diff options
Diffstat (limited to 'arch/arm64/kernel/acpi.c')
-rw-r--r-- | arch/arm64/kernel/acpi.c | 408 |
1 files changed, 408 insertions, 0 deletions
diff --git a/arch/arm64/kernel/acpi.c b/arch/arm64/kernel/acpi.c new file mode 100644 index 000000000..cada0b816 --- /dev/null +++ b/arch/arm64/kernel/acpi.c @@ -0,0 +1,408 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ARM64 Specific Low-Level ACPI Boot Support + * + * Copyright (C) 2013-2014, Linaro Ltd. + * Author: Al Stone <al.stone@linaro.org> + * Author: Graeme Gregory <graeme.gregory@linaro.org> + * Author: Hanjun Guo <hanjun.guo@linaro.org> + * Author: Tomasz Nowicki <tomasz.nowicki@linaro.org> + * Author: Naresh Bhat <naresh.bhat@linaro.org> + */ + +#define pr_fmt(fmt) "ACPI: " fmt + +#include <linux/acpi.h> +#include <linux/cpumask.h> +#include <linux/efi.h> +#include <linux/efi-bgrt.h> +#include <linux/init.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/irq_work.h> +#include <linux/memblock.h> +#include <linux/of_fdt.h> +#include <linux/smp.h> +#include <linux/serial_core.h> +#include <linux/pgtable.h> + +#include <acpi/ghes.h> +#include <asm/cputype.h> +#include <asm/cpu_ops.h> +#include <asm/daifflags.h> +#include <asm/smp_plat.h> + +int acpi_noirq = 1; /* skip ACPI IRQ initialization */ +int acpi_disabled = 1; +EXPORT_SYMBOL(acpi_disabled); + +int acpi_pci_disabled = 1; /* skip ACPI PCI scan and IRQ initialization */ +EXPORT_SYMBOL(acpi_pci_disabled); + +static bool param_acpi_off __initdata; +static bool param_acpi_on __initdata; +static bool param_acpi_force __initdata; + +static int __init parse_acpi(char *arg) +{ + if (!arg) + return -EINVAL; + + /* "acpi=off" disables both ACPI table parsing and interpreter */ + if (strcmp(arg, "off") == 0) + param_acpi_off = true; + else if (strcmp(arg, "on") == 0) /* prefer ACPI over DT */ + param_acpi_on = true; + else if (strcmp(arg, "force") == 0) /* force ACPI to be enabled */ + param_acpi_force = true; + else + return -EINVAL; /* Core will print when we return error */ + + return 0; +} +early_param("acpi", parse_acpi); + +static int __init dt_scan_depth1_nodes(unsigned long node, + const char *uname, int depth, + void *data) +{ + /* + * Ignore anything not directly under the root node; we'll + * catch its parent instead. + */ + if (depth != 1) + return 0; + + if (strcmp(uname, "chosen") == 0) + return 0; + + if (strcmp(uname, "hypervisor") == 0 && + of_flat_dt_is_compatible(node, "xen,xen")) + return 0; + + /* + * This node at depth 1 is neither a chosen node nor a xen node, + * which we do not expect. + */ + return 1; +} + +/* + * __acpi_map_table() will be called before page_init(), so early_ioremap() + * or early_memremap() should be called here to for ACPI table mapping. + */ +void __init __iomem *__acpi_map_table(unsigned long phys, unsigned long size) +{ + if (!size) + return NULL; + + return early_memremap(phys, size); +} + +void __init __acpi_unmap_table(void __iomem *map, unsigned long size) +{ + if (!map || !size) + return; + + early_memunmap(map, size); +} + +bool __init acpi_psci_present(void) +{ + return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_COMPLIANT; +} + +/* Whether HVC must be used instead of SMC as the PSCI conduit */ +bool acpi_psci_use_hvc(void) +{ + return acpi_gbl_FADT.arm_boot_flags & ACPI_FADT_PSCI_USE_HVC; +} + +/* + * acpi_fadt_sanity_check() - Check FADT presence and carry out sanity + * checks on it + * + * Return 0 on success, <0 on failure + */ +static int __init acpi_fadt_sanity_check(void) +{ + struct acpi_table_header *table; + struct acpi_table_fadt *fadt; + acpi_status status; + int ret = 0; + + /* + * FADT is required on arm64; retrieve it to check its presence + * and carry out revision and ACPI HW reduced compliancy tests + */ + status = acpi_get_table(ACPI_SIG_FADT, 0, &table); + if (ACPI_FAILURE(status)) { + const char *msg = acpi_format_exception(status); + + pr_err("Failed to get FADT table, %s\n", msg); + return -ENODEV; + } + + 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. + */ + if (table->revision < 5 || + (table->revision == 5 && fadt->minor_revision < 1)) { + pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 5.1+\n", + table->revision, fadt->minor_revision); + + if (!fadt->arm_boot_flags) { + ret = -EINVAL; + goto out; + } + pr_err("FADT has ARM boot flags set, assuming 5.1\n"); + } + + if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) { + pr_err("FADT not ACPI hardware reduced compliant\n"); + ret = -EINVAL; + } + +out: + /* + * acpi_get_table() creates FADT table mapping that + * should be released after parsing and before resuming boot + */ + acpi_put_table(table); + return ret; +} + +/* + * 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 + * 4. check ACPI FADT HW reduced flag + * + * We can parse ACPI boot-time tables such as MADT after + * this function is called. + * + * On return ACPI is enabled if either: + * + * - ACPI tables are initialized and sanity checks passed + * - acpi=force was passed in the command line and ACPI was not disabled + * explicitly through acpi=off command line parameter + * + * ACPI is disabled on function return otherwise + */ +void __init acpi_boot_table_init(void) +{ + /* + * Enable ACPI instead of device tree unless + * - ACPI has been disabled explicitly (acpi=off), or + * - the device tree is not empty (it has more than just a /chosen node, + * and a /hypervisor node when running on Xen) + * and ACPI has not been [force] enabled (acpi=on|force) + */ + if (param_acpi_off || + (!param_acpi_on && !param_acpi_force && + of_scan_flat_dt(dt_scan_depth1_nodes, NULL))) + goto done; + + /* + * ACPI is disabled at this point. Enable it in order to parse + * the ACPI tables and carry out sanity checks + */ + enable_acpi(); + + /* + * If ACPI tables are initialized and FADT sanity checks passed, + * leave ACPI enabled and carry on booting; otherwise disable ACPI + * on initialization error. + * If acpi=force was passed on the command line it forces ACPI + * to be enabled even if its initialization failed. + */ + if (acpi_table_init() || acpi_fadt_sanity_check()) { + pr_err("Failed to init ACPI tables\n"); + if (!param_acpi_force) + disable_acpi(); + } + +done: + if (acpi_disabled) { + if (earlycon_acpi_spcr_enable) + early_init_dt_scan_chosen_stdout(); + } else { + acpi_parse_spcr(earlycon_acpi_spcr_enable, true); + if (IS_ENABLED(CONFIG_ACPI_BGRT)) + acpi_table_parse(ACPI_SIG_BGRT, acpi_parse_bgrt); + } +} + +pgprot_t __acpi_get_mem_attribute(phys_addr_t addr) +{ + /* + * According to "Table 8 Map: EFI memory types to AArch64 memory + * types" of UEFI 2.5 section 2.3.6.1, each EFI memory type is + * mapped to a corresponding MAIR attribute encoding. + * The EFI memory attribute advises all possible capabilities + * of a memory region. We use the most efficient capability. + */ + + u64 attr; + + attr = efi_mem_attributes(addr); + if (attr & EFI_MEMORY_WB) + return PAGE_KERNEL; + if (attr & EFI_MEMORY_WT) + return __pgprot(PROT_NORMAL_WT); + if (attr & EFI_MEMORY_WC) + return __pgprot(PROT_NORMAL_NC); + return __pgprot(PROT_DEVICE_nGnRnE); +} + +void __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) +{ + efi_memory_desc_t *md, *region = NULL; + pgprot_t prot; + + if (WARN_ON_ONCE(!efi_enabled(EFI_MEMMAP))) + return NULL; + + for_each_efi_memory_desc(md) { + u64 end = md->phys_addr + (md->num_pages << EFI_PAGE_SHIFT); + + if (phys < md->phys_addr || phys >= end) + continue; + + if (phys + size > end) { + pr_warn(FW_BUG "requested region covers multiple EFI memory regions\n"); + return NULL; + } + region = md; + break; + } + + /* + * It is fine for AML to remap regions that are not represented in the + * EFI memory map at all, as it only describes normal memory, and MMIO + * regions that require a virtual mapping to make them accessible to + * the EFI runtime services. + */ + prot = __pgprot(PROT_DEVICE_nGnRnE); + if (region) { + switch (region->type) { + case EFI_LOADER_CODE: + case EFI_LOADER_DATA: + case EFI_BOOT_SERVICES_CODE: + case EFI_BOOT_SERVICES_DATA: + case EFI_CONVENTIONAL_MEMORY: + case EFI_PERSISTENT_MEMORY: + if (memblock_is_map_memory(phys) || + !memblock_is_region_memory(phys, size)) { + pr_warn(FW_BUG "requested region covers kernel memory @ %pa\n", &phys); + return NULL; + } + /* + * Mapping kernel memory is permitted if the region in + * question is covered by a single memblock with the + * NOMAP attribute set: this enables the use of ACPI + * table overrides passed via initramfs, which are + * reserved in memory using arch_reserve_mem_area() + * below. As this particular use case only requires + * read access, fall through to the R/O mapping case. + */ + fallthrough; + + case EFI_RUNTIME_SERVICES_CODE: + /* + * This would be unusual, but not problematic per se, + * as long as we take care not to create a writable + * mapping for executable code. + */ + prot = PAGE_KERNEL_RO; + break; + + case EFI_ACPI_RECLAIM_MEMORY: + /* + * ACPI reclaim memory is used to pass firmware tables + * and other data that is intended for consumption by + * the OS only, which may decide it wants to reclaim + * that memory and use it for something else. We never + * do that, but we usually add it to the linear map + * anyway, in which case we should use the existing + * mapping. + */ + if (memblock_is_map_memory(phys)) + return (void __iomem *)__phys_to_virt(phys); + fallthrough; + + default: + if (region->attribute & EFI_MEMORY_WB) + prot = PAGE_KERNEL; + else if (region->attribute & EFI_MEMORY_WT) + prot = __pgprot(PROT_NORMAL_WT); + else if (region->attribute & EFI_MEMORY_WC) + prot = __pgprot(PROT_NORMAL_NC); + } + } + return __ioremap(phys, size, prot); +} + +/* + * Claim Synchronous External Aborts as a firmware first notification. + * + * Used by KVM and the arch do_sea handler. + * @regs may be NULL when called from process context. + */ +int apei_claim_sea(struct pt_regs *regs) +{ + int err = -ENOENT; + bool return_to_irqs_enabled; + unsigned long current_flags; + + if (!IS_ENABLED(CONFIG_ACPI_APEI_GHES)) + return err; + + current_flags = local_daif_save_flags(); + + /* current_flags isn't useful here as daif doesn't tell us about pNMI */ + return_to_irqs_enabled = !irqs_disabled_flags(arch_local_save_flags()); + + if (regs) + return_to_irqs_enabled = interrupts_enabled(regs); + + /* + * SEA can interrupt SError, mask it and describe this as an NMI so + * that APEI defers the handling. + */ + local_daif_restore(DAIF_ERRCTX); + nmi_enter(); + err = ghes_notify_sea(); + nmi_exit(); + + /* + * APEI NMI-like notifications are deferred to irq_work. Unless + * we interrupted irqs-masked code, we can do that now. + */ + if (!err) { + if (return_to_irqs_enabled) { + local_daif_restore(DAIF_PROCCTX_NOIRQ); + __irq_enter(); + irq_work_run(); + __irq_exit(); + } else { + pr_warn_ratelimited("APEI work queued but not completed"); + err = -EINPROGRESS; + } + } + + local_daif_restore(current_flags); + + return err; +} + +void arch_reserve_mem_area(acpi_physical_address addr, size_t size) +{ + memblock_mark_nomap(addr, size); +} |