aboutsummaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/head-nommu.S
Commit message (Collapse)AuthorAge
* ARM: Fix nommu bootingRussell King2015-04-21
| | | | | | | | | Commit bf35706f3d09 ("ARM: 8314/1: replace PROCINFO embedded branch with relative offset") broke booting on nommu platforms as it didn't update the nommu boot code. This patch fixes that oversight. Fixes: bf35706f3d09 ("ARM: 8314/1: replace PROCINFO embedded branch with relative offset") Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: convert all "mov.* pc, reg" to "bx reg" for ARMv6+Russell King2014-07-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ARMv6 and greater introduced a new instruction ("bx") which can be used to return from function calls. Recent CPUs perform better when the "bx lr" instruction is used rather than the "mov pc, lr" instruction, and this sequence is strongly recommended to be used by the ARM architecture manual (section A.4.1.1). We provide a new macro "ret" with all its variants for the condition code which will resolve to the appropriate instruction. Rather than doing this piecemeal, and miss some instances, change all the "mov pc" instances to use the new macro, with the exception of the "movs" instruction and the kprobes code. This allows us to detect the "mov pc, lr" case and fix it up - and also gives us the possibility of deploying this for other registers depending on the CPU selection. Reported-by: Will Deacon <will.deacon@arm.com> Tested-by: Stephen Warren <swarren@nvidia.com> # Tegra Jetson TK1 Tested-by: Robert Jarzmik <robert.jarzmik@free.fr> # mioa701_bootresume.S Tested-by: Andrew Lunn <andrew@lunn.ch> # Kirkwood Tested-by: Shawn Guo <shawn.guo@freescale.com> Tested-by: Tony Lindgren <tony@atomide.com> # OMAPs Tested-by: Gregory CLEMENT <gregory.clement@free-electrons.com> # Armada XP, 375, 385 Acked-by: Sekhar Nori <nsekhar@ti.com> # DaVinci Acked-by: Christoffer Dall <christoffer.dall@linaro.org> # kvm/hyp Acked-by: Haojian Zhuang <haojian.zhuang@gmail.com> # PXA3xx Acked-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> # Xen Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> # ARMv7M Tested-by: Simon Horman <horms+renesas@verge.net.au> # Shmobile Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: fix asm/memory.h build errorRussell King2013-12-13
| | | | | | | | | | | | | | | | | | | Jason Gunthorpe reports a build failure when ARM_PATCH_PHYS_VIRT is not defined: In file included from arch/arm/include/asm/page.h:163:0, from include/linux/mm_types.h:16, from include/linux/sched.h:24, from arch/arm/kernel/asm-offsets.c:13: arch/arm/include/asm/memory.h: In function '__virt_to_phys': arch/arm/include/asm/memory.h:244:40: error: 'PHYS_OFFSET' undeclared (first use in this function) arch/arm/include/asm/memory.h:244:40: note: each undeclared identifier is reported only once for each function it appears in arch/arm/include/asm/memory.h: In function '__phys_to_virt': arch/arm/include/asm/memory.h:249:13: error: 'PHYS_OFFSET' undeclared (first use in this function) Fixes: ca5a45c06cd4 ("ARM: mm: use phys_addr_t appropriately in p2v and v2p conversions") Tested-By: Jason Gunthorpe <jgunthorpe@obsidianresearch.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: Add .text annotations where required after __CPUINIT removalRussell King2013-08-01
| | | | | | | | | Commit 8bd26e3a7 (arm: delete __cpuinit/__CPUINIT usage from all ARM users) caused some code to leak into sections which are discarded through the removal of __CPUINIT annotations. Add appropriate .text annotations to bring these back into the kernel text. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* arm: delete __cpuinit/__CPUINIT usage from all ARM usersPaul Gortmaker2013-07-14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The __cpuinit type of throwaway sections might have made sense some time ago when RAM was more constrained, but now the savings do not offset the cost and complications. For example, the fix in commit 5e427ec2d0 ("x86: Fix bit corruption at CPU resume time") is a good example of the nasty type of bugs that can be created with improper use of the various __init prefixes. After a discussion on LKML[1] it was decided that cpuinit should go the way of devinit and be phased out. Once all the users are gone, we can then finally remove the macros themselves from linux/init.h. Note that some harmless section mismatch warnings may result, since notify_cpu_starting() and cpu_up() are arch independent (kernel/cpu.c) and are flagged as __cpuinit -- so if we remove the __cpuinit from the arch specific callers, we will also get section mismatch warnings. As an intermediate step, we intend to turn the linux/init.h cpuinit related content into