refactor(spe): enable FEAT_SPE for FEAT_STATE_CHECKED
At the moment we only support FEAT_SPE to be either unconditionally
compiled in, or to be not supported at all.
Add support for runtime detection (ENABLE_SPE_FOR_NS=2), by splitting
is_armv8_2_feat_spe_present() into an ID register reading function and
a second function to report the support status. That function considers
both build time settings and runtime information (if needed), and is
used before we access SPE related registers.
Previously SPE was enabled unconditionally for all platforms, change
this now to the runtime detection version.
Change-Id: I830c094107ce6a398bf1f4aef7ffcb79d4f36552
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/Makefile b/Makefile
index 16279b6..797b2cf 100644
--- a/Makefile
+++ b/Makefile
@@ -1096,7 +1096,6 @@
ENABLE_RUNTIME_INSTRUMENTATION \
ENABLE_SME_FOR_NS \
ENABLE_SME_FOR_SWD \
- ENABLE_SPE_FOR_NS \
ENABLE_SVE_FOR_NS \
ENABLE_SVE_FOR_SWD \
ERROR_DEPRECATED \
@@ -1182,6 +1181,7 @@
ENABLE_FEAT_VHE \
ENABLE_MPAM_FOR_LOWER_ELS \
ENABLE_RME \
+ ENABLE_SPE_FOR_NS \
ENABLE_TRF_FOR_NS \
FW_ENC_STATUS \
NR_OF_FW_BANKS \
diff --git a/bl31/bl31.mk b/bl31/bl31.mk
index b639920..e000f4f 100644
--- a/bl31/bl31.mk
+++ b/bl31/bl31.mk
@@ -87,7 +87,7 @@
services/std_svc/trng/trng_entropy_pool.c
endif
-ifeq (${ENABLE_SPE_FOR_NS},1)
+ifneq (${ENABLE_SPE_FOR_NS},0)
BL31_SOURCES += lib/extensions/spe/spe.c
endif
diff --git a/docs/getting_started/build-options.rst b/docs/getting_started/build-options.rst
index 9241c39..9415871 100644
--- a/docs/getting_started/build-options.rst
+++ b/docs/getting_started/build-options.rst
@@ -428,10 +428,11 @@
handle context switching for SME, SVE, and FPU/SIMD registers to ensure that
no data is leaked to non-secure world. This is experimental. Default is 0.
-- ``ENABLE_SPE_FOR_NS`` : Boolean option to enable Statistical Profiling
+- ``ENABLE_SPE_FOR_NS`` : Numeric value to enable Statistical Profiling
extensions. This is an optional architectural feature for AArch64.
- The default is 1 but is automatically disabled when the target architecture
- is AArch32.
+ This flag can take the values 0 to 2, to align with the ``FEATURE_DETECTION``
+ mechanism. The default is 2 but is automatically disabled when the target
+ architecture is AArch32.
- ``ENABLE_SVE_FOR_NS``: Boolean option to enable Scalable Vector Extension
(SVE) for the Non-secure world only. SVE is an optional architectural feature
diff --git a/include/arch/aarch32/arch_features.h b/include/arch/aarch32/arch_features.h
index a5a5e27..12df6da 100644
--- a/include/arch/aarch32/arch_features.h
+++ b/include/arch/aarch32/arch_features.h
@@ -43,4 +43,10 @@
return read_feat_trf_id_field() != 0U;
}
+static inline bool is_feat_spe_supported(void)
+{
+ /* FEAT_SPE is AArch64 only */
+ return false;
+}
+
#endif /* ARCH_FEATURES_H */
diff --git a/include/arch/aarch64/arch_features.h b/include/arch/aarch64/arch_features.h
index 582aed1..58b3752 100644
--- a/include/arch/aarch64/arch_features.h
+++ b/include/arch/aarch64/arch_features.h
@@ -249,10 +249,22 @@
/**********************************************************************************
* Function to identify the presence of FEAT_SPE (Statistical Profiling Extension)
*********************************************************************************/
-static inline bool is_armv8_2_feat_spe_present(void)
+static inline unsigned int read_feat_spe_id_field(void)
+{
+ return ISOLATE_FIELD(read_id_aa64dfr0_el1(), ID_AA64DFR0_PMS);
+}
+
+static inline bool is_feat_spe_supported(void)
{
- return (((read_id_aa64dfr0_el1() >> ID_AA64DFR0_PMS_SHIFT) &
- ID_AA64DFR0_PMS_MASK) != ID_AA64DFR0_SPE_NOT_SUPPORTED);
+ if (ENABLE_SPE_FOR_NS == FEAT_STATE_DISABLED) {
