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Diffstat (limited to 'arch/riscv/kernel/acpi.c')
-rw-r--r-- | arch/riscv/kernel/acpi.c | 251 |
1 files changed, 251 insertions, 0 deletions
diff --git a/arch/riscv/kernel/acpi.c b/arch/riscv/kernel/acpi.c new file mode 100644 index 000000000000..5ee03ebab80e --- /dev/null +++ b/arch/riscv/kernel/acpi.c @@ -0,0 +1,251 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * RISC-V 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> + * + * Copyright (C) 2021-2023, Ventana Micro Systems Inc. + * Author: Sunil V L <sunilvl@ventanamicro.com> + */ + +#include <linux/acpi.h> +#include <linux/io.h> +#include <linux/pci.h> +#include <linux/efi.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 struct acpi_madt_rintc cpu_madt_rintc[NR_CPUS]; + +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); + +/* + * 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 riscv; 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; + + /* + * The revision in the table header is the FADT's Major revision. The + * FADT also has a minor revision, which is stored in the FADT itself. + * + * TODO: Currently, we check for 6.5 as the minimum version to check + * for HW_REDUCED flag. However, once RISC-V updates are released in + * the ACPI spec, we need to update this check for exact minor revision + */ + if (table->revision < 6 || (table->revision == 6 && fadt->minor_revision < 5)) + pr_err(FW_BUG "Unsupported FADT revision %d.%d, should be 6.5+\n", + table->revision, fadt->minor_revision); + + if (!(fadt->flags & ACPI_FADT_HW_REDUCED)) { + pr_err("FADT not ACPI hardware reduced compliant\n"); + ret = -EINVAL; + } + + /* + * 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 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 + * - firmware has not populated ACPI ptr in EFI system table + * and ACPI has not been [force] enabled (acpi=on|force) + */ + if (param_acpi_off || + (!param_acpi_on && !param_acpi_force && + efi.acpi20 == EFI_INVALID_TABLE_ADDR)) + return; + + /* + * 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(); + } +} + +static int acpi_parse_madt_rintc(union acpi_subtable_headers *header, const unsigned long end) +{ + struct acpi_madt_rintc *rintc = (struct acpi_madt_rintc *)header; + int cpuid; + + if (!(rintc->flags & ACPI_MADT_ENABLED)) + return 0; + + cpuid = riscv_hartid_to_cpuid(rintc->hart_id); + /* + * When CONFIG_SMP is disabled, mapping won't be created for + * all cpus. + * CPUs more than num_possible_cpus, will be ignored. + */ + if (cpuid >= 0 && cpuid < num_possible_cpus()) + cpu_madt_rintc[cpuid] = *rintc; + + return 0; +} + +/* + * Instead of parsing (and freeing) the ACPI table, cache + * the RINTC structures since they are frequently used + * like in cpuinfo. + */ +void __init acpi_init_rintc_map(void) +{ + if (acpi_table_parse_madt(ACPI_MADT_TYPE_RINTC, acpi_parse_madt_rintc, 0) <= 0) { + pr_err("No valid RINTC entries exist\n"); + BUG(); + } +} + +struct acpi_madt_rintc *acpi_cpu_get_madt_rintc(int cpu) +{ + return &cpu_madt_rintc[cpu]; +} + +u32 get_acpi_id_for_cpu(int cpu) +{ + return acpi_cpu_get_madt_rintc(cpu)->uid; +} + +/* + * __acpi_map_table() will be called before paging_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_ioremap(phys, size); +} + +void __init __acpi_unmap_table(void __iomem *map, unsigned long size) +{ + if (!map || !size) + return; + + early_iounmap(map, size); +} + +void *acpi_os_ioremap(acpi_physical_address phys, acpi_size size) +{ + return memremap(phys, size, MEMREMAP_WB); +} + +#ifdef CONFIG_PCI + +/* + * These interfaces are defined just to enable building ACPI core. + * TODO: Update it with actual implementation when external interrupt + * controller support is added in RISC-V ACPI. + */ +int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn, + int reg, int len, u32 *val) +{ + return PCIBIOS_DEVICE_NOT_FOUND; +} + +int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn, + int reg, int len, u32 val) +{ + return PCIBIOS_DEVICE_NOT_FOUND; +} + +int acpi_pci_bus_find_domain_nr(struct pci_bus *bus) +{ + return -1; +} + +struct pci_bus *pci_acpi_scan_root(struct acpi_pci_root *root) +{ + return NULL; +} +#endif /* CONFIG_PCI */ |