no-ops as early as possible, since that will get rid of these warnings. In any case, they are temporary and harmless. This removes all the ARM uses of the __cpuinit macros from C code, and all __CPUINIT from assembly code. It also had two ".previous" section statements that were paired off against __CPUINIT (aka .section ".cpuinit.text") that also get removed here. [1] https://lkml.org/lkml/2013/5/20/589 Cc: Russell King <linux@arm.linux.org.uk> Cc: Will Deacon <will.deacon@arm.com> Cc: linux-arm-kernel@lists.infradead.org Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* ARM: mpu: protect the vectors page with an MPU regionJonathan Austin2013-06-17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | Without an MMU it is possible for userspace programs to start executing code in places that they have no business executing. The MPU allows some level of protection against this. This patch protects the vectors page from access by userspace processes. Userspace tasks that dereference a null pointer are already protected by an svc at 0x0 that kills them. However when tasks use an offset from a null pointer (eg a function in a null struct) they miss this carefully placed svc and enter the exception vectors in user mode, ending up in the kernel. This patch causes programs that do this to receive a SEGV instead of happily entering the kernel in user-mode, and hence avoid a 'Bad Mode' panic. As part of this change it is necessary to make sigreturn happen via the stack when there is not an sa_restorer function. This change is invisible to userspace, and irrelevant to code compiled using a uClibc toolchain, which always uses an sa_restorer function. Because we don't get to remap the vectors in !MMU kuser_helpers are not in a defined location, and hence aren't usable. This means we don't need to worry about keeping them accessible from PL0 Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> CC: Nicolas Pitre <nico@linaro.org> CC: Catalin Marinas <catalin.marinas@arm.com>
* ARM: mpu: add MPU initialisation for secondary coresJonathan Austin2013-06-07
| | | | | | | | | | | | | | | | | | | | The MPU initialisation on the primary core is performed in two stages, one minimal stage to ensure the CPU can boot and a second one after sanity_check_meminfo. As the memory configuration is known by the time we boot secondary cores only a single step is necessary, provided the values for DRSR are passed to secondaries. This patch implements this arrangement. The configuration generated for the MPU regions is made available to the secondary core, which can then use the asm MPU intialisation code to program a complete region configuration. This is necessary for SMP configurations without an MMU, as the MPU initialisation is the only way to ensure that memory is specified as 'shared'. Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> CC: Nicolas Pitre <nico@linaro.org>
* ARM: mpu: add early bring-up code for the ARMv7 PMSA-compliant MPUJonathan Austin2013-06-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds initial support for using the MPU, which is necessary for SMP operation on PMSAv7 processors because it is the only way to ensure memory is shared. This is an initial patch and full SMP support is added later in this series. The setup of the MPU is performed in a way analagous to that for the MMU: Very early initialisation before the C environment is brought up, followed by a sanity check and more complete initialisation in C. This patch provides the simplest possible memory region configuration: MPU_PROBE_REGION: Reserved for probing MPU details, not enabled MPU_BG_REGION: A 'background' region that specifies all memory strongly ordered MPU_RAM_REGION: A single shared, cacheable, normal region for the valid RAM. In this early initialisation code we simply map the whole of the address space with the BG_REGION and (at least) the kernel with the RAM_REGION. The MPU has region alignment constraints that require us to round past the end of the kernel. As region 2 has a higher priority than region 1, it overrides the strongly- ordered behaviour for RAM only. Subsequent patches will add more complete initialisation from the C-world and support for bringing up secondary CPUs. Signed-off-by: Jonathan Austin <jonathan.austin@arm.com> Reviewed-by: Will Deacon <will.deacon@arm.com> CC: Hyok S. Choi <hyok.choi@samsung.com>
* ARM: nommu: add entry point for secondary CPUs to head-nommu.SWill Deacon2013-06-07
| | | | | | | | | This patch adds a secondary_startup entry point to head-nommu.S so that we can boot secondary CPUs on an SMP nommu configuration. Signed-off-by: Will Deacon <will.deacon@arm.com> CC: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> CC: Nicolas Pitre <nico@linaro.org>
