According to ARM DDI 0487F.b, a profiling buffer management event occurs:
* On a fault.
* On an external abort.
* When the buffer fills.
* When software sets the service bit, PMBSR_EL1.S.
Set up the buffer to trigger the events and check that they are reported
correctly.
Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx>
---
arm/spe.c | 342 +++++++++++++++++++++++++++++++++++++++++++++-
arm/unittests.cfg | 8 ++
2 files changed, 346 insertions(+), 4 deletions(-)
diff --git a/arm/spe.c b/arm/spe.c
index c199cd239194..c185883d079a 100644
--- a/arm/spe.c
+++ b/arm/spe.c
@@ -15,8 +15,10 @@
#include <bitops.h>
#include <devicetree.h>
#include <libcflat.h>
+#include <vmalloc.h>
#include <asm/gic.h>
+#include <asm/mmu.h>
#include <asm/processor.h>
#include <asm/sysreg.h>
@@ -41,6 +43,44 @@
#define SYS_PMSIDR_EL1_COUNTSIZE_SHIFT 16
#define SYS_PMSIDR_EL1_COUNTSIZE_MASK 0xfUL
+#define SYS_PMSCR_EL1 sys_reg(3, 0, 9, 9, 0)
+#define SYS_PMSCR_EL1_E1SPE_SHIFT 1
+#define SYS_PMSCR_EL1_PA_SHIFT 4
+#define SYS_PMSCR_EL1_TS_SHIFT 5
+
+#define SYS_PMSICR_EL1 sys_reg(3, 0, 9, 9, 2)
+
+#define SYS_PMSIRR_EL1 sys_reg(3, 0, 9, 9, 3)
+#define SYS_PMSIRR_EL1_INTERVAL_SHIFT 8
+#define SYS_PMSIRR_EL1_INTERVAL_MASK 0xffffffUL
+
+#define SYS_PMSFCR_EL1 sys_reg(3, 0, 9, 9, 4)
+#define SYS_PMSFCR_EL1_FE_SHIFT 0
+#define SYS_PMSFCR_EL1_FT_SHIFT 1
+#define SYS_PMSFCR_EL1_FL_SHIFT 2
+#define SYS_PMSFCR_EL1_B_SHIFT 16
+#define SYS_PMSFCR_EL1_LD_SHIFT 17
+#define SYS_PMSFCR_EL1_ST_SHIFT 18
+
+#define SYS_PMSEVFR_EL1 sys_reg(3, 0, 9, 9, 5)
+#define SYS_PMSLATFR_EL1 sys_reg(3, 0, 9, 9, 6)
+
+#define SYS_PMBLIMITR_EL1 sys_reg(3, 0, 9, 10, 0)
+#define SYS_PMBLIMITR_EL1_E_SHIFT 0
+
+#define SYS_PMBPTR_EL1 sys_reg(3, 0, 9, 10, 1)
+
+#define SYS_PMBSR_EL1 sys_reg(3, 0, 9, 10, 3)
+#define SYS_PMBSR_EL1_S_SHIFT 17
+#define SYS_PMBSR_EL1_EA_SHIFT 18
+#define SYS_PMBSR_EL1_BSC_BUF_FULL 1
+#define SYS_PMBSR_EL1_EC_SHIFT 26
+#define SYS_PMBSR_EL1_EC_MASK 0x3fUL
+#define SYS_PMBSR_EL1_EC_FAULT_S1 0x24
+#define SYS_PMBSR_EL1_RES0 0x00000000fc0fffffUL
+
+#define psb_csync() asm volatile("hint #17" : : : "memory")
+
struct spe {
uint32_t intid;
int min_interval;
@@ -53,6 +93,15 @@ struct spe {
};
static struct spe spe;
+struct spe_buffer {
+ uint64_t base;
+ uint64_t limit;
+};
+static struct spe_buffer buffer;
+
+static volatile bool pmbirq_asserted, reassert_irq;
+static volatile uint64_t irq_pmbsr;
+
static int spe_min_interval(uint8_t interval)
{
switch (interval) {
@@ -131,6 +180,273 @@ static bool spe_probe(void)
return true;
}
+/*
+ * Resets and starts a profiling session. Must be called with sampling and
+ * buffer disabled.
