Fix ARMv7 memory typing

* Russell King - ARM Linux <linux@arm.linux.org.uk> [081103 07:09]:
> Solving ARMv7 seems to be fairly simple, at the expense of making
> build_mem_types_table() slightly more complex.  If that was the only
> problem, then I wouldn't be mentioning the idea of dropping the
> patchset.

Well, this is the fix for ARMv7 (and a few others).  In making these
changes, I went back to DDI0100I (ARMv6 ARM), DDI0406A (ARMv7 ARM)
and the Marvell Xscale3 documentation.
...

Note that this version has a bug with xscale handling, but works
for omap. This patch will get reverted once the final patch is
available.

Signed-off-by: Tony Lindgren <tony@atomide.com>

diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 7aad78420f18df6b9e375d2023a8ccb998d528e0..568020b34e3e9b1c5883afb935228d2d53d58a40 100644 (file)
--- a/arch/arm/include/asm/system.h
+++ b/arch/arm/include/asm/system.h
@@ -42,6 +42,10 @@
 #define CR_U   (1 << 22)       /* Unaligned access operation           */
 #define CR_XP  (1 << 23)       /* Extended page tables                 */
 #define CR_VE  (1 << 24)       /* Vectored interrupts                  */
+#define CR_EE  (1 << 25)       /* Exception (Big) Endian               */
+#define CR_TRE (1 << 28)       /* TEX remap enable                     */
+#define CR_AFE (1 << 29)       /* Access flag enable                   */
+#define CR_TE  (1 << 30)       /* Thumb exception enable               */
 
 /*
  * This is used to ensure the compiler did actually allocate the register we

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 64c5451151bdaaabef934a8c65bb757c4039b557..697320aab3c8503456b0b84e6fe3816333f752ae 100644 (file)
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -180,20 +180,20 @@ void adjust_cr(unsigned long mask, unsigned long set)
 #endif
 
 #define PROT_PTE_DEVICE                L_PTE_PRESENT|L_PTE_YOUNG|L_PTE_DIRTY|L_PTE_WRITE
-#define PROT_SECT_DEVICE       PMD_TYPE_SECT|PMD_SECT_XN|PMD_SECT_AP_WRITE
+#define PROT_SECT_DEVICE       PMD_TYPE_SECT|PMD_SECT_AP_WRITE
 
 static struct mem_type mem_types[] = {
        [MT_DEVICE] = {           /* Strongly ordered / ARMv6 shared 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,
+               .prot_sect      = PROT_SECT_DEVICE | PMD_SECT_S,
                .domain         = DOMAIN_IO,
        },
        [MT_DEVICE_NONSHARED] = { /* ARMv6 non-shared device */
                .prot_pte       = PROT_PTE_DEVICE | L_PTE_MT_DEV_NONSHARED,
                .prot_l1        = PMD_TYPE_TABLE,
-               .prot_sect      = PROT_SECT_DEVICE | PMD_SECT_TEX(2),
+               .prot_sect      = PROT_SECT_DEVICE,
                .domain         = DOMAIN_IO,
        },
        [MT_DEVICE_CACHED] = {    /* ioremap_cached */
@@ -205,7 +205,7 @@ static struct mem_type mem_types[] = {
        [MT_DEVICE_WC] = {      /* ioremap_wc */
                .prot_pte       = PROT_PTE_DEVICE | L_PTE_MT_DEV_WC,
                .prot_l1        = PMD_TYPE_TABLE,
-               .prot_sect      = PROT_SECT_DEVICE | PMD_SECT_BUFFERABLE,
+               .prot_sect      = PROT_SECT_DEVICE,
                .domain         = DOMAIN_IO,
        },
        [MT_CACHECLEAN] = {
@@ -277,22 +277,23 @@ static void __init build_mem_type_table(void)
 #endif
 
