Re: [PATCH 0/6] 8xx MMU fixes
From: Joakim Tjernlund <hidden>
Date: 2009-10-09 11:06:32
Subsystem:
linux for powerpc (32-bit and 64-bit), the rest · Maintainers:
Madhavan Srinivasan, Linus Torvalds
Rex Feany [off-list ref] wrote on 09/10/2009 08:46:49:
Thus spake Joakim Tjernlund (joakim.tjernlund@transmode.se):quoted
Rex Feany [off-list ref] wrote on 09/10/2009 02:15:27:quoted
quoted
open("/proc/mounts", O_RDONLY) = 3 fstat64(0x3, 0x7fe7e2a8) = 0 mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANONYMOUS, -1, 0) =0x3001f000 read(3, 0x3001f000, 1024) = -1 EFAULT (Bad address) exit_group(0) = ?Try making the tlbil_va in fault.c unconditional, just to make sure there isn't any old TLBs around.didn't make a difference
OK, so how about:
diff --git a/arch/powerpc/kernel/head_8xx.S b/arch/powerpc/kernel/head_8xx.S
index 6541855..f4b5dca 100644
--- a/arch/powerpc/kernel/head_8xx.S
+++ b/arch/powerpc/kernel/head_8xx.S@@ -339,9 +339,9 @@ InstructionTLBMiss: mfspr r11, SPRN_MD_TWC /* ....and get the pte address */ lwz r10, 0(r11) /* Get the pte */ - /* r10=(r10&~_PAGE_PRESENT)|((r10&_PAGE_ACCESSED)>>5) */ - rlwimi. r10, r10, 27, 31, 31 - beq- cr0, 2f /* Can be removed, costs a ITLB Err */ + andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT + cmpwi cr0, r11, _PAGE_ACCESSED | _PAGE_PRESENT + bne- cr0, 2f #if 0 /* Dont' bother with PP lsb, bit 21 for now */ /* r10 = (r10 & ~0x0400) | ((r10 & _PAGE_EXEC) << 7) */
@@ -429,9 +429,11 @@ DataStoreTLBMiss: /* Need to know if load/store -> force a TLB Error * by copying ACCESSED to PRESENT. */ - /* r10=(r10&~_PAGE_PRESENT)|((r10&_PAGE_ACCESSED)>>5) */ - rlwimi r10, r10, 27, 31, 31 - + andi. r11, r10, _PAGE_ACCESSED | _PAGE_PRESENT + cmpwi cr0, r11, _PAGE_ACCESSED | _PAGE_PRESENT + beq+ cr0, 6f + rlwinm r10, r10, 0, 0, 30 /* Clear _PAGE_PRESENT */ +6: #if 0 /* Not yet */ /* Honour kernel RO, User NA */ andi. r11, r10, _PAGE_USER | _PAGE_RW
@@ -492,7 +494,7 @@ DataTLBError: cmpwi cr0, r10, 0x00f0 beq- FixDAR /* must be a buggy dcbX, icbi insn. */ DARFix: /* Return from dcbx instruction bug workaround, r10 holds value of DAR */ - + b 2f /* Do DIRTY in C */ mfspr r11, SPRN_DSISR andis. r11, r11, 0x4800 /* !translation or protection */ bne 2f /* branch if either is set */