security: tlk_driver: Use CPU0 for smc calls

- All smc calls need to be done through CPU0.
- Add the sched_setaffinity logic to tlk_generic_smc(), will solve
  the occasional prefetch abort.
- Also adding sched_setaffinity logic to tlk_extended_smc().

bug 1322280

Change-Id: I67716bec49aec1f1c9a2e33ec3de90aec2048870
Signed-off-by: James Zhao <jamesz@nvidia.com>
Signed-off-by: Aaron Gamble <jgamble@nvidia.com>
Reviewed-on: http://git-master/r/264177
Tested-by: Varun Wadekar <vwadekar@nvidia.com>
Reviewed-by: Automatic_Commit_Validation_User
Reviewed-by: Chris Johnson <cwj@nvidia.com>
Tested-by: Chris Johnson <cwj@nvidia.com>
Reviewed-by: Varun Wadekar <vwadekar@nvidia.com>

1 files changed, 63 insertions, 31 deletions

diff --git a/security/tlk_driver/ote_comms.c b/security/tlk_driver/ote_comms.c
index 40a3ec723ce8..02232ac74964 100644
--- a/security/tlk_driver/ote_comms.c
+++ b/security/tlk_driver/ote_comms.c
@@ -193,11 +193,32 @@ static void te_unpin_temp_buffers(struct te_request *request,
 
 uint32_t tlk_generic_smc(uint32_t arg0, uint32_t arg1, uint32_t arg2)
 {
+#ifdef CONFIG_SMP
+	cpumask_t saved_cpu_mask;
+#endif
 	uint32_t saved_regs[9];
-	register uint32_t r0 asm("r0") = arg0;
-	register uint32_t r1 asm("r1") = arg1;
-	register uint32_t r2 asm("r2") = arg2;
-	register uint32_t r3 asm("r3") = (uint32_t)saved_regs;
+	register uint32_t r0 asm("r0");
+	register uint32_t r1 asm("r1");
+	register uint32_t r2 asm("r2");
+	register uint32_t r3 asm("r3");
+
+#ifdef CONFIG_SMP
+{
+	long ret;
+	cpumask_t local_cpu_mask = CPU_MASK_NONE;
+
+	cpu_set(0, local_cpu_mask);
+	cpumask_copy(&saved_cpu_mask, tsk_cpus_allowed(current));
+	ret = sched_setaffinity(0, &local_cpu_mask);
+	if (ret)
+		pr_err("sched_setaffinity #1 -> 0x%lX", ret);
+}
+#endif
+
+	r0 = arg0;
+	r1 = arg1;
+	r2 = arg2;
+	r3 = (uint32_t)saved_regs;
 
 	asm volatile(
 		__asmeq("%0", "r0")
@@ -216,12 +237,39 @@ uint32_t tlk_generic_smc(uint32_t arg0, uint32_t arg1, uint32_t arg2)
 		: "r" (r0), "r" (r1), "r" (r2), "r" (r3)
 	);
 
+#ifdef CONFIG_SMP
+{
+	long ret = sched_setaffinity(0, &saved_cpu_mask);
+	if (ret)
+		pr_err("sched_setaffinity #2 -> 0x%lX", ret);
+}
+#endif
+
 	return r0;
 }
 
-uint32_t __naked tlk_extended_smc(uint32_t *regs)
+uint32_t tlk_extended_smc(uint32_t *regs)
 {
-	register uint32_t r0 asm("r0") = (uint32_t)regs;
+#ifdef CONFIG_SMP
+	cpumask_t saved_cpu_mask;
+#endif
+
+	register uint32_t r0 asm("r0");
+
+#ifdef CONFIG_SMP
+{
+	long ret;
+	cpumask_t local_cpu_mask = CPU_MASK_NONE;
+
+	cpu_set(0, local_cpu_mask);
+	cpumask_copy(&saved_cpu_mask, tsk_cpus_allowed(current));
+	ret = sched_setaffinity(0, &local_cpu_mask);
+	if (ret)
+		pr_err("sched_setaffinity #1 -> 0x%lX", ret);
+}
+#endif
+
+	r0 = (uint32_t)regs;
 
 	/* allows MAX_EXT_SMC_ARGS (r0-r11) to be passed in registers */
 	asm volatile(
@@ -234,10 +282,18 @@ uint32_t __naked tlk_extended_smc(uint32_t *regs)
 #endif
 		"smc	#0		@ switch to secure world\n"
 		"ldmfd	sp!, {r4-r12}	@ restore saved regs\n"
-		"bx	lr"
 		: "=r" (r0)
 		: "r" (r0)
 	);
+
+#ifdef CONFIG_SMP
+{
+	long ret = sched_setaffinity(0, &saved_cpu_mask);
+	if (ret)
+		pr_err("sched_setaffinity #2 -> 0x%lX", ret);
+}
+#endif
+
 	return r0;
 }
 
@@ -246,37 +302,13 @@ uint32_t __naked tlk_extended_smc(uint32_t *regs)
  */
 static void do_smc(struct te_request *request)
 {
-#ifdef CONFIG_SMP
-	cpumask_t saved_cpu_mask;
-#endif
 	phys_addr_t smc_args = virt_to_phys(request);
 	phys_addr_t smc_params = 0;
 
 	if (request->params)
 		smc_params = virt_to_phys(request->params);
 
-#ifdef CONFIG_SMP
-{
-	long ret;
-	cpumask_t local_cpu_mask = CPU_MASK_NONE;
-
-	cpu_set(0, local_cpu_mask);
-	cpumask_copy(&saved_cpu_mask, tsk_cpus_allowed(current));
-	ret = sched_setaffinity(0, &local_cpu_mask);
-	if (ret)
-		pr_err("sched_setaffinity #1 -> 0x%lX", ret);
-}
-#endif
-
 	tlk_generic_smc(request->type, smc_args, smc_params);
-
-#ifdef CONFIG_SMP
-{
-	long ret = sched_setaffinity(0, &saved_cpu_mask);
-	if (ret)
-		pr_err("sched_setaffinity #2 -> 0x%lX", ret);
-}
-#endif
 }
 
 /*