+ */
+static void spe_reset_and_start(struct spe_buffer *spe_buffer)
+{
+ uint64_t pmscr;
+
+ assert(spe_buffer->base);
+ assert(spe_buffer->limit > spe_buffer->base);
+
+ write_sysreg_s(spe_buffer->base, SYS_PMBPTR_EL1);
+ /* Change the buffer pointer before PMBLIMITR_EL1. */
+ isb();
+
+ write_sysreg_s(spe_buffer->limit | BIT(SYS_PMBLIMITR_EL1_E_SHIFT),
+ SYS_PMBLIMITR_EL1);
+ write_sysreg_s(0, SYS_PMBSR_EL1);
+ write_sysreg_s(0, SYS_PMSICR_EL1);
+ /* PMSICR_EL1 must be written to zero before a new sampling session. */
+ isb();
+
+ pmscr = BIT(SYS_PMSCR_EL1_E1SPE_SHIFT) |
+ BIT(SYS_PMSCR_EL1_PA_SHIFT) |
+ BIT(SYS_PMSCR_EL1_TS_SHIFT);
+ write_sysreg_s(pmscr, SYS_PMSCR_EL1);
+ isb();
+}
+
+static void spe_stop_and_drain(void)
+{
+ write_sysreg_s(0, SYS_PMSCR_EL1);
+ isb();
+
+ psb_csync();
+ dsb(nsh);
+ write_sysreg_s(0, SYS_PMBLIMITR_EL1);
+ isb();
+}
+
+static void spe_irq_handler(struct pt_regs *regs)
+{
+ uint32_t intid = gic_read_iar();
+
+ spe_stop_and_drain();
+
+ irq_pmbsr = read_sysreg_s(SYS_PMBSR_EL1);
+
+ if (intid != PPI(spe.intid)) {
+ report_info("Unexpected interrupt: %u", intid);
+ /*
+ * When we get the interrupt, at least one bit, PMBSR_EL1.S,
+ * will be set. We can the value zero for an error.
+ */
+ irq_pmbsr = 0;
+ goto out;
+ }
+
+ if (irq_pmbsr && reassert_irq) {
+ /*
+ * Don't clear the service bit now, but ack the interrupt so it
+ * can be handled again.
+ */
+ gic_write_eoir(intid);
+ reassert_irq = false;
+ irq_pmbsr = 0;
+ return;
+ }
+
+out:
+ write_sysreg_s(0, SYS_PMBSR_EL1);
+ /* Clear PMBSR_EL1 before EOI'ing the interrupt */
+ isb();
+ gic_write_eoir(intid);
+
+ pmbirq_asserted = true;
+}
+
+static void spe_enable_interrupt(void)
+{
+ void *gic_isenabler;
+
+ switch (gic_version()) {
+ case 2:
+ gic_isenabler = gicv2_dist_base() + GICD_ISENABLER;
+ break;
+ case 3:
+ gic_isenabler = gicv3_sgi_base() + GICR_ISENABLER0;
+ break;
+ default:
+ report_abort("Unknown GIC version %d", gic_version());
+ }
+
+ writel(1 << PPI(spe.intid), gic_isenabler);
+}
+
+static void spe_init(void)
+{
+ uint64_t pmsfcr, pmsirr;
+
+ /*
+ * PMSCR_EL1.E1SPE resets to UNKNOWN value, make sure sampling is
+ * disabled.
