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>

arch/arm/cpu/armv7/cache_v7.c

@@ -340,6 +340,9 @@ void mmu_page_table_flush(unsigned long start, unsigned long stop)
 {
 }
 
+void arm_init_domains(void)
+{
+}
 #endif /* #ifndef CONFIG_SYS_DCACHE_OFF */
 
 #ifndef CONFIG_SYS_ICACHE_OFF

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

arch/arm/include/asm/system.h

@@ -81,6 +81,20 @@ static inline void set_cr(unsigned int val)
 	isb();
 }
 
+static inline unsigned int get_dacr(void)
+{
+	unsigned int val;
+	asm("mrc p15, 0, %0, c3, c0, 0	@ get DACR" : "=r" (val) : : "cc");
+	return val;
+}
+
+static inline void set_dacr(unsigned int val)
+{
+	asm volatile("mcr p15, 0, %0, c3, c0, 0	@ set DACR"
+	  : : "r" (val) : "cc");
+	isb();
+}
+
 /* options available for data cache on each page */
 enum dcache_option {
 	DCACHE_OFF = 0x12,

arch/arm/lib/cache-cp15.c

@@ -36,6 +36,10 @@ void __arm_init_before_mmu(void)
 void arm_init_before_mmu(void)
 	__attribute__((weak, alias("__arm_init_before_mmu")));
 
+__weak void arm_init_domains(void)
+{
+}
+
 static void cp_delay (void)
 {
 	volatile int i;
@@ -117,6 +121,9 @@ static inline void mmu_setup(void)
 	/* Set the access control to all-supervisor */
 	asm volatile("mcr p15, 0, %0, c3, c0, 0"
 		     : : "r" (~0));
+
+	arm_init_domains();
+
 	/* and enable the mmu */
 	reg = get_cr();	/* get control reg. */
 	cp_delay();