Re: [PATCH v9 02/21] ACPI / processor: Introduce phys_cpuid_t for CPU hardware ID

From: Rafael J. Wysocki
Date: Wed Mar 04 2015 - 17:06:16 EST


On Wednesday, February 25, 2015 04:39:42 PM Hanjun Guo wrote:
> CPU hardware ID (phys_id) is defined as u32 in structure acpi_processor,
> but phys_id is used as int in acpi processor driver, so it will lead to
> some inconsistence for the drivers.
>
> Furthermore, to cater for ACPI arch ports that implement 64 bits CPU
> ids a generic CPU physical id type is required.
>
> So introduce typedef u32 phys_cpuid_t for x86 and ia64, and introduce
> a macro CPU_PHYS_ID_INVALID as (u32)(-1), use phys_cpuid_t when phys_id
> defined in acpi processor driver, and replace CPU_PHYS_ID_INVALID as -1
> for phys_id, this will solve the inconsistence in acpi processor driver,
> and will prepare for the ACPI on ARM64 too.
>
> CC: Rafael J Wysocki <rjw@xxxxxxxxxxxxx>
> Suggested-by: Lorenzo Pieralisi <lorenzo.pieralisi@xxxxxxx>
> Acked-by: Sudeep Holla <sudeep.holla@xxxxxxx>
> Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
> [hj: reworked cpu physid map return codes]
> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> ---
> arch/ia64/include/asm/acpi.h | 4 ++++
> arch/ia64/kernel/acpi.c | 2 +-
> arch/x86/include/asm/acpi.h | 4 ++++
> arch/x86/kernel/acpi/boot.c | 2 +-
> drivers/acpi/acpi_processor.c | 7 ++++---
> drivers/acpi/processor_core.c | 30 +++++++++++++++---------------
> include/acpi/processor.h | 6 +++---
> include/linux/acpi.h | 2 +-
> 8 files changed, 33 insertions(+), 24 deletions(-)
>
> diff --git a/arch/ia64/include/asm/acpi.h b/arch/ia64/include/asm/acpi.h
> index a1d91ab..ca1f0e4 100644
> --- a/arch/ia64/include/asm/acpi.h
> +++ b/arch/ia64/include/asm/acpi.h
> @@ -34,6 +34,10 @@
> #include <linux/numa.h>
> #include <asm/numa.h>
>
> +typedef u32 phys_cpuid_t;
> +
> +#define CPU_PHYS_ID_INVALID (u32)(-1)
> +
> #ifdef CONFIG_ACPI
> extern int acpi_lapic;
> #define acpi_disabled 0 /* ACPI always enabled on IA64 */
> diff --git a/arch/ia64/kernel/acpi.c b/arch/ia64/kernel/acpi.c
> index 2c44989..067ef44 100644
> --- a/arch/ia64/kernel/acpi.c
> +++ b/arch/ia64/kernel/acpi.c
> @@ -887,7 +887,7 @@ static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
> }
>
> /* wrapper to silence section mismatch warning */
> -int __ref acpi_map_cpu(acpi_handle handle, int physid, int *pcpu)
> +int __ref acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu)
> {
> return _acpi_map_lsapic(handle, physid, pcpu);
> }
> diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h
> index 3a45668..cd788dd 100644
> --- a/arch/x86/include/asm/acpi.h
> +++ b/arch/x86/include/asm/acpi.h
> @@ -32,6 +32,10 @@
> #include <asm/mpspec.h>
> #include <asm/realmode.h>
>
> +typedef u32 phys_cpuid_t;
> +
> +#define CPU_PHYS_ID_INVALID (u32)(-1)

Can we define those things in one common place instead of having to duplicate
the definitions for every arch?

Also, I'd like to have

static inline bool invalid_cpu_phys_id(phys_cpuid_t phys_id)
{
return (int)phys_id < 0;
}

as that would cover error codes too.

Moreover, why don't you use (phys_cpuid_t)(-1) in the #define? And call is
PHYS_CPUID_INVALID for that matter (so that the name of the symbol corresponds
to the name of the type)?


