Re: [PATCH v9 05/21] ARM64 / ACPI: Get RSDP and ACPI boot-time tables

From: Grant Likely
Date: Fri Mar 06 2015 - 15:28:12 EST


On Wed, 25 Feb 2015 16:39:45 +0800
, Hanjun Guo <hanjun.guo@xxxxxxxxxx>
wrote:
> From: Al Stone <al.stone@xxxxxxxxxx>
>
> As we want to get ACPI tables to parse and then use the information
> for system initialization, we should get the RSDP (Root System
> Description Pointer) first, it then locates Extended Root Description
> Table (XSDT) which contains all the 64-bit physical address that
> pointer to other boot-time tables.
>
> Introduce acpi.c and its related head file in this patch to provide
> fundamental needs of extern variables and functions for ACPI core,
> and then get boot-time tables as needed.
> - asm/acenv.h for arch specific ACPICA environments and
> implementation, It is needed unconditionally by ACPI core;
> - asm/acpi.h for arch specific variables and functions needed by
> ACPI driver core;
> - acpi.c for ARM64 related ACPI implementation for ACPI driver
> core;
>
> acpi_boot_table_init() is introduced to get RSDP and boot-time tables,
> it will be called in setup_arch() before paging_init(), so we should
> use eary_memremap() mechanism here to get the RSDP and all the table
> pointers.
>
> FADT Major.Minor version was introduced in ACPI 5.1, it is the same
> as ACPI version.
>
> In ACPI 5.1, some major gaps are fixed for ARM, such as updates in
> MADT table for GIC and SMP init, without those updates, we can not
> get the MPIDR for SMP init, and GICv2/3 related init information, so
> we can't boot arm64 ACPI properly with table versions predating 5.1.
>
> If firmware provides ACPI tables with ACPI version less than 5.1,
> OS has no way to retrieve the configuration data that is necessary
> to init SMP boot protocol and the GIC properly, so disable ACPI if
> we get an FADT table with version less that 5.1 when acpi_boot_table_init()
> called.
>
> CC: Catalin Marinas <catalin.marinas@xxxxxxx>
> CC: Will Deacon <will.deacon@xxxxxxx>
> CC: Lorenzo Pieralisi <lorenzo.pieralisi@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: Al Stone <al.stone@xxxxxxxxxx>
> Signed-off-by: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
> Signed-off-by: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
> Signed-off-by: Hanjun Guo <hanjun.guo@xxxxxxxxxx>

