This has a known failure on QEMU TCG machines where the decrementer interrupt is not lowered when the DEC wraps from -ve to +ve. Signed-off-by: Nicholas Piggin <npiggin@xxxxxxxxx> --- lib/powerpc/asm/reg.h | 1 + powerpc/Makefile.common | 1 + powerpc/timebase.c | 331 ++++++++++++++++++++++++++++++++++++++++ powerpc/unittests.cfg | 8 + 4 files changed, 341 insertions(+) create mode 100644 powerpc/timebase.c diff --git a/lib/powerpc/asm/reg.h b/lib/powerpc/asm/reg.h index d2ca964c4..12f9e8ac6 100644 --- a/lib/powerpc/asm/reg.h +++ b/lib/powerpc/asm/reg.h @@ -35,6 +35,7 @@ #define SPR_HSRR1 0x13b #define SPR_LPCR 0x13e #define LPCR_HDICE UL(0x1) +#define LPCR_LD UL(0x20000) #define SPR_HEIR 0x153 #define SPR_MMCR0 0x31b #define MMCR0_FC UL(0x80000000) diff --git a/powerpc/Makefile.common b/powerpc/Makefile.common index 420103c87..b273033d1 100644 --- a/powerpc/Makefile.common +++ b/powerpc/Makefile.common @@ -15,6 +15,7 @@ tests-common = \ $(TEST_DIR)/tm.elf \ $(TEST_DIR)/smp.elf \ $(TEST_DIR)/sprs.elf \ + $(TEST_DIR)/timebase.elf \ $(TEST_DIR)/interrupts.elf tests-all = $(tests-common) $(tests) diff --git a/powerpc/timebase.c b/powerpc/timebase.c new file mode 100644 index 000000000..02a4e33c0 --- /dev/null +++ b/powerpc/timebase.c @@ -0,0 +1,331 @@ +/* SPDX-License-Identifier: LGPL-2.0-only */ +/* + * Test Timebase + * + * Copyright 2024 Nicholas Piggin, IBM Corp. + * + * This contains tests of timebase facility, TB, DEC, etc. + */ +#include <libcflat.h> +#include <util.h> +#include <migrate.h> +#include <alloc.h> +#include <asm/handlers.h> +#include <devicetree.h> +#include <asm/hcall.h> +#include <asm/processor.h> +#include <asm/time.h> +#include <asm/barrier.h> + +static int dec_bits = 0; + +static void cpu_dec_bits(int fdtnode, u64 regval __unused, void *arg __unused) +{ + const struct fdt_property *prop; + int plen; + + prop = fdt_get_property(dt_fdt(), fdtnode, "ibm,dec-bits", &plen); + if (!prop) { + dec_bits = 32; + return; + } + + /* Sanity check for the property layout (first two bytes are header) */ + assert(plen == 4); + + dec_bits = fdt32_to_cpu(*(uint32_t *)prop->data); +} + +/* Check amount of CPUs nodes that have the TM flag */ +static int find_dec_bits(void) +{ + int ret; + + ret = dt_for_each_cpu_node(cpu_dec_bits, NULL); + if (ret < 0) + return ret; + + return dec_bits; +} + + +static bool do_migrate = false; +static volatile bool got_interrupt; +static volatile struct pt_regs recorded_regs; + +static uint64_t dec_max; +static uint64_t dec_min; + +static void test_tb(int argc, char **argv) +{ + uint64_t tb; + + tb = get_tb(); + if (do_migrate) + migrate(); + report(get_tb() >= tb, "timebase is incrementing"); +} + +static void dec_stop_handler(struct pt_regs *regs, void *data) +{ + mtspr(SPR_DEC, dec_max); +} + +static void dec_handler(struct pt_regs *regs, void *data) +{ + got_interrupt = true; + memcpy((void *)&recorded_regs, regs, sizeof(struct pt_regs)); + regs->msr &= ~MSR_EE; +} + +static void test_dec(int argc, char **argv) +{ + uint64_t tb1, tb2, dec; + int i; + + handle_exception(0x900, &dec_handler, NULL); + + for (i = 0; i < 100; i++) { + tb1 = get_tb(); + mtspr(SPR_DEC, dec_max); + dec = mfspr(SPR_DEC); + tb2 = get_tb(); + if (tb2 - tb1 < dec_max - dec) + break; + } + /* POWER CPUs can have a slight (few ticks) variation here */ + report_kfail(true, tb2 - tb1 >= dec_max - dec, "decrementer remains within TB after mtDEC"); + + tb1 = get_tb(); + mtspr(SPR_DEC, dec_max); + mdelay(1000); + dec = mfspr(SPR_DEC); + tb2 = get_tb(); + report(tb2 - tb1 >= dec_max - dec, "decrementer remains within TB after 1s"); + + mtspr(SPR_DEC, dec_max); + local_irq_enable(); + local_irq_disable(); + if (mfspr(SPR_DEC) <= dec_max) { + report(!got_interrupt, "no interrupt on decrementer positive"); + } + got_interrupt = false; + + mtspr(SPR_DEC, 1); + mdelay(100); /* Give the timer a chance to run */ + if (do_migrate) + migrate(); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "interrupt on decrementer underflow"); + got_interrupt = false; + + if (do_migrate) + migrate(); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "interrupt on decrementer still underflown"); + got_interrupt = false; + + mtspr(SPR_DEC, 0); + mdelay(100); /* Give the timer a chance to run */ + if (do_migrate) + migrate(); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "DEC deal with set to 0"); + got_interrupt = false; + + /* Test for level-triggered decrementer */ + mtspr(SPR_DEC, -1ULL); + if (do_migrate) + migrate(); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "interrupt on decrementer write MSB"); + got_interrupt = false; + + mtspr(SPR_DEC, dec_max); + local_irq_enable(); + if (do_migrate) + migrate(); + mtspr(SPR_DEC, -1); + local_irq_disable(); + report(got_interrupt, "interrupt on decrementer write MSB with irqs on"); + got_interrupt = false; + + mtspr(SPR_DEC, dec_min + 1); + mdelay(100); + local_irq_enable(); + local_irq_disable(); + /* TCG does not model this correctly */ + report_kfail(true, !got_interrupt, "no interrupt after wrap to positive"); + got_interrupt = false; + + handle_exception(0x900, NULL, NULL); +} + +static void test_hdec(int argc, char **argv) +{ + uint64_t tb1, tb2, hdec; + + if (!machine_is_powernv()) { + report_skip("skipping on !powernv machine"); + return; + } + + handle_exception(0x900, &dec_stop_handler, NULL); + handle_exception(0x980, &dec_handler, NULL); + + mtspr(SPR_HDEC, dec_max); + mtspr(SPR_LPCR, mfspr(SPR_LPCR) | LPCR_HDICE); + + tb1 = get_tb(); + mtspr(SPR_HDEC, dec_max); + hdec = mfspr(SPR_HDEC); + tb2 = get_tb(); + report(tb2 - tb1 >= dec_max - hdec, "hdecrementer remains within TB"); + + tb1 = get_tb(); + mtspr(SPR_HDEC, dec_max); + mdelay(1000); + hdec = mfspr(SPR_HDEC); + tb2 = get_tb(); + report(tb2 - tb1 >= dec_max - hdec, "hdecrementer remains within TB after 1s"); + + mtspr(SPR_HDEC, dec_max); + local_irq_enable(); + local_irq_disable(); + if (mfspr(SPR_HDEC) <= dec_max) { + report(!got_interrupt, "no interrupt on decrementer positive"); + } + got_interrupt = false; + + mtspr(SPR_HDEC, 1); + mdelay(100); /* Give the timer a chance to run */ + if (do_migrate) + migrate(); + /* HDEC is edge triggered so ensure it still fires */ + mtspr(SPR_HDEC, dec_max); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "interrupt