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path: root/arch/powerpc/include/asm/pte-8xx.h
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2009-12-09powerpc/8xx: Restore _PAGE_WRITETHRUJoakim Tjernlund1-2/+3
8xx has not had WRITETHRU due to lack of bits in the pte. After the recent rewrite of the 8xx TLB code, there are two bits left. Use one of them to WRITETHRU. Perhaps use the last SW bit to PAGE_SPECIAL or PAGE_FILE? Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-12-09powerpc/8xx: Update TLB asm so it behaves as linux mm expects.Joakim Tjernlund1-7/+6
Update the TLB asm to make proper use of _PAGE_DIRY and _PAGE_ACCESSED. Get rid of _PAGE_HWWRITE too. Pros: - I/D TLB Miss never needs to write to the linux pte. - _PAGE_ACCESSED is only set on TLB Error fixing accounting - _PAGE_DIRTY is mapped to 0x100, the changed bit, and is set directly when a page has been made dirty. - Proper RO/RW mapping of user space. - Free up 2 SW TLB bits in the linux pte(add back _PAGE_WRITETHRU ?) - kernel RO/user NA support. Cons: - A few more instructions in the TLB Miss routines. Signed-off-by: Joakim Tjernlund <Joakim.Tjernlund@transmode.se> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-09-24powerpc/mm: Fix 40x and 8xx vs. _PAGE_SPECIALBenjamin Herrenschmidt1-0/+1
The test to check whether we have _PAGE_SPECIAL defined is broken, since we always define it, just not always to a meaninful value :-) That broke 8xx and 40x under some circumstances. This fixes it by adding _PAGE_SPECIAL for both of these since they had a free PTE bit, and removing the condition around advertising it. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-08-27powerpc/mm: Cleanup handling of execute permissionBenjamin Herrenschmidt1-1/+0
This is an attempt at cleaning up a bit the way we handle execute permission on powerpc. _PAGE_HWEXEC is gone, _PAGE_EXEC is now only defined by CPUs that can do something with it, and the myriad of #ifdef's in the I$/D$ coherency code is reduced to 2 cases that hopefully should cover everything. The logic on BookE is a little bit different than what it was though not by much. Since now, _PAGE_EXEC will be set by the generic code for executable pages, we need to filter out if they are unclean and recover it. However, I don't expect the code to be more bloated than it already was in that area due to that change. I could boast that this brings proper enforcing of per-page execute permissions to all BookE and 40x but in fact, we've had that now for some time as a side effect of my previous rework in that area (and I didn't even know it :-) We would only enable execute permission if the page was cache clean and we would only cache clean it if we took and exec fault. Since we now enforce that the later only work if VM_EXEC is part of the VMA flags, we de-fact already enforce per-page execute permissions... Unless I missed something Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-24powerpc/mm: Tweak PTE bit combination definitionsBenjamin Herrenschmidt1-0/+3
This patch tweaks the way some PTE bit combinations are defined, in such a way that the 32 and 64-bit variant become almost identical and that will make it easier to bring in a new common pte-* file for the new variant of the Book3-E support. The combination of bits defining access to kernel pages are now clearly separated from the combination used by userspace and the core VM. The resulting generated code should remain identical unless I made a mistake. Note: While at it, I removed a non-sensical statement related to CONFIG_KGDB in ppc_mmu_32.c which could cause kernel mappings to be user accessible when that option is enabled. Probably something that bitrot. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-20powerpc/mm: Split the various pgtable-* headers based on MMU typeBenjamin Herrenschmidt1-0/+64
This patch moves the definition of the PTE format for each MMU type to separate files instead of all in one file. This improves overall maintainability and will make it easier to add new types. On 64-bit, additionally, I've separated the headers relative to the format of the page table tree (3 vs. 4 levels for 64K vs 4K pages) from the headers specific to the PTE format for hash based processors, this will make it easier to add support for Book3 "E" 64-bit implementations. There are still some type-related ifdef's in the generic headers, we might remove them in the long run, but this patch shouldn't result in any code change, -hopefully- just definitions being moved around. Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>