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

> ---
> arch/arm64/include/asm/acenv.h | 18 ++++++++
> arch/arm64/include/asm/acpi.h | 45 ++++++++++++++++++
> arch/arm64/kernel/Makefile | 1 +
> arch/arm64/kernel/acpi.c | 101 +++++++++++++++++++++++++++++++++++++++++
> arch/arm64/kernel/setup.c | 5 ++
> 5 files changed, 170 insertions(+)
> create mode 100644 arch/arm64/include/asm/acenv.h
> create mode 100644 arch/arm64/include/asm/acpi.h
> create mode 100644 arch/arm64/kernel/acpi.c
>
> diff --git a/arch/arm64/include/asm/acenv.h b/arch/arm64/include/asm/acenv.h
> new file mode 100644
> index 0000000..b49166f
> --- /dev/null
> +++ b/arch/arm64/include/asm/acenv.h
> @@ -0,0 +1,18 @@
> +/*
> + * ARM64 specific ACPICA environments and implementation
> + *
> + * Copyright (C) 2014, Linaro Ltd.
> + * Author: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> + * Author: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#ifndef _ASM_ACENV_H
> +#define _ASM_ACENV_H
> +
> +/* It is required unconditionally by ACPI core, update it when needed. */
> +
> +#endif /* _ASM_ACENV_H */
> diff --git a/arch/arm64/include/asm/acpi.h b/arch/arm64/include/asm/acpi.h
> new file mode 100644
> index 0000000..8b837ab
> --- /dev/null
> +++ b/arch/arm64/include/asm/acpi.h
> @@ -0,0 +1,45 @@
> +/*
> + * Copyright (C) 2013-2014, Linaro Ltd.
> + * Author: Al Stone <al.stone@xxxxxxxxxx>
> + * Author: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
> + * Author: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation;
> + */
> +
> +#ifndef _ASM_ACPI_H
> +#define _ASM_ACPI_H
> +
> +/* Basic configuration for ACPI */
> +#ifdef CONFIG_ACPI
> +#define acpi_strict 1 /* No out-of-spec workarounds on ARM64 */
> +extern int acpi_disabled;
> +extern int acpi_noirq;
> +extern int acpi_pci_disabled;
> +
> +static inline void disable_acpi(void)
> +{
> + acpi_disabled = 1;
> + acpi_pci_disabled = 1;
> + acpi_noirq = 1;
> +}
> +
> +/*
> + * It's used from ACPI core in kdump to boot UP system with SMP kernel,
> + * with this check the ACPI core will not override the CPU index
> + * obtained from GICC with 0 and not print some error message as well.
> + * Since MADT must provide at least one GICC structure for GIC
> + * initialization, CPU will be always available in MADT on ARM64.
> + */
> +static inline bool acpi_has_cpu_in_madt(void)
> +{
> + return true;
> +}
> +
> +static inline void arch_fix_phys_package_id(int num, u32 slot) { }
> +
> +#endif /* CONFIG_ACPI */
> +
> +#endif /*_ASM_ACPI_H*/
> diff --git a/arch/arm64/kernel/Makefile b/arch/arm64/kernel/Makefile
> index bef04af..218eb7e 100644
> --- a/arch/arm64/kernel/Makefile
> +++ b/arch/arm64/kernel/Makefile
> @@ -34,6 +34,7 @@ arm64-obj-$(CONFIG_KGDB) += kgdb.o
> arm64-obj-$(CONFIG_EFI) += efi.o efi-stub.o efi-entry.o
> arm64-obj-$(CONFIG_PCI) += pci.o
> arm64-obj-$(CONFIG_ARMV8_DEPRECATED) += armv8_deprecated.o
> +arm64-obj-$(CONFIG_ACPI) += acpi.o
>
> obj-y += $(arm64-obj-y) vdso/
> obj-m += $(arm64-obj-m)
> diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c
> new file mode 100644
> index 0000000..f052e7a
> --- /dev/null
> +++ b/arch/arm64/kernel/acpi.c
> @@ -0,0 +1,101 @@
> +/*
> + * ARM64 Specific Low-Level ACPI Boot Support
> + *
> + * Copyright (C) 2013-2014, Linaro Ltd.
> + * Author: Al Stone <al.stone@xxxxxxxxxx>
> + * Author: Graeme Gregory <graeme.gregory@xxxxxxxxxx>
> + * Author: Hanjun Guo <hanjun.guo@xxxxxxxxxx>
> + * Author: Tomasz Nowicki <tomasz.nowicki@xxxxxxxxxx>
> + * Author: Naresh Bhat <naresh.bhat@xxxxxxxxxx>
> + *
> + * This program is free software; you can redistribute it and/or modify
> + * it under the terms of the GNU General Public License version 2 as
> + * published by the Free Software Foundation.
> + */
> +
> +#define pr_fmt(fmt) "ACPI: " fmt
> +
> +#include <linux/acpi.h>
> +#include <linux/bootmem.h>
> +#include <linux/cpumask.h>
> +#include <linux/init.h>
> +#include <linux/irq.h>
> +#include <linux/irqdomain.h>
> +#include <linux/memblock.h>
> +#include <linux/smp.h>
> +
> +int acpi_noirq; /* skip ACPI IRQ initialization */
> +int acpi_disabled;
> +EXPORT_SYMBOL(acpi_disabled);
> +
> +int acpi_pci_disabled; /* skip ACPI PCI scan and IRQ initialization */
> +EXPORT_SYMBOL(acpi_pci_disabled);
> +
> +/*
> + * __acpi_map_table() will be called before page_init(), so early_ioremap()
> + * or early_memremap() should be called here to for ACPI table mapping.
> + */
> +char *__init __acpi_map_table(unsigned long phys, unsigned long size)
> +{
> + if (!phys || !size)
> + return NULL;
> +
> + return early_memremap(phys, size);
> +}
> +
> +void __init __acpi_unmap_table(char *map, unsigned long size)
> +{
> + if (!map || !size)
> + return;
> +
> + early_memunmap(map, size);
> +}
> +
> +static int __init acpi_parse_fadt(struct acpi_table_header *table)
> +{
> + struct acpi_table_fadt *fadt = (struct acpi_table_fadt *)table;
> +
> + /*
> + * Revision in table header is the FADT Major revision, and there
> + * is a minor revision of FADT which was introduced by ACPI 5.1,
> + * we only deal with ACPI 5.1 or newer revision to get GIC and SMP
> + * boot protocol configuration data, or we will disable ACPI.
> + */
> + if (table->revision > 5 ||
> + (table->revision == 5 && fadt->minor_revision >= 1))
> + return 0;
> +
> + pr_warn("Unsupported FADT revision %d.%d, should be 5.1+, will disable ACPI\n",
> + table->revision, fadt->minor_revision);
> + disable_acpi();
> +
> + return -EINVAL;
> +}
> +
> +/*
> + * acpi_boot_table_init() called from setup_arch(), always.
> + * 1. find RSDP and get its address, and then find XSDT
> + * 2. extract all tables and checksums them all
> + * 3. check ACPI FADT revision
> + *
> + * We can parse ACPI boot-time tables such as MADT after
> + * this function is called.
> + */
> +void __init acpi_boot_table_init(void)
> +{
> + /* If acpi_disabled, bail out */
> + if (acpi_disabled)
> + return;
> +
> + /* Initialize the ACPI boot-time table parser. */
> + if (acpi_table_init()) {
> + disable_acpi();
> + return;
> + }
> +
> + if (acpi_table_parse(ACPI_SIG_FADT, acpi_parse_fadt)) {
> + /* disable ACPI if no FADT is found */
> + disable_acpi();
> + pr_err("Can't find FADT\n");
> + }
> +}
> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c
> index e8420f6..4f1a014 100644
> --- a/arch/arm64/kernel/setup.c
> +++ b/arch/arm64/kernel/setup.c
> @@ -17,6 +17,7 @@
> * along with this program. If not, see <http://www.gnu.org/licenses/>.
> */
>
> +#include <linux/acpi.h>
> #include <linux/export.h>
> #include <linux/kernel.h>
> #include <linux/stddef.h>
> @@ -46,6 +47,7 @@
> #include <linux/efi.h>
> #include <linux/personality.h>
>
> +#include <asm/acpi.h>
> #include <asm/fixmap.h>
> #include <asm/cpu.h>
> #include <asm/cputype.h>
> @@ -380,6 +382,9 @@ void __init setup_arch(char **cmdline_p)
> efi_init();
> arm64_memblock_init();
>
> + /* Parse the ACPI tables for possible boot-time configuration */
> + acpi_boot_table_init();
> +
> paging_init();
> request_standard_resources();
>
> --
> 1.9.1
>

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