+ return false;
+ }
+
+ if (ENABLE_SPE_FOR_NS == FEAT_STATE_ALWAYS) {
+ return true;
+ }
+
+ return read_feat_spe_id_field() != 0U;
}
/*******************************************************************************
diff --git a/include/lib/extensions/spe.h b/include/lib/extensions/spe.h
index d4b925f..d443f18 100644
--- a/include/lib/extensions/spe.h
+++ b/include/lib/extensions/spe.h
@@ -9,8 +9,16 @@
#include <stdbool.h>
-bool spe_supported(void);
+#if ENABLE_SPE_FOR_NS
void spe_enable(bool el2_unused);
void spe_disable(void);
+#else
+void spe_enable(bool el2_unused)
+{
+}
+void spe_disable(void)
+{
+}
+#endif
#endif /* SPE_H */
diff --git a/lib/el3_runtime/aarch64/context_mgmt.c b/lib/el3_runtime/aarch64/context_mgmt.c
index 50fddc5..c5f20ad 100644
--- a/lib/el3_runtime/aarch64/context_mgmt.c
+++ b/lib/el3_runtime/aarch64/context_mgmt.c
@@ -482,9 +482,9 @@
static void manage_extensions_nonsecure(bool el2_unused, cpu_context_t *ctx)
{
#if IMAGE_BL31
-#if ENABLE_SPE_FOR_NS
- spe_enable(el2_unused);
-#endif
+ if (is_feat_spe_supported()) {
+ spe_enable(el2_unused);
+ }
#if ENABLE_AMU
amu_enable(el2_unused, ctx);
diff --git a/lib/extensions/spe/spe.c b/lib/extensions/spe/spe.c
index d747efc..b1fe39f 100644
--- a/lib/extensions/spe/spe.c
+++ b/lib/extensions/spe/spe.c
@@ -7,6 +7,7 @@
#include <stdbool.h>
#include <arch.h>
+#include <arch_features.h>
#include <arch_helpers.h>
#include <lib/el3_runtime/pubsub.h>
#include <lib/extensions/spe.h>
@@ -20,21 +21,10 @@
__asm__ volatile("hint #17");
}
-bool spe_supported(void)
-{
- uint64_t features;
-
- features = read_id_aa64dfr0_el1() >> ID_AA64DFR0_PMS_SHIFT;
- return (features & ID_AA64DFR0_PMS_MASK) > 0ULL;
-}
-
void spe_enable(bool el2_unused)
{
uint64_t v;
- if (!spe_supported())
- return;
-
if (el2_unused) {
/*
* MDCR_EL2.TPMS (ARM v8.2): Do not trap statistical
@@ -69,9 +59,6 @@
{
uint64_t v;
- if (!spe_supported())
- return;
-
/* Drain buffered data */
psb_csync();
dsbnsh();
@@ -85,7 +72,7 @@
static void *spe_drain_buffers_hook(const void *arg)
{
- if (!spe_supported())
+ if (!is_feat_spe_supported())
return (void *)-1;
/* Drain buffered data */
diff --git a/make_helpers/defaults.mk b/make_helpers/defaults.mk
index 63ac82e..b928fcf 100644
--- a/make_helpers/defaults.mk
+++ b/make_helpers/defaults.mk
@@ -355,7 +355,7 @@
WARMBOOT_ENABLE_DCACHE_EARLY := 0
# Build option to enable/disable the Statistical Profiling Extensions
-ENABLE_SPE_FOR_NS := 1
+ENABLE_SPE_FOR_NS := 2
# SPE is only supported on AArch64 so disable it on AArch32.
ifeq (${ARCH},aarch32)
diff --git a/plat/arm/board/arm_fpga/fpga_bl31_setup.c b/plat/arm/board/arm_fpga/fpga_bl31_setup.c
index e1b3abb..5cc1e76 100644
--- a/plat/arm/board/arm_fpga/fpga_bl31_setup.c
+++ b/plat/arm/board/arm_fpga/fpga_bl31_setup.c
@@ -364,7 +364,7 @@
fpga_dtb_update_clock(fdt, system_freq);
/* Check whether we support the SPE PMU. Remove the DT node if not. */
- if (!spe_supported()) {
+ if (!is_feat_spe_supported()) {
int node = fdt_node_offset_by_compatible(fdt, 0,
"arm,statistical-profiling-extension-v1");
diff --git a/plat/arm/board/fvp/fvp_pm.c b/plat/arm/board/fvp/fvp_pm.c
index 9d93862..3d53388 100644
--- a/plat/arm/board/fvp/fvp_pm.c
+++ b/plat/arm/board/fvp/fvp_pm.c
@@ -6,6 +6,7 @@
#include <assert.h>
+#include <arch_features.h>
#include <arch_helpers.h>
#include <common/debug.h>
#include <drivers/arm/gicv3.h>
@@ -53,13 +54,13 @@
{
uint64_t mpidr = read_mpidr_el1();
-#if ENABLE_SPE_FOR_NS
/*
* On power down we need to disable statistical profiling extensions
* before exiting coherency.
*/
- spe_disable();
-#endif
+ if (is_feat_spe_supported()) {
+ spe_disable();
+ }
/* Disable coherency if this cluster is to be turned off */
fvp_interconnect_disable();