[PATCH v3 18/62] arm/acpi: Parse MADT to map logical cpu to MPIDR and get cpu_possible_map
Stefano Stabellini
stefano.stabellini at eu.citrix.com
Mon Nov 23 07:18:01 PST 2015
On Tue, 17 Nov 2015, shannon.zhao at linaro.org wrote:
> From: Parth Dixit <parth.dixit at linaro.org>
>
> 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.
>
> Signed-off-by: Hanjun Guo <hanjun.guo at linaro.org>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki at linaro.org>
> Signed-off-by: Naresh Bhat <naresh.bhat at linaro.org>
> Signed-off-by: Parth Dixit <parth.dixit at linaro.org>
> Signed-off-by: Shannon Zhao <shannon.zhao at linaro.org>
> ---
> xen/arch/arm/acpi/boot.c | 121 +++++++++++++++++++++++++++++++++++++++++++++
> xen/include/asm-arm/acpi.h | 2 +
> xen/include/xen/acpi.h | 4 ++
> 3 files changed, 127 insertions(+)
>
> diff --git a/xen/arch/arm/acpi/boot.c b/xen/arch/arm/acpi/boot.c
> index 0fabe7d..913d2a5 100644
> --- a/xen/arch/arm/acpi/boot.c
> +++ b/xen/arch/arm/acpi/boot.c
> @@ -32,6 +32,127 @@
> #include <xen/mm.h>
>
> #include <asm/acpi.h>
> +#include <asm/smp.h>
> +
> +/* Processors with enabled flag and sane MPIDR */
> +static int enabled_cpus;
unsigned int
> +/* Boot CPU is valid or not in MADT */
> +static bool_t __initdata bootcpu_valid;
> +
> +/* total number of cpus in this system */
> +static unsigned int __initdata total_cpus = 0;
no need to explicitly initialize to 0
> +/*
> + * acpi_map_gic_cpu_interface - generates a logical cpu number
> + * and map to MPIDR represented by GICC structure
> + */
> +static void __init
> +acpi_map_gic_cpu_interface(struct acpi_madt_generic_interrupt *processor)
> +{
> + int i;
> + u64 mpidr = processor->arm_mpidr & MPIDR_HWID_MASK;
> + bool enabled = !!(processor->flags & ACPI_MADT_ENABLED);
bool_t
> + if (mpidr == MPIDR_INVALID) {
> + printk("Skip MADT cpu entry with invalid MPIDR\n");
> + return;
> + }
I am not sure which coding style we are supposed to follow in this file.
This is the Linux coding style, not the Xen coding style.
> + total_cpus++;
> + if (!enabled)
> + return;
> +
> + if (enabled_cpus >= NR_CPUS) {
unnecessary space
> + printk("NR_CPUS limit of %d reached, Processor %d/0x%"PRIx64" ignored.\n",
> + NR_CPUS, total_cpus, mpidr);
> + return;
> + }
> +
> + /* Check if GICC structure of boot CPU is available in the MADT */
> + if (cpu_logical_map(0) == mpidr) {
> + if (bootcpu_valid) {
> + printk("Firmware bug, duplicate CPU MPIDR: 0x%"PRIx64" in MADT\n",
> + mpidr);
> + return;
> + }
> +
> + 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) {
> + printk("Firmware bug, duplicate CPU MPIDR: 0x%"PRIx64" in MADT\n",
> + mpidr);
> + return;
> + }
> + }
I would merge this loop with the previous if statement and just add one
cpu_logical_map(0) check to set bootcpu_valid.
> + if (!acpi_psci_present())
> + return;
> +
> + /* CPU 0 was already initialized */
> + if (enabled_cpus) {
> + if (arch_cpu_init(enabled_cpus, NULL) < 0)
> + return;
> +
> + /* map the logical cpu id to cpu MPIDR */
> + cpu_logical_map(enabled_cpus) = mpidr;
> + }
> +
> + 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;
struct acpi_madt_generic_interrupt *processor =
container_of(header, 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);
> + return 0;
> +}
> +
> +/* Parse GIC cpu interface entries in MADT for SMP init */
> +void __init acpi_smp_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 <= 0) {
> + printk("Error parsing GIC CPU interface entry\n");
> + return;
> + }
> +
> + if (!bootcpu_valid) {
> + printk("MADT missing boot CPU MPIDR, not enabling secondaries\n");
> + return;
> + }
> +
> + for (i = 0; i < enabled_cpus; i++)
> + cpumask_set_cpu(i, &cpu_possible_map);
> +
> + /* Make boot-up look pretty */
> + printk("%d CPUs enabled, %d CPUs total\n", enabled_cpus, total_cpus);
> +}
>
> static int __init acpi_parse_fadt(struct acpi_table_header *table)
> {
> diff --git a/xen/include/asm-arm/acpi.h b/xen/include/asm-arm/acpi.h
> index 65f80b1..1efa29d 100644
> --- a/xen/include/asm-arm/acpi.h
> +++ b/xen/include/asm-arm/acpi.h
> @@ -33,9 +33,11 @@ extern bool_t acpi_disabled;
> #ifdef CONFIG_ACPI
> bool_t __init acpi_psci_present(void);
> bool_t __init acpi_psci_hvc_present(void);
> +void __init acpi_smp_init_cpus(void);
> #else
> static inline bool_t acpi_psci_present(void) { return false; }
> static inline bool_t acpi_psci_hvc_present(void) {return false; }
> +static inline void acpi_smp_init_cpus(void) { }
> #endif /* CONFIG_ACPI */
>
> /* Basic configuration for ACPI */
> diff --git a/xen/include/xen/acpi.h b/xen/include/xen/acpi.h
> index 48d7810..723ece8 100644
> --- a/xen/include/xen/acpi.h
> +++ b/xen/include/xen/acpi.h
> @@ -39,6 +39,10 @@
> #define ACPI_MADT_GET_POLARITY(inti) ACPI_MADT_GET_(POLARITY, inti)
> #define ACPI_MADT_GET_TRIGGER(inti) ACPI_MADT_GET_(TRIGGER, inti)
>
> +#define BAD_MADT_ENTRY(entry, end) ( \
> + (!entry) || (unsigned long)entry + sizeof(*entry) > end || \
> + ((struct acpi_subtable_header *)entry)->length < sizeof(*entry))
> +
> #ifdef CONFIG_ACPI_BOOT
>
> enum acpi_interrupt_id {
> --
> 2.1.0
>
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