ARM: mmu: Set domain permissions to client access

 The 'XN' execute never bit is set in the pagetables. This will
 prevent speculative prefetches to non executable regions. But the
 domain permissions are set as master in the DACR register.
 So the pagetable attribute for 'XN' is not effective. Change the
 permissions to client.

 This fixes lot of speculative prefetch aborts seen on OMAP5
 secure devices.

Signed-off-by: R Sricharan <r.sricharan@ti.com>
Tested-by: Vincent Stehle <v-stehle@ti.com>
Cc: Vincent Stehle <v-stehle@ti.com>
Cc: Tom Rini <trini@ti.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>

1 files changed, 35 insertions, 0 deletions

diff --git a/arch/arm/cpu/armv7/omap-common/hwinit-common.c b/arch/arm/cpu/armv7/omap-common/hwinit-common.c
index 05ff2e8..70d16a8 100644
--- a/arch/arm/cpu/armv7/omap-common/hwinit-common.c
+++ b/arch/arm/cpu/armv7/omap-common/hwinit-common.c
@@ -34,6 +34,12 @@
 #include <asm/emif.h>
 #include <asm/omap_common.h>
 #include <linux/compiler.h>
+#include <asm/cache.h>
+#include <asm/system.h>
+
+#define ARMV7_DCACHE_WRITEBACK  0xe
+#define	ARMV7_DOMAIN_CLIENT	1
+#define ARMV7_DOMAIN_MASK	(0x3 << 0)
 
 DECLARE_GLOBAL_DATA_PTR;
 
@@ -269,4 +275,33 @@ void enable_caches(void)
 	/* Enable D-cache. I-cache is already enabled in start.S */
 	dcache_enable();
 }
+
+void dram_bank_mmu_setup(int bank)
+{
+	bd_t *bd = gd->bd;
+	int	i;
+
+	u32 start = bd->bi_dram[bank].start >> 20;
+	u32 size = bd->bi_dram[bank].size >> 20;
+	u32 end = start + size;
+
+	debug("%s: bank: %d\n", __func__, bank);
+	for (i = start; i < end; i++)
+		set_section_dcache(i, ARMV7_DCACHE_WRITEBACK);
+
+}
+
+void arm_init_domains(void)
+{
+	u32 reg;
+
+	reg = get_dacr();
+	/*
+	* Set DOMAIN to client access so that all permissions
+	* set in pagetables are validated by the mmu.
+	*/
+	reg &= ~ARMV7_DOMAIN_MASK;
+	reg |= ARMV7_DOMAIN_CLIENT;
+	set_dacr(reg);
+}
 #endif