        /*
-        * On non-Xscale3 ARMv5-and-older systems, use CB=01
-        * (Uncached/Buffered) for ioremap_wc() mappings.  On XScale3
-        * and ARMv6+, use TEXCB=00100 mappings (Inner/Outer Uncacheable
-        * in xsc3 parlance, Uncached Normal in ARMv6 parlance).
+        * Strip out features not present on earlier architectures.
+        * Pre-ARMv5 CPUs don't have TEX bits.  Pre-ARMv6 CPUs or those
+        * without extended page tables don't have the 'Shared' bit.
         */
-       if (cpu_is_xsc3() || cpu_arch >= CPU_ARCH_ARMv6) {
-               mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
-               mem_types[MT_DEVICE_WC].prot_sect &= ~PMD_SECT_BUFFERABLE;
-       }
+       if (cpu_arch < CPU_ARCH_ARMv5)
+               for (i = 0; i < ARRAY_SIZE(mem_types); i++)
+                       mem_types[i].prot_sect &= ~PMD_SECT_TEX(7);
+       if (cpu_arch < CPU_ARCH_ARMv6 || !(cr & CR_XP))
+               for (i = 0; i < ARRAY_SIZE(mem_types); i++)
+                       mem_types[i].prot_sect &= ~PMD_SECT_S;
 
        /*
-        * ARMv5 and lower, bit 4 must be set for page tables.
-        * (was: cache "update-able on write" bit on ARM610)
-        * However, Xscale cores require this bit to be cleared.
+        * ARMv5 and lower, bit 4 must be set for page tables (was: cache
+        * "update-able on write" bit on ARM610).  However, Xscale and
+        * Xscale3 require this bit to be cleared.
         */
-       if (cpu_is_xscale()) {
+       if (cpu_is_xscale() || cpu_is_xsc3()) {
                for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
                        mem_types[i].prot_sect &= ~PMD_BIT4;
                        mem_types[i].prot_l1 &= ~PMD_BIT4;
@@ -306,6 +307,54 @@ static void __init build_mem_type_table(void)
                }
        }
 
+       /*
+        * Mark the device areas according to the CPU/architecture.
+        */
+       if (cpu_is_xsc3() || (cpu_arch >= CPU_ARCH_ARMv6 && (cr & CR_XP))) {
+               if (!cpu_is_xsc3()) {
+                       /*
+                        * Mark device regions on ARMv6+ as execute-never
+                        * to prevent speculative instruction fetches.
+                        */
+                       mem_types[MT_DEVICE].prot_sect |= PMD_SECT_XN;
+                       mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_XN;
+                       mem_types[MT_DEVICE_CACHED].prot_sect |= PMD_SECT_XN;
+                       mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_XN;
+               }
+               if (cpu_arch >= CPU_ARCH_ARMv7 && (cr & CR_TRE)) {
+                       /*
+                        * For ARMv7 with TEX remapping,
+                        * - shared device is SXCB=1100
+                        * - nonshared device is SXCB=0100
+                        * - write combine device mem is SXCB=0001
+                        * (Uncached Normal memory)
+                        */
+                       mem_types[MT_DEVICE].prot_sect |= PMD_SECT_TEX(1);
+                       mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(1);
+                       mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
+               } else {
+                       /*
+                        * For Xscale3, ARMv6 and ARMv7 without TEX remapping,
+                        * - shared device is TEXCB=00001
+                        * - nonshared device is TEXCB=01000
+                        * - write combine device mem is TEXCB=00100
+                        * (Inner/Outer Uncacheable in xsc3 parlance, Uncached
+                        * Normal in ARMv6 parlance).
+                        */
+                       mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
+                       mem_types[MT_DEVICE_NONSHARED].prot_sect |= PMD_SECT_TEX(2);
+                       mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_TEX(1);
+               }
+       } else {
+               /*
+                * On others, write combining is "Uncached/Buffered"
+                */
+               mem_types[MT_DEVICE_WC].prot_sect |= PMD_SECT_BUFFERABLE;
+       }
+
+       /*
+        * Now deal with the memory-type mappings
+        */
        cp = &cache_policies[cachepolicy];
        vecs_pgprot = kern_pgprot = user_pgprot = cp->pte;
 
