diff options
Diffstat (limited to 'arch/powerpc/kernel/crash_dump.c')
| -rw-r--r-- | arch/powerpc/kernel/crash_dump.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c new file mode 100644 index 000000000..9a3b85bfc --- /dev/null +++ b/arch/powerpc/kernel/crash_dump.c @@ -0,0 +1,122 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Routines for doing kexec-based kdump. + * + * Copyright (C) 2005, IBM Corp. + * + * Created by: Michael Ellerman + */ + +#undef DEBUG + +#include <linux/crash_dump.h> +#include <linux/io.h> +#include <linux/memblock.h> +#include <linux/of.h> +#include <asm/code-patching.h> +#include <asm/kdump.h> +#include <asm/firmware.h> +#include <linux/uio.h> +#include <asm/rtas.h> +#include <asm/inst.h> + +#ifdef DEBUG +#include <asm/udbg.h> +#define DBG(fmt...) udbg_printf(fmt) +#else +#define DBG(fmt...) +#endif + +#ifndef CONFIG_NONSTATIC_KERNEL +void __init reserve_kdump_trampoline(void) +{ + memblock_reserve(0, KDUMP_RESERVE_LIMIT); +} + +static void __init create_trampoline(unsigned long addr) +{ + u32 *p = (u32 *)addr; + + /* The maximum range of a single instruction branch, is the current + * instruction's address + (32 MB - 4) bytes. For the trampoline we + * need to branch to current address + 32 MB. So we insert a nop at + * the trampoline address, then the next instruction (+ 4 bytes) + * does a branch to (32 MB - 4). The net effect is that when we + * branch to "addr" we jump to ("addr" + 32 MB). Although it requires + * two instructions it doesn't require any registers. + */ + patch_instruction(p, ppc_inst(PPC_RAW_NOP())); + patch_branch(p + 1, addr + PHYSICAL_START, 0); +} + +void __init setup_kdump_trampoline(void) +{ + unsigned long i; + + DBG(" -> setup_kdump_trampoline()\n"); + + for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) { + create_trampoline(i); + } + +#ifdef CONFIG_PPC_PSERIES + create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START); + create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START); +#endif /* CONFIG_PPC_PSERIES */ + + DBG(" <- setup_kdump_trampoline()\n"); +} +#endif /* CONFIG_NONSTATIC_KERNEL */ + +ssize_t copy_oldmem_page(struct iov_iter *iter, unsigned long pfn, + size_t csize, unsigned long offset) +{ + void *vaddr; + phys_addr_t paddr; + + if (!csize) + return 0; + + csize = min_t(size_t, csize, PAGE_SIZE); + paddr = pfn << PAGE_SHIFT; + + if (memblock_is_region_memory(paddr, csize)) { + vaddr = __va(paddr); + csize = copy_to_iter(vaddr + offset, csize, iter); + } else { + vaddr = ioremap_cache(paddr, PAGE_SIZE); + csize = copy_to_iter(vaddr + offset, csize, iter); + iounmap(vaddr); + } + + return csize; +} + +#ifdef CONFIG_PPC_RTAS +/* + * The crashkernel region will almost always overlap the RTAS region, so + * we have to be careful when shrinking the crashkernel region. + */ +void crash_free_reserved_phys_range(unsigned long begin, unsigned long end) +{ + unsigned long addr; + const __be32 *basep, *sizep; + unsigned int rtas_start = 0, rtas_end = 0; + + basep = of_get_property(rtas.dev, "linux,rtas-base", NULL); + sizep = of_get_property(rtas.dev, "rtas-size", NULL); + + if (basep && sizep) { + rtas_start = be32_to_cpup(basep); + rtas_end = rtas_start + be32_to_cpup(sizep); + } + + for (addr = begin; addr < end; addr += PAGE_SIZE) { + /* Does this page overlap with the RTAS region? */ + if (addr <= rtas_end && ((addr + PAGE_SIZE) > rtas_start)) + continue; + + free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); + } +} +#endif |