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// SPDX-License-Identifier: GPL-2.0
/*
* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 2.4
*
* Copyright (C) 2013 - 2015 Linaro Ltd.
*/
#define pr_fmt(fmt) "efi: " fmt
#include <linux/efi.h>
#include <linux/fwnode.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/mm_types.h>
#include <linux/of.h>
#include <linux/of_address.h>
#include <linux/of_fdt.h>
#include <linux/platform_device.h>
#include <linux/screen_info.h>
#include <asm/efi.h>
static int __init is_memory(efi_memory_desc_t *md)
{
if (md->attribute & (EFI_MEMORY_WB|EFI_MEMORY_WT|EFI_MEMORY_WC))
return 1;
return 0;
}
/*
* Translate a EFI virtual address into a physical address: this is necessary,
* as some data members of the EFI system table are virtually remapped after
* SetVirtualAddressMap() has been called.
*/
static phys_addr_t __init efi_to_phys(unsigned long addr)
{
efi_memory_desc_t *md;
for_each_efi_memory_desc(md) {
if (!(md->attribute & EFI_MEMORY_RUNTIME))
continue;
if (md->virt_addr == 0)
/* no virtual mapping has been installed by the stub */
break;
if (md->virt_addr <= addr &&
(addr - md->virt_addr) < (md->num_pages << EFI_PAGE_SHIFT))
return md->phys_addr + addr - md->virt_addr;
}
return addr;
}
static __initdata unsigned long screen_info_table = EFI_INVALID_TABLE_ADDR;
static __initdata unsigned long cpu_state_table = EFI_INVALID_TABLE_ADDR;
static const efi_config_table_type_t arch_tables[] __initconst = {
{LINUX_EFI_ARM_SCREEN_INFO_TABLE_GUID, &screen_info_table},
{LINUX_EFI_ARM_CPU_STATE_TABLE_GUID, &cpu_state_table},
{}
};
static void __init init_screen_info(void)
{
struct screen_info *si;
if (IS_ENABLED(CONFIG_ARM) &&
screen_info_table != EFI_INVALID_TABLE_ADDR) {
si = early_memremap_ro(screen_info_table, sizeof(*si));
if (!si) {
pr_err("Could not map screen_info config table\n");
return;
}
screen_info = *si;
early_memunmap(si, sizeof(*si));
/* dummycon on ARM needs non-zero values for columns/lines */
screen_info.orig_video_cols = 80;
screen_info.orig_video_lines = 25;
}
if (screen_info.orig_video_isVGA == VIDEO_TYPE_EFI &&
memblock_is_map_memory(screen_info.lfb_base))
memblock_mark_nomap(screen_info.lfb_base, screen_info.lfb_size);
}
static int __init uefi_init(u64 efi_system_table)
{
efi_config_table_t *config_tables;
efi_system_table_t *systab;
size_t table_size;
int retval;
systab = early_memremap_ro(efi_system_table, sizeof(efi_system_table_t));
if (systab == NULL) {
pr_warn("Unable to map EFI system table.\n");
return -ENOMEM;
}
set_bit(EFI_BOOT, &efi.flags);
if (IS_ENABLED(CONFIG_64BIT))
set_bit(EFI_64BIT, &efi.flags);
retval = efi_systab_check_header(&systab->hdr, 2);
if (retval)
goto out;
efi.runtime = systab->runtime;
efi.runtime_version = systab->hdr.revision;
efi_systab_report_header(&systab->hdr, efi_to_phys(systab->fw_vendor));
table_size = sizeof(efi_config_table_t) * systab->nr_tables;
config_tables = early_memremap_ro(efi_to_phys(systab->tables),
table_size);
if (config_tables == NULL) {
pr_warn("Unable to map EFI config table array.\n");
retval = -ENOMEM;
goto out;
}
retval = efi_config_parse_tables(config_tables, systab->nr_tables,
IS_ENABLED(CONFIG_ARM) ? arch_tables
: NULL);
early_memunmap(config_tables, table_size);
out:
early_memunmap(systab, sizeof(efi_system_table_t));
return retval;
}
/*
* Return true for regions that can be used as System RAM.
