powerpc/mm: Rework usage of _PAGE_COHERENT/NO_CACHE/GUARDED
Currently, we never set _PAGE_COHERENT in the PTEs, we just OR it in
in the hash code based on some CPU feature bit. We also manipulate
_PAGE_NO_CACHE and _PAGE_GUARDED by hand in all sorts of places.
This changes the logic so that instead, the PTE now contains
_PAGE_COHERENT for all normal RAM pages thay have I = 0 on platforms
that need it. The hash code clears it if the feature bit is not set.
It also adds some clean accessors to setup various valid combinations
of access flags and change various bits of code to use them instead.
This should help having the PTE actually containing the bit
combinations that we really want.
I also removed _PAGE_GUARDED from _PAGE_BASE on 44x and instead
set it explicitely from the TLB miss. I will ultimately remove it
completely as it appears that it might not be needed after all
but in the meantime, having it in the TLB miss makes things a
lot easier.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/include/asm/pgtable-ppc32.h b/arch/powerpc/include/asm/pgtable-ppc32.h
index 6ab7c67..f69a4d9 100644
--- a/arch/powerpc/include/asm/pgtable-ppc32.h
+++ b/arch/powerpc/include/asm/pgtable-ppc32.h
@@ -228,9 +228,10 @@
* - FILE *must* be in the bottom three bits because swap cache
* entries use the top 29 bits for TLB2.
*
- * - CACHE COHERENT bit (M) has no effect on PPC440 core, because it
- * doesn't support SMP. So we can use this as software bit, like
- * DIRTY.
+ * - CACHE COHERENT bit (M) has no effect on original PPC440 cores,
+ * because it doesn't support SMP. However, some later 460 variants
+ * have -some- form of SMP support and so I keep the bit there for
+ * future use
*
* With the PPC 44x Linux implementation, the 0-11th LSBs of the PTE are used
* for memory protection related functions (see PTE structure in
@@ -436,20 +437,23 @@
_PAGE_USER | _PAGE_ACCESSED | \
_PAGE_RW | _PAGE_HWWRITE | _PAGE_DIRTY | \
_PAGE_EXEC | _PAGE_HWEXEC)
-/*
- * Note: the _PAGE_COHERENT bit automatically gets set in the hardware
- * PTE if CONFIG_SMP is defined (hash_page does this); there is no need
- * to have it in the Linux PTE, and in fact the bit could be reused for
- * another purpose. -- paulus.
- */
-#ifdef CONFIG_44x
-#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_GUARDED)
+/*
+ * We define 2 sets of base prot bits, one for basic pages (ie,
+ * cacheable kernel and user pages) and one for non cacheable
+ * pages. We always set _PAGE_COHERENT when SMP is enabled or
+ * the processor might need it for DMA coherency.