+ */
+ write_sysreg_s(0, SYS_PMSCR_EL1);
+ isb();
+
+ install_irq_handler(EL1H_IRQ, spe_irq_handler);
+
+ gic_enable_defaults();
+ spe_enable_interrupt();
+ local_irq_enable();
+
+ buffer.base = (u64)memalign(PAGE_SIZE, PAGE_SIZE);
+ assert_msg(buffer.base, "Cannot allocate profiling buffer");
+ buffer.limit = buffer.base + PAGE_SIZE;
+
+ /* Select all operations for sampling */
+ pmsfcr = BIT(SYS_PMSFCR_EL1_FT_SHIFT) |
+ BIT(SYS_PMSFCR_EL1_B_SHIFT) |
+ BIT(SYS_PMSFCR_EL1_LD_SHIFT) |
+ BIT(SYS_PMSFCR_EL1_ST_SHIFT);
+ write_sysreg_s(pmsfcr, SYS_PMSFCR_EL1);
+
+ /*
+ * From ARM DDI 0487F.b: "[..] Software should set this to a value
+ * greater than the minimum indicated by PMSIDR_EL1.Interval"
+ */
+ pmsirr = (spe.min_interval + 1) & SYS_PMSIRR_EL1_INTERVAL_MASK;
+ pmsirr <<= SYS_PMSIRR_EL1_INTERVAL_SHIFT;
+ write_sysreg_s(pmsirr, SYS_PMSIRR_EL1);
+ isb();
+}
+
+static bool spe_test_buffer_service(void)
+{
+ uint64_t expected_pmbsr;
+ int i;
+
+ spe_stop_and_drain();
+
+ reassert_irq = true;
+ pmbirq_asserted = false;
+
+ expected_pmbsr = 0x12345678 | BIT(SYS_PMBSR_EL1_S_SHIFT);
+ expected_pmbsr &= SYS_PMBSR_EL1_RES0;
+
+ /*
+ * ARM DDI 0487F.b, page D9-2803:
+ *
+ * "PMBIRQ is a level-sensitive interrupt request driven by PMBSR_EL1.S.
+ * This means that a direct write that sets PMBSR_EL1.S to 1 causes the
+ * interrupt to be asserted, and PMBIRQ remains asserted until software
+ * clears PMBSR_EL1.S to 0."
+ */
+ write_sysreg_s(expected_pmbsr, SYS_PMBSR_EL1);
+ isb();
+
+ /* Wait for up to 1 second for the GIC to assert the interrupt. */
+ for (i = 0; i < 10; i++) {
+ if (pmbirq_asserted)
+ break;
+ mdelay(100);
+ }
+ reassert_irq = false;
+
+ return irq_pmbsr == expected_pmbsr;
+}
+
+static bool spe_test_buffer_full(void)
+{
+ volatile uint64_t cnt = 0;
+ uint64_t expected_pmbsr, pmbptr;
+
+ spe_stop_and_drain();
+
+ pmbirq_asserted = false;
+ expected_pmbsr = BIT(SYS_PMBSR_EL1_S_SHIFT) | SYS_PMBSR_EL1_BSC_BUF_FULL;
+
+ spe_reset_and_start(&buffer);
+ for (;;) {
+ cnt++;
+ if (pmbirq_asserted)
+ break;
+ }
+
+ pmbptr = read_sysreg_s(SYS_PMBPTR_EL1);
+ /*
+ * ARM DDI 0487F.b, page D9-2804:
+ *
+ * "[..] the Profiling Buffer management event is generated when the PE
+ * writes past the write limit pointer minus 2^(PMSIDR_EL1.MaxSize)."
