From b91540d52a08b65eb6a2b09132e1bd54fa82754c Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Thu, 17 Sep 2020 15:37:15 -0700 Subject: RISC-V: Add EFI runtime services This patch adds EFI runtime service support for RISC-V. Signed-off-by: Atish Patra [ardb: - Remove the page check] Signed-off-by: Ard Biesheuvel Acked-by: Ard Biesheuvel Signed-off-by: Palmer Dabbelt --- drivers/firmware/efi/Makefile | 2 + drivers/firmware/efi/libstub/efi-stub.c | 11 ++- drivers/firmware/efi/riscv-runtime.c | 143 ++++++++++++++++++++++++++++++++ 3 files changed, 155 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/efi/riscv-runtime.c (limited to 'drivers/firmware/efi') diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index 61fd1e8b26fb..4d628081bb2f 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -35,6 +35,8 @@ fake_map-$(CONFIG_X86) += x86_fake_mem.o arm-obj-$(CONFIG_EFI) := efi-init.o arm-runtime.o obj-$(CONFIG_ARM) += $(arm-obj-y) obj-$(CONFIG_ARM64) += $(arm-obj-y) +riscv-obj-$(CONFIG_EFI) := efi-init.o riscv-runtime.o +obj-$(CONFIG_RISCV) += $(riscv-obj-y) obj-$(CONFIG_EFI_CAPSULE_LOADER) += capsule-loader.o obj-$(CONFIG_EFI_EARLYCON) += earlycon.o obj-$(CONFIG_UEFI_CPER_ARM) += cper-arm.o diff --git a/drivers/firmware/efi/libstub/efi-stub.c b/drivers/firmware/efi/libstub/efi-stub.c index 311a16802dd6..914a343c7785 100644 --- a/drivers/firmware/efi/libstub/efi-stub.c +++ b/drivers/firmware/efi/libstub/efi-stub.c @@ -17,7 +17,10 @@ /* * This is the base address at which to start allocating virtual memory ranges - * for UEFI Runtime Services. This is in the low TTBR0 range so that we can use + * for UEFI Runtime Services. + * + * For ARM/ARM64: + * This is in the low TTBR0 range so that we can use * any allocation we choose, and eliminate the risk of a conflict after kexec. * The value chosen is the largest non-zero power of 2 suitable for this purpose * both on 32-bit and 64-bit ARM CPUs, to maximize the likelihood that it can @@ -25,6 +28,12 @@ * Since 32-bit ARM could potentially execute with a 1G/3G user/kernel split, * map everything below 1 GB. (512 MB is a reasonable upper bound for the * entire footprint of the UEFI runtime services memory regions) + * + * For RISC-V: + * There is no specific reason for which, this address (512MB) can't be used + * EFI runtime virtual address for RISC-V. It also helps to use EFI runtime + * services on both RV32/RV64. Keep the same runtime virtual address for RISC-V + * as well to minimize the code churn. */ #define EFI_RT_VIRTUAL_BASE SZ_512M #define EFI_RT_VIRTUAL_SIZE SZ_512M diff --git a/drivers/firmware/efi/riscv-runtime.c b/drivers/firmware/efi/riscv-runtime.c new file mode 100644 index 000000000000..d28e715d2bcc --- /dev/null +++ b/drivers/firmware/efi/riscv-runtime.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Extensible Firmware Interface + * + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + * + * Based on Extensible Firmware Interface Specification version 2.4 + * Adapted from drivers/firmware/efi/arm-runtime.c + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include + +static bool __init efi_virtmap_init(void) +{ + efi_memory_desc_t *md; + + efi_mm.pgd = pgd_alloc(&efi_mm); + mm_init_cpumask(&efi_mm); + init_new_context(NULL, &efi_mm); + + for_each_efi_memory_desc(md) { + phys_addr_t phys = md->phys_addr; + int ret; + + if (!(md->attribute & EFI_MEMORY_RUNTIME)) + continue; + if (md->virt_addr == 0) + return false; + + ret = efi_create_mapping(&efi_mm, md); + if (ret) { + pr_warn(" EFI remap %pa: failed to create mapping (%d)\n", + &phys, ret); + return false; + } + } + + if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions)) + return false; + + return true; +} + +/* + * Enable the UEFI Runtime Services if all prerequisites are in place, i.e., + * non-early mapping of the UEFI system table and virtual mappings for all + * EFI_MEMORY_RUNTIME regions. + */ +static int __init riscv_enable_runtime_services(void) +{ + u64 mapsize; + + if (!efi_enabled(EFI_BOOT)) { + pr_info("EFI services will not be available.\n"); + return 0; + } + + efi_memmap_unmap(); + + mapsize = efi.memmap.desc_size * efi.memmap.nr_map; + + if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) { + pr_err("Failed to remap EFI memory map\n"); + return 0; + } + + if (efi_soft_reserve_enabled()) { + efi_memory_desc_t *md; + + for_each_efi_memory_desc(md) { + int md_size = md->num_pages << EFI_PAGE_SHIFT; + struct resource *res; + + if (!(md->attribute & EFI_MEMORY_SP)) + continue; + + res = kzalloc(sizeof(*res), GFP_KERNEL); + if (WARN_ON(!res)) + break; + + res->start = md->phys_addr; + res->end = md->phys_addr + md_size - 1; + res->name = "Soft Reserved"; + res->flags = IORESOURCE_MEM; + res->desc = IORES_DESC_SOFT_RESERVED; + + insert_resource(&iomem_resource, res); + } + } + + if (efi_runtime_disabled()) { + pr_info("EFI runtime services will be disabled.\n"); + return 0; + } + + if (efi_enabled(EFI_RUNTIME_SERVICES)) { + pr_info("EFI runtime services access via paravirt.\n"); + return 0; + } + + pr_info("Remapping and enabling EFI services.\n"); + + if (!efi_virtmap_init()) { + pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n"); + return -ENOMEM; + } + + /* Set up runtime services function pointers */ + efi_native_runtime_setup(); + set_bit(EFI_RUNTIME_SERVICES, &efi.flags); + + return 0; +} +early_initcall(riscv_enable_runtime_services); + +void efi_virtmap_load(void) +{ + preempt_disable(); + switch_mm(current->active_mm, &efi_mm, NULL); +} + +void efi_virtmap_unload(void) +{ + switch_mm(&efi_mm, current->active_mm, NULL); + preempt_enable(); +} -- cgit