* ARM: Add base support for ARMv7-MCatalin Marinas2013-04-17
| | | | | | | | | | | | | | | | | | | | This patch adds the base support for the ARMv7-M architecture. It consists of the corresponding arch/arm/mm/ files and various #ifdef's around the kernel. Exception handling is implemented by a subsequent patch. [ukleinek: squash in some changes originating from commit b5717ba (Cortex-M3: Add support for the Microcontroller Prototyping System) from the v2.6.33-arm1 patch stack, port to post 3.6, drop zImage support, drop reorganisation of pt_regs, assert CONFIG_CPU_V7M doesn't leak into installed headers and a few cosmetic changes] Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Jonathan Austin <jonathan.austin@arm.com> Tested-by: Jonathan Austin <jonathan.austin@arm.com> Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
* ARM: let CPUs not being able to run in ARM mode enter in THUMB modeUwe Kleine-König2013-01-31
| | | | | | | | | | Some ARM cores are not capable to run in ARM mode (e.g. Cortex-M3). So obviously these cannot enter the kernel in ARM mode. Make an exception for them and let them enter in THUMB mode. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Message-Id: 1358162123-30113-1-git-send-email-u.kleine-koenig@pengutronix.de Acked-by: Nicolas Pitre <nico@linaro.org>
* ARM: 7591/1: nommu: Enable the strict alignment (CR_A) bit only if ARCH < v6Armando Visconti2012-12-07
| | | | | | | | | This patch keeps disabled the strict alignment CP15 bit for all armv6 and armv7 processor without the mmu. This behaviour is now same as in the mmu case. Signed-off-by: Armando Visconti <armando.visconti@st.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: move CP15 definitions to separate header fileRussell King2012-03-28
| | | | | | | | | | | | | | | Avoid namespace conflicts with drivers over the CP15 definitions by moving CP15 related prototypes and definitions to a private header file. Acked-by: Stephen Warren <swarren@nvidia.com> Tested-by: Stephen Warren <swarren@nvidia.com> [Tegra] Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com> Tested-by: H Hartley Sweeten <hsweeten@visionengravers.com> [EP93xx] Acked-by: Nicolas Pitre <nico@linaro.org> Acked-by: Kukjin Kim <kgene.kim@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> Signed-off-by: David Howells <dhowells@redhat.com>
* ARM: 6999/1: head, zImage: Always Enter the kernel in ARM stateDave Martin2011-07-19
| | | | | | | | | | | | | | | | | | | | | | | | Currently, the documented kernel entry requirements are not explicit about whether the kernel should be entered in ARM or Thumb, leading to an ambiguitity about how to enter Thumb-2 kernels. As a result, the kernel is reliant on the zImage decompressor to enter the kernel proper in the correct instruction set state. This patch changes the boot entry protocol for head.S and Image to be the same as for zImage: in all cases, the kernel is now entered in ARM. Documentation/arm/Booting is updated to reflect this new policy. A different rule will be needed for Cortex-M class CPUs as and when support for those lands in mainline, since these CPUs don't support the ARM instruction set at all: a note is added to the effect that the kernel must be entered in Thumb on such systems. Signed-off-by: Dave Martin <dave.martin@linaro.org> Acked-by: Nicolas Pitre <nicolas.pitre@linaro.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: Defer lookup of machine_type to setup.cRussell King2011-02-15
| | | | | | | | | | | | | | | | | Since the debug macros no longer depend on the machine type information, the machine type lookup can be deferred to setup_arch() in setup.c which simplifies the code somewhat. We also move the __error_a functionality into setup.c for displaying a message when a bad machine ID is passed to the kernel via the LL debug code. We also log this into the kernel ring buffer which makes it possible to retrieve the message via a debugger. Original idea from Grant Likely. Acked-by: Grant Likely <grant.likely@secretlab.ca> Tested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: no need for nommu to jump through the hoops that mmu doesRussell King2010-10-08
| | | | | | | | nommu can jump directly to __mmap_switched without the absolute address branching which the mmuful kernel does. Acked-by: Greg Ungerer <gerg@uclinux.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* ARM: convert to use __HEAD and HEAD_TEXT macros.Tim Abbott2009-11-23
