From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/powerpc/kernel/crash_dump.c | 148 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 148 insertions(+) create mode 100644 arch/powerpc/kernel/crash_dump.c (limited to 'arch/powerpc/kernel/crash_dump.c') diff --git a/arch/powerpc/kernel/crash_dump.c b/arch/powerpc/kernel/crash_dump.c new file mode 100644 index 000000000..cfa0f81a5 --- /dev/null +++ b/arch/powerpc/kernel/crash_dump.c @@ -0,0 +1,148 @@ +/* + * Routines for doing kexec-based kdump. + * + * Copyright (C) 2005, IBM Corp. + * + * Created by: Michael Ellerman + * + * This source code is licensed under the GNU General Public License, + * Version 2. See the file COPYING for more details. + */ + +#undef DEBUG + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#ifdef DEBUG +#include +#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) +{ + unsigned int *p = (unsigned int *)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_NOP); + patch_branch(++p, 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 */ + +static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize, + unsigned long offset, int userbuf) +{ + if (userbuf) { + if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) + return -EFAULT; + } else + memcpy(buf, (vaddr + offset), csize); + + return csize; +} + +/** + * copy_oldmem_page - copy one page from "oldmem" + * @pfn: page frame number to be copied + * @buf: target memory address for the copy; this can be in kernel address + * space or user address space (see @userbuf) + * @csize: number of bytes to copy + * @offset: offset in bytes into the page (based on pfn) to begin the copy + * @userbuf: if set, @buf is in user address space, use copy_to_user(), + * otherwise @buf is in kernel address space, use memcpy(). + * + * Copy a page from "oldmem". For this page, there is no pte mapped + * in the current kernel. We stitch up a pte, similar to kmap_atomic. + */ +ssize_t copy_oldmem_page(unsigned long pfn, char *buf, + size_t csize, unsigned long offset, int userbuf) +{ + 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_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + } else { + vaddr = __ioremap(paddr, PAGE_SIZE, 0); + csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); + 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 -- cgit v1.2.3-54-g00ecf