On Wed, Jan 14, 2015 at 03:04:59PM +0000, Hanjun Guo wrote:
Introduce a new function map_gicc_mpidr() to allow MPIDRs to be obtained from the GICC Structure introduced by ACPI 5.1.
MPIDR is the CPU hardware ID as local APIC ID on x86 platform, so we use MPIDR not the GIC CPU interface ID to identify CPUs.
Tested-by: Suravee Suthikulpanit Suravee.Suthikulpanit@amd.com Tested-by: Yijing Wang wangyijing@huawei.com Signed-off-by: Hanjun Guo hanjun.guo@linaro.org
arch/arm64/include/asm/acpi.h | 29 +++++++++++++++++++++++++++++ arch/arm64/kernel/acpi.c | 1 - drivers/acpi/processor_core.c | 37 +++++++++++++++++++++++++++++++++++++ 3 files changed, 66 insertions(+), 1 deletion(-)
diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h index c82d4a1..639bb2a 100644 --- a/arch/arm64/include/asm/acpi.h +++ b/arch/arm64/include/asm/acpi.h @@ -12,6 +12,8 @@ #ifndef _ASM_ACPI_H #define _ASM_ACPI_H +#include <asm/smp_plat.h>
/* Basic configuration for ACPI */ #ifdef CONFIG_ACPI #define acpi_strict 1 /* No out-of-spec workarounds on ARM64 */ @@ -45,6 +47,33 @@ static inline void enable_acpi(void) acpi_noirq = 0; } +/* MPIDR value provided in GICC structure is 64 bits, but the
- existing apic_id (CPU hardware ID) using in acpi processor
- driver is 32-bit, to conform to the same datatype we need
- to repack the GICC structure MPIDR.
- Only 32 bits of MPIDR are used:
- Bits [0:7] Aff0;
- Bits [8:15] Aff1;
- Bits [16:23] Aff2;
- Bits [32:39] Aff3;
- */
+static inline u32 pack_mpidr(u64 mpidr) +{
- return (u32) ((mpidr & 0xff00000000) >> 8) | mpidr;
+}
+/*
- The ACPI processor driver for ACPI core code needs this macro
- to find out this cpu was already mapped (mapping from CPU hardware
- ID to CPU logical ID) or not.
- cpu_logical_map(cpu) is the mapping of MPIDR and the logical cpu,
- and MPIDR is the cpu hardware ID we needed to pack.
- */
+#define cpu_physical_id(cpu) pack_mpidr(cpu_logical_map(cpu))
Do we need this mpidr packing only because in drivers/acpi/processor_core.c phys_id is defined as an int ?
What you could do, is to typedef a cpuid_t type in arch code (with appropriate size and a corresponding invalid value, say ~0) and use that instead of an int in drivers/acpi/processor_core.c to store phys_id.
phys_id is used as an error value too (ie -1 as a magic number), see drivers/acpi/acpi_processor.c, retrieved through acpi_get_phys_id(), it should not be that difficult to change the parsing API to keep current code behaviour unchanged and define at the same time a proper type for the cpu physical identifier, with no mpidr packing needed whatsoever.
Thanks, Lorenzo