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* sparc64: Fix tsb_grow() in atomic context.David S. Miller2013-02-20
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | If our first THP installation for an MM is via the set_pmd_at() done during khugepaged's collapsing we'll end up in tsb_grow() trying to do a GFP_KERNEL allocation with several locks held. Simply using GFP_ATOMIC in this situation is not the best option because we really can't have this fail, so we'd really like to keep this an order 0 GFP_KERNEL allocation if possible. Also, doing the TSB allocation from khugepaged is a really bad idea because we'll allocate it potentially from the wrong NUMA node in that context. So what we do is defer the hugepage TSB allocation until the first TLB miss we take on a hugepage. This is slightly tricky because we have to handle two unusual cases: 1) Taking the first hugepage TLB miss in the window trap handler. We'll call the winfix_trampoline when that is detected. 2) An initial TSB allocation via TLB miss races with a hugetlb fault on another cpu running the same MM. We handle this by unconditionally loading the TSB we see into the current cpu even if it's non-NULL at hugetlb_setup time. Reported-by: Meelis Roos <mroos@ut.ee> Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc64: Support transparent huge pages.David Miller2012-10-09
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is relatively easy since PMD's now cover exactly 4MB of memory. Our PMD entries are 32-bits each, so we use a special encoding. The lowest bit, PMD_ISHUGE, determines the interpretation. This is possible because sparc64's page tables are purely software entities so we can use whatever encoding scheme we want. We just have to make the TLB miss assembler page table walkers aware of the layout. set_pmd_at() works much like set_pte_at() but it has to operate in two page from a table of non-huge PTEs, so we have to queue up TLB flushes based upon what mappings are valid in the PTE table. In the second regime we are going from huge-page to non-huge-page, and in that case we need only queue up a single TLB flush to push out the huge page mapping. We still have 5 bits remaining in the huge PMD encoding so we can very likely support any new pieces of THP state tracking that might get added in the future. With lots of help from Johannes Weiner. Signed-off-by: David S. Miller <davem@davemloft.net> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* sparc64: Fix sun4u execute bit check in TSB I-TLB load.David S. Miller2010-02-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Thanks to testcase and report from Brad Spengler: -------------------- #include <stdio.h> typedef int (* _wee)(void); int main(void) { char buf[8] = { '\x81', '\xc7', '\xe0', '\x08', '\x81', '\xe8', '\x00', '\x00' }; _wee wee; printf("%p\n", &buf); wee = (_wee)&buf; wee(); return 0; } -------------------- TSB I-tlb load code tries to use andcc to check the _PAGE_EXEC_4U bit, but that's bit 12 so it gets sign extended all the way up to bit 63 and the test nearly always passes as a result. Use sethi to fix the bug. Signed-off-by: David S. Miller <davem@davemloft.net>
* sparc,sparc64: unify kernel/Sam Ravnborg2008-12-04
o Move all files from sparc64/kernel/ to sparc/kernel - rename as appropriate o Update sparc/Makefile to the changes o Update sparc/kernel/Makefile to include the sparc64 files NOTE: This commit changes link order on sparc64! Link order had to change for either of sparc32 and sparc64. And assuming sparc64 see more testing than sparc32 change link order on sparc64 where issues will be caught faster. Signed-off-by: Sam Ravnborg <sam@ravnborg.org> Signed-off-by: David S. Miller <davem@davemloft.net>