[PATCH] ARM: Fix XScale PMD setting

The ARM Architecture Reference Manual lists bit 4 of the PMD as "implementation
defined" and it must be set to zero on Intel XScale CPUs or the cache does
not behave properly. Found by Mike Rapoport while debugging a flash issue
on the PXA255:

	http://marc.10east.com/?l=linux-arm-kernel&m=114845287600782&w=1

Signed-off-by: Deepak Saxena <dsaxena@plexity.net>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

diff --git a/arch/arm/mm/mm-armv.c b/arch/arm/mm/mm-armv.c
index f14b2d0f3690a002cf396bfa521c57eae068a242..95273de4f772515780e2eac97ed2ae892ac52a0d 100644 (file)
--- a/arch/arm/mm/mm-armv.c
+++ b/arch/arm/mm/mm-armv.c
@@ -376,7 +376,7 @@ void __init build_mem_type_table(void)
                ecc_mask = 0;
        }
 
-       if (cpu_arch <= CPU_ARCH_ARMv5TEJ) {
+       if (cpu_arch <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale()) {
                for (i = 0; i < ARRAY_SIZE(mem_types); i++) {
                        if (mem_types[i].prot_l1)
                                mem_types[i].prot_l1 |= PMD_BIT4;
@@ -631,7 +631,7 @@ void setup_mm_for_reboot(char mode)
                pgd = init_mm.pgd;
 
        base_pmdval = PMD_SECT_AP_WRITE | PMD_SECT_AP_READ | PMD_TYPE_SECT;
-       if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ)
+       if (cpu_architecture() <= CPU_ARCH_ARMv5TEJ && !cpu_is_xscale())
                base_pmdval |= PMD_BIT4;
 
        for (i = 0; i < FIRST_USER_PGD_NR + USER_PTRS_PER_PGD; i++, pgd++) {

diff --git a/include/asm-arm/system.h b/include/asm-arm/system.h
index 95b3abf4851bb9cc70596edd3a239076910939ee..7c9568d30307ff46ffafec33122de19d4f4f9e29 100644 (file)
--- a/include/asm-arm/system.h
+++ b/include/asm-arm/system.h
@@ -127,6 +127,12 @@ static inline int cpu_is_xsc3(void)
 }
 #endif
 
+#if !defined(CONFIG_CPU_XSCALE) && !defined(CONFIG_CPU_XSC3)
+#define        cpu_is_xscale() 0
+#else
+#define        cpu_is_xscale() 1
+#endif
+
 #define set_cr(x)                                      \
        __asm__ __volatile__(                           \
        "mcr    p15, 0, %0, c1, c0, 0   @ set CR"       \