From: Jonathan Cameron <Jonathan.Cameron@huawei.com> To: Thomas Gleixner <tglx@linutronix.de>, Peter Zijlstra <peterz@infradead.org>, <linux-pm@vger.kernel.org>, <loongarch@lists.linux.dev>, <linux-acpi@vger.kernel.org>, <linux-arch@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <kvmarm@lists.linux.dev>, <x86@kernel.org>, Russell King <linux@armlinux.org.uk>, "Rafael J . Wysocki" <rafael@kernel.org>, Miguel Luis <miguel.luis@oracle.com>, James Morse <james.morse@arm.com>, Salil Mehta <salil.mehta@huawei.com>, Jean-Philippe Brucker <jean-philippe@linaro.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org> Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>, <linuxarm@huawei.com>, <justin.he@arm.com>, <jianyong.wu@arm.com> Subject: [PATCH v6 11/16] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Date: Wed, 17 Apr 2024 14:19:04 +0100 [thread overview] Message-ID: <20240417131909.7925-12-Jonathan.Cameron@huawei.com> (raw) In-Reply-To: <20240417131909.7925-1-Jonathan.Cameron@huawei.com> From: James Morse <james.morse@arm.com> To support virtual CPU hotplug, ACPI has added an 'online capable' bit to the MADT GICC entries. This indicates a disabled CPU entry may not be possible to online via PSCI until firmware has set enabled bit in _STA. This means that a "usable" GIC is one that is marked as either enabled, or online capable. Therefore, change acpi_gicc_is_usable() to check both bits. However, we need to change the test in gic_acpi_match_gicc() back to testing just the enabled bit so the count of enabled distributors is correct. What about the redistributor in the GICC entry? ACPI doesn't want to say. Assume the worst: When a redistributor is described in the GICC entry, but the entry is marked as disabled at boot, assume the redistributor is inaccessible. The GICv3 driver doesn't support late online of redistributors, so this means the corresponding CPU can't be brought online either. Clear the possible and present bits. Systems that want CPU hotplug in a VM can ensure their redistributors are always-on, and describe them that way with a GICR entry in the MADT. When mapping redistributors found via GICC entries, handle the case where the arch code believes the CPU is present and possible, but it does not have an accessible redistributor. Print a warning and clear the present and possible bits. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- v5: No Change. --- drivers/irqchip/irq-gic-v3.c | 21 +++++++++++++++++++-- include/linux/acpi.h | 3 ++- 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 10af15f93d4d..66132251c1bb 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -2363,11 +2363,25 @@ gic_acpi_parse_madt_gicc(union acpi_subtable_headers *header, (struct acpi_madt_generic_interrupt *)header; u32 reg = readl_relaxed(acpi_data.dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK; u32 size = reg == GIC_PIDR2_ARCH_GICv4 ? SZ_64K * 4 : SZ_64K * 2; + int cpu = get_cpu_for_acpi_id(gicc->uid); void __iomem *redist_base; if (!acpi_gicc_is_usable(gicc)) return 0; + /* + * Capable but disabled CPUs can be brought online later. What about + * the redistributor? ACPI doesn't want to say! + * Virtual hotplug systems can use the MADT's "always-on" GICR entries. + * Otherwise, prevent such CPUs from being brought online. + */ + if (!