SPM: Move SPM processing in Library mode to Secure Privileged Thread
This patch moves the bulk of SPM processing in Library mode
to request or return from a secure partition from Handler
to Secure Privileged Thread mode.
Signed-off-by: Antonio de Angelis <antonio.deangelis@arm.com>
Change-Id: I95b61661daa3a8e865b468e91be9a512832607a2
diff --git a/secure_fw/spm/cmsis_func/spm_func.c b/secure_fw/spm/cmsis_func/spm_func.c
index 443ea02..53bebfd 100644
--- a/secure_fw/spm/cmsis_func/spm_func.c
+++ b/secure_fw/spm/cmsis_func/spm_func.c
@@ -8,6 +8,7 @@
#include <stdint.h>
#include <stdbool.h>
#include <arm_cmse.h>
+#include "arch.h"
#include "bitops.h"
#include "fih.h"
#include "tfm_nspm.h"
@@ -789,7 +790,7 @@
tfm_secure_api_initializing = 0;
}
-enum tfm_status_e tfm_spm_sfn_request_handler(
+static enum tfm_status_e tfm_spm_sfn_request_handler(
struct tfm_sfn_req_s *desc_ptr, uint32_t excReturn)
{
enum tfm_status_e res;
@@ -900,13 +901,30 @@
return TFM_ERROR_INVALID_PARAMETER;
}
-/* This SVC handler is called if veneer is running in thread mode */
-uint32_t tfm_spm_partition_request_svc_handler(
- const uint32_t *svc_ctx, uint32_t excReturn)
+static void tfm_spm_partition_requests_thread(struct tfm_sfn_req_s *desc_ptr,
+ uint32_t exc_return,
+ uint32_t is_return,
+ uintptr_t msp)
{
- struct tfm_sfn_req_s *desc_ptr;
+ enum tfm_status_e res;
+ uint32_t exc_ret;
- if (!(excReturn & EXC_RETURN_STACK_PROCESS)) {
+ if (!is_return) {
+ res = tfm_spm_sfn_request_handler(desc_ptr, exc_return);
+ exc_ret = EXC_RETURN_SECURE_FUNCTION;
+ } else {
+ res = tfm_return_from_partition(&exc_return);
+ exc_ret = exc_return;
+ }
+ /* Reset MSP at top of stack and do TFM_SVC_SFN_COMPLETION */
+ tfm_sfn_completion(res, exc_ret, msp);
+}
+
+/* This SVC handler is called if veneer is running in thread mode */
+void tfm_spm_partition_request_return_handler(
+ const uint32_t *svc_ctx, uint32_t exc_return, uint32_t *msp)
+{
+ if (!(exc_return & EXC_RETURN_STACK_PROCESS)) {
/* Service request SVC called with MSP active.
* Either invalid configuration for Thread mode or SVC called
* from Handler mode, which is not supported.
@@ -916,13 +934,30 @@
tfm_secure_api_error_handler();
}
- desc_ptr = (struct tfm_sfn_req_s *)svc_ctx[0];
+ /* Setup a context on the stack to trigger exception return */
+ struct tfm_state_context_t ctx = {0};
- if (tfm_spm_sfn_request_handler(desc_ptr, excReturn) != TFM_SUCCESS) {
+ ctx.r0 = svc_ctx ? svc_ctx[0] : (uintptr_t) NULL;
+ ctx.r1 = exc_return;
+ ctx.r2 = svc_ctx ? 0 : 1;
+ ctx.r3 = (uintptr_t) msp;
+ ctx.xpsr = XPSR_T32;
+ ctx.ra = (uint32_t) tfm_spm_partition_requests_thread & ~0x1UL;
+
+ __set_MSP((uint32_t)&ctx);
+
+ tfm_arch_trigger_exc_return(EXC_RETURN_THREAD_S_MSP);
+}
+
+void tfm_spm_partition_completion_handler(enum tfm_status_e res, uint32_t exc_return, uint32_t *msp)
+{
+ if (res != TFM_SUCCESS) {
tfm_secure_api_error_handler();
}
- return EXC_RETURN_SECURE_FUNCTION;
+ __set_MSP((uint32_t)msp + sizeof(struct tfm_state_context_t));
+
+ tfm_arch_trigger_exc_return(exc_return);
}
/* This SVC handler is called, if a thread mode execution environment is to
@@ -955,31 +990,6 @@
return EXC_RETURN_SECURE_FUNCTION;
}
-/* This SVC handler is called when sfn returns */
-uint32_t tfm_spm_partition_return_handler(uint32_t lr)
-{
- enum tfm_status_e res;
-
- if (!(lr & EXC_RETURN_STACK_PROCESS)) {
- /* Partition return SVC called with MSP active.
- * This should not happen!
- */
- ERROR_MSG("Partition return SVC called with MSP active!");
- tfm_secure_api_error_handler();
- }
-
- res = tfm_return_from_partition(&lr);
- if (res != TFM_SUCCESS) {
- /* Unlock errors indicate ctx database corruption or unknown anomalies
- * Halt execution
- */
- ERROR_MSG("Secure API error during unlock!");
- tfm_secure_api_error_handler();
- }
-
- return lr;
-}
-
/* This SVC handler is called if a deprivileged IRQ handler was executed, and
* the execution environment is to be set back for the privileged handler mode
*/