10cc4746cSMichael Ellerman /* 20cc4746cSMichael Ellerman * Routines for doing kexec-based kdump. 30cc4746cSMichael Ellerman * 40cc4746cSMichael Ellerman * Copyright (C) 2005, IBM Corp. 50cc4746cSMichael Ellerman * 60cc4746cSMichael Ellerman * Created by: Michael Ellerman 70cc4746cSMichael Ellerman * 80cc4746cSMichael Ellerman * This source code is licensed under the GNU General Public License, 90cc4746cSMichael Ellerman * Version 2. See the file COPYING for more details. 100cc4746cSMichael Ellerman */ 110cc4746cSMichael Ellerman 120cc4746cSMichael Ellerman #undef DEBUG 130cc4746cSMichael Ellerman 14cc532915SMichael Ellerman #include <linux/crash_dump.h> 15cc532915SMichael Ellerman #include <linux/bootmem.h> 16edcee77fSMichael Ellerman #include <linux/io.h> 1795f72d1eSYinghai Lu #include <linux/memblock.h> 18aaddd3eaSMichael Ellerman #include <asm/code-patching.h> 190cc4746cSMichael Ellerman #include <asm/kdump.h> 20d9b2b2a2SDavid S. Miller #include <asm/prom.h> 210cc4746cSMichael Ellerman #include <asm/firmware.h> 2254c32021SMichael Ellerman #include <asm/uaccess.h> 23d72e063bSAnton Blanchard #include <asm/rtas.h> 240cc4746cSMichael Ellerman 250cc4746cSMichael Ellerman #ifdef DEBUG 260cc4746cSMichael Ellerman #include <asm/udbg.h> 270cc4746cSMichael Ellerman #define DBG(fmt...) udbg_printf(fmt) 280cc4746cSMichael Ellerman #else 290cc4746cSMichael Ellerman #define DBG(fmt...) 300cc4746cSMichael Ellerman #endif 310cc4746cSMichael Ellerman 320f890c8dSSuzuki Poulose #ifndef CONFIG_NONSTATIC_KERNEL 33d56c3aaaSStephen Rothwell void __init reserve_kdump_trampoline(void) 3447310413SMichael Ellerman { 3595f72d1eSYinghai Lu memblock_reserve(0, KDUMP_RESERVE_LIMIT); 3647310413SMichael Ellerman } 3747310413SMichael Ellerman 380cc4746cSMichael Ellerman static void __init create_trampoline(unsigned long addr) 390cc4746cSMichael Ellerman { 40e7a57273SMichael Ellerman unsigned int *p = (unsigned int *)addr; 41e7a57273SMichael Ellerman 420cc4746cSMichael Ellerman /* The maximum range of a single instruction branch, is the current 430cc4746cSMichael Ellerman * instruction's address + (32 MB - 4) bytes. For the trampoline we 440cc4746cSMichael Ellerman * need to branch to current address + 32 MB. So we insert a nop at 450cc4746cSMichael Ellerman * the trampoline address, then the next instruction (+ 4 bytes) 460cc4746cSMichael Ellerman * does a branch to (32 MB - 4). The net effect is that when we 470cc4746cSMichael Ellerman * branch to "addr" we jump to ("addr" + 32 MB). Although it requires 480cc4746cSMichael Ellerman * two instructions it doesn't require any registers. 490cc4746cSMichael Ellerman */ 5016c57b36SKumar Gala patch_instruction(p, PPC_INST_NOP); 51e7a57273SMichael Ellerman patch_branch(++p, addr + PHYSICAL_START, 0); 520cc4746cSMichael Ellerman } 530cc4746cSMichael Ellerman 5447310413SMichael Ellerman void __init setup_kdump_trampoline(void) 550cc4746cSMichael Ellerman { 560cc4746cSMichael Ellerman unsigned long i; 570cc4746cSMichael Ellerman 5847310413SMichael Ellerman DBG(" -> setup_kdump_trampoline()\n"); 590cc4746cSMichael Ellerman 600cc4746cSMichael Ellerman for (i = KDUMP_TRAMPOLINE_START; i < KDUMP_TRAMPOLINE_END; i += 8) { 610cc4746cSMichael Ellerman create_trampoline(i); 620cc4746cSMichael Ellerman } 630cc4746cSMichael Ellerman 649e4859efSStephen Rothwell #ifdef CONFIG_PPC_PSERIES 650cc4746cSMichael Ellerman create_trampoline(__pa(system_reset_fwnmi) - PHYSICAL_START); 660cc4746cSMichael Ellerman create_trampoline(__pa(machine_check_fwnmi) - PHYSICAL_START); 679e4859efSStephen Rothwell #endif /* CONFIG_PPC_PSERIES */ 680cc4746cSMichael Ellerman 6947310413SMichael Ellerman DBG(" <- setup_kdump_trampoline()\n"); 700cc4746cSMichael Ellerman } 