(gicc->flags & ACPI_MADT_ENABLED)) { + pr_warn_once("CPU %u's redistributor is inaccessible: this CPU can't be brought online\n", cpu); + set_cpu_present(cpu, false); + set_cpu_possible(cpu, false); + return 0; + } + redist_base = ioremap(gicc->gicr_base_address, size); if (!redist_base) return -ENOMEM; @@ -2413,9 +2427,12 @@ static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header, /* * If GICC is enabled and has valid gicr base address, then it means - * GICR base is presented via GICC + * GICR base is presented via GICC. The redistributor is only known to + * be accessible if the GICC is marked as enabled. If this bit is not + * set, we'd need to add the redistributor at runtime, which isn't + * supported. */ - if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) + if (gicc->flags & ACPI_MADT_ENABLED && gicc->gicr_base_address) acpi_data.enabled_rdists++; return 0; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 9844a3f9c4e5..fcfb7bb6789e 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -239,7 +239,8 @@ void acpi_table_print_madt_entry (struct acpi_subtable_header *madt); static inline bool acpi_gicc_is_usable(struct acpi_madt_generic_interrupt *gicc) { - return gicc->flags & ACPI_MADT_ENABLED; + return gicc->flags & (ACPI_MADT_ENABLED | + ACPI_MADT_GICC_ONLINE_CAPABLE); } /* the following numa functions are architecture-dependent */ -- 2.39.2
WARNING: multiple messages have this Message-ID (diff)
From: Jonathan Cameron <Jonathan.Cameron@huawei.com> To: Thomas Gleixner <tglx@linutronix.de>, Peter Zijlstra <peterz@infradead.org>, <linux-pm@vger.kernel.org>, <loongarch@lists.linux.dev>, <linux-acpi@vger.kernel.org>, <linux-arch@vger.kernel.org>, <linux-kernel@vger.kernel.org>, <linux-arm-kernel@lists.infradead.org>, <kvmarm@lists.linux.dev>, <x86@kernel.org>, Russell King <linux@armlinux.org.uk>, "Rafael J . Wysocki" <rafael@kernel.org>, Miguel Luis <miguel.luis@oracle.com>, James Morse <james.morse@arm.com>, Salil Mehta <salil.mehta@huawei.com>, Jean-Philippe Brucker <jean-philippe@linaro.org>, Catalin Marinas <catalin.marinas@arm.com>, Will Deacon <will@kernel.org> Cc: Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>, Dave Hansen <dave.hansen@linux.intel.com>, <linuxarm@huawei.com>, <justin.he@arm.com>, <jianyong.wu@arm.com> Subject: [PATCH v6 11/16] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Date: Wed, 17 Apr 2024 14:19:04 +0100 [thread overview] Message-ID: <20240417131909.7925-12-Jonathan.Cameron@huawei.com> (raw) In-Reply-To: <20240417131909.7925-1-Jonathan.Cameron@huawei.com> From: James Morse <james.morse@arm.com> To support virtual CPU hotplug, ACPI has added an 'online capable' bit to the MADT GICC entries. This indicates a disabled CPU entry may not be possible to online via PSCI until firmware has set enabled bit in _STA. This means that a "usable" GIC is one that is marked as either enabled, or online capable. Therefore, change acpi_gicc_is_usable() to check both bits. However, we need to change the test in gic_acpi_match_gicc() back to testing just the enabled bit so the count of enabled distributors is correct. What about the redistributor in the GICC entry? ACPI doesn't want to say. Assume the worst: When a redistributor is described in the GICC entry, but the entry is marked as disabled at boot, assume the redistributor is inaccessible. The GICv3 driver doesn't support late online of redistributors, so this means the corresponding CPU can't be brought online either. Clear the possible and present bits. Systems that want CPU hotplug in a VM can ensure their redistributors are always-on, and describe them that way with a GICR entry in the MADT. When mapping redistributors found via GICC entries, handle the case where the arch code believes the CPU is