From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sudeep Holla Subject: Re: [PATCH v2 09/18] ACPI / processor: Make it possible to get CPU hardware ID via GICC Date: Mon, 18 Aug 2014 19:34:23 +0100 Message-ID: <53F2472F.5060400@arm.com> References: <1407166105-17675-1-git-send-email-hanjun.guo@linaro.org> <1407166105-17675-10-git-send-email-hanjun.guo@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset=WINDOWS-1252; format=flowed Content-Transfer-Encoding: 8BIT Return-path: Received: from service87.mimecast.com ([91.220.42.44]:58398 "EHLO service87.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752014AbaHRScn convert rfc822-to-8bit (ORCPT ); Mon, 18 Aug 2014 14:32:43 -0400 In-Reply-To: <1407166105-17675-10-git-send-email-hanjun.guo@linaro.org> Sender: linux-acpi-owner@vger.kernel.org List-Id: linux-acpi@vger.kernel.org To: Hanjun Guo , Catalin Marinas , "Rafael J. Wysocki" , Mark Rutland Cc: Sudeep Holla , "graeme.gregory@linaro.org" , Arnd Bergmann , Olof Johansson , "grant.likely@linaro.org" , Will Deacon , Jason Cooper , Marc Zyngier , Bjorn Helgaas , Daniel Lezcano , Mark Brown , Rob Herring , Robert Richter , Lv Zheng , Robert Moore , Lorenzo Pieralisi , Liviu Dudau , Randy Dunlap , Charles Garcia-Tobin , "linux-acpi@vger.kernel.org" , "linux-arm-kernel@lists.infradead.org" On 04/08/14 16:28, 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. > > Signed-off-by: Hanjun Guo > --- > arch/arm64/include/asm/acpi.h | 14 ++++++++++++++ > arch/arm64/kernel/acpi.c | 21 ++++++++++++++++++++- > drivers/acpi/processor_core.c | 37 +++++++++++++++++++++++++++++++++++++ > 3 files changed, 71 insertions(+), 1 deletion(-) > > diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h > index 022f4ad..a81898d 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 > + > /* Basic configuration for ACPI */ > #ifdef CONFIG_ACPI > /* > @@ -59,6 +61,18 @@ static inline void disable_acpi(void) > acpi_noirq = 1; > } > > +u32 pack_mpidr_into_32_bits(u64 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. You need to specify this is packed version of cpu_logical_map or better is to move pack_mpidr_into_32_bits here along with the description you have so that it's easy to understand. > + */ > +#define cpu_physical_id(cpu) pack_mpidr_into_32_bits(cpu_logical_map(cpu)) > + > /* > * Checking for the posibility that the CPU can be initialized from the MADT. > * It's used from ACPI core in crash kernel case where boot CPU is not > diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c > index 8a54b4e..ac7ab34 100644 > --- a/arch/arm64/kernel/acpi.c > +++ b/arch/arm64/kernel/acpi.c > @@ -22,7 +22,6 @@ > #include > #include > > -#include > #include > > int acpi_noirq; /* skip ACPI IRQ initialization */ > @@ -239,6 +238,26 @@ int __init acpi_boot_init(void) > return err; > } > > +/* MPIDR value provided in GICC structure is 64 bits, but > + * the acpi processor driver use the 32 bits cpu hardware > + * ID (apic_id on intel platform) everywhere, it is pretty > + * hard to modify the acpi processor driver to accept the > + * 64 bits MPIDR value, at the same time, only 32 bits of > + * the MPIDR is used in the 64 bits MPIDR, just pack the > + * Affx fields into a single 32 bit identifier to accommodate > + * the acpi processor drivers. > + */ > +u32 pack_mpidr_into_32_bits(u64 mpidr) > +{ > + /* > + * Bits [0:7] Aff0; > + * Bits [8:15] Aff1; > + * Bits [16:23] Aff2; > + * Bits [32:39] Aff3; > + */ > + return (u32) ((mpidr & 0xff00000000) >> 8) | mpidr; > +} > + > /* > * acpi_suspend_lowlevel() - save kernel state and suspend. > * > diff --git a/drivers/acpi/processor_core.c b/drivers/acpi/processor_core.c > index e32321c..4007313 100644 > --- a/drivers/acpi/processor_core.c > +++ b/drivers/acpi/processor_core.c > @@ -64,6 +64,38 @@ static int map_lsapic_id(struct acpi_subtable_header *entry, > return 0; > } > > +/* > + * On ARM platform, MPIDR value is the hardware ID as apic ID > + * on Intel platforms > + */ > +static int map_gicc_mpidr(struct acpi_subtable_header *entry, > + int device_declaration, u32 acpi_id, int *mpidr) > +{ > + struct acpi_madt_generic_interrupt *gicc = > + container_of(entry, struct acpi_madt_generic_interrupt, header); > + > + if (!(gicc->flags & ACPI_MADT_ENABLED)) > + return -ENODEV; > + > + /* In the GIC interrupt model, logical processors are > + * required to have a Processor Device object in the DSDT, > + * so we should check device_declaration here > + */ > + if (device_declaration && (gicc->uid == acpi_id)) { > + /* > + * Only bits [0:7] Aff0, bits [8:15] Aff1, bits [16:23] Aff2 > + * and bits [32:39] Aff3 are meaningful, so pack the Affx > + * fields into a single 32 bit identifier to accommodate the > + * acpi processor drivers. > + */ > + *mpidr = ((gicc->arm_mpidr & 0xff00000000) >> 8) > + | gicc->arm_mpidr; Reuse pack_mpidr_into_32_bits > + return 0; > + } > + > + return -EINVAL; > +} > + > static int map_madt_entry(int type, u32 acpi_id) > { > unsigned long madt_end, entry; > @@ -99,6 +131,9 @@ static int map_madt_entry(int type, u32 acpi_id) > } else if (header->type == ACPI_MADT_TYPE_LOCAL_SAPIC) { > if (!map_lsapic_id(header, type, acpi_id, &apic_id)) > break; > + } else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) { > + if (!map_gicc_mpidr(header, type, acpi_id, &apic_id)) > + break; > } > entry += header->length; > } > @@ -131,6 +166,8 @@ static int map_mat_entry(acpi_handle handle, int type, u32 acpi_id) > map_lsapic_id(header, type, acpi_id, &apic_id); > } else if (header->type == ACPI_MADT_TYPE_LOCAL_X2APIC) { > map_x2apic_id(header, type, acpi_id, &apic_id); > + } else if (header->type == ACPI_MADT_TYPE_GENERIC_INTERRUPT) { > + map_gicc_mpidr(header, type, acpi_id, &apic_id); > } > > exit: >