[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 <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

arch/arm/mm/mm-armv.c

···
 		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;
···
 		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++) {

include/asm-arm/system.h

···
 }
 #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"	\