From: Arnd Bergmann Date: Wed, 4 Oct 2006 15:26:16 +0000 (+0200) Subject: [POWERPC] spufs: use correct pg_prot for mapping SPU local store X-Git-Tag: v2.6.19-rc1~3^2~8 X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=ac91cb8dae061ced64e475d0d70fac4a95298819;p=linux-2.6 [POWERPC] spufs: use correct pg_prot for mapping SPU local store This hopefully fixes a long-standing bug in the spu file system. An spu context comes with local memory that can be either saved in kernel pages or point directly to a physical SPE. When mapping the physical SPE, that mapping needs to be cache-inhibited. For simplicity, we used to map the kernel backing memory that way too, but unfortunately that was not only inefficient, but also incorrect because the same page could then be accessed simultaneously through a cacheable and a cache-inhibited mapping, which is not allowed by the powerpc specification and in our case caused data inconsistency for which we did a really ugly workaround in user space. Signed-off-by: Arnd Bergmann Signed-off-by: Paul Mackerras --- diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c index 64f8b0a9b9..514a1d5080 100644 --- a/arch/powerpc/platforms/cell/spufs/file.c +++ b/arch/powerpc/platforms/cell/spufs/file.c @@ -102,12 +102,16 @@ spufs_mem_mmap_nopage(struct vm_area_struct *vma, spu_acquire(ctx); - if (ctx->state == SPU_STATE_SAVED) + if (ctx->state == SPU_STATE_SAVED) { + vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot) + & ~(_PAGE_NO_CACHE | _PAGE_GUARDED)); page = vmalloc_to_page(ctx->csa.lscsa->ls + offset); - else + } else { + vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot) + | _PAGE_NO_CACHE | _PAGE_GUARDED); page = pfn_to_page((ctx->spu->local_store_phys + offset) >> PAGE_SHIFT); - + } spu_release(ctx); if (type)