From ea3cc330ac0cd521ff07c7cd432a1848c19a7e92 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Tue, 18 Aug 2009 19:00:34 +0000 Subject: powerpc/mm: Cleanup handling of execute permission 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 --- arch/powerpc/kernel/head_44x.S | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/powerpc/kernel/head_44x.S') diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S index 656cfb2d666..711368b993f 100644 --- a/arch/powerpc/kernel/head_44x.S +++ b/arch/powerpc/kernel/head_44x.S @@ -497,7 +497,7 @@ tlb_44x_patch_hwater_D: mtspr SPRN_MMUCR,r12 /* Make up the required permissions */ - li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_HWEXEC + li r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_EXEC /* Compute pgdir/pmd offset */ rlwinm r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29 -- cgit v1.2.3