diff options
Diffstat (limited to 'drivers/firmware/efi')
| -rw-r--r-- | drivers/firmware/efi/Kconfig | 3 | ||||
| -rw-r--r-- | drivers/firmware/efi/Makefile | 2 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/Makefile | 10 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/efi-stub.c | 11 | ||||
| -rw-r--r-- | drivers/firmware/efi/libstub/riscv-stub.c | 109 | ||||
| -rw-r--r-- | drivers/firmware/efi/riscv-runtime.c | 143 |
6 files changed, 276 insertions, 2 deletions
diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index da1887f72a51..36ec1f718893 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -106,7 +106,7 @@ config EFI_GENERIC_STUB config EFI_ARMSTUB_DTB_LOADER bool "Enable the DTB loader" - depends on EFI_GENERIC_STUB + depends on EFI_GENERIC_STUB && !RISCV default y help Select this config option to add support for the dtb= command @@ -123,6 +123,7 @@ config EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER bool "Enable the command line initrd loader" if !X86 depends on EFI_STUB && (EFI_GENERIC_STUB || X86) default y + depends on !RISCV help Select this config option to add support for the initrd= command line parameter, allowing an initrd that resides on the same volume diff --git a/drivers/firmware/efi/Makefile b/drivers/firmware/efi/Makefile index e8da782280b6..d6ca2da19339 100644 --- a/drivers/firmware/efi/Makefile +++ b/drivers/firmware/efi/Makefile @@ -36,6 +36,8 @@ 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/Makefile b/drivers/firmware/efi/libstub/Makefile index 039a9acab817..8a94388e38b3 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -23,6 +23,8 @@ cflags-$(CONFIG_ARM64) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ cflags-$(CONFIG_ARM) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ -fno-builtin -fpic \ $(call cc-option,-mno-single-pic-base) +cflags-$(CONFIG_RISCV) := $(subst $(CC_FLAGS_FTRACE),,$(KBUILD_CFLAGS)) \ + -fpic cflags-$(CONFIG_EFI_GENERIC_STUB) += -I$(srctree)/scripts/dtc/libfdt @@ -64,6 +66,7 @@ lib-$(CONFIG_EFI_GENERIC_STUB) += efi-stub.o fdt.o string.o \ lib-$(CONFIG_ARM) += arm32-stub.o lib-$(CONFIG_ARM64) += arm64-stub.o lib-$(CONFIG_X86) += x86-stub.o +lib-$(CONFIG_RISCV) += riscv-stub.o CFLAGS_arm32-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) # Even when -mbranch-protection=none is set, Clang will generate a @@ -112,6 +115,13 @@ STUBCOPY_FLAGS-$(CONFIG_ARM64) += --prefix-alloc-sections=.init \ --prefix-symbols=__efistub_ STUBCOPY_RELOC-$(CONFIG_ARM64) := R_AARCH64_ABS +# For RISC-V, we don't need anything special other than arm64. Keep all the +# symbols in .init section and make sure that no absolute symbols references +# doesn't exist. +STUBCOPY_FLAGS-$(CONFIG_RISCV) += --prefix-alloc-sections=.init \ + --prefix-symbols=__efistub_ +STUBCOPY_RELOC-$(CONFIG_RISCV) := R_RISCV_HI20 + $(obj)/%.stub.o: $(obj)/%.o FORCE $(call if_changed,stubcopy) 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/libstub/riscv-stub.c b/drivers/firmware/efi/libstub/riscv-stub.c new file mode 100644 index 000000000000..380e4e251399 --- /dev/null +++ b/drivers/firmware/efi/libstub/riscv-stub.c @@ -0,0 +1,109 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + */ + +#include <linux/efi.h> +#include <linux/libfdt.h> + +#include <asm/efi.h> +#include <asm/sections.h> + +#include "efistub.h" + +/* + * RISC-V requires the kernel image to placed 2 MB aligned base for 64 bit and + * 4MB for 32 bit. + */ +#ifdef CONFIG_64BIT +#define MIN_KIMG_ALIGN SZ_2M +#else +#define MIN_KIMG_ALIGN SZ_4M +#endif + +typedef void __noreturn (*jump_kernel_func)(unsigned int, unsigned long); + +static u32 hartid; + +static u32 get_boot_hartid_from_fdt(void) +{ + const void *fdt; + int chosen_node, len; + const fdt32_t *prop; + + fdt = get_efi_config_table(DEVICE_TREE_GUID); + if (!fdt) + return U32_MAX; + + chosen_node = fdt_path_offset(fdt, "/chosen"); + if (chosen_node < 0) + return U32_MAX; + + prop = fdt_getprop((void *)fdt, chosen_node, "boot-hartid", &len); + if (!prop || len != sizeof(u32)) + return U32_MAX; + + return fdt32_to_cpu(*prop); +} + +efi_status_t check_platform_features(void) +{ + hartid = get_boot_hartid_from_fdt(); + if (hartid == U32_MAX) { + efi_err("/chosen/boot-hartid missing or invalid!\n"); + return EFI_UNSUPPORTED; + } + return EFI_SUCCESS; +} + +void __noreturn efi_enter_kernel(unsigned long entrypoint, unsigned long fdt, + unsigned long fdt_size) +{ + unsigned long stext_offset = _start_kernel - _start; + unsigned long kernel_entry = entrypoint + stext_offset; + jump_kernel_func jump_kernel = (jump_kernel_func)kernel_entry; + + /* + * Jump to real kernel here with following constraints. + * 1. MMU should be disabled. + * 2. a0 should contain hartid + * 3. a1 should DT address + */ + csr_write(CSR_SATP, 0); + jump_kernel(hartid, fdt); +} + +efi_status_t handle_kernel_image(unsigned long *image_addr, + unsigned long *image_size, + unsigned long *reserve_addr, + unsigned long *reserve_size, + efi_loaded_image_t *image) +{ + unsigned long kernel_size = 0; + unsigned long preferred_addr; + efi_status_t status; + + kernel_size = _edata - _start; + *image_addr = (unsigned long)_start; + *image_size = kernel_size + (_end - _edata); + + /* + * RISC-V kernel maps PAGE_OFFSET virtual address to the same physical + * address where kernel is booted. That's why kernel should boot from + * as low as possible to avoid wastage of memory. Currently, dram_base + * is occupied by the firmware. So the preferred address for kernel to + * boot is next aligned address. If preferred address is not available, + * relocate_kernel will fall back to efi_low_alloc_above to allocate + * lowest possible memory region as long as the address and size meets + * the alignment constraints. + */ + preferred_addr = MIN_KIMG_ALIGN; + status = efi_relocate_kernel(image_addr, kernel_size, *image_size, + preferred_addr, MIN_KIMG_ALIGN, 0x0); + + if (status != EFI_SUCCESS) { + efi_err("Failed to relocate kernel\n"); + *image_size = 0; + } + return status; +} 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 <linux/dmi.h> +#include <linux/efi.h> +#include <linux/io.h> +#include <linux/memblock.h> +#include <linux/mm_types.h> +#include <linux/preempt.h> +#include <linux/rbtree.h> +#include <linux/rwsem.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/pgtable.h> + +#include <asm/cacheflush.h> +#include <asm/efi.h> +#include <asm/mmu.h> +#include <asm/pgalloc.h> + +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(); +} |