[ARM] Introduce new PTE memory type bits
Provide L_PTE_MT_xxx definitions to describe the memory types that we
use in Linux/ARM. These definitions are carefully picked such that:
1. their LSBs match what is required for pre-ARMv6 CPUs.
2. they all have a unique encoding, including after modification
by build_mem_type_table() (the result being that some have more
than one combination.)
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/pgtable.h b/arch/arm/include/asm/pgtable.h
index 5c75e02..8df2e25 100644
--- a/arch/arm/include/asm/pgtable.h
+++ b/arch/arm/include/asm/pgtable.h
@@ -164,14 +164,35 @@
#define L_PTE_PRESENT (1 << 0)
#define L_PTE_FILE (1 << 1) /* only when !PRESENT */
#define L_PTE_YOUNG (1 << 1)
-#define L_PTE_BUFFERABLE (1 << 2) /* matches PTE */
-#define L_PTE_CACHEABLE (1 << 3) /* matches PTE */
+#define L_PTE_BUFFERABLE (1 << 2) /* obsolete, matches PTE */
+#define L_PTE_CACHEABLE (1 << 3) /* obsolete, matches PTE */
#define L_PTE_DIRTY (1 << 6)
#define L_PTE_WRITE (1 << 7)
#define L_PTE_USER (1 << 8)
#define L_PTE_EXEC (1 << 9)
#define L_PTE_SHARED (1 << 10) /* shared(v6), coherent(xsc3) */
+/*
+ * These are the memory types, defined to be compatible with
+ * pre-ARMv6 CPUs cacheable and bufferable bits: XXCB
+ * (note: build_mem_type_table modifies these bits
+ * to work with our existing proc-*.S setup.)
+ */
+#define L_PTE_MT_UNCACHED (0x00 << 2) /* 0000 */
+#define L_PTE_MT_BUFFERABLE (0x01 << 2) /* 0001 */
+#define L_PTE_MT_WRITETHROUGH (0x02 << 2) /* 0010 */
+#define L_PTE_MT_WRITEBACK (0x03 << 2) /* 0011 */
+#define L_PTE_MT_MINICACHE (0x06 << 2) /* 0110 (sa1100, xscale) */
+#define L_PTE_MT_WRITEALLOC (0x07 << 2) /* 0111 */
+#define L_PTE_MT_DEV_SHARED (0x04 << 2) /* 0100 (pre-v6) */
+#define L_PTE_MT_DEV_SHARED2 (0x05 << 2) /* 0101 (v6) */
+#define L_PTE_MT_DEV_NONSHARED (0x0c << 2) /* 1100 */
+#define L_PTE_MT_DEV_IXP2000 (0x0d << 2) /* 1101 */
+#define L_PTE_MT_DEV_WC (0x09 << 2) /* 1001 (pre-v6, !xsc3) */
+#define L_PTE_MT_DEV_WC2 (0x08 << 2) /* 1000 (xsc3, v6) */
+#define L_PTE_MT_DEV_CACHED (0x0b << 2) /* 1011 */
+#define L_PTE_MT_MASK (0x0f << 2)
+
#ifndef __ASSEMBLY__
/*
@@ -180,7 +201,7 @@
* as well as any architecture dependent bits like global/ASID and SMP
* shared mapping bits.
*/
-#define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG | L_PTE_CACHEABLE | L_PTE_BUFFERABLE
+#define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG
#define _L_PTE_READ L_PTE_USER | L_PTE_EXEC
extern pgprot_t pgprot_user;
@@ -286,8 +307,10 @@
/*
* Mark the prot value as uncacheable and unbufferable.
*/
-#define pgprot_noncached(prot) __pgprot(pgprot_val(prot) & ~(L_PTE_CACHEABLE | L_PTE_BUFFERABLE))
-#define pgprot_writecombine(prot) __pgprot(pgprot_val(prot) & ~L_PTE_CACHEABLE)
+#define pgprot_noncached(prot) \
+ __pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_UNCACHED)
+#define pgprot_writecombine(prot) \
+ __pgprot((pgprot_val(prot) & ~L_PTE_MT_MASK) | L_PTE_MT_BUFFERABLE)
#define pmd_none(pmd) (!pmd_val(pmd))
#define pmd_present(pmd) (pmd_val(pmd))
diff --git a/arch/arm/mm/copypage-v4mc.c b/arch/arm/mm/copypage-v4mc.c
index ded0e96..8d33e25 100644
--- a/arch/arm/mm/copypage-v4mc.c
+++ b/arch/arm/mm/copypage-v4mc.c
@@ -28,7 +28,7 @@
* specific hacks for copying pages efficiently.
