diff options
Diffstat (limited to 'arch')
| -rw-r--r-- | arch/riscv/Kconfig | 3 | ||||
| -rw-r--r-- | arch/riscv/include/asm/fixmap.h | 44 | ||||
| -rw-r--r-- | arch/riscv/mm/init.c | 34 |
3 files changed, 81 insertions, 0 deletions
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index b60f4e3e36f4..ceed055179c8 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -89,6 +89,9 @@ config GENERIC_CSUM config GENERIC_HWEIGHT def_bool y +config FIX_EARLYCON_MEM + def_bool y + config PGTABLE_LEVELS int default 3 if 64BIT diff --git a/arch/riscv/include/asm/fixmap.h b/arch/riscv/include/asm/fixmap.h new file mode 100644 index 000000000000..57afe604b495 --- /dev/null +++ b/arch/riscv/include/asm/fixmap.h @@ -0,0 +1,44 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* + * Copyright (C) 2019 Western Digital Corporation or its affiliates. + */ + +#ifndef _ASM_RISCV_FIXMAP_H +#define _ASM_RISCV_FIXMAP_H + +#include <linux/kernel.h> +#include <linux/sizes.h> +#include <asm/page.h> +#include <asm/pgtable.h> + +/* + * Here we define all the compile-time 'special' virtual addresses. + * The point is to have a constant address at compile time, but to + * set the physical address only in the boot process. + * + * These 'compile-time allocated' memory buffers are page-sized. Use + * set_fixmap(idx,phys) to associate physical memory with fixmap indices. + */ +enum fixed_addresses { + FIX_HOLE, + FIX_EARLYCON_MEM_BASE, + __end_of_fixed_addresses +}; + +#define FIXADDR_SIZE (__end_of_fixed_addresses * PAGE_SIZE) +#define FIXADDR_TOP (PAGE_OFFSET) +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + +#define FIXMAP_PAGE_IO PAGE_KERNEL + +#define __early_set_fixmap __set_fixmap + +#define __late_set_fixmap __set_fixmap +#define __late_clear_fixmap(idx) __set_fixmap((idx), 0, FIXMAP_PAGE_CLEAR) + +extern void __set_fixmap(enum fixed_addresses idx, + phys_addr_t phys, pgprot_t prot); + +#include <asm-generic/fixmap.h> + +#endif /* _ASM_RISCV_FIXMAP_H */ diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index ee9cf26b3855..9e7b3ee78089 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -19,6 +19,7 @@ #include <linux/sizes.h> #include <linux/of_fdt.h> +#include <asm/fixmap.h> #include <asm/tlbflush.h> #include <asm/sections.h> #include <asm/pgtable.h> @@ -148,8 +149,28 @@ pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); #define NUM_SWAPPER_PMDS ((uintptr_t)-PAGE_OFFSET >> PGDIR_SHIFT) pmd_t swapper_pmd[PTRS_PER_PMD*((-PAGE_OFFSET)/PGDIR_SIZE)] __page_aligned_bss; pmd_t trampoline_pmd[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); +pmd_t fixmap_pmd[PTRS_PER_PMD] __page_aligned_bss; #endif +pte_t fixmap_pte[PTRS_PER_PTE] __page_aligned_bss; + +void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *ptep; + + BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); + + ptep = &fixmap_pte[pte_index(addr)]; + + if (pgprot_val(prot)) { + set_pte(ptep, pfn_pte(phys >> PAGE_SHIFT, prot)); + } else { + pte_clear(&init_mm, addr, ptep); + local_flush_tlb_page(addr); + } +} + asmlinkage void __init setup_vm(void) { extern char _start; @@ -172,20 +193,33 @@ asmlinkage void __init setup_vm(void) for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) { size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i; + swapper_pg_dir[o] = pfn_pgd(PFN_DOWN((uintptr_t)swapper_pmd) + i, __pgprot(_PAGE_TABLE)); } for (i = 0; i < ARRAY_SIZE(swapper_pmd); i++) swapper_pmd[i] = pfn_pmd(PFN_DOWN(pa + i * PMD_SIZE), prot); + + swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pmd), + __pgprot(_PAGE_TABLE)); + fixmap_pmd[(FIXADDR_START >> PMD_SHIFT) % PTRS_PER_PMD] = + pfn_pmd(PFN_DOWN((uintptr_t)fixmap_pte), + __pgprot(_PAGE_TABLE)); #else trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] = pfn_pgd(PFN_DOWN(pa), prot); for (i = 0; i < (-PAGE_OFFSET)/PGDIR_SIZE; ++i) { size_t o = (PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD + i; + swapper_pg_dir[o] = pfn_pgd(PFN_DOWN(pa + i * PGDIR_SIZE), prot); } + + swapper_pg_dir[(FIXADDR_START >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)fixmap_pte), + __pgprot(_PAGE_TABLE)); #endif } |