*/
static __init int is_usable_memory(efi_memory_desc_t *md)
{
switch (md->type) {
case EFI_LOADER_CODE:
case EFI_LOADER_DATA:
case EFI_ACPI_RECLAIM_MEMORY:
case EFI_BOOT_SERVICES_CODE:
case EFI_BOOT_SERVICES_DATA:
case EFI_CONVENTIONAL_MEMORY:
case EFI_PERSISTENT_MEMORY:
/*
* Special purpose memory is 'soft reserved', which means it
* is set aside initially, but can be hotplugged back in or
* be assigned to the dax driver after boot.
*/
if (efi_soft_reserve_enabled() &&
(md->attribute & EFI_MEMORY_SP))
return false;
/*
* According to the spec, these regions are no longer reserved
* after calling ExitBootServices(). However, we can only use
* them as System RAM if they can be mapped writeback cacheable.
*/
return (md->attribute & EFI_MEMORY_WB);
default:
break;
}
return false;
}
static __init void reserve_regions(void)
{
efi_memory_desc_t *md;
u64 paddr, npages, size;
if (efi_enabled(EFI_DBG))
pr_info("Processing EFI memory map:\n");
/*
* Discard memblocks discovered so far: if there are any at this
* point, they originate from memory nodes in the DT, and UEFI
* uses its own memory map instead.
*/
memblock_dump_all();
memblock_remove(0, PHYS_ADDR_MAX);
for_each_efi_memory_desc(md) {
paddr = md->phys_addr;
npages = md->num_pages;
if (efi_enabled(EFI_DBG)) {
char buf[64];
pr_info(" 0x%012llx-0x%012llx %s\n",
paddr, paddr + (npages << EFI_PAGE_SHIFT) - 1,
efi_md_typeattr_format(buf, sizeof(buf), md));
}
memrange_efi_to_native(&paddr, &npages);
size = npages << PAGE_SHIFT;
if (is_memory(md)) {
early_init_dt_add_memory_arch(paddr, size);
if (!is_usable_memory(md))
memblock_mark_nomap(paddr, size);
/* keep ACPI reclaim memory intact for kexec etc. */
if (md->type == EFI_ACPI_RECLAIM_MEMORY)
memblock_reserve(paddr, size);
}
}
}
void __init efi_init(void)
{
struct efi_memory_map_data data;
u64 efi_system_table;
/* Grab UEFI information placed in FDT by stub */
efi_system_table = efi_get_fdt_params(&data);
if (!efi_system_table)
return;
if (efi_memmap_init_early(&data) < 0) {
/*
* If we are booting via UEFI, the UEFI memory map is the only
* description of memory we have, so there is little point in
* proceeding if we cannot access it.
