On Tue, Jul 19, 2022 at 12:14:37PM +0100, Alexandru Elisei wrote: > Hi, > > Since you're touching the PMU tests, I took the liberty to suggest changes > somewhat related to this patch. If you don't want to implement them, let me > know and I'll try to make a patch/series out of them. > > On Mon, Jul 18, 2022 at 08:49:08AM -0700, Ricardo Koller wrote: > > There are various pmu tests that require an isb() between enabling > > counting and the actual counting. This can lead to count registers > > reporting less events than expected; the actual enabling happens after > > some events have happened. For example, some missing isb()'s in the > > pmu-sw-incr test lead to the following errors on bare-metal: > > > > INFO: pmu: pmu-sw-incr: SW_INCR counter #0 has value 4294967280 > > PASS: pmu: pmu-sw-incr: PWSYNC does not increment if PMCR.E is unset > > FAIL: pmu: pmu-sw-incr: counter #1 after + 100 SW_INCR > > FAIL: pmu: pmu-sw-incr: counter #0 after + 100 SW_INCR > > INFO: pmu: pmu-sw-incr: counter values after 100 SW_INCR #0=82 #1=98 > > PASS: pmu: pmu-sw-incr: overflow on counter #0 after 100 SW_INCR > > SUMMARY: 4 tests, 2 unexpected failures > > > > Add the missing isb()'s on all failing tests, plus some others that are > > not currently required but might in the future (like an isb() after > > clearing the overflow signal in the IRQ handler). > > > > Signed-off-by: Ricardo Koller <ricarkol@xxxxxxxxxx> > > --- > > arm/pmu.c | 11 +++++++++++ > > 1 file changed, 11 insertions(+) > > > > diff --git a/arm/pmu.c b/arm/pmu.c > > index 15c542a2..fd838392 100644 > > --- a/arm/pmu.c > > +++ b/arm/pmu.c > > @@ -307,6 +307,7 @@ static void irq_handler(struct pt_regs *regs) > > } > > } > > write_sysreg(ALL_SET, pmovsclr_el0); > > + isb(); > > } else { > > pmu_stats.unexpected = true; > > } > > @@ -534,6 +535,7 @@ static void test_sw_incr(void) > > write_sysreg_s(0x3, PMCNTENSET_EL0); > > > > write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); > > + isb(); > > > > for (i = 0; i < 100; i++) > > write_sysreg(0x1, pmswinc_el0); > > @@ -547,6 +549,7 @@ static void test_sw_incr(void) > > write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); > > write_sysreg_s(0x3, PMCNTENSET_EL0); > > set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); > > + isb(); > > > > for (i = 0; i < 100; i++) > > write_sysreg(0x3, pmswinc_el0); > > @@ -618,6 +621,8 @@ static void test_chained_sw_incr(void) > > > > write_regn_el0(pmevcntr, 0, PRE_OVERFLOW); > > set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); > > + isb(); > > + > > for (i = 0; i < 100; i++) > > write_sysreg(0x1, pmswinc_el0); > > > > @@ -634,6 +639,8 @@ static void test_chained_sw_incr(void) > > write_regn_el0(pmevcntr, 1, ALL_SET); > > write_sysreg_s(0x3, PMCNTENSET_EL0); > > set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); > > + isb(); > > + > > for (i = 0; i < 100; i++) > > write_sysreg(0x1, pmswinc_el0); > > > > @@ -821,6 +828,8 @@ static void test_overflow_interrupt(void) > > report(expect_interrupts(0), "no overflow interrupt after preset"); > > > > set_pmcr(pmu.pmcr_ro | PMU_PMCR_E); > > + isb(); > > + > > for (i = 0; i < 100; i++) > > write_sysreg(0x2, pmswinc_el0); > > You missed the set_pmcr(pmu.pmcr_ro) call on the next line. Will add this in V2. > > Also the comment "enable interrupts" below: > > [..] > 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(); > [..] > > is misleading, because pmu_reset_stats() doesn't enable the PMU. Unless the > intention was to call pmu_reset(), in which case the comment is correct and > the code is wrong. My guess is that the comment is incorrect, the test > seems to be working fine when the PMU is enabled in the mem_access_loop() > call. Yes, it seems that the comment is incorrect. Will fix this in V2. > > > > > @@ -879,6 +888,7 @@ static bool check_cycles_increase(void) > > set_pmccfiltr(0); /* count cycles in EL0, EL1, but not EL2 */ > > > > set_pmcr(get_pmcr() | PMU_PMCR_LC | PMU_PMCR_C | PMU_PMCR_E); > > + isb(); > > > > for (int i = 0; i < NR_SAMPLES; i++) { > > uint64_t a, b; > > @@ -894,6 +904,7 @@ static bool check_cycles_increase(void) > > } > > > > set_pmcr(get_pmcr() & ~PMU_PMCR_E); > > + isb(); > > Those look good to me. > > Thanks, > Alex Thanks for the reviews, Ricardo > > > > > return success; > > } > > -- > > 2.37.0.170.g444d1eabd0-goog > > _______________________________________________ kvmarm mailing list kvmarm@xxxxxxxxxxxxxxxxxxxxx https://lists.cs.columbia.edu/mailman/listinfo/kvmarm