Re: [PATCH v9 13/21] ARM64 / ACPI: Parse MADT for SMP initialization

From: Grant Likely
Date: Sat Mar 07 2015 - 17:49:25 EST

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On Wed, 25 Feb 2015 16:39:53 +0800
, Hanjun Guo <hanjun.guo@xxxxxxxxxx>
wrote:
> 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.
>
> ACPI 5.1 only has two explicit methods to boot up SMP, PSCI and
> Parking protocol, but the Parking protocol is only specified for
> ARMv7 now, so make PSCI as the only way for the SMP boot protocol
> before some updates for the ACPI spec or the Parking protocol spec.
>
> Parking protocol patches for SMP boot will be sent to upstream when
> the new version of Parking protocol is ready.
>
> CC: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> CC: Catalin Marinas <catalin.marinas@xxxxxxx>
> CC: Will Deacon <will.deacon@xxxxxxx>
> CC: Mark Rutland <mark.rutland@xxxxxxx>
> Tested-by: Suravee Suthikulpanit <Suravee.Suthikulpanit@xxxxxxx>
> Tested-by: Yijing Wang <wangyijing@xxxxxxxxxx>
> Tested-by: Mark Langsdorf <mlangsdo@xxxxxxxxxx>
> Tested-by: Jon Masters <jcm@xxxxxxxxxx>
> Tested-by: Timur Tabi <timur@xxxxxxxxxxxxxx>
> Tested-by: Robert Richter <rrichter@xxxxxxxxxx>
> Acked-by: Robert Richter <rrichter@xxxxxxxxxx>
> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>

