[PATCH] spufs: Fix endless protection fault on LS writes by SPE.

Arnd Bergmann
2006-03-24T18:49:49Z

If an SPE attempts a DMA put to a local store after already doing
a get, the kernel must update the HW PTE to allow the write access.
This case was not being handled correctly.

From: Mike Kistler <mkistler@us.ibm.com>
Signed-off-by: Mike Kistler <mkistler@us.ibm.com>
Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

---
diff -ur linux-2.6.15/arch/powerpc/platforms/cell/spu_base.c linux-2.6.15.fixed/arch/powerpc/platforms/cell/spu_base.c
--- linux-2.6.15/arch/powerpc/platforms/cell/spu_base.c 2006-03-22 12:30:07.000000000 -0600
+++ linux-2.6.15.fixed/arch/powerpc/platforms/cell/spu_base.c 2006-03-22 10:21:26.000000000 -0600
@@ -486,14 +486,13 @@

ea = spu->dar;
dsisr = spu->dsisr;
- if (dsisr & MFC_DSISR_PTE_NOT_FOUND) {
+ if (dsisr & (MFC_DSISR_PTE_NOT_FOUND | MFC_DSISR_ACCESS_DENIED)) {
access = (_PAGE_PRESENT | _PAGE_USER);
access |= (dsisr & MFC_DSISR_ACCESS_PUT) ? _PAGE_RW : 0UL;
if (hash_page(ea, access, 0x300) != 0)
error |= CLASS1_ENABLE_STORAGE_FAULT_INTR;
}
- if ((error & CLASS1_ENABLE_STORAGE_FAULT_INTR) ||
- (dsisr & MFC_DSISR_ACCESS_DENIED)) {
+ if (error & CLASS1_ENABLE_STORAGE_FAULT_INTR) {
if ((ret = spu_handle_mm_fault(spu)) != 0)
error |= CLASS1_ENABLE_STORAGE_FAULT_INTR;
else