MADT contains the information for MPIDR which is essential for SMP initialization, parse the GIC cpu interface structures to get the MPIDR value and map it to cpu_logical_map(), and add enabled cpu with valid MPIDR into cpu_possible_map and cpu_present_map.
Signed-off-by: Hanjun Guo hanjun.guo@linaro.org Signed-off-by: Tomasz Nowicki tomasz.nowicki@linaro.org --- arch/arm64/include/asm/acpi.h | 2 + arch/arm64/kernel/acpi.c | 129 ++++++++++++++++++++++++++++++++++++++++- arch/arm64/kernel/smp.c | 10 +++- 3 files changed, 138 insertions(+), 3 deletions(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index 6e04868..e877967 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -64,6 +64,8 @@ static inline void arch_fix_phys_package_id(int num, u32 slot) { } extern int (*acpi_suspend_lowlevel)(void); #define acpi_wakeup_address 0
+#define MAX_GIC_CPU_INTERFACE 65535 + #endif /* CONFIG_ACPI */
#endif /*_ASM_ACPI_H*/ diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c index 69a315d..9e07d99 100644 --- a/arch/arm64/kernel/acpi.c +++ b/arch/arm64/kernel/acpi.c @@ -22,6 +22,9 @@ #include <linux/bootmem.h> #include <linux/smp.h>
+#include <asm/smp_plat.h> +#include <asm/cputype.h> + int acpi_noirq; /* skip ACPI IRQ initialization */ int acpi_disabled; EXPORT_SYMBOL(acpi_disabled); @@ -29,6 +32,8 @@ EXPORT_SYMBOL(acpi_disabled); int acpi_pci_disabled; /* skip ACPI PCI scan and IRQ initialization */ EXPORT_SYMBOL(acpi_pci_disabled);
+static int enabled_cpus; /* Processors (GICC) with enabled flag in MADT */ + /* * __acpi_map_table() will be called before page_init(), so early_ioremap() * or early_memremap() should be called here to for ACPI table mapping. @@ -49,6 +54,122 @@ void __init __acpi_unmap_table(char *map, unsigned long size) early_memunmap(map, size); }
+/** + * acpi_register_gic_cpu_interface - register a gic cpu interface and + * generates a logical cpu number + * @mpidr: CPU's hardware id to register, MPIDR represented in MADT + * @enabled: this cpu is enabled or not + * + * Returns the logical cpu number which maps to the gic cpu interface + */ +static int acpi_register_gic_cpu_interface(u64 mpidr, u8 enabled) +{ + int cpu; + + if (mpidr == INVALID_HWID) { + pr_info("Skip invalid cpu hardware ID\n"); + return -EINVAL; + } + + total_cpus++; + if (!enabled) + return -EINVAL; + + if (enabled_cpus >= NR_CPUS) { + pr_warn("NR_CPUS limit of %d reached, Processor %d/0x%llx ignored.\n", + NR_CPUS, total_cpus, mpidr); + return -EINVAL; + } + + /* If it is the first CPU, no need to check duplicate MPIDRs */ + if (!enabled_cpus) + goto skip_mpidr_check; + + /* + * Duplicate MPIDRs are a recipe for disaster. Scan + * all initialized entries and check for + * duplicates. If any is found just ignore the CPU. + */ + for_each_present_cpu(cpu) { + if (cpu_logical_map(cpu) == mpidr) { + pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n", + mpidr); + return -EINVAL; + } + } + +skip_mpidr_check: + enabled_cpus++; + + /* allocate a logical cpu id for the new comer */ + if (cpu_logical_map(0) == mpidr) { + /* + * boot_cpu_init() already hold bit 0 in cpu_present_mask + * for BSP, no need to allocate again. + */ + cpu = 0; + } else { + cpu = cpumask_next_zero(-1, cpu_present_mask); + } + + /* map the logical cpu id to cpu MPIDR */ + cpu_logical_map(cpu) = mpidr; + + set_cpu_possible(cpu, true); + set_cpu_present(cpu, true); + + return cpu; +} + +static int __init +acpi_parse_gic_cpu_interface(struct acpi_subtable_header *header, + const unsigned long end) +{ + struct acpi_madt_generic_interrupt *processor; + + processor = (struct acpi_madt_generic_interrupt *)header; + + if (BAD_MADT_ENTRY(processor, end)) + return -EINVAL; + + acpi_table_print_madt_entry(header); + + acpi_register_gic_cpu_interface(processor->arm_mpidr, + processor->flags & ACPI_MADT_ENABLED); + + return 0; +} + +/* + * Parse GIC cpu interface related entries in MADT + * returns 0 on success, < 0 on error + */ +static int __init acpi_parse_madt_gic_cpu_interface_entries(void) +{ + int count; + + /* + * do a partial walk of MADT to determine how many CPUs + * we have including disabled CPUs, and get information + * we need for SMP init + */ + count = acpi_table_parse_madt(ACPI_MADT_TYPE_GENERIC_INTERRUPT, + acpi_parse_gic_cpu_interface, MAX_GIC_CPU_INTERFACE); + + if (!count) { + pr_err("No GIC CPU interface entries present\n"); + return -ENODEV; + } else if (count < 0) { + pr_err("Error parsing GIC CPU interface entry\n"); + return count; + } + + /* Make boot-up look pretty */ + pr_info("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus); + + return 0; +} + static int __init acpi_parse_fadt(struct acpi_table_header *table) { struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table; @@ -99,8 +220,12 @@ int __init acpi_boot_init(void) return -ENODEV;
err = acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt); - if (err) - pr_err("Can't find FADT\n"); + if (err) { + pr_err("Can't find FADT or error happened during parsing FADT\n"); + return err; + } + + err = acpi_parse_madt_gic_cpu_interface_entries();
return err; } diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c index 40f38f4..8f1d37c 100644 --- a/arch/arm64/kernel/smp.c +++ b/arch/arm64/kernel/smp.c @@ -36,6 +36,7 @@ #include <linux/completion.h> #include <linux/of.h> #include <linux/irq_work.h> +#include <linux/acpi.h>
#include <asm/atomic.h> #include <asm/cacheflush.h> @@ -458,7 +459,14 @@ void __init smp_prepare_cpus(unsigned int max_cpus) if (err) continue;
- set_cpu_present(cpu, true); + /* + * In ACPI mode, cpu_present_map was initialised when + * MADT table was parsed which before this function + * is called. + */ + if (acpi_disabled) + set_cpu_present(cpu, true); + max_cpus--; } }