From d7071743db31b4f6898b1c742e4b451bb4bc4b02 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Thu, 17 Sep 2020 15:37:14 -0700 Subject: RISC-V: Add EFI stub support. Add a RISC-V architecture specific stub code that actually copies the actual kernel image to a valid address and jump to it after boot services are terminated. Enable UEFI related kernel configs as well for RISC-V. Signed-off-by: Atish Patra Link: https://lore.kernel.org/r/20200421033336.9663-4-atish.patra@wdc.com [ardb: - move hartid fetch into check_platform_features() - use image_size not reserve_size - select ISA_C - do not use dram_base] Signed-off-by: Ard Biesheuvel Signed-off-by: Palmer Dabbelt --- drivers/firmware/efi/Kconfig | 3 +- drivers/firmware/efi/libstub/Makefile | 10 +++ drivers/firmware/efi/libstub/riscv-stub.c | 109 ++++++++++++++++++++++++++++++ 3 files changed, 121 insertions(+), 1 deletion(-) create mode 100644 drivers/firmware/efi/libstub/riscv-stub.c (limited to 'drivers') diff --git a/drivers/firmware/efi/Kconfig b/drivers/firmware/efi/Kconfig index 3939699e62fe..a29fbd6e657e 100644 --- a/drivers/firmware/efi/Kconfig +++ b/drivers/firmware/efi/Kconfig @@ -111,7 +111,7 @@ 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 @@ -128,6 +128,7 @@ 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/libstub/Makefile b/drivers/firmware/efi/libstub/Makefile index 296b18fbd7a2..e9fc2ddabd5f 100644 --- a/drivers/firmware/efi/libstub/Makefile +++ b/drivers/firmware/efi/libstub/Makefile @@ -22,6 +22,8 @@ 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 @@ -63,6 +65,7 @@ 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) CFLAGS_arm64-stub.o := -DTEXT_OFFSET=$(TEXT_OFFSET) @@ -106,6 +109,13 @@ STUBCOPY_FLAGS-$(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/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 +#include + +#include +#include + +#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; +} -- cgit v1.2.3 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 --- arch/riscv/Kconfig | 2 + arch/riscv/include/asm/efi.h | 20 +++++ arch/riscv/include/asm/mmu.h | 2 + arch/riscv/include/asm/pgtable.h | 4 + arch/riscv/kernel/Makefile | 2 + arch/riscv/kernel/efi.c | 96 +++++++++++++++++++++ arch/riscv/kernel/setup.c | 7 +- arch/riscv/mm/init.c | 2 +- drivers/firmware/efi/Makefile | 2 + drivers/firmware/efi/libstub/efi-stub.c | 11 ++- drivers/firmware/efi/riscv-runtime.c | 143 ++++++++++++++++++++++++++++++++ 11 files changed, 287 insertions(+), 4 deletions(-) create mode 100644 arch/riscv/kernel/efi.c create mode 100644 drivers/firmware/efi/riscv-runtime.c (limited to 'drivers') diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 6ef2394be857..c8e57d77c144 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -412,7 +412,9 @@ config EFI select EFI_PARAMS_FROM_FDT select EFI_STUB select EFI_GENERIC_STUB + select EFI_RUNTIME_WRAPPERS select RISCV_ISA_C + depends on MMU default y help This option provides support for runtime services provided diff --git a/arch/riscv/include/asm/efi.h b/arch/riscv/include/asm/efi.h index bf6a40e20a8e..7542282f1141 100644 --- a/arch/riscv/include/asm/efi.h +++ b/arch/riscv/include/asm/efi.h @@ -5,11 +5,28 @@ #ifndef _ASM_EFI_H #define _ASM_EFI_H +#include #include #include #include #include +#ifdef CONFIG_EFI +extern void efi_init(void); +#else +#define efi_init() +#endif + +int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md); +int efi_set_mapping_permissions(struct mm_struct *mm, efi_memory_desc_t *md); + +#define arch_efi_call_virt_setup() efi_virtmap_load() +#define arch_efi_call_virt_teardown() efi_virtmap_unload() + +#define arch_efi_call_virt(p, f, args...) p->f(args) + +#define ARCH_EFI_IRQ_FLAGS_MASK (SR_IE | SR_SPIE) + /* on RISC-V, the FDT may be located anywhere in system RAM */ static inline unsigned long efi_get_max_fdt_addr(unsigned long image_addr) { @@ -32,4 +49,7 @@ static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt) { } +void efi_virtmap_load(void); +void efi_virtmap_unload(void); + #endif /* _ASM_EFI_H */ diff --git a/arch/riscv/include/asm/mmu.h b/arch/riscv/include/asm/mmu.h index 967eacb01ab5..dabcf2cfb3dc 100644 --- a/arch/riscv/include/asm/mmu.h +++ b/arch/riscv/include/asm/mmu.h @@ -20,6 +20,8 @@ typedef struct { #endif } mm_context_t; +void __init create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, + phys_addr_t sz, pgprot_t prot); #endif /* __ASSEMBLY__ */ #endif /* _ASM_RISCV_MMU_H */ diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 815f8c959dd4..183f1f4b2ae6 