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 +- 8 files changed, 132 insertions(+), 3 deletions(-) create mode 100644 arch/riscv/kernel/efi.c (limited to 'arch/riscv') 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) { -- cgit v1.2.3