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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_node *sup_np;
- 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;
- fwnode_link_add(fwnode, of_fwnode_handle(sup_np));
- of_node_put(sup_np);
- 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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