From de63ac278cbaaa387da3efaf0b21b819c2b0c496 Mon Sep 17 00:00:00 2001
From: R Sricharan <r.sricharan@ti.com>
Date: Mon, 4 Mar 2013 20:04:45 +0000
Subject: [PATCH] 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 | 3 ++
.../arm/cpu/armv7/omap-common/hwinit-common.c | 35 +++++++++++++++++++
arch/arm/include/asm/system.h | 14 ++++++++
arch/arm/lib/cache-cp15.c | 7 ++++
4 files changed, 59 insertions(+)
diff --git a/arch/arm/cpu/armv7/cache_v7.c b/arch/arm/cpu/armv7/cache_v7.c
index 5f6d0396f3..8748c145c4 100644
--- a/arch/arm/cpu/armv7/cache_v7.c
+++ b/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
diff --git a/arch/arm/cpu/armv7/omap-common/hwinit-common.c b/arch/arm/cpu/armv7/omap-common/hwinit-common.c
index 05ff2e868f..70d16a8160 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
diff --git a/arch/arm/include/asm/system.h b/arch/arm/include/asm/system.h
index 1918492eae..760345f847 100644
--- a/arch/arm/include/asm/system.h
+++ b/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,
diff --git a/arch/arm/lib/cache-cp15.c b/arch/arm/lib/cache-cp15.c
index 6ecbedfed9..4abe1cf061 100644
--- a/arch/arm/lib/cache-cp15.c
+++ b/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();
--
2.39.5