Using the long-descriptor translation table format changes
the layout of the CONTEXTIDR register.
Signed-off-by: Christopher Covington <c...@codeaurora.org>
---
arch/arm/mm/context.c | 37 +++++++++++++++++++++++++++----------
1 file changed, 27 insertions(+), 10 deletions(-)
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 2ac3737..272c249 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -37,6 +37,11 @@
*
* In big endian operation, the two 32 bit words are swapped if accesed by
* non 64-bit operations.
+ *
+ * The above layout is also used by ARMv7 when the short-descriptor translation
+ * table format is used, but when the long-descriptor translation table format
+ * (LPAE) is used, all 32 bits are devoted to the process identifier. (The ASID
+ * is in TTBRx.)
*/
#define ASID_FIRST_VERSION (1ULL << ASID_BITS)
#define NUM_USER_ASIDS (ASID_FIRST_VERSION - 1)
@@ -68,6 +73,13 @@ static void cpu_set_reserved_ttbr0(void)
: "r" (ttbl), "r" (ttbh));
isb();
}
+
+static void write_contextidr(pid_t pid)
+{
+ asm volatile(
+ " mcr p15, 0, %0, c13, c0, 1\n"
+ : : "r" (pid));
+}
#else
static void cpu_set_reserved_ttbr0(void)
{
@@ -79,20 +91,12 @@ static void cpu_set_reserved_ttbr0(void)
: "=r" (ttb));
isb();
}
-#endif
-#ifdef CONFIG_PID_IN_CONTEXTIDR
-static int contextidr_notifier(struct notifier_block *unused, unsigned long
cmd,
- void *t)
+static void write_contextidr(pid_t pid)
{
u32 contextidr;
- pid_t pid;
- struct thread_info *thread = t;
-
- if (cmd != THREAD_NOTIFY_SWITCH)
- return NOTIFY_DONE;
- pid = task_pid_nr(thread->task) << ASID_BITS;
+ pid <<= ASID_BITS;
asm volatile(
" mrc p15, 0, %0, c13, c0, 1\n"
" and %0, %0, %2\n"
@@ -100,6 +104,19 @@ static int contextidr_notifier(struct notifier_block
*unused, unsigned long cmd,
" mcr p15, 0, %0, c13, c0, 1\n"
: "=r" (contextidr), "+r" (pid)
: "I" (~ASID_MASK));
+}
+#endif
+
+#ifdef CONFIG_PID_IN_CONTEXTIDR
+static int contextidr_notifier(struct notifier_block *unused, unsigned long
cmd,
+ void *t)
+{
+ struct thread_info *thread = t;
+
+ if (cmd != THREAD_NOTIFY_SWITCH)
+ return NOTIFY_DONE;
+
+ write_contextidr(task_pid_nr(thread->task));
isb();
return NOTIFY_OK;
--
Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
hosted by the Linux Foundation.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majord...@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