*/
panic("Unable to map EFI memory map.\n");
}
WARN(efi.memmap.desc_version != 1,
"Unexpected EFI_MEMORY_DESCRIPTOR version %ld",
efi.memmap.desc_version);
if (uefi_init(efi_system_table) < 0) {
efi_memmap_unmap();
return;
}
reserve_regions();
efi_esrt_init();
efi_mokvar_table_init();
memblock_reserve(data.phys_map & PAGE_MASK,
PAGE_ALIGN(data.size + (data.phys_map & ~PAGE_MASK)));
init_screen_info();
#ifdef CONFIG_ARM
/* ARM does not permit early mappings to persist across paging_init() */
efi_memmap_unmap();
if (cpu_state_table != EFI_INVALID_TABLE_ADDR) {
struct efi_arm_entry_state *state;
bool dump_state = true;
state = early_memremap_ro(cpu_state_table,
sizeof(struct efi_arm_entry_state));
if (state == NULL) {
pr_warn("Unable to map CPU entry state table.\n");
return;
}
if ((state->sctlr_before_ebs & 1) == 0)
pr_warn(FW_BUG "EFI stub was entered with MMU and Dcache disabled, please fix your firmware!\n");
else if ((state->sctlr_after_ebs & 1) == 0)
pr_warn(FW_BUG "ExitBootServices() returned with MMU and Dcache disabled, please fix your firmware!\n");
else
dump_state = false;
if (dump_state || efi_enabled(EFI_DBG)) {
pr_info("CPSR at EFI stub entry : 0x%08x\n", state->cpsr_before_ebs);
pr_info("SCTLR at EFI stub entry : 0x%08x\n", state->sctlr_before_ebs);
pr_info("CPSR after ExitBootServices() : 0x%08x\n", state->cpsr_after_ebs);
pr_info("SCTLR after ExitBootServices(): 0x%08x\n", state->sctlr_after_ebs);
}
early_memunmap(state, sizeof(struct efi_arm_entry_state));
}
#endif
}
static bool efifb_overlaps_pci_range(const struct of_pci_range *range)
{
u64 fb_base = screen_info.lfb_base;
if (screen_info.capabilities & VIDEO_CAPABILITY_64BIT_BASE)
fb_base |= (u64)(unsigned long)screen_info.ext_lfb_base << 32;
return fb_base >= range->cpu_addr &&
fb_base < (range->cpu_addr + range->size);
}
static struct device_node *find_pci_overlap_node(void)
{
struct device_node *np;
for_each_node_by_type(np, "pci") {
struct of_pci_range_parser parser;
struct of_pci_range range;
int err;
err = of_pci_range_parser_init(&parser, np);
if (err) {
pr_warn("of_pci_range_parser_init() failed: %d\n", err);
continue;
}
for_each_of_pci_range(&parser, &range)
if (efifb_overlaps_pci_range(&range))
return np;
}
return NULL;
}
/*
* If the efifb framebuffer is backed by a PCI graphics controller, we have
* to ensure that this relation is expressed using a device link when
* running in DT mode, or the probe order may be reversed, resulting in a
* resource reservation conflict on the memory window that the efifb
* framebuffer steals from the PCIe host bridge.
*/
static int efifb_add_links(struct fwnode_handle *fwnode,
struct device *dev)
{
struct device_node *sup_np;
struct device *sup_dev;
sup_np = find_pci_overlap_node();
/*
* If there's no PCI graphics controller backing the efifb, we are
* done here.
*/
if (!sup_np)
return 0;
sup_dev = get_dev_from_fwnode(&sup_np->fwnode);
of_node_put(sup_np);
/*
* Return -ENODEV if the PCI graphics controller device hasn't been
* registered yet. This ensures that efifb isn't allowed to probe
* and this function is retried again when new devices are
* registered.
*/
if (!sup_dev)
return -ENODEV;
/*
* If this fails, retrying this function at a later point won't
* change anything. So, don't return an error after this.
*/
if (!device_link_add(dev, sup_dev, fw_devlink_get_flags()))
dev_warn(dev, "device_link_add() failed\n");
put_device(sup_dev);
return 0;
}
static const struct fwnode_operations efifb_fwnode_ops = {
.add_links = efifb_add_links,
};
static struct fwnode_handle efifb_fwnode;
static int __init register_gop_device(void)
{
struct platform_device *pd;
int err;
if (screen_info.orig_video_isVGA != VIDEO_TYPE_EFI)
return 0;
pd = platform_device_alloc("efi-framebuffer", 0);
if (!pd)
return -ENOMEM;
if (IS_ENABLED(CONFIG_PCI)) {
fwnode_init(&efifb_fwnode, &efifb_fwnode_ops);
pd->dev.fwnode = &efifb_fwnode;
}
err = platform_device_add_data(pd, &screen_info, sizeof(screen_info));
if (err)
return err;
return platform_device_add(pd);
}
subsys_initcall(register_gop_device);
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