*/
#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
- L_PTE_CACHEABLE)
+ L_PTE_MT_MINICACHE)
static DEFINE_SPINLOCK(minicache_lock);
diff --git a/arch/arm/mm/copypage-xscale.c b/arch/arm/mm/copypage-xscale.c
index 2e455f8..bad4933 100644
--- a/arch/arm/mm/copypage-xscale.c
+++ b/arch/arm/mm/copypage-xscale.c
@@ -30,7 +30,7 @@
#define COPYPAGE_MINICACHE 0xffff8000
#define minicache_pgprot __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | \
- L_PTE_CACHEABLE)
+ L_PTE_MT_MINICACHE)
static DEFINE_SPINLOCK(minicache_lock);
diff --git a/arch/arm/mm/fault-armv.c b/arch/arm/mm/fault-armv.c
index a8ec97b..6f92904 100644
--- a/arch/arm/mm/fault-armv.c
+++ b/arch/arm/mm/fault-armv.c
@@ -21,7 +21,7 @@
#include <asm/pgtable.h>
#include <asm/tlbflush.h>
-static unsigned long shared_pte_mask = L_PTE_CACHEABLE;
+static unsigned long shared_pte_mask = L_PTE_MT_BUFFERABLE;
/*
* We take the easy way out of this problem - we make the
@@ -63,9 +63,10 @@
* If this page isn't present, or is already setup to
* fault (ie, is old), we can safely ignore any issues.
*/
- if (ret && pte_val(entry) & shared_pte_mask) {
+ if (ret && (pte_val(entry) & L_PTE_MT_MASK) != shared_pte_mask) {
flush_cache_page(vma, address, pte_pfn(entry));
- pte_val(entry) &= ~shared_pte_mask;
+ pte_val(entry) &= ~L_PTE_MT_MASK;
+ pte_val(entry) |= shared_pte_mask;
set_pte_at(vma->vm_mm, address, pte, entry);
flush_tlb_page(vma, address);
}
@@ -197,7 +198,7 @@
unsigned long *p1, *p2;
pgprot_t prot = __pgprot(L_PTE_PRESENT|L_PTE_YOUNG|
L_PTE_DIRTY|L_PTE_WRITE|
- L_PTE_BUFFERABLE);
+ L_PTE_MT_BUFFERABLE);
p1 = vmap(&page, 1, VM_IOREMAP, prot);
p2 = vmap(&page, 1, VM_IOREMAP, prot);
@@ -218,7 +219,7 @@
if (v) {
printk("failed, %s\n", reason);
- shared_pte_mask |= L_PTE_BUFFERABLE;
+ shared_pte_mask = L_PTE_MT_UNCACHED;
} else {
printk("ok\n");
}
diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index a713e40..cfc0add 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -68,27 +68,27 @@
.policy = "uncached",
.cr_mask = CR_W|CR_C,
.pmd = PMD_SECT_UNCACHED,
- .pte = 0,
+ .pte = L_PTE_MT_UNCACHED,
}, {
.policy = "buffered",
.cr_mask = CR_C,
.pmd = PMD_SECT_BUFFERED,
- .pte = PTE_BUFFERABLE,
+ .pte = L_PTE_MT_BUFFERABLE,
}, {
.policy = "writethrough",
.cr_mask = 0,
.pmd = PMD_SECT_WT,
- .pte = PTE_CACHEABLE,
+ .pte = L_PTE_MT_WRITETHROUGH,
}, {
.policy = "writeback",
.cr_mask = 0,
.pmd = PMD_SECT_WB,
- .pte = PTE_BUFFERABLE|PTE_CACHEABLE,
+ .pte = L_PTE_MT_WRITEBACK,
}, {
.policy = "writealloc",
.cr_mask = 0,
.pmd = PMD_SECT_WBWA,
- .pte = PTE_BUFFERABLE|PTE_CACHEABLE,
+ .pte = L_PTE_MT_WRITEALLOC,
}
};
@@ -186,35 +186,36 @@
static struct mem_type mem_types[] = {
[MT_DEVICE] = { /* Strongly ordered / ARMv6 shared device */
- .prot_pte = PROT_PTE_DEVICE,
+ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_SHARED |
+ L_PTE_SHARED,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_UNCACHED,
.domain = DOMAIN_IO,
},
[MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */
- .prot_pte = PROT_PTE_DEVICE,
+ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED,
.prot_pte_ext = PTE_EXT_TEX(2),
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_TEX(2),
.domain = DOMAIN_IO,
},