+ */
+#if defined(CONFIG_SMP) || defined(CONFIG_PPC_STD_MMU)
+#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_COHERENT)
#else
#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED)
#endif
+#define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_NO_CACHE)
+
#define _PAGE_WRENABLE (_PAGE_RW | _PAGE_DIRTY | _PAGE_HWWRITE)
#define _PAGE_KERNEL (_PAGE_BASE | _PAGE_SHARED | _PAGE_WRENABLE)
+#define _PAGE_KERNEL_NC (_PAGE_BASE_NC | _PAGE_SHARED | _PAGE_WRENABLE)
#ifdef CONFIG_PPC_STD_MMU
/* On standard PPC MMU, no user access implies kernel read/write access,
@@ -459,7 +463,7 @@
#define _PAGE_KERNEL_RO (_PAGE_BASE | _PAGE_SHARED)
#endif
-#define _PAGE_IO (_PAGE_KERNEL | _PAGE_NO_CACHE | _PAGE_GUARDED)
+#define _PAGE_IO (_PAGE_KERNEL_NC | _PAGE_GUARDED)
#define _PAGE_RAM (_PAGE_KERNEL | _PAGE_HWEXEC)
#if defined(CONFIG_KGDB) || defined(CONFIG_XMON) || defined(CONFIG_BDI_SWITCH) ||\
@@ -552,9 +556,6 @@
static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE; }
static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
-static inline void pte_uncache(pte_t pte) { pte_val(pte) |= _PAGE_NO_CACHE; }
-static inline void pte_cache(pte_t pte) { pte_val(pte) &= ~_PAGE_NO_CACHE; }
-
static inline pte_t pte_wrprotect(pte_t pte) {
pte_val(pte) &= ~(_PAGE_RW | _PAGE_HWWRITE); return pte; }
static inline pte_t pte_mkclean(pte_t pte) {
@@ -693,10 +694,11 @@
#endif
}
+
static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
-#if defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP)
+#if defined(CONFIG_PTE_64BIT) && defined(CONFIG_SMP) && defined(CONFIG_DEBUG_VM)
WARN_ON(pte_present(*ptep));
#endif
__set_pte_at(mm, addr, ptep, pte);
@@ -760,16 +762,6 @@
__changed; \
})
-/*
- * Macro to mark a page protection value as "uncacheable".
- */
-#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | _PAGE_NO_CACHE | _PAGE_GUARDED))
-
-struct file;
-extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
- unsigned long size, pgprot_t vma_prot);
-#define __HAVE_PHYS_MEM_ACCESS_PROT
-
#define __HAVE_ARCH_PTE_SAME
#define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0)
diff --git a/arch/powerpc/include/asm/pgtable-ppc64.h b/arch/powerpc/include/asm/pgtable-ppc64.h
index 1f0a330..b0f18be 100644
--- a/arch/powerpc/include/asm/pgtable-ppc64.h
+++ b/arch/powerpc/include/asm/pgtable-ppc64.h
@@ -245,9 +245,6 @@
static inline int pte_file(pte_t pte) { return pte_val(pte) & _PAGE_FILE;}
static inline int pte_special(pte_t pte) { return pte_val(pte) & _PAGE_SPECIAL; }
-static inline void pte_uncache(pte_t pte) { pte_val(pte) |= _PAGE_NO_CACHE; }
-static inline void pte_cache(pte_t pte) { pte_val(pte) &= ~_PAGE_NO_CACHE; }
-
static inline pte_t pte_wrprotect(pte_t pte) {
pte_val(pte) &= ~(_PAGE_RW); return pte; }
static inline pte_t pte_mkclean(pte_t pte) {
@@ -405,16 +402,6 @@
__changed; \
})
-/*
- * Macro to mark a page protection value as "uncacheable".
- */
-#define pgprot_noncached(prot) (__pgprot(pgprot_val(prot) | _PAGE_NO_CACHE | _PAGE_GUARDED))
-
-struct file;
-extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
- unsigned long size, pgprot_t vma_prot);
-#define __HAVE_PHYS_MEM_ACCESS_PROT
-
#define __HAVE_ARCH_PTE_SAME
#define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HPTEFLAGS) == 0)
diff --git a/arch/powerpc/include/asm/pgtable.h b/arch/powerpc/include/asm/pgtable.h
index dbb8ca1..07f55e6 100644
--- a/arch/powerpc/include/asm/pgtable.h
+++ b/arch/powerpc/include/asm/pgtable.h
@@ -16,6 +16,32 @@
#endif
#ifndef __ASSEMBLY__
+
+/*
+ * Macro to mark a page protection value as "uncacheable".
+ */
+
+#define _PAGE_CACHE_CTL (_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \
+ _PAGE_WRITETHRU)
+
+#define pgprot_noncached(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+ _PAGE_NO_CACHE | _PAGE_GUARDED))
+
+#define pgprot_noncached_wc(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+ _PAGE_NO_CACHE))
+
+#define pgprot_cached(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+ _PAGE_COHERENT))
+
+#define pgprot_cached_wthru(prot) (__pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | \
+ _PAGE_COHERENT | _PAGE_WRITETHRU))
+
+
+struct file;
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot);
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+
/*
* ZERO_PAGE is a global shared page that is always zero: used
* for zero-mapped memory areas etc..