on hdecrementer underflow"); + got_interrupt = false; + + if (do_migrate) + migrate(); + local_irq_enable(); + local_irq_disable(); + report(!got_interrupt, "no interrupt on hdecrementer still underflown"); + got_interrupt = false; + + mtspr(SPR_HDEC, -1ULL); + if (do_migrate) + migrate(); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "no interrupt on hdecrementer underflown write MSB"); + got_interrupt = false; + + mtspr(SPR_HDEC, 0); + mdelay(100); /* Give the timer a chance to run */ + if (do_migrate) + migrate(); + /* HDEC is edge triggered so ensure it still fires */ + mtspr(SPR_HDEC, dec_max); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "HDEC deal with set to 0"); + got_interrupt = false; + + mtspr(SPR_HDEC, dec_max); + local_irq_enable(); + if (do_migrate) + migrate(); + mtspr(SPR_HDEC, -1ULL); + local_irq_disable(); + report(got_interrupt, "interrupt on hdecrementer write MSB with irqs on"); + got_interrupt = false; + + mtspr(SPR_HDEC, dec_max); + got_interrupt = false; + mtspr(SPR_HDEC, dec_min + 1); + if (do_migrate) + migrate(); + mdelay(100); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "got interrupt after wrap to positive"); + got_interrupt = false; + + mtspr(SPR_HDEC, -1ULL); + local_irq_enable(); + local_irq_disable(); + got_interrupt = false; + mtspr(SPR_HDEC, dec_min + 1000000); + if (do_migrate) + migrate(); + mdelay(100); + mtspr(SPR_HDEC, -1ULL); + local_irq_enable(); + local_irq_disable(); + report(got_interrupt, "edge re-armed after wrap to positive"); + got_interrupt = false; + + mtspr(SPR_LPCR, mfspr(SPR_LPCR) & ~LPCR_HDICE); + + handle_exception(0x900, NULL, NULL); + handle_exception(0x980, NULL, NULL); +} + +struct { + const char *name; + void (*func)(int argc, char **argv); +} hctests[] = { + { "tb", test_tb }, + { "dec", test_dec }, + { "hdec", test_hdec }, + { NULL, NULL } +}; + +int main(int argc, char **argv) +{ + bool all; + int i; + + all = argc == 1 || !strcmp(argv[1], "all"); + + for (i = 1; i < argc; i++) { + if (!strcmp(argv[i], "-w")) { + do_migrate = true; + if (!all && argc == 2) + all = true; + } + } + + find_dec_bits(); + dec_max = (1ULL << (dec_bits - 1)) - 1; + dec_min = (1ULL << (dec_bits - 1)); + + if (machine_is_powernv() && dec_bits > 32) { + mtspr(SPR_LPCR, mfspr(SPR_LPCR) | LPCR_LD); + } + + report_prefix_push("timebase"); + + for (i = 0; hctests[i].name != NULL; i++) { + if (all || strcmp(argv[1], hctests[i].name) == 0) { + report_prefix_push(hctests[i].name); + hctests[i].func(argc, argv); + report_prefix_pop(); + } + } + + report_prefix_pop(); + + if (machine_is_powernv() && dec_bits > 32) { + mtspr(SPR_LPCR, mfspr(SPR_LPCR) & ~LPCR_LD); + } + + return report_summary(); +} diff --git a/powerpc/unittests.cfg b/powerpc/unittests.cfg index a4210ab2a..39e6dea3c 100644 --- a/powerpc/unittests.cfg +++ b/powerpc/unittests.cfg @@ -92,6 +92,14 @@ machine = pseries extra_params = -append "migration -m" groups = migration +[timebase] +file = timebase.elf + +[timebase-icount] +file = timebase.elf +accel = tcg +extra_params = -icount shift=5 + [h_cede_tm] file = tm.elf machine = pseries -- 2.43.0