Reviewed-by: Grant Likely <grant.likely@xxxxxxxxxx>

> ---
> arch/arm64/include/asm/acpi.h | 2 +
> arch/arm64/include/asm/cpu_ops.h | 1 +
> arch/arm64/include/asm/smp.h | 5 +-
> arch/arm64/kernel/acpi.c | 149 ++++++++++++++++++++++++++++++++++++++-
> arch/arm64/kernel/cpu_ops.c | 2 +-
> arch/arm64/kernel/setup.c | 7 +-
> arch/arm64/kernel/smp.c | 2 +-
> 7 files changed, 160 insertions(+), 8 deletions(-)
>
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> index 9ea650c..9719921 100644
> --- a/arch/arm64/include/asm/acpi.h
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -71,10 +71,12 @@ static inline bool acpi_has_cpu_in_madt(void)
> }
>
> static inline void arch_fix_phys_package_id(int num, u32 slot) { }
> +void __init acpi_init_cpus(void);
>
> #else
> static inline bool acpi_psci_present(void) { return false; }
> static inline bool acpi_psci_use_hvc(void) { return false; }
> +static inline void acpi_init_cpus(void) { }
> #endif /* CONFIG_ACPI */
>
> #endif /*_ASM_ACPI_H*/
> diff --git a/arch/arm64/include/asm/cpu_ops.h b/arch/arm64/include/asm/cpu_ops.h
> index da301ee..5a31d67 100644
> --- a/arch/arm64/include/asm/cpu_ops.h
> +++ b/arch/arm64/include/asm/cpu_ops.h
> @@ -66,5 +66,6 @@ struct cpu_operations {
> extern const struct cpu_operations *cpu_ops[NR_CPUS];
> int __init cpu_read_ops(struct device_node *dn, int cpu);
> void __init cpu_read_bootcpu_ops(void);
> +const struct cpu_operations *cpu_get_ops(const char *name);
>
> #endif /* ifndef __ASM_CPU_OPS_H */
> diff --git a/arch/arm64/include/asm/smp.h b/arch/arm64/include/asm/smp.h
> index 780f82c..bf22650 100644
> --- a/arch/arm64/include/asm/smp.h
> +++ b/arch/arm64/include/asm/smp.h
> @@ -39,9 +39,10 @@ extern void show_ipi_list(struct seq_file *p, int prec);
> extern void handle_IPI(int ipinr, struct pt_regs *regs);
>
> /*
> - * Setup the set of possible CPUs (via set_cpu_possible)
> + * Discover the set of possible CPUs and determine their
> + * SMP operations.
> */
> -extern void smp_init_cpus(void);
> +extern void of_smp_init_cpus(void);
>
> /*
> * Provide a function to raise an IPI cross call on CPUs in callmap.
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> index bdcc9fc..0f35d87 100644
> --- a/arch/arm64/kernel/acpi.c
> +++ b/arch/arm64/kernel/acpi.c
> @@ -25,6 +25,10 @@
> #include <linux/of_fdt.h>
> #include <linux/smp.h>
>
> +#include <asm/cputype.h>
> +#include <asm/cpu_ops.h>
> +#include <asm/smp_plat.h>
> +
> int acpi_noirq = 1; /* skip ACPI IRQ initialization */
> int acpi_disabled = 1;
> EXPORT_SYMBOL(acpi_disabled);
> @@ -32,6 +36,12 @@ EXPORT_SYMBOL(acpi_disabled);
> int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */
> EXPORT_SYMBOL(acpi_pci_disabled);
>
> +/* Processors with enabled flag and sane MPIDR */
> +static int enabled_cpus;
> +
> +/* Boot CPU is valid or not in MADT */
> +static bool __initdata bootcpu_valid;
> +
> static bool __initdata param_acpi_off;
> static bool __initdata param_acpi_force;
>
> @@ -85,6 +95,129 @@ void __init __acpi_unmap_table(char *map, unsigned long size)
> early_memunmap(map, size);
> }
>
> +/**
> + * acpi_map_gic_cpu_interface - generates a logical cpu number
> + * and map to MPIDR represented by GICC structure
> + * @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 MPIDR
> + */
> +static int __init acpi_map_gic_cpu_interface(u64 mpidr, u8 enabled)
> +{
> + int i;
> +
> + if (mpidr == INVALID_HWID) {
> + pr_info("Skip MADT cpu entry with invalid MPIDR\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;
> + }
> +
> + /* Check if GICC structure of boot CPU is available in the MADT */
> + if (cpu_logical_map(0) == mpidr) {
> + if (bootcpu_valid) {
> + pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
> + mpidr);
> + return -EINVAL;
> + }
> +
> + bootcpu_valid = true;
> + }
> +
> + /*
> + * Duplicate MPIDRs are a recipe for disaster. Scan
> + * all initialized entries and check for
> + * duplicates. If any is found just ignore the CPU.
> + */
> + for (i = 1; i < enabled_cpus; i++) {
> + if (cpu_logical_map(i) == mpidr) {
> + pr_err("Firmware bug, duplicate CPU MPIDR: 0x%llx in MADT\n",
> + mpidr);
> + return -EINVAL;
> + }
> + }
> +
> + if (!acpi_psci_present())
> + return -EOPNOTSUPP;