@@ -321,12 +370,8 @@ static void __init build_mem_type_table(void)
         * Enable CPU-specific coherency if supported.
         * (Only available on XSC3 at the moment.)
         */
-       if (arch_is_coherent()) {
-               if (cpu_is_xsc3()) {
-                       mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
-                       mem_types[MT_MEMORY].prot_pte |= L_PTE_SHARED;
-               }
-       }
+       if (arch_is_coherent() && cpu_is_xsc3())
+               mem_types[MT_MEMORY].prot_sect |= PMD_SECT_S;
 
        /*
         * ARMv6 and above have extended page tables.
@@ -340,11 +385,6 @@ static void __init build_mem_type_table(void)
                mem_types[MT_MINICLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
                mem_types[MT_CACHECLEAN].prot_sect |= PMD_SECT_APX|PMD_SECT_AP_WRITE;
 
-               /*
-                * Mark the device area as "shared device"
-                */
-               mem_types[MT_DEVICE].prot_sect |= PMD_SECT_BUFFERED;
-
 #ifdef CONFIG_SMP
                /*
                 * Mark memory with the "shared" attribute for SMP systems
@@ -364,9 +404,6 @@ static void __init build_mem_type_table(void)
        mem_types[MT_LOW_VECTORS].prot_pte |= vecs_pgprot;
        mem_types[MT_HIGH_VECTORS].prot_pte |= vecs_pgprot;
 
-       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 |
                                 L_PTE_DIRTY | L_PTE_WRITE |
@@ -391,6 +428,22 @@ static void __init build_mem_type_table(void)
 
        for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
                struct mem_type *t = &mem_types[i];
+               const char *s;
+#define T(n)   if (i == (n)) s = #n;
+               s = "???";
+               T(MT_DEVICE);
+               T(MT_DEVICE_NONSHARED);
+               T(MT_DEVICE_CACHED);
+               T(MT_DEVICE_WC);
+               T(MT_CACHECLEAN);
+               T(MT_MINICLEAN);
+               T(MT_LOW_VECTORS);
+               T(MT_HIGH_VECTORS);
+               T(MT_MEMORY);
+               T(MT_ROM);
+               printk(KERN_INFO "%-19s: DOM=%#3x S=%#010x L1=%#010x P=%#010x\n",
+                       s, t->domain, t->prot_sect, t->prot_l1, t->prot_pte);
+
                if (t->prot_l1)
                        t->prot_l1 |= PMD_DOMAIN(t->domain);
                if (t->prot_sect)

diff --git a/arch/arm/mm/proc-v7.S b/arch/arm/mm/proc-v7.S
index 07f82db70945f7d3582dcd6c9f589ebcce648af9..f1d158f26f6dbb912805fa9247a849785e466c5f 100644 (file)
--- a/arch/arm/mm/proc-v7.S
+++ b/arch/arm/mm/proc-v7.S
@@ -192,11 +192,11 @@ __v7_setup:
        mov     pc, lr                          @ return to head.S:__ret
 ENDPROC(__v7_setup)
 
-       /*
-        *         V X F   I D LR
-        * .... ...E PUI. .T.T 4RVI ZFRS BLDP WCAM
-        * rrrr rrrx xxx0 0101 xxxx xxxx x111 xxxx < forced
-        *         0 110       0011 1.00 .111 1101 < we want
+       /*   AT
+        *  TFR   EV X F   I D LR
+        * .EEE ..EE PUI. .T.T 4RVI ZFRS BLDP WCAM
+        * rxxx rrxx xxx0 0101 xxxx xxxx x111 xxxx < forced
+        *    1    0 110       0011 1.00 .111 1101 < we want
         */
        .type   v7_crval, #object
 v7_crval: