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[Qemu-devel] [PATCH 2/2] [RFC] ARMv7: Support for simplified access perm
From: |
Bahadir Balban |
Subject: |
[Qemu-devel] [PATCH 2/2] [RFC] ARMv7: Support for simplified access permissions checking |
Date: |
Mon, 25 Jan 2010 09:38:48 +0200 |
ARMv7 has a simplified access permissions model that is enabled
by setting the AFE bit of the SCTLR. This patch adds checking
for permission values for when this mode is selected.
Signed-off-by: Bahadir Balban <address@hidden>
---
target-arm/helper.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++--
1 files changed, 48 insertions(+), 2 deletions(-)
diff --git a/target-arm/helper.c b/target-arm/helper.c
index 334832d..732d142 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -837,11 +837,48 @@ void do_interrupt(CPUARMState *env)
env->interrupt_request |= CPU_INTERRUPT_EXITTB;
}
+
+/*
+ * Simplified access permissions:
+ * AP[2:1] has below meanings:
+ * User/None Kern/RW 0
+ * User/RW Kern/RW 1
+ * User/None Kern/RO 2
+ * User/RO Kern/RO 3
+ */
+#define AP_SIMPLE_USER_NONE_KERN_RW 0
+#define AP_SIMPLE_USER_RW_KERN_RW 1
+#define AP_SIMPLE_USER_NONE_KERN_RO 2
+#define AP_SIMPLE_USER_RO_KERN_RO 3
+
+static int check_ap_simplified(CPUState *env, int ap, int domain,
+ int access_type, int is_user)
+{
+ switch(ap) {
+ case AP_SIMPLE_USER_NONE_KERN_RW:
+ if (is_user)
+ return 0;
+ else
+ return PAGE_READ | PAGE_WRITE;
+ case AP_SIMPLE_USER_RW_KERN_RW:
+ return PAGE_READ | PAGE_WRITE;
+ case AP_SIMPLE_USER_NONE_KERN_RO:
+ if (is_user)
+ return 0;
+ else
+ return PAGE_READ;
+ case AP_SIMPLE_USER_RO_KERN_RO:
+ return PAGE_READ;
+ default:
+ return 0;
+ }
+}
+
/* Check section/page access permissions.
Returns the page protection flags, or zero if the access is not
permitted. */
-static inline int check_ap(CPUState *env, int ap, int domain, int access_type,
- int is_user)
+static inline int check_ap_normal(CPUState *env, int ap, int domain,
+ int access_type, int is_user)
{
int prot_ro;
@@ -889,6 +926,15 @@ static inline int check_ap(CPUState *env, int ap, int
domain, int access_type,
}
}
+static inline int check_ap(CPUState *env, int ap, int domain,
+ int access_type, int is_user)
+{
+ if (env->cp15.c1_sys & (1 << 29))
+ return check_ap_simplified(env, ap, domain, access_type, is_user);
+ else
+ return check_ap_normal(env, ap, domain, access_type, is_user);
+}
+
static uint32_t get_level1_table_address(CPUState *env, uint32_t address)
{
uint32_t table;
--
1.6.3.3