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -100,6 +100,10 @@ #define PAGE_KERNEL __pgprot(_PAGE_KERNEL) #define PAGE_KERNEL_EXEC __pgprot(_PAGE_KERNEL | _PAGE_EXEC) +#define PAGE_KERNEL_READ __pgprot(_PAGE_KERNEL & ~_PAGE_WRITE) +#define PAGE_KERNEL_EXEC __pgprot(_PAGE_KERNEL | _PAGE_EXEC) +#define PAGE_KERNEL_READ_EXEC __pgprot((_PAGE_KERNEL & ~_PAGE_WRITE) \ + | _PAGE_EXEC) #define PAGE_TABLE __pgprot(_PAGE_TABLE) diff --git a/arch/riscv/kernel/Makefile b/arch/riscv/kernel/Makefile index dc93710f0b2f..fa896c5f7ccb 100644 --- a/arch/riscv/kernel/Makefile +++ b/arch/riscv/kernel/Makefile @@ -55,4 +55,6 @@ obj-$(CONFIG_KGDB) += kgdb.o obj-$(CONFIG_JUMP_LABEL) += jump_label.o +obj-$(CONFIG_EFI) += efi.o + clean: diff --git a/arch/riscv/kernel/efi.c b/arch/riscv/kernel/efi.c new file mode 100644 index 000000000000..024159298231 --- /dev/null +++ b/arch/riscv/kernel/efi.c @@ -0,0 +1,96 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2020 Western Digital Corporation or its affiliates. + * Adapted from arch/arm64/kernel/efi.c + */ + +#include +#include + +#include +#include +#include + +/* + * Only regions of type EFI_RUNTIME_SERVICES_CODE need to be + * executable, everything else can be mapped with the XN bits + * set. Also take the new (optional) RO/XP bits into account. + */ +static __init pgprot_t efimem_to_pgprot_map(efi_memory_desc_t *md) +{ + u64 attr = md->attribute; + u32 type = md->type; + + if (type == EFI_MEMORY_MAPPED_IO) + return PAGE_KERNEL; + + /* R-- */ + if ((attr & (EFI_MEMORY_XP | EFI_MEMORY_RO)) == + (EFI_MEMORY_XP | EFI_MEMORY_RO)) + return PAGE_KERNEL_READ; + + /* R-X */ + if (attr & EFI_MEMORY_RO) + return PAGE_KERNEL_READ_EXEC; + + /* RW- */ + if (((attr & (EFI_MEMORY_RP | EFI_MEMORY_WP | EFI_MEMORY_XP)) == + EFI_MEMORY_XP) || + type != EFI_RUNTIME_SERVICES_CODE) + return PAGE_KERNEL; + + /* RWX */ + return PAGE_KERNEL_EXEC; +} + +int __init efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md) +{ + pgprot_t prot = __pgprot(pgprot_val(efimem_to_pgprot_map(md)) & + ~(_PAGE_GLOBAL)); + int i; + + /* RISC-V maps one page at a time */ + for (i = 0; i < md->num_pages; i++) + create_pgd_mapping(mm->pgd, md->virt_addr + i * PAGE_SIZE, + md->phys_addr + i * PAGE_SIZE, + PAGE_SIZE, prot); + return 0; +} + +static int __init set_permissions(pte_t *ptep, unsigned long addr, void *data) +{ + efi_memory_desc_t *md = data; + pte_t pte = READ_ONCE(*ptep); + unsigned long val; + + if (md->attribute & EFI_MEMORY_RO) { + val = pte_val(pte) & ~_PAGE_WRITE; + val = pte_val(pte) | _PAGE_READ; + pte = __pte(val); + } + if (md->attribute & EFI_MEMORY_XP) { + val = pte_val(pte) & ~_PAGE_EXEC; + pte = __pte(val); + } + set_pte(ptep, pte); + + return 0; +} + +int __init efi_set_mapping_permissions(struct mm_struct *mm, + efi_memory_desc_t *md) +{ + BUG_ON(md->type != EFI_RUNTIME_SERVICES_CODE && + md->type != EFI_RUNTIME_SERVICES_DATA); + + /* + * Calling apply_to_page_range() is only safe on regions that are + * guaranteed to be mapped down to pages. Since we are only called + * for regions that have been mapped using efi_create_mapping() above + * (and this is checked by the generic Memory Attributes table parsing + * routines), there is no need to check that again here. + */ + return apply_to_page_range(mm, md->virt_addr, + md->num_pages << EFI_PAGE_SHIFT, + set_permissions, md); +} diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c index 41ef96d0d97a..4c96ac198e14 100644 --- a/arch/riscv/kernel/setup.c +++ b/arch/riscv/kernel/setup.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include @@ -26,11 +27,12 @@ #include #include #include +#include #include "head.h" -#ifdef CONFIG_DUMMY_CONSOLE -struct screen_info screen_info = { +#if defined(CONFIG_DUMMY_CONSOLE) || defined(CONFIG_EFI) +struct screen_info screen_info __section(.data) = { .orig_video_lines = 30, .orig_video_cols = 80, .orig_video_mode = 0, @@ -75,6 +77,7 @@ void __init setup_arch(char **cmdline_p) early_ioremap_setup(); parse_early_param(); + efi_init(); setup_bootmem(); paging_init(); #if IS_ENABLED(CONFIG_BUILTIN_DTB) diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 63acc8185bfa..c888c4470b34 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -390,7 +390,7 @@ static void __init create_pmd_mapping(pmd_t *pmdp, #define fixmap_pgd_next fixmap_pte #endif -static void __init create_pgd_mapping(pgd_t *pgdp, +void __init create_pgd_mapping(pgd_t *pgdp, uintptr_t va, phys_addr_t pa, phys_addr_t sz, pgprot_t prot) { 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 v1.2.3