> +
> #ifdef CONFIG_ACPI
> extern int acpi_lapic;
> extern int acpi_ioapic;
> diff --git a/arch/x86/kernel/acpi/boot.c b/arch/x86/kernel/acpi/boot.c
> index 3d525c6..e4f8582 100644
> --- a/arch/x86/kernel/acpi/boot.c
> +++ b/arch/x86/kernel/acpi/boot.c
> @@ -757,7 +757,7 @@ static int _acpi_map_lsapic(acpi_handle handle, int physid, int *pcpu)
> }
>
> /* wrapper to silence section mismatch warning */
> -int __ref acpi_map_cpu(acpi_handle handle, int physid, int *pcpu)
> +int __ref acpi_map_cpu(acpi_handle handle, phys_cpuid_t physid, int *pcpu)
> {
> return _acpi_map_lsapic(handle, physid, pcpu);
> }
> diff --git a/drivers/acpi/acpi_processor.c b/drivers/acpi/acpi_processor.c
> index 1020b1b..e6c7c56 100644
> --- a/drivers/acpi/acpi_processor.c
> +++ b/drivers/acpi/acpi_processor.c
> @@ -170,7 +170,7 @@ static int acpi_processor_hotadd_init(struct acpi_processor *pr)
> acpi_status status;
> int ret;
>
> - if (pr->phys_id == -1)
> + if (pr->phys_id == CPU_PHYS_ID_INVALID)
> return -ENODEV;
>
> status = acpi_evaluate_integer(pr->handle, "_STA", NULL, &sta);
> @@ -215,7 +215,8 @@ static int acpi_processor_get_info(struct acpi_device *device)
> union acpi_object object = { 0 };
> struct acpi_buffer buffer = { sizeof(union acpi_object), &object };
> struct acpi_processor *pr = acpi_driver_data(device);
> - int phys_id, cpu_index, device_declaration = 0;
> + phys_cpuid_t phys_id;
> + int cpu_index, device_declaration = 0;
> acpi_status status = AE_OK;
> static int cpu0_initialized;
> unsigned long long value;
> @@ -263,7 +264,7 @@ static int acpi_processor_get_info(struct acpi_device *device)
> }
>
> phys_id = acpi_get_phys_id(pr->handle, device_declaration, pr->acpi_id);
> - if (phys_id < 0)
> + if (phys_id == CPU_PHYS_ID_INVALID)
> acpi_handle_debug(pr->handle, "failed to get CPU physical ID.\n");
> pr->phys_id = phys_id;
>
> diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c
> index 7962651..a5547dc 100644
> --- a/drivers/acpi/processor_core.c
> +++ b/drivers/acpi/processor_core.c
> @@ -32,7 +32,7 @@ static struct acpi_table_madt *get_madt_table(void)
> }
>
> static int map_lapic_id(struct acpi_subtable_header *entry,
> - u32 acpi_id, int *apic_id)
> + u32 acpi_id, phys_cpuid_t *apic_id)
> {
> struct acpi_madt_local_apic *lapic =
> container_of(entry, struct acpi_madt_local_apic, header);
> @@ -48,7 +48,7 @@ static int map_lapic_id(struct acpi_subtable_header *entry,
> }
>
> static int map_x2apic_id(struct acpi_subtable_header *entry,
> - int device_declaration, u32 acpi_id, int *apic_id)
> + int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
> {
> struct acpi_madt_local_x2apic *apic =
> container_of(entry, struct acpi_madt_local_x2apic, header);
> @@ -65,7 +65,7 @@ static int map_x2apic_id(struct acpi_subtable_header *entry,
> }
>
> static int map_lsapic_id(struct acpi_subtable_header *entry,
> - int device_declaration, u32 acpi_id, int *apic_id)
> + int device_declaration, u32 acpi_id, phys_cpuid_t *apic_id)
> {
> struct acpi_madt_local_sapic *lsapic =
> container_of(entry, struct acpi_madt_local_sapic, header);
> @@ -83,10 +83,10 @@ static int map_lsapic_id(struct acpi_subtable_header *entry,
> return 0;
> }
>
> -static int map_madt_entry(int type, u32 acpi_id)
> +static phys_cpuid_t map_madt_entry(int type, u32 acpi_id)
> {
> unsigned long madt_end, entry;
> - int phys_id = -1; /* CPU hardware ID */
> + phys_cpuid_t phys_id = CPU_PHYS_ID_INVALID; /* CPU hardware ID */
> struct acpi_table_madt *madt;
>
> madt = get_madt_table();
> @@ -117,12 +117,12 @@ static int map_madt_entry(int type, u32 acpi_id)
> return phys_id;
> }
>
> -static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
> +static phys_cpuid_t map_mat_entry(acpi_handle handle, int type, u32 acpi_id)
> {
> struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
> union acpi_object *obj;
> struct acpi_subtable_header *header;
> - int phys_id = -1;
> + phys_cpuid_t phys_id = CPU_PHYS_ID_INVALID;
>
> if (ACPI_FAILURE(acpi_evaluate_object(handle, "_MAT", NULL, &buffer)))
> goto exit;
> @@ -149,27 +149,27 @@ exit:
> return phys_id;
> }
>
> -int acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
> +phys_cpuid_t acpi_get_phys_id(acpi_handle handle, int type, u32 acpi_id)
> {
> - int phys_id;
> + phys_cpuid_t phys_id;
>
> phys_id = map_mat_entry(handle, type, acpi_id);
> - if (phys_id == -1)
> + if (phys_id == CPU_PHYS_ID_INVALID)
> phys_id = map_madt_entry(type, acpi_id);
>
> return phys_id;
> }
>
> -int acpi_map_cpuid(int phys_id, u32 acpi_id)
> +int acpi_map_cpuid(phys_cpuid_t phys_id, u32 acpi_id)
> {
> #ifdef CONFIG_SMP
> int i;
> #endif
>
> - if (phys_id == -1) {
> + if (phys_id == CPU_PHYS_ID_INVALID) {
> /*
> * On UP processor, there is no _MAT or MADT table.
> - * So above phys_id is always set to -1.
> + * So above phys_id is always set to CPU_PHYS_ID_INVALID.
> *
> * BIOS may define multiple CPU handles even for UP processor.
> * For example,
> @@ -190,7 +190,7 @@ int acpi_map_cpuid(int phys_id, u32 acpi_id)
> if (nr_cpu_ids <= 1 && acpi_id == 0)
> return acpi_id;
> else
> - return phys_id;
> + return -1;

Can we use a proper error code here?

> }
>
> #ifdef CONFIG_SMP


--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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