aboutsummaryrefslogtreecommitdiff
path: root/lib/extensions
diff options
context:
space:
mode:
authorDimitris Papastamos <dimitris.papastamos@arm.com>2017-11-28 13:47:06 +0000
committerDimitris Papastamos <dimitris.papastamos@arm.com>2018-01-11 14:36:45 +0000
commitb6eb39327c5b009bc0bbecdb6867d8bf7c05f2fd (patch)
tree9c92eaf9474d4db1397295349b2354bf4183c9a3 /lib/extensions
parent0767d50e699d3d9cb827172dd7742618d37aabe0 (diff)
downloadtrusted-firmware-a-b6eb39327c5b009bc0bbecdb6867d8bf7c05f2fd.tar.gz
AMU: Add hooks to save/restore AMU context
On some systems, the AMU counters might reset to 0 when a CPU powerdown happens. This behaviour conflicts with the intended use-case of AMU as lower ELs are only expected to see non-decreasing counter values. Change-Id: If25519965d4e6e47e09225d0e732947986cbb5ec Signed-off-by: Dimitris Papastamos <dimitris.papastamos@arm.com>
Diffstat (limited to 'lib/extensions')
-rw-r--r--lib/extensions/amu/aarch32/amu.c73
-rw-r--r--lib/extensions/amu/aarch64/amu.c78
2 files changed, 151 insertions, 0 deletions
diff --git a/lib/extensions/amu/aarch32/amu.c b/lib/extensions/amu/aarch32/amu.c
index be37006636..55462cbf21 100644
--- a/lib/extensions/amu/aarch32/amu.c
+++ b/lib/extensions/amu/aarch32/amu.c
@@ -8,6 +8,16 @@
#include <arch.h>
#include <arch_helpers.h>
#include <debug.h>
+#include <platform.h>
+#include <pubsub_events.h>
+
+#define AMU_GROUP0_NR_COUNTERS 4
+
+struct amu_ctx {
+ uint64_t group0_cnts[AMU_GROUP0_NR_COUNTERS];
+};
+
+static struct amu_ctx amu_ctxs[PLATFORM_CORE_COUNT];
void amu_enable(int el2_unused)
{
@@ -34,3 +44,66 @@ void amu_enable(int el2_unused)
/* Enable group 0 counters */
write_amcntenset0(AMU_GROUP0_COUNTERS_MASK);
}
+
+static void *amu_context_save(const void *arg)
+{
+ struct amu_ctx *ctx;
+ uint64_t features;
+
+ features = read_id_pfr0() >> ID_PFR0_AMU_SHIFT;
+ if ((features & ID_PFR0_AMU_MASK) != 1)
+ return (void *)-1;
+
+ ctx = &amu_ctxs[plat_my_core_pos()];
+
+ /* Assert that group 0 counter configuration is what we expect */
+ assert(read_amcntenset0() == AMU_GROUP0_COUNTERS_MASK);
+
+ /*
+ * Disable group 0 counters to avoid other observers like SCP sampling
+ * counter values from the future via the memory mapped view.
+ */
+ write_amcntenclr0(AMU_GROUP0_COUNTERS_MASK);
+ isb();
+
+ ctx->group0_cnts[0] = read64_amevcntr00();
+ ctx->group0_cnts[1] = read64_amevcntr01();
+ ctx->group0_cnts[2] = read64_amevcntr02();
+ ctx->group0_cnts[3] = read64_amevcntr03();
+
+ return 0;
+}
+
+static void *amu_context_restore(const void *arg)
+{
+ struct amu_ctx *ctx;
+ uint64_t features;
+
+ features = read_id_pfr0() >> ID_PFR0_AMU_SHIFT;
+ if ((features & ID_PFR0_AMU_MASK) != 1)
+ return (void *)-1;
+
+ ctx = &amu_ctxs[plat_my_core_pos()];
+
+ /* Counters were disabled in `amu_context_save()` */
+ assert(read_amcntenset0() == 0);
+
+ /* Restore group 0 counters */
+ if (AMU_GROUP0_COUNTERS_MASK & (1U << 0))
+ write64_amevcntr00(ctx->group0_cnts[0]);
+ if (AMU_GROUP0_COUNTERS_MASK & (1U << 1))
+ write64_amevcntr01(ctx->group0_cnts[1]);
+ if (AMU_GROUP0_COUNTERS_MASK & (1U << 2))
+ write64_amevcntr02(ctx->group0_cnts[2]);
