RISC-V: Add ACPI initialization in setup_arch() (724f4c0d) · Commits · EulixOS / Software / Kernel

Documentation/admin-guide/kernel-parameters.txt

+4 −4

Original line number	Diff line number	Diff line
		acpi= [HW,ACPI,X86,ARM64]
		acpi= [HW,ACPI,X86,ARM64,RISCV64]
		Advanced Configuration and Power Interface
		Format: { force \| on \| off \| strict \| noirq \| rsdt \|
		copy_dsdt }
		force -- enable ACPI if default was off
		on -- enable ACPI but allow fallback to DT [arm64]
		on -- enable ACPI but allow fallback to DT [arm64,riscv64]
		off -- disable ACPI if default was on
		noirq -- do not use ACPI for IRQ routing
		strict -- Be less tolerant of platforms that are not
		strictly ACPI specification compliant.
		rsdt -- prefer RSDT over (default) XSDT
		copy_dsdt -- copy DSDT to memory
		For ARM64, ONLY "acpi=off", "acpi=on" or "acpi=force"
		are available
		For ARM64 and RISCV64, ONLY "acpi=off", "acpi=on" or
		"acpi=force" are available

		See also Documentation/power/runtime_pm.rst, pci=noacpi

arch/riscv/kernel/acpi.c

+126 −0

Original line number	Diff line number	Diff line
		@@ -16,6 +16,7 @@
		#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;
		@@ -24,6 +25,131 @@ 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);

		/*
		* 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();
		}
		}

		/*
		* __acpi_map_table() will be called before paging_init(), so early_ioremap()
		* or early_memremap() should be called here to for ACPI table mapping.

arch/riscv/kernel/setup.c

+5 −0

Original line number	Diff line number	Diff line
		@@ -8,6 +8,7 @@
		* Nick Kossifidis <mick@ics.forth.gr>
		*/

		#include <linux/acpi.h>
		#include <linux/cpu.h>
		#include <linux/init.h>
		#include <linux/mm.h>
		@@ -276,6 +277,10 @@ void __init setup_arch(char **cmdline_p)

		efi_init();
		paging_init();

		/* Parse the ACPI tables for possible boot-time configuration */
		acpi_boot_table_init();

		#if IS_ENABLED(CONFIG_BUILTIN_DTB)
		unflatten_and_copy_device_tree();
		#else