// 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 __iomem *acpi_os_ioremap(acpi_physical_address phys, acpi_size size)
{
return (void __iomem *)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 */