Messages in this thread | | | Subject | Re: [PATCH 3/4] arm_pmu: acpi: spe: Add initial MADT/SPE probing | From | Jeremy Linton <> | Date | Tue, 2 Apr 2019 14:14:29 -0500 |
| |
Hi,
First thanks for taking a look at this, second sorry about the delay...
On 3/28/19 7:40 AM, John Garry wrote: > On 26/03/2019 22:39, Jeremy Linton wrote: >> ACPI 6.3 adds additional fields to the MADT GICC >> structure to describe SPE PPI's. We pick these out >> of the cached reference to the madt_gicc structure >> similarly to the core PMU code. We then create a platform >> device referring to the IRQ and let the user/module loader >> decide whether to load the SPE driver. >> >> Signed-off-by: Jeremy Linton <jeremy.linton@arm.com> >> --- >> arch/arm64/include/asm/acpi.h | 3 ++ >> drivers/perf/arm_pmu_acpi.c | 69 +++++++++++++++++++++++++++++++++++ >> 2 files changed, 72 insertions(+) >> >> diff --git a/arch/arm64/include/asm/acpi.h >> b/arch/arm64/include/asm/acpi.h >> index 7628efbe6c12..d10399b9f998 100644 >> --- a/arch/arm64/include/asm/acpi.h >> +++ b/arch/arm64/include/asm/acpi.h >> @@ -41,6 +41,9 @@ >> (!(entry) || (entry)->header.length < ACPI_MADT_GICC_MIN_LENGTH || \ >> (unsigned long)(entry) + (entry)->header.length > (end)) >> >> +#define ACPI_MADT_GICC_SPE (ACPI_OFFSET(struct >> acpi_madt_generic_interrupt, \ >> + spe_interrupt) + sizeof(u16)) >> + >> /* Basic configuration for ACPI */ >> #ifdef CONFIG_ACPI >> pgprot_t __acpi_get_mem_attribute(phys_addr_t addr); >> diff --git a/drivers/perf/arm_pmu_acpi.c b/drivers/perf/arm_pmu_acpi.c >> index 0f197516d708..a2418108eab2 100644 >> --- a/drivers/perf/arm_pmu_acpi.c >> +++ b/drivers/perf/arm_pmu_acpi.c >> @@ -74,6 +74,73 @@ static void arm_pmu_acpi_unregister_irq(int cpu) >> acpi_unregister_gsi(gsi); >> } >> >> +static struct resource spe_resources[] = { >> + { >> + /* irq */ >> + .flags = IORESOURCE_IRQ, >> + } >> +}; >> + >> +static struct platform_device spe_dev = { >> + .name = "arm,spe-v1", >> + .id = -1, >> + .resource = spe_resources, >> + .num_resources = ARRAY_SIZE(spe_resources) >> +}; >> + >> +/* >> + * For lack of a better place, > > It seems that the kernel Image size can now increase due to this part of > SPE support even if ARM_SPE_PMU config is disabled.
That is true, but it should be fairly small.
> > And I don't even think that ARM_SPE_PMU depends on ARM_PMU (which > ARM_PMU_ACPI depends on).
Well I don't think we want the generic SPE_PMU dependent on ACPI. So this chunk of code could be wrapped in a SPE_PMU_ACPI block, and made dependent on PMU_ACPI. OTOH, It seems a little trivial for that, and maybe just tweaking the PMU_ACPI documentation to mention that it also enables ACPI/SPE is a better plan.
Opinions?
> > Thanks, > John > > hook the normal PMU MADT walk >> + * and create a SPE device if we detect a recent MADT with >> + * a homogeneous PPI mapping. >> + */ >> +static int arm_spe_acpi_parse_irqs(void) >> +{ >> + int cpu, ret, irq; >> + int hetid; >> + u16 gsi = 0; >> + bool first = true; >> + >> + struct acpi_madt_generic_interrupt *gicc; >> + >> + /* >> + * sanity check all the GICC tables for the same interrupt number >> + * for now we only support homogeneous ACPI/SPE machines. >> + */ >> + for_each_possible_cpu(cpu) { >> + gicc = acpi_cpu_get_madt_gicc(cpu); >> + >> + if (gicc->header.length < ACPI_MADT_GICC_SPE) >> + return -ENODEV; >> + if (first) { >> + gsi = gicc->spe_interrupt; >> + if (!gsi) >> + return -ENODEV; >> + hetid = find_acpi_cpu_topology_hetero_id(cpu); >> + first = false; >> + } else if ((gsi != gicc->spe_interrupt) || >> + (hetid != find_acpi_cpu_topology_hetero_id(cpu))) { >> + pr_warn("ACPI: SPE must be homogeneous\n"); >> + return -EINVAL; >> + } >> + } >> + >> + irq = acpi_register_gsi(NULL, gsi, ACPI_LEVEL_SENSITIVE, >> + ACPI_ACTIVE_HIGH); >> + if (irq < 0) { >> + pr_warn("ACPI: SPE Unable to register interrupt: %d\n", gsi); >> + return irq; >> + } >> + >> + spe_resources[0].start = irq; >> + ret = platform_device_register(&spe_dev); >> + if (ret < 0) { >> + pr_warn("ACPI: SPE: Unable to register device\n"); >> + acpi_unregister_gsi(gsi); >> + } >> + >> + return ret; >> +} >> + >> static int arm_pmu_acpi_parse_irqs(void) >> { >> int irq, cpu, irq_cpu, err; >> @@ -279,6 +346,8 @@ static int arm_pmu_acpi_init(void) >> if (acpi_disabled) >> return 0; >> >> + arm_spe_acpi_parse_irqs(); /* failures are expected */ >> + >> ret = arm_pmu_acpi_parse_irqs(); >> if (ret) >> return ret; >> > >
| |