[kvm-unit-tests PATCH v4 12/12] arm: pmu: Test overflow interrupts

[Eric Auger <eric.auger@redhat.com>]

Test overflows for MEM_ACCESS and SW_INCR events. Also tests
overflows with 64-bit events.

Signed-off-by: Eric Auger <eric.auger@redhat.com>

---
v3 -> v4:
- all report messages are different

v2 -> v3:
- added prefix pop
- added pmu_stats.unexpected
- added pmu- prefix
- remove traces in irq_handler()

v1 -> v2:
- inline setup_irq() code
---
 arm/pmu.c         | 139 ++++++++++++++++++++++++++++++++++++++++++++++
 arm/unittests.cfg |   6 ++
 2 files changed, 145 insertions(+)

diff --git a/arm/pmu.c b/arm/pmu.c
index f8d9a18..39831c3 100644
--- a/arm/pmu.c
+++ b/arm/pmu.c
@@ -59,12 +59,20 @@
 #define PRE_OVERFLOW		0xFFFFFFF0
 #define PRE_OVERFLOW2		0xFFFFFFDC
 
+#define PMU_PPI			23
+
 struct pmu {
 	unsigned int version;
 	unsigned int nb_implemented_counters;
 	uint32_t pmcr_ro;
 };
 
+struct pmu_stats {
+	unsigned long bitmap;
+	uint32_t interrupts[32];
+	bool unexpected;
+};
+
 static struct pmu pmu;
 
 #if defined(__arm__)
@@ -146,6 +154,7 @@ static void test_sw_incr(void) {}
 static void test_chained_counters(void) {}
 static void test_chained_sw_incr(void) {}
 static void test_chain_promotion(void) {}
+static void test_overflow_interrupt(void) {}
 
 #elif defined(__aarch64__)
 #define ID_AA64DFR0_PERFMON_SHIFT 8
@@ -276,6 +285,43 @@ asm volatile(
 	: "x9", "x10", "cc");
 }
 
+static struct pmu_stats pmu_stats;
+
+static void irq_handler(struct pt_regs *regs)
+{
+	uint32_t irqstat, irqnr;
+
+	irqstat = gic_read_iar();
+	irqnr = gic_iar_irqnr(irqstat);
+
+	if (irqnr == PMU_PPI) {
+		unsigned long overflows = read_sysreg(pmovsclr_el0);
+		int i;
+
+		for (i = 0; i < 32; i++) {
+			if (test_and_clear_bit(i, &overflows)) {
+				pmu_stats.interrupts[i]++;
+				pmu_stats.bitmap |= 1 << i;
+			}
+		}
+		write_sysreg(ALL_SET, pmovsclr_el0);
+	} else {
+		pmu_stats.unexpected = true;
+	}
+	gic_write_eoir(irqstat);
+}
+
+static void pmu_reset_stats(void)
+{
+	int i;
+
+	for (i = 0; i < 32; i++)
+		pmu_stats.interrupts[i] = 0;
+
+	pmu_stats.bitmap = 0;
+	pmu_stats.unexpected = false;
+}
+
 static void pmu_reset(void)
 {
 	/* reset all counters, counting disabled at PMCR level*/
@@ -286,6 +332,7 @@ static void pmu_reset(void)
 	write_sysreg(ALL_SET, pmovsclr_el0);
 	/* disable overflow interrupts on all counters */
 	write_sysreg(ALL_SET, pmintenclr_el1);
+	pmu_reset_stats();
 	isb();
 }
 
@@ -729,6 +776,94 @@ static void test_chain_promotion(void)
 			read_sysreg(pmovsclr_el0));
 }
 