> +
> + cpu_ops[enabled_cpus] = cpu_get_ops("psci");
> + /* CPU 0 was already initialized */
> + if (enabled_cpus) {
> + if (!cpu_ops[enabled_cpus])
> + return -EINVAL;
> +
> + if (cpu_ops[enabled_cpus]->cpu_init(NULL, enabled_cpus))
> + return -EOPNOTSUPP;
> +
> + /* map the logical cpu id to cpu MPIDR */
> + cpu_logical_map(enabled_cpus) = mpidr;
> + }
> +
> + enabled_cpus++;
> + return enabled_cpus;
> +}
> +
> +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_map_gic_cpu_interface(processor->arm_mpidr & MPIDR_HWID_BITMASK,
> + processor->flags & ACPI_MADT_ENABLED);
> +
> + return 0;
> +}
> +
> +/* Parse GIC cpu interface entries in MADT for SMP init */
> +void __init acpi_init_cpus(void)
> +{
> + int count, i;
> +
> + /*
> + * 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, 0);
> +
> + if (!count) {
> + pr_err("No GIC CPU interface entries present\n");
> + return;
> + } else if (count < 0) {
> + pr_err("Error parsing GIC CPU interface entry\n");
> + return;
> + }
> +
> + if (!bootcpu_valid) {
> + pr_err("MADT missing boot CPU MPIDR, not enabling secondaries\n");
> + return;
> + }
> +
> + for (i = 0; i < enabled_cpus; i++)
> + set_cpu_possible(i, true);
> +
> + /* Make boot-up look pretty */
> + pr_info("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
> +}
> +
> static int __init acpi_parse_fadt(struct acpi_table_header *table)
> {
> struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
> @@ -96,8 +229,20 @@ static int __init acpi_parse_fadt(struct acpi_table_header *table)
> * boot protocol configuration data, or we will disable ACPI.
> */
> if (table->revision > 5 ||
> - (table->revision == 5 && fadt->minor_revision >= 1))
> - return 0;
> + (table->revision == 5 && fadt->minor_revision >= 1)) {
> + /*
> + * ACPI 5.1 only has two explicit methods to boot up SMP,
> + * PSCI and Parking protocol, but the Parking protocol is
> + * only specified for ARMv7 now, so make PSCI as the only
> + * way for the SMP boot protocol before some updates for
> + * the Parking protocol spec.
> + */
> + if (acpi_psci_present())
> + return 0;
> +
> + pr_warn("No PSCI support, will not bring up secondary CPUs\n");
> + return -EOPNOTSUPP;
> + }
>
> pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n",
> table->revision, fadt->minor_revision);
> diff --git a/arch/arm64/kernel/cpu_ops.c b/arch/arm64/kernel/cpu_ops.c
> index cce9524..fb8ff9b 100644
> --- a/arch/arm64/kernel/cpu_ops.c
> +++ b/arch/arm64/kernel/cpu_ops.c
> @@ -35,7 +35,7 @@ static const struct cpu_operations *supported_cpu_ops[] __initconst = {
> NULL,
> };
>
> -static const struct cpu_operations * __init cpu_get_ops(const char *name)
> +const struct cpu_operations * __init cpu_get_ops(const char *name)
> {
> const struct cpu_operations **ops = supported_cpu_ops;
>
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index 97fa7f3..b278311 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -393,13 +393,16 @@ void __init setup_arch(char **cmdline_p)
> if (acpi_disabled) {
> unflatten_device_tree();
> psci_dt_init();
> + cpu_read_bootcpu_ops();
> +#ifdef CONFIG_SMP
> + of_smp_init_cpus();
> +#endif
> } else {
> psci_acpi_init();
> + acpi_init_cpus();
> }
>
> - cpu_read_bootcpu_ops();
> #ifdef CONFIG_SMP
> - smp_init_cpus();
> smp_build_mpidr_hash();
> #endif
>
> diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
> index 328b8ce..52998b7 100644
> --- a/arch/arm64/kernel/smp.c
> +++ b/arch/arm64/kernel/smp.c
> @@ -322,7 +322,7 @@ void __init smp_prepare_boot_cpu(void)
> * cpu logical map array containing MPIDR values related to logical
> * cpus. Assumes that cpu_logical_map(0) has already been initialized.
> */
> -void __init smp_init_cpus(void)
> +void __init of_smp_init_cpus(void)
> {
> struct device_node *dn = NULL;
> unsigned int i, cpu = 1;
> --
> 1.9.1
>

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Next message: Jason Cooper: "[GIT PULL] irqchip: Core changes for v4.0"
Previous message: Paul Bolle: "Re: [PATCH 1/2] Input: add support for Semtech SX8654 I2C touchscreen controller"
In reply to: Olof Johansson: "Re: [PATCH v9 13/21] ARM64 / ACPI: Parse MADT for SMP initialization"
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