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-rw-r--r--drivers/irqchip/irq-gic-v3.c14
-rw-r--r--include/linux/acpi.h2
2 files changed, 15 insertions, 1 deletions
diff --git a/drivers/irqchip/irq-gic-v3.c b/drivers/irqchip/irq-gic-v3.c
index ebecd4546830..6d0f98d3540e 100644
--- a/drivers/irqchip/irq-gic-v3.c
+++ b/drivers/irqchip/irq-gic-v3.c
@@ -2370,11 +2370,25 @@ 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;
diff --git a/include/linux/acpi.h b/include/linux/acpi.h
index 19d009ca9e7a..00be66683505 100644
--- a/include/linux/acpi.h
+++ b/include/linux/acpi.h
@@ -238,7 +238,7 @@ 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_CPU_CAPABLE);
}
/* the following numa functions are architecture-dependent */