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author | Palmer Dabbelt <palmer@dabbelt.com> | 2017-07-11 03:00:26 +0200 |
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committer | Palmer Dabbelt <palmer@dabbelt.com> | 2017-09-27 00:26:44 +0200 |
commit | 76d2a0493a17d4c8ecc781366850c3c4f8e1a446 (patch) | |
tree | 5612f17472f4f3bd6fb49e217cb998f5c32836c4 /arch/riscv/kernel/setup.c | |
parent | dt-bindings: RISC-V CPU Bindings (diff) | |
download | linux-76d2a0493a17d4c8ecc781366850c3c4f8e1a446.tar.xz linux-76d2a0493a17d4c8ecc781366850c3c4f8e1a446.zip |
RISC-V: Init and Halt Code
This contains the various __init C functions, the initial assembly
kernel entry point, and the code to reset the system. When a file was
init-related this patch contains the entire file.
Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
Diffstat (limited to 'arch/riscv/kernel/setup.c')
-rw-r--r-- | arch/riscv/kernel/setup.c | 257 |
1 files changed, 257 insertions, 0 deletions
diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c new file mode 100644 index 000000000000..de7db114c315 --- /dev/null +++ b/arch/riscv/kernel/setup.c @@ -0,0 +1,257 @@ +/* + * Copyright (C) 2009 Sunplus Core Technology Co., Ltd. + * Chen Liqin <liqin.chen@sunplusct.com> + * Lennox Wu <lennox.wu@sunplusct.com> + * Copyright (C) 2012 Regents of the University of California + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, see the file COPYING, or write + * to the Free Software Foundation, Inc., + */ + +#include <linux/init.h> +#include <linux/mm.h> +#include <linux/memblock.h> +#include <linux/sched.h> +#include <linux/initrd.h> +#include <linux/console.h> +#include <linux/screen_info.h> +#include <linux/of_fdt.h> +#include <linux/of_platform.h> +#include <linux/sched/task.h> + +#include <asm/setup.h> +#include <asm/sections.h> +#include <asm/pgtable.h> +#include <asm/smp.h> +#include <asm/sbi.h> +#include <asm/tlbflush.h> +#include <asm/thread_info.h> + +#ifdef CONFIG_HVC_RISCV_SBI +#include <asm/hvc_riscv_sbi.h> +#endif + +#ifdef CONFIG_DUMMY_CONSOLE +struct screen_info screen_info = { + .orig_video_lines = 30, + .orig_video_cols = 80, + .orig_video_mode = 0, + .orig_video_ega_bx = 0, + .orig_video_isVGA = 1, + .orig_video_points = 8 +}; +#endif + +#ifdef CONFIG_CMDLINE_BOOL +static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE; +#endif /* CONFIG_CMDLINE_BOOL */ + +unsigned long va_pa_offset; +unsigned long pfn_base; + +/* The lucky hart to first increment this variable will boot the other cores */ +atomic_t hart_lottery; + +#ifdef CONFIG_BLK_DEV_INITRD +static void __init setup_initrd(void) +{ + extern char __initramfs_start[]; + extern unsigned long __initramfs_size; + unsigned long size; + + if (__initramfs_size > 0) { + initrd_start = (unsigned long)(&__initramfs_start); + initrd_end = initrd_start + __initramfs_size; + } + + if (initrd_start >= initrd_end) { + printk(KERN_INFO "initrd not found or empty"); + goto disable; + } + if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { + printk(KERN_ERR "initrd extends beyond end of memory"); + goto disable; + } + + size = initrd_end - initrd_start; + memblock_reserve(__pa(initrd_start), size); + initrd_below_start_ok = 1; + + printk(KERN_INFO "Initial ramdisk at: 0x%p (%lu bytes)\n", + (void *)(initrd_start), size); + return; +disable: + pr_cont(" - disabling initrd\n"); + initrd_start = 0; + initrd_end = 0; +} +#endif /* CONFIG_BLK_DEV_INITRD */ + +pgd_t swapper_pg_dir[PTRS_PER_PGD] __page_aligned_bss; +pgd_t trampoline_pg_dir[PTRS_PER_PGD] __initdata __aligned(PAGE_SIZE); + +#ifndef __PAGETABLE_PMD_FOLDED +#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); +#endif + +asmlinkage void __init setup_vm(void) +{ + extern char _start; + uintptr_t i; + uintptr_t pa = (uintptr_t) &_start; + pgprot_t prot = __pgprot(pgprot_val(PAGE_KERNEL) | _PAGE_EXEC); + + va_pa_offset = PAGE_OFFSET - pa; + pfn_base = PFN_DOWN(pa); + + /* Sanity check alignment and size */ + BUG_ON((PAGE_OFFSET % PGDIR_SIZE) != 0); + BUG_ON((pa % (PAGE_SIZE * PTRS_PER_PTE)) != 0); + +#ifndef __PAGETABLE_PMD_FOLDED + trampoline_pg_dir[(PAGE_OFFSET >> PGDIR_SHIFT) % PTRS_PER_PGD] = + pfn_pgd(PFN_DOWN((uintptr_t)trampoline_pmd), + __pgprot(_PAGE_TABLE)); + trampoline_pmd[0] = pfn_pmd(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((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); +#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); + } +#endif +} + +void __init sbi_save(unsigned int hartid, void *dtb) +{ + early_init_dt_scan(__va(dtb)); +} + +/* + * Allow the user to manually add a memory region (in case DTS is broken); + * "mem_end=nn[KkMmGg]" + */ +static int __init mem_end_override(char *p) +{ + resource_size_t base, end; + + if (!p) + return -EINVAL; + base = (uintptr_t) __pa(PAGE_OFFSET); + end = memparse(p, &p) & PMD_MASK; + if (end == 0) + return -EINVAL; + memblock_add(base, end - base); + return 0; +} +early_param("mem_end", mem_end_override); + +static void __init setup_bootmem(void) +{ + struct memblock_region *reg; + phys_addr_t mem_size = 0; + + /* Find the memory region containing the kernel */ + for_each_memblock(memory, reg) { + phys_addr_t vmlinux_end = __pa(_end); + phys_addr_t end = reg->base + reg->size; + + if (reg->base <= vmlinux_end && vmlinux_end <= end) { + /* + * Reserve from the start of the region to the end of + * the kernel + */ + memblock_reserve(reg->base, vmlinux_end - reg->base); + mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); + } + } + BUG_ON(mem_size == 0); + + set_max_mapnr(PFN_DOWN(mem_size)); + max_low_pfn = pfn_base + PFN_DOWN(mem_size); + +#ifdef CONFIG_BLK_DEV_INITRD + setup_initrd(); +#endif /* CONFIG_BLK_DEV_INITRD */ + + early_init_fdt_reserve_self(); + early_init_fdt_scan_reserved_mem(); + memblock_allow_resize(); + memblock_dump_all(); +} + +void __init setup_arch(char **cmdline_p) +{ +#if defined(CONFIG_HVC_RISCV_SBI) + if (likely(early_console == NULL)) { + early_console = &riscv_sbi_early_console_dev; + register_console(early_console); + } +#endif + +#ifdef CONFIG_CMDLINE_BOOL +#ifdef CONFIG_CMDLINE_OVERRIDE + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); +#else + if (builtin_cmdline[0] != '\0') { + /* Append bootloader command line to built-in */ + strlcat(builtin_cmdline, " ", COMMAND_LINE_SIZE); + strlcat(builtin_cmdline, boot_command_line, COMMAND_LINE_SIZE); + strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); + } +#endif /* CONFIG_CMDLINE_OVERRIDE */ +#endif /* CONFIG_CMDLINE_BOOL */ + *cmdline_p = boot_command_line; + + parse_early_param(); + + init_mm.start_code = (unsigned long) _stext; + init_mm.end_code = (unsigned long) _etext; + init_mm.end_data = (unsigned long) _edata; + init_mm.brk = (unsigned long) _end; + + setup_bootmem(); + paging_init(); + unflatten_device_tree(); + +#ifdef CONFIG_SMP + setup_smp(); +#endif + +#ifdef CONFIG_DUMMY_CONSOLE + conswitchp = &dummy_con; +#endif + + riscv_fill_hwcap(); +} + +static int __init riscv_device_init(void) +{ + return of_platform_populate(NULL, of_default_bus_match_table, NULL, NULL); +} +subsys_initcall_sync(riscv_device_init); |