present and possible, but it does not have an accessible redistributor. Print a warning and clear the present and possible bits. Signed-off-by: James Morse <james.morse@arm.com> Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk> Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com> --- v5: No Change. --- drivers/irqchip/irq-gic-v3.c | 21 +++++++++++++++++++-- include/linux/acpi.h | 3 ++- 2 files changed, 21 insertions(+), 3 deletions(-) diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c index 10af15f93d4d..66132251c1bb 100644 --- a/drivers/irqchip/irq-gic-v3.c +++ b/drivers/irqchip/irq-gic-v3.c @@ -2363,11 +2363,25 @@ gic_acpi_parse_madt_gicc(union acpi_subtable_headers *header, (struct acpi_madt_generic_interrupt *)header; u32 reg = readl_relaxed(acpi_data.dist_base + GICD_PIDR2) & GIC_PIDR2_ARCH_MASK; u32 size = reg == GIC_PIDR2_ARCH_GICv4 ? SZ_64K * 4 : SZ_64K * 2; + int cpu = get_cpu_for_acpi_id(gicc->uid); void __iomem *redist_base; if (!acpi_gicc_is_usable(gicc)) return 0; + /* + * Capable but disabled CPUs can be brought online later. What about + * the redistributor? ACPI doesn't want to say! + * Virtual hotplug systems can use the MADT's "always-on" GICR entries. + * Otherwise, prevent such CPUs from being brought online. + */ + if (!(gicc->flags & ACPI_MADT_ENABLED)) { + pr_warn_once("CPU %u's redistributor is inaccessible: this CPU can't be brought online\n", cpu); + set_cpu_present(cpu, false); + set_cpu_possible(cpu, false); + return 0; + } + redist_base = ioremap(gicc->gicr_base_address, size); if (!redist_base) return -ENOMEM; @@ -2413,9 +2427,12 @@ static int __init gic_acpi_match_gicc(union acpi_subtable_headers *header, /* * If GICC is enabled and has valid gicr base address, then it means - * GICR base is presented via GICC + * GICR base is presented via GICC. The redistributor is only known to + * be accessible if the GICC is marked as enabled. If this bit is not + * set, we'd need to add the redistributor at runtime, which isn't + * supported. */ - if (acpi_gicc_is_usable(gicc) && gicc->gicr_base_address) + if (gicc->flags & ACPI_MADT_ENABLED && gicc->gicr_base_address) acpi_data.enabled_rdists++; return 0; diff --git a/include/linux/acpi.h b/include/linux/acpi.h index 9844a3f9c4e5..fcfb7bb6789e 100644 --- a/include/linux/acpi.h +++ b/include/linux/acpi.h @@ -239,7 +239,8 @@ void acpi_table_print_madt_entry (struct acpi_subtable_header *madt); static inline bool acpi_gicc_is_usable(struct acpi_madt_generic_interrupt *gicc) { - return gicc->flags & ACPI_MADT_ENABLED; + return gicc->flags & (ACPI_MADT_ENABLED | + ACPI_MADT_GICC_ONLINE_CAPABLE); } /* the following numa functions are architecture-dependent */ -- 2.39.2 _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
next prev parent reply other threads:[~2024-04-17 13:24 UTC|newest] Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-04-17 13:18 [PATCH v6 00/16] ACPI/arm64: add support for virtual cpu hotplug Jonathan Cameron 2024-04-17 13:18 ` Jonathan Cameron 2024-04-17 13:18 ` [PATCH v6 01/16] ACPI: processor: Simplify initial onlining to use same path for cold and hotplug Jonathan Cameron 2024-04-17 13:18 ` Jonathan Cameron 2024-04-17 13:18 ` [PATCH v6 02/16] cpu: Do not warn on arch_register_cpu() returning -EPROBE_DEFER Jonathan Cameron 2024-04-17 13:18 ` Jonathan Cameron 2024-04-17 14:01 ` Russell King (Oracle) 2024-04-17 14:01 ` Russell King (Oracle) 2024-04-17 14:41 ` Jonathan Cameron 2024-04-17 14:41 ` Jonathan Cameron 2024-04-17 13:18 ` [PATCH v6 03/16] ACPI: processor: Drop