From: Jonathan Cameron <Jonathan.Cameron@huawei.com> To: <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: <linuxarm@huawei.com>, <justin.he@arm.com>, <jianyong.wu@arm.com> Subject: [PATCH v5 13/18] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Date: Fri, 12 Apr 2024 15:37:14 +0100 [thread overview] Message-ID: <20240412143719.11398-14-Jonathan.Cameron@huawei.com> (raw) In-Reply-To: <20240412143719.11398-1-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 2629c459738a..6dd396825bb5 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: <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: <linuxarm@huawei.com>, <justin.he@arm.com>, <jianyong.wu@arm.com> Subject: [PATCH v5 13/18] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Date: Fri, 12 Apr 2024 15:37:14 +0100 [thread overview] Message-ID: <20240412143719.11398-14-Jonathan.Cameron@huawei.com> (raw) In-Reply-To: <20240412143719.11398-1-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 2629c459738a..6dd396825bb5 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:[~2024-04-12 14:43 UTC|newest] Thread overview: 116+ messages / expand[flat|nested] mbox.gz Atom feed top 2024-04-12 14:37 [PATCH v5 00/18] ACPI/arm64: add support for virtual cpu hotplug Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 01/18] cpu: Do not warn on arch_register_cpu() returning -EPROBE_DEFER Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 17:42 ` Rafael J. Wysocki 2024-04-12 17:42 ` Rafael J. Wysocki 2024-04-22 3:53 ` Gavin Shan 2024-04-22 3:53 ` Gavin Shan 2024-04-12 14:37 ` [PATCH v5 02/18] ACPI: processor: Set the ACPI_COMPANION for the struct cpu instance Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 18:10 ` Rafael J. Wysocki 2024-04-12 18:10 ` Rafael J. Wysocki 2024-04-15 15:48 ` Jonathan Cameron 2024-04-15 15:48 ` Jonathan Cameron 2024-04-15 16:16 ` Rafael J. Wysocki 2024-04-15 16:16 ` Rafael J. Wysocki 2024-04-15 16:19 ` Rafael J. Wysocki 2024-04-15 16:19 ` Rafael J. Wysocki 2024-04-15 16:50 ` Jonathan Cameron 2024-04-15 16:50 ` Jonathan Cameron 2024-04-15 17:34 ` Jonathan Cameron 2024-04-15 17:34 ` Jonathan Cameron 2024-04-15 17:41 ` Rafael J. Wysocki 2024-04-15 17:41 ` Rafael J. Wysocki 2024-04-16 17:35 ` Jonathan Cameron 2024-04-16 17:35 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 03/18] ACPI: processor: Register deferred CPUs from acpi_processor_get_info() Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 18:30 ` Rafael J. Wysocki 2024-04-12 18:30 ` Rafael J. Wysocki 2024-04-12 20:16 ` Russell King (Oracle) 2024-04-12 20:16 ` Russell King (Oracle) 2024-04-12 20:54 ` Thomas Gleixner 2024-04-12 20:54 ` Thomas Gleixner 2024-04-12 21:52 ` Russell King (Oracle) 2024-04-12 21:52 ` Russell King (Oracle) 2024-04-12 23:23 ` Thomas Gleixner 2024-04-12 23:23 ` Thomas Gleixner 2024-04-15 8:45 ` Jonathan Cameron 2024-04-15 8:45 ` Jonathan Cameron 2024-04-15 9:16 ` Jonathan Cameron 2024-04-15 9:16 ` Jonathan Cameron 2024-04-15 9:31 ` Jonathan Cameron 2024-04-15 9:31 ` Jonathan Cameron 2024-04-15 11:57 ` Jonathan Cameron 2024-04-15 11:57 ` Jonathan Cameron 2024-04-15 11:37 ` Rafael J. Wysocki 2024-04-15 11:37 ` Rafael J. Wysocki 2024-04-15 11:56 ` Jonathan Cameron 2024-04-15 11:56 ` Jonathan Cameron 2024-04-15 12:04 ` Rafael J. Wysocki 2024-04-15 12:04 ` Rafael J. Wysocki 2024-04-15 12:23 ` Jonathan Cameron 2024-04-15 12:23 ` Jonathan Cameron 2024-04-16 17:41 ` Jonathan Cameron 2024-04-16 17:41 ` Jonathan Cameron 2024-04-16 19:02 ` Rafael J. Wysocki 2024-04-16 19:02 ` Rafael J. Wysocki 2024-04-17 10:39 ` Jonathan Cameron 2024-04-17 10:39 ` Jonathan Cameron 2024-04-15 12:37 ` Salil Mehta 2024-04-15 12:37 ` Salil Mehta 2024-04-15 12:41 ` Rafael J. Wysocki 2024-04-15 12:41 ` Rafael J. Wysocki 2024-04-15 11:51 ` Salil Mehta 2024-04-15 11:51 ` Salil Mehta 2024-04-15 12:51 ` Rafael J. Wysocki 2024-04-15 12:51 ` Rafael J. Wysocki 2024-04-15 15:31 ` Salil Mehta 2024-04-15 15:31 ` Salil Mehta 2024-04-15 16:38 ` Rafael J. Wysocki 2024-04-15 16:38 ` Rafael J. Wysocki 2024-04-17 15:01 ` Salil Mehta 2024-04-17 15:01 ` Salil Mehta 2024-04-17 16:19 ` Rafael J. Wysocki 2024-04-17 16:19 ` Rafael J. Wysocki 2024-04-15 10:52 ` Jonathan Cameron 2024-04-15 10:52 ` Jonathan Cameron 2024-04-15 11:11 ` Jonathan Cameron 2024-04-15 11:11 ` Jonathan Cameron 2024-04-15 11:52 ` Rafael J. Wysocki 2024-04-15 11:52 ` Rafael J. Wysocki 2024-04-15 11:07 ` Salil Mehta 2024-04-15 11:07 ` Salil Mehta 2024-04-16 14:00 ` Jonathan Cameron 2024-04-16 14:00 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 04/18] ACPI: Rename acpi_processor_hotadd_init and remove pre-processor guards Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 05/18] ACPI: utils: Add an acpi_sta_enabled() helper and use it in acpi_processor_make_present() Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 06/18] ACPI: scan: Add parameter to allow defering some actions in acpi_scan_check_and_detach Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 07/18] ACPI: Add post_eject to struct acpi_scan_handler for cpu hotplug Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 08/18] ACPI: convert acpi_processor_post_eject() to use IS_ENABLED() Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 09/18] ACPI: Check _STA present bit before making CPUs not present Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 10/18] ACPI: Warn when the present bit changes but the feature is not enabled Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 11/18] arm64: acpi: Move get_cpu_for_acpi_id() to a header Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 12/18] irqchip/gic-v3: Don't return errors from gic_acpi_match_gicc() Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron [this message] 2024-04-12 14:37 ` [PATCH v5 13/18] irqchip/gic-v3: Add support for ACPI's disabled but 'online capable' CPUs Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 14/18] arm64: psci: Ignore DENIED CPUs Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 15/18] arm64: arch_register_cpu() variant to allow checking of ACPI _STA Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 16/18] ACPI: add support to (un)register CPUs based on the _STA enabled bit Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 17/18] arm64: document virtual CPU hotplug's expectations Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron 2024-04-12 14:37 ` [PATCH v5 18/18] cpumask: Add enabled cpumask for present CPUs that can be brought online Jonathan Cameron 2024-04-12 14:37 ` Jonathan Cameron
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