Hi Eric,
A few comments when looking through the PMU test code (2 years after
the series was merged).
On 2020/4/3 15:13, Eric Auger wrote:
Adds the following tests:
- event-counter-config: test event counter configuration
- basic-event-count:
- programs counters #0 and #1 to count 2 required events
(resp. CPU_CYCLES and INST_RETIRED). Counter #0 is preset
to a value close enough to the 32b
overflow limit so that we check the overflow bit is set
after the execution of the asm loop.
- mem-access: counts MEM_ACCESS event on counters #0 and #1
with and without 32-bit overflow.
Signed-off-by: Eric Auger <eric.auger@xxxxxxxxxx>
Reviewed-by: Andre Przywara <andre.przywara@xxxxxxx>
[...]
diff --git a/arm/pmu.c b/arm/pmu.c
index 8c49e50..45dccf7 100644
--- a/arm/pmu.c
+++ b/arm/pmu.c
@@ -38,6 +43,7 @@
#define SW_INCR 0x0
#define INST_RETIRED 0x8
#define CPU_CYCLES 0x11
+#define MEM_ACCESS 0x13
#define INST_PREC 0x1B
The spec spells event 0x001B as INST_SPEC.
#define STALL_FRONTEND 0x23
#define STALL_BACKEND 0x24
[...]
@@ -175,6 +188,11 @@ static inline void precise_instrs_loop(int loop, uint32_t pmcr)
}
#define PMCEID1_EL0 sys_reg(3, 3, 9, 12, 7)
+#define PMCNTENSET_EL0 sys_reg(3, 3, 9, 12, 1)
+#define PMCNTENCLR_EL0 sys_reg(3, 3, 9, 12, 2)
+
+#define PMEVTYPER_EXCLUDE_EL1 BIT(31)
Unused macro.
+#define PMEVTYPER_EXCLUDE_EL0 BIT(30)
static bool is_event_supported(uint32_t n, bool warn)
{
@@ -228,6 +246,224 @@ static void test_event_introspection(void)
report(required_events, "Check required events are implemented");
}
+/*
+ * Extra instructions inserted by the compiler would be difficult to compensate
+ * for, so hand assemble everything between, and including, the PMCR accesses
+ * to start and stop counting. isb instructions are inserted to make sure
+ * pmccntr read after this function returns the exact instructions executed
+ * in the controlled block. Loads @loop times the data at @address into x9.
+ */
+static void mem_access_loop(void *addr, int loop, uint32_t pmcr)
+{
+asm volatile(
+ " msr pmcr_el0, %[pmcr]\n"
+ " isb\n"
+ " mov x10, %[loop]\n"
+ "1: sub x10, x10, #1\n"
+ " ldr x9, [%[addr]]\n"
+ " cmp x10, #0x0\n"
+ " b.gt 1b\n"
+ " msr pmcr_el0, xzr\n"
+ " isb\n"
+ :
+ : [addr] "r" (addr), [pmcr] "r" (pmcr), [loop] "r" (loop)
+ : "x9", "x10", "cc");
+}
+
+static void pmu_reset(void)
+{
+ /* reset all counters, counting disabled at PMCR level*/
+ set_pmcr(pmu.pmcr_ro | PMU_PMCR_LC | PMU_PMCR_C | PMU_PMCR_P);
+ /* Disable all counters */
+ write_sysreg_s(ALL_SET, PMCNTENCLR_EL0);
+ /* clear overflow reg */
+ write_sysreg(ALL_SET, pmovsclr_el0);
+ /* disable overflow interrupts on all counters */
+ write_sysreg(ALL_SET, pmintenclr_el1);
+ isb();
+}
+
+static void test_event_counter_config(void)
+{
+ int i;
+
+ if (!pmu.nb_implemented_counters) {
+ report_skip("No event counter, skip ...");
+ return;
+ }
+
+ pmu_reset();
+
+ /*
+ * Test setting through PMESELR/PMXEVTYPER and PMEVTYPERn read,
s/PMESELR/PMSELR/ ?
+ * select counter 0
+ */
+ write_sysreg(1, PMSELR_EL0);
+ /* program this counter to count unsupported event */
+ write_sysreg(0xEA, PMXEVTYPER_EL0);
+ write_sysreg(0xdeadbeef, PMXEVCNTR_EL0);
+ report((read_regn_el0(pmevtyper, 1) & 0xFFF) == 0xEA,
+ "PMESELR/PMXEVTYPER/PMEVTYPERn");
Ditto
+ report((read_regn_el0(pmevcntr, 1) == 0xdeadbeef),
+ "PMESELR/PMXEVCNTR/PMEVCNTRn");
Ditto
+
+ /* try to configure an unsupported event within the range [0x0, 0x3F] */
+ for (i = 0; i <= 0x3F; i++) {
+ if (!is_event_supported(i, false))
+ break;
+ }
+ if (i > 0x3F) {
+ report_skip("pmevtyper: all events within [0x0, 0x3F] are supported");
+ return;
+ }
+
+ /* select counter 0 */
+ write_sysreg(0, PMSELR_EL0);
+ /* program this counter to count unsupported event */
We get the unsupported event number *i* but don't program it into
PMXEVTYPER_EL0 (or PMEVTYPER0_EL0). Is it intentional?
+ write_sysreg(i, PMXEVCNTR_EL0);
+ /* read the counter value */
+ read_sysreg(PMXEVCNTR_EL0);
+ report(read_sysreg(PMXEVCNTR_EL0) == i,
+ "read of a counter programmed with unsupported event");
+
+}
[...]
+
+static void test_mem_access(void)
+{
+ void *addr = malloc(PAGE_SIZE);
*addr* isn't freed at the end of test_mem_access(). The same in
test_chain_promotion() and test_overflow_interrupt().
Zenghui
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