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index f3a1ea9..2623735 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -570,6 +570,7 @@
rlwimi r10,r12,29,30,30 /* DIRTY -> SW position */
and r11,r12,r10 /* Mask PTE bits to keep */
andi. r10,r12,_PAGE_USER /* User page ? */
+ ori r11,r11,_PAGE_GUARDED /* 440 errata, needs G set */
beq 1f /* nope, leave U bits empty */
rlwimi r11,r11,3,26,28 /* yes, copy S bits to U */
1: tlbwe r11,r13,PPC44x_TLB_ATTRIB /* Write ATTRIB */
diff --git a/arch/powerpc/kernel/pci-common.c b/arch/powerpc/kernel/pci-common.c
index 1a32db3..2538030 100644
--- a/arch/powerpc/kernel/pci-common.c
+++ b/arch/powerpc/kernel/pci-common.c
@@ -370,13 +370,10 @@
}
/* XXX would be nice to have a way to ask for write-through */
- prot |= _PAGE_NO_CACHE;
if (write_combine)
- prot &= ~_PAGE_GUARDED;
+ return pgprot_noncached_wc(prot);
else
- prot |= _PAGE_GUARDED;
-
- return __pgprot(prot);
+ return pgprot_noncached(prot);
}
/*
@@ -387,19 +384,17 @@
pgprot_t pci_phys_mem_access_prot(struct file *file,
unsigned long pfn,
unsigned long size,
- pgprot_t protection)
+ pgprot_t prot)
{
struct pci_dev *pdev = NULL;
struct resource *found = NULL;
- unsigned long prot = pgprot_val(protection);
resource_size_t offset = ((resource_size_t)pfn) << PAGE_SHIFT;
int i;
if (page_is_ram(pfn))
- return __pgprot(prot);
+ return prot;
- prot |= _PAGE_NO_CACHE | _PAGE_GUARDED;
-
+ prot = pgprot_noncached(prot);
for_each_pci_dev(pdev) {
for (i = 0; i <= PCI_ROM_RESOURCE; i++) {
struct resource *rp = &pdev->resource[i];
@@ -420,14 +415,14 @@
}
if (found) {
if (found->flags & IORESOURCE_PREFETCH)
- prot &= ~_PAGE_GUARDED;
+ prot = pgprot_noncached_wc(prot);
pci_dev_put(pdev);
}
pr_debug("PCI: Non-PCI map for %llx, prot: %lx\n",
- (unsigned long long)offset, prot);
+ (unsigned long long)offset, pgprot_val(prot));
- return __pgprot(prot);
+ return prot;
}
@@ -583,8 +578,7 @@
pr_debug(" -> mapping phys %llx\n", (unsigned long long)offset);
vma->vm_pgoff = offset >> PAGE_SHIFT;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE | _PAGE_GUARDED);
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
vma->vm_end - vma->vm_start,
vma->vm_page_prot);
diff --git a/arch/powerpc/mm/hash_low_32.S b/arch/powerpc/mm/hash_low_32.S
index c8eac22..2884560 100644
--- a/arch/powerpc/mm/hash_low_32.S
+++ b/arch/powerpc/mm/hash_low_32.S
@@ -323,8 +323,8 @@
ori r8,r8,0xe14 /* clear out reserved bits and M */
andc r8,r5,r8 /* PP = user? (rw&dirty? 2: 3): 0 */
BEGIN_FTR_SECTION
- ori r8,r8,_PAGE_COHERENT /* set M (coherence required) */
-END_FTR_SECTION_IFSET(CPU_FTR_NEED_COHERENT)
+ rlwinm r8,r8,0,~_PAGE_COHERENT /* clear M (coherence not required) */
+END_FTR_SECTION_IFCLR(CPU_FTR_NEED_COHERENT)
#ifdef CONFIG_PTE_64BIT
/* Put the XPN bits into the PTE */
rlwimi r8,r10,8,20,22
diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c
index 8fee696f..53b06eb 100644
--- a/arch/powerpc/mm/mem.c
+++ b/arch/powerpc/mm/mem.c
@@ -102,8 +102,8 @@