duplicated check on _STA (enabled + present) Jonathan Cameron 2024-04-17 13:18 ` Jonathan Cameron 2024-04-17 13:18 ` [PATCH v6 04/16] ACPI: processor: Move checks and availability of acpi_processor earlier Jonathan Cameron 2024-04-17 13:18 ` Jonathan Cameron 2024-04-17 15:08 ` Salil Mehta 2024-04-17 15:08 ` Salil Mehta 2024-04-17 15:19 ` Jonathan Cameron 2024-04-17 15:19 ` Jonathan Cameron 2024-04-18 8:16 ` Jonathan Cameron 2024-04-18 8:16 ` Jonathan Cameron 2024-04-17 13:18 ` [PATCH v6 05/16] ACPI: processor: Add acpi_get_processor_handle() helper Jonathan Cameron 2024-04-17 13:18 ` Jonathan Cameron 2024-04-17 13:18 ` [PATCH v6 06/16] ACPI: processor: Register deferred CPUs from acpi_processor_get_info() Jonathan Cameron 2024-04-17 13:18 ` Jonathan Cameron 2024-04-17 15:03 ` Salil Mehta 2024-04-17 15:03 ` Salil Mehta 2024-04-17 15:38 ` Jonathan Cameron 2024-04-17 15:38 ` Jonathan Cameron 2024-04-17 15:59 ` Rafael J. Wysocki 2024-04-17 15:59 ` Rafael J. Wysocki 2024-04-17 17:09 ` Jonathan Cameron 2024-04-17 17:09 ` Jonathan Cameron 2024-04-17 17:59 ` Rafael J. Wysocki 2024-04-17 17:59 ` Rafael J. Wysocki 2024-04-17 18:57 ` Jonathan Cameron 2024-04-17 18:57 ` Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 07/16] ACPI: scan: switch to flags for acpi_scan_check_and_detach(); Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 08/16] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 09/16] arm64: acpi: Move get_cpu_for_acpi_id() to a header Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 10/16] irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc() Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron [this message] 2024-04-17 13:19 ` [PATCH v6 11/16] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 12/16] arm64: psci: Ignore DENIED CPUs Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 13/16] arm64: arch_register_cpu() variant to check if an ACPI handle is now available Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 16:33 ` Salil Mehta 2024-04-17 16:33 ` Salil Mehta 2024-04-17 16:55 ` Jonathan Cameron 2024-04-17 16:55 ` Jonathan Cameron 2024-04-17 17:03 ` Salil Mehta 2024-04-17 17:03 ` Salil Mehta 2024-04-17 13:19 ` [PATCH v6 14/16] arm64: Kconfig: Enable hotplug CPU on arm64 if ACPI_PROCESSOR is enabled Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 15/16] arm64: document virtual CPU hotplug's expectations Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 13:19 ` [PATCH v6 16/16] cpumask: Add enabled cpumask for present CPUs that can be brought online Jonathan Cameron 2024-04-17 13:19 ` Jonathan Cameron 2024-04-17 17:01 ` Salil Mehta 2024-04-17 17:01 ` Salil Mehta
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20240417131909.7925-12-Jonathan.Cameron@huawei.com \ --to=jonathan.cameron@huawei.com \ --cc=bp@alien8.de \ --cc=catalin.marinas@arm.com \ --cc=dave.hansen@linux.intel.com \ --cc=james.morse@arm.com \ --cc=jean-philippe@linaro.org \ --cc=jianyong.wu@arm.com \ --cc=justin.he@arm.com \ --cc=kvmarm@lists.linux.dev \ --cc=linux-acpi@vger.kernel.org \ --cc=linux-arch@vger.kernel.org \ --cc=linux-arm-kernel@lists.infradead.org \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-pm@vger.kernel.org \ --cc=linux@armlinux.org.uk \ --cc=linuxarm@huawei.com \ --cc=loongarch@lists.linux.dev \ --cc=miguel.luis@oracle.com \ --cc=mingo@redhat.com \ --cc=peterz@infradead.org \ --cc=rafael@kernel.org \ --cc=salil.mehta@huawei.com \ --cc=tglx@linutronix.de \ --cc=will@kernel.org \ --cc=x86@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.