+ if (AMU_GROUP0_COUNTERS_MASK & (1U << 3))
+ write64_amevcntr03(ctx->group0_cnts[3]);
+ isb();
+
+ /* Enable group 0 counters */
+ write_amcntenset0(AMU_GROUP0_COUNTERS_MASK);
+
+ return 0;
+}
+
+SUBSCRIBE_TO_EVENT(psci_suspend_pwrdown_start, amu_context_save);
+SUBSCRIBE_TO_EVENT(psci_suspend_pwrdown_finish, amu_context_restore);
diff --git a/lib/extensions/amu/aarch64/amu.c b/lib/extensions/amu/aarch64/amu.c
index 27936a2e17..f743e209f9 100644
--- a/lib/extensions/amu/aarch64/amu.c
+++ b/lib/extensions/amu/aarch64/amu.c
@@ -10,9 +10,18 @@
#include <arch_helpers.h>
#include <assert.h>
#include <debug.h>
+#include <platform.h>
+#include <pubsub_events.h>
#define AMU_GROUP0_NR_COUNTERS 4
+struct amu_ctx {
+ uint64_t group0_cnts[AMU_GROUP0_NR_COUNTERS];
+ uint64_t group1_cnts[AMU_GROUP1_NR_COUNTERS];
+};
+
+static struct amu_ctx amu_ctxs[PLATFORM_CORE_COUNT];
+
int amu_supported(void)
{
uint64_t features;
@@ -108,3 +117,72 @@ void amu_group1_set_evtype(int idx, unsigned int val)
amu_group1_set_evtype_internal(idx, val);
isb();
}
+
+static void *amu_context_save(const void *arg)
+{
+ struct amu_ctx *ctx = &amu_ctxs[plat_my_core_pos()];
+ int i;
+
+ if (!amu_supported())
+ return (void *)-1;
+
+ /* Assert that group 0/1 counter configuration is what we expect */
+ assert(read_amcntenset0_el0() == AMU_GROUP0_COUNTERS_MASK &&
+ read_amcntenset1_el0() == AMU_GROUP1_COUNTERS_MASK);
+
+ assert((sizeof(int) * 8) - __builtin_clz(AMU_GROUP1_COUNTERS_MASK)
+ <= AMU_GROUP1_NR_COUNTERS);
+
+ /*
+ * Disable group 0/1 counters to avoid other observers like SCP sampling
+ * counter values from the future via the memory mapped view.
+ */
+ write_amcntenclr0_el0(AMU_GROUP0_COUNTERS_MASK);
+ write_amcntenclr1_el0(AMU_GROUP1_COUNTERS_MASK);
+ isb();
+
+ /* Save group 0 counters */
+ for (i = 0; i < AMU_GROUP0_NR_COUNTERS; i++)
+ ctx->group0_cnts[i] = amu_group0_cnt_read(i);
+
+ /* Save group 1 counters */
+ for (i = 0; i < AMU_GROUP1_NR_COUNTERS; i++)
+ ctx->group1_cnts[i] = amu_group1_cnt_read(i);
+
+ return 0;
+}
+
+static void *amu_context_restore(const void *arg)
+{
+ struct amu_ctx *ctx = &amu_ctxs[plat_my_core_pos()];
+ int i;
+
+ if (!amu_supported())
+ return (void *)-1;
+
+ /* Counters were disabled in `amu_context_save()` */
+ assert(read_amcntenset0_el0() == 0 && read_amcntenset1_el0() == 0);
+
+ assert((sizeof(int) * 8) - __builtin_clz(AMU_GROUP1_COUNTERS_MASK)
+ <= AMU_GROUP1_NR_COUNTERS);
+
+ /* Restore group 0 counters */
+ for (i = 0; i < AMU_GROUP0_NR_COUNTERS; i++)
+ if (AMU_GROUP0_COUNTERS_MASK & (1U << i))
+ amu_group0_cnt_write(i, ctx->group0_cnts[i]);
+
+ /* Restore group 1 counters */
+ for (i = 0; i < AMU_GROUP1_NR_COUNTERS; i++)
+ if (AMU_GROUP1_COUNTERS_MASK & (1U << i))
+ amu_group1_cnt_write(i, ctx->group1_cnts[i]);
+ isb();
+
+ /* Restore group 0/1 counter configuration */
+ write_amcntenset0_el0(AMU_GROUP0_COUNTERS_MASK);
+ write_amcntenset1_el0(AMU_GROUP1_COUNTERS_MASK);
+
+ return 0;
+}
+
+SUBSCRIBE_TO_EVENT(psci_suspend_pwrdown_start, amu_context_save);
+SUBSCRIBE_TO_EVENT(psci_suspend_pwrdown_finish, amu_context_restore);