return ppc_md.phys_mem_access_prot(file, pfn, size, vma_prot);
if (!page_is_ram(pfn))
- vma_prot = __pgprot(pgprot_val(vma_prot)
- | _PAGE_GUARDED | _PAGE_NO_CACHE);
+ vma_prot = pgprot_noncached(vma_prot);
+
return vma_prot;
}
EXPORT_SYMBOL(phys_mem_access_prot);
diff --git a/arch/powerpc/platforms/cell/spufs/file.c b/arch/powerpc/platforms/cell/spufs/file.c
index 1b26071..7106b63 100644
--- a/arch/powerpc/platforms/cell/spufs/file.c
+++ b/arch/powerpc/platforms/cell/spufs/file.c
@@ -273,12 +273,10 @@
return VM_FAULT_NOPAGE;
if (ctx->state == SPU_STATE_SAVED) {
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- & ~_PAGE_NO_CACHE);
+ vma->vm_page_prot = pgprot_cached(vma->vm_page_prot);
pfn = vmalloc_to_pfn(ctx->csa.lscsa->ls + offset);
} else {
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE);
+ vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot);
pfn = (ctx->spu->local_store_phys + offset) >> PAGE_SHIFT;
}
vm_insert_pfn(vma, address, pfn);
@@ -338,8 +336,7 @@
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE);
+ vma->vm_page_prot = pgprot_noncached_wc(vma->vm_page_prot);
vma->vm_ops = &spufs_mem_mmap_vmops;
return 0;
@@ -452,8 +449,7 @@
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE | _PAGE_GUARDED);
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_ops = &spufs_cntl_mmap_vmops;
return 0;
@@ -1155,8 +1151,7 @@
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE | _PAGE_GUARDED);
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_ops = &spufs_signal1_mmap_vmops;
return 0;
@@ -1292,8 +1287,7 @@
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE | _PAGE_GUARDED);
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_ops = &spufs_signal2_mmap_vmops;
return 0;
@@ -1414,8 +1408,7 @@
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE | _PAGE_GUARDED);
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_ops = &spufs_mss_mmap_vmops;
return 0;
@@ -1476,8 +1469,7 @@
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE | _PAGE_GUARDED);
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_ops = &spufs_psmap_mmap_vmops;
return 0;
@@ -1536,8 +1528,7 @@
return -EINVAL;
vma->vm_flags |= VM_IO | VM_PFNMAP;
- vma->vm_page_prot = __pgprot(pgprot_val(vma->vm_page_prot)
- | _PAGE_NO_CACHE | _PAGE_GUARDED);
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
vma->vm_ops = &spufs_mfc_mmap_vmops;
return 0;
diff --git a/drivers/video/controlfb.c b/drivers/video/controlfb.c
index b0be7ea..49fcbe8 100644
--- a/drivers/video/controlfb.c
+++ b/drivers/video/controlfb.c
@@ -298,10 +298,10 @@
return -EINVAL;
start = info->fix.mmio_start;
len = PAGE_ALIGN((start & ~PAGE_MASK)+info->fix.mmio_len);
- pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE|_PAGE_GUARDED;
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
} else {
/* framebuffer */
- pgprot_val(vma->vm_page_prot) |= _PAGE_WRITETHRU;
+ vma->vm_page_prot = pgprot_cached_wthru(vma->vm_page_prot);
}
start &= PAGE_MASK;
if ((vma->vm_end - vma->vm_start + off) > len)