SMCCC: Introduce function to check SMCCC function availability
Currently, 'SMCCC_ARCH_FEATURES' SMC call handler unconditionally
returns 'SMC_OK' for 'SMCCC_ARCH_SOC_ID' function. This seems to
be not correct for the platform which doesn't implement soc-id
functionality i.e. functions to retrieve both soc-version and
soc-revision.
Hence introduced a platform function which will check whether SMCCC
feature is available for the platform.
Also, updated porting guide for the newly added platform function.
Change-Id: I389f0ef6b0837bb24c712aa995b7176117bc7961
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>
diff --git a/docs/getting_started/porting-guide.rst b/docs/getting_started/porting-guide.rst
index c98f3cc..7aaeae2 100644
--- a/docs/getting_started/porting-guide.rst
+++ b/docs/getting_started/porting-guide.rst
@@ -1130,6 +1130,7 @@
soc_version[30:24] = JEP-106 continuation code for the SiP
soc_version[23:16] = JEP-106 identification code with parity bit for the SiP
+ soc_version[15:0] = Implementation defined SoC ID
Function : plat_get_soc_revision()
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
@@ -1145,6 +1146,18 @@
soc_revision[0:30] = SOC revision of specific SOC
+Function : plat_is_smccc_feature_available()
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+
+::
+
+ Argument : u_register_t
+ Return : int32_t
+
+This function returns SMC_ARCH_CALL_SUCCESS if the platform supports
+the SMCCC function specified in the argument; otherwise returns
+SMC_ARCH_CALL_NOT_SUPPORTED.
+
Modifications specific to a Boot Loader stage
---------------------------------------------
diff --git a/include/plat/common/platform.h b/include/plat/common/platform.h
index 658b423..2c1a180 100644
--- a/include/plat/common/platform.h
+++ b/include/plat/common/platform.h
@@ -341,4 +341,9 @@
*/
int32_t plat_get_soc_revision(void);
+/*
+ * Optional function to check for SMCCC function availability for platform
+ */
+int32_t plat_is_smccc_feature_available(u_register_t fid);
+
#endif /* PLATFORM_H */
diff --git a/plat/common/plat_bl_common.c b/plat/common/plat_bl_common.c
index d38fc6f..89b77ba 100644
--- a/plat/common/plat_bl_common.c
+++ b/plat/common/plat_bl_common.c
@@ -11,6 +11,7 @@
#include <common/debug.h>
#include <lib/xlat_tables/xlat_tables_compat.h>
#include <plat/common/platform.h>
+#include <services/arm_arch_svc.h>
#include <smccc_helpers.h>
#include <tools_share/firmware_encrypted.h>
@@ -25,6 +26,7 @@
#pragma weak bl2_plat_handle_post_image_load
#pragma weak plat_try_next_boot_source
#pragma weak plat_get_enc_key_info
+#pragma weak plat_is_smccc_feature_available
#pragma weak plat_get_soc_version
#pragma weak plat_get_soc_revision
@@ -38,6 +40,11 @@
return SMC_ARCH_CALL_NOT_SUPPORTED;
}
+int32_t plat_is_smccc_feature_available(u_register_t fid __unused)
+{
+ return SMC_ARCH_CALL_NOT_SUPPORTED;
+}
+
void bl2_el3_plat_prepare_exit(void)
{
}
diff --git a/services/arm_arch_svc/arm_arch_svc_setup.c b/services/arm_arch_svc/arm_arch_svc_setup.c
index 588656d..37bfc62 100644
--- a/services/arm_arch_svc/arm_arch_svc_setup.c
+++ b/services/arm_arch_svc/arm_arch_svc_setup.c
@@ -24,8 +24,9 @@
switch (arg1) {
case SMCCC_VERSION:
case SMCCC_ARCH_FEATURES:
+ return SMC_ARCH_CALL_SUCCESS;
case SMCCC_ARCH_SOC_ID:
- return SMC_OK;
+ return plat_is_smccc_feature_available(arg1);
#if WORKAROUND_CVE_2017_5715
case SMCCC_ARCH_WORKAROUND_1:
if (check_wa_cve_2017_5715() == ERRATA_NOT_APPLIES)