+static bool expect_interrupts(uint32_t bitmap)
+{
+	int i;
+
+	if (pmu_stats.bitmap ^ bitmap || pmu_stats.unexpected)
+		return false;
+
+	for (i = 0; i < 32; i++) {
+		if (test_and_clear_bit(i, &pmu_stats.bitmap))
+			if (pmu_stats.interrupts[i] != 1)
+				return false;
+	}
+	return true;
+}
+
+static void test_overflow_interrupt(void)
+{
+	uint32_t events[] = {MEM_ACCESS, SW_INCR};
+	void *addr = malloc(PAGE_SIZE);
+	int i;
+
+	if (!satisfy_prerequisites(events, ARRAY_SIZE(events)))
+		return;
+
+	gic_enable_defaults();
+	install_irq_handler(EL1H_IRQ, irq_handler);
+	local_irq_enable();
+	gic_enable_irq(23);
+
+	pmu_reset();
+
+	write_regn_el0(pmevtyper, 0, MEM_ACCESS | PMEVTYPER_EXCLUDE_EL0);
+	write_regn_el0(pmevtyper, 1, SW_INCR | PMEVTYPER_EXCLUDE_EL0);
+	write_sysreg_s(0x3, PMCNTENSET_EL0);
+	write_regn_el0(pmevcntr, 0, PRE_OVERFLOW);
+	write_regn_el0(pmevcntr, 1, PRE_OVERFLOW);
+	isb();
+
+	/* interrupts are disabled */
+
+	mem_access_loop(addr, 200, pmu.pmcr_ro | PMU_PMCR_E);
+	report(expect_interrupts(0), "no overflow interrupt after preset");
+
+	set_pmcr(pmu.pmcr_ro | PMU_PMCR_E);
+	for (i = 0; i < 100; i++)
+		write_sysreg(0x2, pmswinc_el0);
+
+	set_pmcr(pmu.pmcr_ro);
+	report(expect_interrupts(0), "no overflow interrupt after counting");
+
+	/* enable interrupts */
+
+	pmu_reset_stats();
+
+	write_regn_el0(pmevcntr, 0, PRE_OVERFLOW);
+	write_regn_el0(pmevcntr, 1, PRE_OVERFLOW);
+	write_sysreg(ALL_SET, pmintenset_el1);
+	isb();
+
+	mem_access_loop(addr, 200, pmu.pmcr_ro | PMU_PMCR_E);
+	for (i = 0; i < 100; i++)
+		write_sysreg(0x3, pmswinc_el0);
+
+	mem_access_loop(addr, 200, pmu.pmcr_ro);
+	report_info("overflow=0x%lx", read_sysreg(pmovsclr_el0));
+	report(expect_interrupts(0x3),
+		"overflow interrupts expected on #0 and #1");
+
+	/* promote to 64-b */
+
+	pmu_reset_stats();
+
+	write_regn_el0(pmevtyper, 1, CHAIN | PMEVTYPER_EXCLUDE_EL0);
+	write_regn_el0(pmevcntr, 0, PRE_OVERFLOW);
+	isb();
+	mem_access_loop(addr, 200, pmu.pmcr_ro | PMU_PMCR_E);
+	report(expect_interrupts(0),
+		"no overflow interrupt expected on 32b boundary");
+
+	/* overflow on odd counter */
+	pmu_reset_stats();
+	write_regn_el0(pmevcntr, 0, PRE_OVERFLOW);
+	write_regn_el0(pmevcntr, 1, ALL_SET);
+	isb();
+	mem_access_loop(addr, 400, pmu.pmcr_ro | PMU_PMCR_E);
+	report(expect_interrupts(0x2),
+		"expect overflow interrupt on odd counter");
+}
 #endif
 
 /*
@@ -931,6 +1066,10 @@ int main(int argc, char *argv[])
 		report_prefix_push(argv[1]);
 		test_chain_promotion();
 		report_prefix_pop();
+	} else if (strcmp(argv[1], "pmu-overflow-interrupt") == 0) {
+		report_prefix_push(argv[1]);
+		test_overflow_interrupt();
+		report_prefix_pop();
 	} else {
 		report_abort("Unknown sub-test '%s'", argv[1]);
 	}
diff --git a/arm/unittests.cfg b/arm/unittests.cfg
index 1b0c8c8..455fd10 100644
--- a/arm/unittests.cfg
+++ b/arm/unittests.cfg
@@ -114,6 +114,12 @@ groups = pmu
 arch = arm64
 extra_params = -append 'pmu-chain-promotion'
 
+[pmu-overflow-interrupt]
+file = pmu.flat
+groups = pmu
+arch = arm64
+extra_params = -append 'pmu-overflow-interrupt'
+
 # Test PMU support (TCG) with -icount IPC=1
 #[pmu-tcg-icount-1]
 #file = pmu.flat
-- 
2.20.1