+ */
+ return (pmbptr >= buffer.limit - spe.max_record_size) &&
+ (irq_pmbsr == expected_pmbsr);
+}
+
+static bool spe_test_buffer_stage1_dabt(void)
+{
+ volatile uint64_t cnt = 0;
+ struct spe_buffer dabt_buffer;
+ uint8_t pmbsr_ec;
+
+ spe_stop_and_drain();
+
+ dabt_buffer.base = (u64)memalign(PAGE_SIZE, PAGE_SIZE);
+ assert_msg(dabt_buffer.base, "Cannot allocate profiling buffer");
+ dabt_buffer.limit = dabt_buffer.base + PAGE_SIZE;
+ mmu_unmap_page(current_thread_info()->pgtable, dabt_buffer.base);
+
+ pmbirq_asserted = false;
+
+ spe_reset_and_start(&dabt_buffer);
+ for (;;) {
+ cnt++;
+ if (pmbirq_asserted)
+ break;
+ }
+
+ pmbsr_ec = (irq_pmbsr >> SYS_PMBSR_EL1_EC_SHIFT) & SYS_PMBSR_EL1_EC_MASK;
+ return (irq_pmbsr & BIT(SYS_PMBSR_EL1_S_SHIFT)) &&
+ (pmbsr_ec == SYS_PMBSR_EL1_EC_FAULT_S1);
+}
+
+static bool spe_test_buffer_extabt(void)
+{
+ struct spe_buffer extabt_buffer;
+ volatile uint64_t cnt = 0;
+ phys_addr_t highest_end = 0;
+ struct mem_region *r;
+
+ spe_stop_and_drain();
+
+ /*
+ * Find a physical address most likely to be absent from the stage 2
+ * tables. Full explanation in arm/selftest.c, in check_pabt_init().
+ */
+ for (r = mem_regions; r->end; r++) {
+ if (r->flags & MR_F_IO)
+ continue;
+ if (r->end > highest_end)
+ highest_end = PAGE_ALIGN(r->end);
+ }
+
+ if (mem_region_get_flags(highest_end) != MR_F_UNKNOWN)
+ return false;
+
+ extabt_buffer.base = (u64)vmap(highest_end, PAGE_SIZE);
+ extabt_buffer.limit = extabt_buffer.base + PAGE_SIZE;
+
+ pmbirq_asserted = false;
+
+ report_info("Expecting KVM Stage 2 Data Abort at pmbptr=0x%lx",
+ extabt_buffer.base);
+
+ spe_reset_and_start(&extabt_buffer);
+ for (;;) {
+ cnt++;
+ if (pmbirq_asserted)
+ break;
+ }
+
+ return (irq_pmbsr & BIT(SYS_PMBSR_EL1_S_SHIFT)) &&
+ (irq_pmbsr & BIT(SYS_PMBSR_EL1_EA_SHIFT));
+
+}
+
static void spe_test_introspection(void)
{
report_prefix_push("spe-introspection");
@@ -146,8 +462,22 @@ static void spe_test_introspection(void)
report_prefix_pop();
}
+static void spe_test_buffer(void)
+{
+ report_prefix_push("spe-buffer");
+
+ report(spe_test_buffer_service(), "Service management event");
+ report(spe_test_buffer_full(), "Buffer full management event");
+ report(spe_test_buffer_stage1_dabt(), "Stage 1 data abort management event");
+ report(spe_test_buffer_extabt(), "Buffer external abort management event");
+
+ report_prefix_pop();
+}
+
int main(int argc, char *argv[])
{
+ int i;
+
if (!spe_probe()) {
report_skip("SPE not supported");
return report_summary();
@@ -161,12 +491,16 @@ int main(int argc, char *argv[])
if (argc < 2)
report_abort("no test specified");
+ spe_init();
+
report_prefix_push("spe");
- if (strcmp(argv[1], "spe-introspection") == 0)
- spe_test_introspection();
- else
- report_abort("Unknown subtest '%s'", argv[1]);
+ for (i = 1; i < argc; i++) {
+ if (strcmp(argv[i], "spe-introspection") == 0)
+ spe_test_introspection();
+ if (strcmp(argv[i], "spe-buffer") == 0)
+ spe_test_buffer();
+ }
return report_summary();
}
diff --git a/arm/unittests.cfg b/arm/unittests.cfg
index ad10be123774..ba21421e81aa 100644
--- a/arm/unittests.cfg
+++ b/arm/unittests.cfg
@@ -141,6 +141,14 @@ arch = arm64
accel = kvm
extra_params = -append 'spe-introspection'
+[spe-buffer]
+file = spe.flat
+groups = spe
+arch = arm64
+timeout = 10s
+accel = kvm
+extra_params = -append 'spe-buffer'
+
# Test GIC emulation
[gicv2-ipi]
file = gic.flat
--
2.29.1
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