From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeremy Linton Subject: Re: [PATCH 3/4] arm_pmu: acpi: spe: Add initial MADT/SPE probing Date: Tue, 2 Apr 2019 14:14:29 -0500 Message-ID: References: <20190326223938.5365-1-jeremy.linton@arm.com> <20190326223938.5365-4-jeremy.linton@arm.com> <2b53e957-6d36-fdfe-20e4-1664108c07ef@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <2b53e957-6d36-fdfe-20e4-1664108c07ef@huawei.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: John Garry , linux-arm-kernel@lists.infradead.org Cc: linux-acpi@vger.kernel.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will.deacon@arm.com, rjw@rjwysocki.net, lenb@kernel.org, mark.rutland@arm.com, sudeep.holla@arm.com, james.morse@arm.com, lorenzo.pieralisi@arm.com, linuxarm@huawei.com List-Id: linux-acpi@vger.kernel.org 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 >> --- >>  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; >> > >