| | | | | | | | | | | | | | This has the consequence of changing the section name used for head code from ".text.head" to ".head.text". Since this commit changes all users in the architecture, this change should be harmless. The .text.head output section is eliminated and the head text code is included at the start of the .init output section. Signed-off-by: Tim Abbott <tabbott@ksplice.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Acked-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* nommu: Do not override the CP15 control reg value returned from initfuncCatalin Marinas2009-07-24
| | | | | | | | | | The patch removes the "mrc" instruction in head-nommu.S overriding the r0 register containing the value to be written in the CP15 system control register. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* Thumb-2: Implementation of the unified start-up and exceptions codeCatalin Marinas2009-07-24
| | | | | | | This patch implements the ARM/Thumb-2 unified kernel start-up and exception handling code. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
* [ARM] 5227/1: Add the ENDPROC declarations to the .S filesCatalin Marinas2008-09-01
| | | | | | | | | This declaration specifies the "function" type and size for various assembly functions, mainly needed for generating the correct branch instructions in Thumb-2. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] Eliminate useless includes of asm/mach-types.hRussell King2008-08-07
| | | | | | | | There are 43 includes of asm/mach-types.h by files that don't reference anything from that file. Remove these unnecessary includes. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] Ensure head text is always placed at the start of kernelRussell King2007-05-08
| | | | | | | | | | Commit 86c0baf123e474b6eb404798926ecf62b426bf3a highlighted that we may end up with the head text placed elsewhere in the kernel image. Introduce a new .text.head section to contain the initial kernel startup code, and always place this section at the beginning of the kernel image. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] Include asm/elf.h instead of asm/procinfo.hRussell King2006-11-30
| | | | | | | These files want to provide/access ELF hwcap information, so should be including asm/elf.h rather than asm/procinfo.h Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] nommu: confirms the CR_V bit in nommu modeHyok S. Choi2006-09-28
| | | | | | | | | | | | | | In nommu mode, the exception vector location depends on the platforms. Some of the implementations may have some special exception control forwarding method in their ROM/flash and for some of them has its own re-mapping mechanism by the h/w. This patch introduces a special configuration CONFIG_CPU_HIGH_VECTOR which turns on the CR_V bit in nommu mode. The CR_V bit is turned off by default. This feature depends on CP15 and does not supported by ARM740. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] nommu: manage the CP15 thingsHyok S. Choi2006-09-27
| | | | | | | | | | | | | | | | | | | | | | | All the current CP15 access codes in ARM arch can be categorized and conditioned by the defines as follows: Related operation Safe condition a. any CP15 access !CPU_CP15 b. alignment trap CPU_CP15_MMU c. D-cache(C-bit) CPU_CP15 d. I-cache CPU_CP15 && !( CPU_ARM610 || CPU_ARM710 || CPU_ARM720 || CPU_ARM740 || CPU_XSCALE || CPU_XSC3 ) e. alternate vector CPU_CP15 && !CPU_ARM740 f. TTB CPU_CP15_MMU g. Domain CPU_CP15_MMU h. FSR/FAR CPU_CP15_MMU For example, alternate vector is supported if and only if "CPU_CP15 && !CPU_ARM740" is satisfied. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* Remove obsolete #include <linux/config.h>Jörn Engel2006-06-30
| | | | | Signed-off-by: Jörn Engel <joern@wohnheim.fh-wedel.de> Signed-off-by: Adrian Bunk <bunk@stusta.de>
* [ARM] Remove MODE_(SVC|IRQ|FIQ|USR) and DEFAULT_FIQRussell King2006-06-25
| | | | | | | DEFAULT_FIQ was entirely unused. MODE_* are just redefinitions of *_MODE. Use *_MODE instead. Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] 3496/1: more constants for asm-offsets.hUwe Zeisberger2006-05-05
| | | | | | | | | | | | | | | | | Patch from Uwe Zeisberger added the following constants: - MACHINFO_TYPE - MACHINFO_NAME - MACHINFO_PHYSIO - MACHINFO_PGOFFIO - PROCINFO_INITFUNC - PROCINFO_MMUFLAGS and removed their definition from head.S and head-nommu.S Signed-off-by: Uwe Zeisberger <Uwe_Zeisberger@digi.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] nommu: trivial fixups for head-nommu.S and the MakefileHyok S. Choi2006-04-24
| | | | | | | | This patch fix compilation problem of start-up codes. (head-nommu.S, arch/arm/kernel/Makefile) Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
* [ARM] nommu: start-up codeHyok S. Choi2006-03-27
This patch adds nommu version start-up code head-nommu.S. The common part of the start-up codes is moved to head-common.S. Signed-off-by: Hyok S. Choi <hyok.choi@samsung.com> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>