[MT_DEVICE_CACHED] = { /* ioremap_cached */
- .prot_pte = PROT_PTE_DEVICE | L_PTE_CACHEABLE | L_PTE_BUFFERABLE,
+ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_CACHED,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_WB,
.domain = DOMAIN_IO,
},
[MT_DEVICE_IXP2000] = { /* IXP2400 requires XCB=101 for on-chip I/O */
- .prot_pte = PROT_PTE_DEVICE,
+ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_IXP2000,
.prot_l1 = PMD_TYPE_TABLE,
.prot_sect = PROT_SECT_DEVICE | PMD_SECT_BUFFERABLE |
PMD_SECT_TEX(1),
.domain = DOMAIN_IO,
},
[MT_DEVICE_WC] = { /* ioremap_wc */
- .prot_pte = PROT_PTE_DEVICE,
+ .prot_pte = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
.prot_l1 = PMD_TYPE_TABLE,
- .prot_sect = PROT_SECT_DEVICE,
+ .prot_sect = PROT_SECT_DEVICE | PMD_SECT_BUFFERABLE,
.domain = DOMAIN_IO,
},
[MT_CACHECLEAN] = {
@@ -259,7 +260,7 @@
{
struct cachepolicy *cp;
unsigned int cr = get_cr();
- unsigned int user_pgprot, kern_pgprot;
+ unsigned int user_pgprot, kern_pgprot, vecs_pgprot;
int cpu_arch = cpu_architecture();
int i;
@@ -277,6 +278,9 @@
cachepolicy = CPOLICY_WRITEBACK;
ecc_mask = 0;
}
+#ifdef CONFIG_SMP
+ cachepolicy = CPOLICY_WRITEALLOC;
+#endif
/*
* On non-Xscale3 ARMv5-and-older systems, use CB=01
@@ -286,10 +290,9 @@
*/
if (cpu_is_xsc3() || cpu_arch >= CPU_ARCH_ARMv6) {
mem_types[MT_DEVICE_WC].prot_pte_ext |= PTE_EXT_TEX(1);
+ mem_types[MT_DEVICE_WC].prot_pte &= ~L_PTE_BUFFERABLE;
mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
- } else {
- mem_types[MT_DEVICE_WC].prot_pte |= L_PTE_BUFFERABLE;
- mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
+ mem_types[MT_DEVICE_WC].prot_sect &= ~PMD_SECT_BUFFERABLE;
}
/*
@@ -312,7 +315,15 @@
}
cp = &cache_policies[cachepolicy];
- kern_pgprot = user_pgprot = cp->pte;
+ vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
+
+#ifndef CONFIG_SMP
+ /*
+ * Only use write-through for non-SMP systems
+ */
+ if (cpu_arch >= CPU_ARCH_ARMv5 && cachepolicy > CPOLICY_WRITETHROUGH)
+ vecs_pgprot = cache_policies[CPOLICY_WRITETHROUGH].pte;
+#endif
/*
* Enable CPU-specific coherency if supported.
@@ -349,30 +360,21 @@
*/
user_pgprot |= L_PTE_SHARED;
kern_pgprot |= L_PTE_SHARED;
+ vecs_pgprot |= L_PTE_SHARED;
mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
#endif
}
for (i = 0; i < 16; i++) {
unsigned long v = pgprot_val(protection_map[i]);
- v = (v & ~(L_PTE_BUFFERABLE|L_PTE_CACHEABLE)) | user_pgprot;
- protection_map[i] = __pgprot(v);
+ protection_map[i] = __pgprot(v | user_pgprot);
}
- mem_types[MT_LOW_VECTORS].prot_pte |= kern_pgprot;
- mem_types[MT_HIGH_VECTORS].prot_pte |= kern_pgprot;
+ mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot;
+ mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot;
- if (cpu_arch >= CPU_ARCH_ARMv5) {
-#ifndef CONFIG_SMP
- /*
- * Only use write-through for non-SMP systems
- */
- mem_types[MT_LOW_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
- mem_types[MT_HIGH_VECTORS].prot_pte &= ~L_PTE_BUFFERABLE;
-#endif
- } else {
+ if (cpu_arch < CPU_ARCH_ARMv5)
mem_types[MT_MINICLEAN].prot_sect &= ~PMD_SECT_TEX(1);
- }
pgprot_user = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG | user_pgprot);
pgprot_kernel = __pgprot(L_PTE_PRESENT | L_PTE_YOUNG |