, as shown by the small exemple below. int ffs_test(void) { return 4 << ffs(31); } c0012334 <ffs_test>: c0012334: 39 20 00 01 li r9,1 c0012338: 38 60 00 04 li r3,4 c001233c: 7d 29 00 34 cntlzw r9,r9 c0012340: 21 29 00 20 subfic r9,r9,32 c0012344: 7c 63 48 30 slw r3,r3,r9 c0012348: 4e 80 00 20 blr With this patch, the same function will compile as follows: c0012334 <ffs_test>: c0012334: 38 60 00 08 li r3,8 c0012338: 4e 80 00 20 blr The same happens with __ffs() For non constant calls, the generated code is doing the same, allthought it is slightly different on 64 bits for ffs(): unsigned long test__ffs(unsigned long x) { return __ffs(x); } int testffs(int x) { return ffs(x); } On PPC32, before the patch: 0000003c <test__ffs>: 3c: 7d 23 00 d0 neg r9,r3 40: 7d 23 18 38 and r3,r9,r3 44: 7c 63 00 34 cntlzw r3,r3 48: 20 63 00 1f subfic r3,r3,31 4c: 4e 80 00 20 blr 00000050 <testffs>: 50: 7d 23 00 d0 neg r9,r3 54: 7d 23 18 38 and r3,r9,r3 58: 7c 63 00 34 cntlzw r3,r3 5c: 20 63 00 20 subfic r3,r3,32 60: 4e 80 00 20 blr On PPC32, after the patch: 0000002c <test__ffs>: 2c: 7d 23 00 d0 neg r9,r3 30: 7d 23 18 38 and r3,r9,r3 34: 7c 63 00 34 cntlzw r3,r3 38: 20 63 00 1f subfic r3,r3,31 3c: 4e 80 00 20 blr 00000040 <testffs>: 40: 7d 23 00 d0 neg r9,r3 44: 7d 23 18 38 and r3,r9,r3 48: 7c 63 00 34 cntlzw r3,r3 4c: 20 63 00 20 subfic r3,r3,32 50: 4e 80 00 20 blr On PPC64, before the patch: 0000000000000060 <.test__ffs>: 60: 7c 03 00 d0 neg r0,r3 64: 7c 03 18 38 and r3,r0,r3 68: 7c 63 00 74 cntlzd r3,r3 6c: 20 63 00 3f subfic r3,r3,63 70: 7c 63 07 b4 extsw r3,r3 74: 4e 80 00 20 blr 0000000000000080 <.testffs>: 80: 7c 03 00 d0 neg r0,r3 84: 7c 03 18 38 and r3,r0,r3 88: 7c 63 00 74 cntlzd r3,r3 8c: 20 63 00 40 subfic r3,r3,64 90: 7c 63 07 b4 extsw r3,r3 94: 4e 80 00 20 blr On PPC64, after the patch: 0000000000000050 <.test__ffs>: 50: 7c 03 00 d0 neg r0,r3 54: 7c 03 18 38 and r3,r0,r3 58: 7c 63 00 74 cntlzd r3,r3 5c: 20 63 00 3f subfic r3,r3,63 60: 4e 80 00 20 blr 0000000000000070 <.testffs>: 70: 7c 03 00 d0 neg r0,r3 74: 7c 03 18 38 and r3,r0,r3 78: 7c 63 00 34 cntlzw r3,r3 7c: 20 63 00 20 subfic r3,r3,32 80: 7c 63 07 b4 extsw r3,r3 84: 4e 80 00 20 blr (ffs() operates on an int so cntlzw is equivalent to cntlzd) In addition, when reading the generated vmlinux, we can observe that with the builtin functions, GCC sometimes efficiently spreads the instructions within the generated functions while the inline assembly force them to remain grouped together. __builtin_ffs() is already used in arch/powerpc/include/asm/page_32.h Those builtins have been in GCC since at least 3.4.6 (see https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Other-Builtins.html ) Signed-off-by: Christophe Leroy <christophe.leroy@c-s.fr> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
| * | | | powerpc/64: Tool to check head sections location sanityNicholas Piggin2017-05-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use a tool to check that the location of "fixed sections" are where we expected them to be, which catches cases the linker script can't (stubs being added to start of .text section), and which ends up being neater. Sample output: ERROR: start_text address is c000000000008100, should be c000000000008000 ERROR: see comments in arch/powerpc/tools/head_check.sh Signed-off-by: Nicholas Piggin <npiggin@gmail.com> [mpe: Fold in fix from Nick for 4.6 era toolchains] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
generated by cgit v1.2.2 (git 2.25.0) at 2025-07-23 22:27:08 -0400