diff options
Diffstat (limited to '')
| -rw-r--r-- | drivers/firmware/efi/efi-init.c | 387 |
1 files changed, 387 insertions, 0 deletions
diff --git a/drivers/firmware/efi/efi-init.c b/drivers/firmware/efi/efi-init.c new file mode 100644 index 000000000..f55a92ff1 --- /dev/null +++ b/drivers/firmware/efi/efi-init.c @@ -0,0 +1,387 @@ +// 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(const 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 = { + .ops = &efifb_fwnode_ops, +}; + +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)) + 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); |