710f890c8dSSuzuki Poulose #endif /* CONFIG_NONSTATIC_KERNEL */ 72cc532915SMichael Ellerman 737230ced4SMichael Ellerman static size_t copy_oldmem_vaddr(void *vaddr, char *buf, size_t csize, 747230ced4SMichael Ellerman unsigned long offset, int userbuf) 757230ced4SMichael Ellerman { 767230ced4SMichael Ellerman if (userbuf) { 777230ced4SMichael Ellerman if (copy_to_user((char __user *)buf, (vaddr + offset), csize)) 787230ced4SMichael Ellerman return -EFAULT; 797230ced4SMichael Ellerman } else 807230ced4SMichael Ellerman memcpy(buf, (vaddr + offset), csize); 817230ced4SMichael Ellerman 827230ced4SMichael Ellerman return csize; 837230ced4SMichael Ellerman } 847230ced4SMichael Ellerman 8540681b95SMichael Ellerman /** 8654c32021SMichael Ellerman * copy_oldmem_page - copy one page from "oldmem" 8754c32021SMichael Ellerman * @pfn: page frame number to be copied 8854c32021SMichael Ellerman * @buf: target memory address for the copy; this can be in kernel address 8954c32021SMichael Ellerman * space or user address space (see @userbuf) 9054c32021SMichael Ellerman * @csize: number of bytes to copy 9154c32021SMichael Ellerman * @offset: offset in bytes into the page (based on pfn) to begin the copy 9254c32021SMichael Ellerman * @userbuf: if set, @buf is in user address space, use copy_to_user(), 9354c32021SMichael Ellerman * otherwise @buf is in kernel address space, use memcpy(). 9454c32021SMichael Ellerman * 9554c32021SMichael Ellerman * Copy a page from "oldmem". For this page, there is no pte mapped 9654c32021SMichael Ellerman * in the current kernel. We stitch up a pte, similar to kmap_atomic. 9754c32021SMichael Ellerman */ 9854c32021SMichael Ellerman ssize_t copy_oldmem_page(unsigned long pfn, char *buf, 9954c32021SMichael Ellerman size_t csize, unsigned long offset, int userbuf) 10054c32021SMichael Ellerman { 10154c32021SMichael Ellerman void *vaddr; 102f5295bd8SLaurent Dufour phys_addr_t paddr; 10354c32021SMichael Ellerman 10454c32021SMichael Ellerman if (!csize) 10554c32021SMichael Ellerman return 0; 10654c32021SMichael Ellerman 107bbc8e30fSMatthew McClintock csize = min_t(size_t, csize, PAGE_SIZE); 108f5295bd8SLaurent Dufour paddr = pfn << PAGE_SHIFT; 1097230ced4SMichael Ellerman 110f5295bd8SLaurent Dufour if (memblock_is_region_memory(paddr, csize)) { 111f5295bd8SLaurent Dufour vaddr = __va(paddr); 1127230ced4SMichael Ellerman csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); 1137230ced4SMichael Ellerman } else { 114f5295bd8SLaurent Dufour vaddr = __ioremap(paddr, PAGE_SIZE, 0); 1157230ced4SMichael Ellerman csize = copy_oldmem_vaddr(vaddr, buf, csize, offset, userbuf); 11654c32021SMichael Ellerman iounmap(vaddr); 11754c32021SMichael Ellerman } 11854c32021SMichael Ellerman 11954c32021SMichael Ellerman return csize; 12054c32021SMichael Ellerman } 121d72e063bSAnton Blanchard 122d72e063bSAnton Blanchard #ifdef CONFIG_PPC_RTAS 123d72e063bSAnton Blanchard /* 124d72e063bSAnton Blanchard * The crashkernel region will almost always overlap the RTAS region, so 125d72e063bSAnton Blanchard * we have to be careful when shrinking the crashkernel region. 126d72e063bSAnton Blanchard */ 127d72e063bSAnton Blanchard void crash_free_reserved_phys_range(unsigned long begin, unsigned long end) 128d72e063bSAnton Blanchard { 129d72e063bSAnton Blanchard unsigned long addr; 130a29e30efSAnton Blanchard const __be32 *basep, *sizep; 131d72e063bSAnton Blanchard unsigned int rtas_start = 0, rtas_end = 0; 132d72e063bSAnton Blanchard 133d72e063bSAnton Blanchard basep = of_get_property(rtas.dev, "linux,rtas-base", NULL); 134d72e063bSAnton Blanchard sizep = of_get_property(rtas.dev, "rtas-size", NULL); 135d72e063bSAnton Blanchard 136d72e063bSAnton Blanchard if (basep && sizep) { 137a29e30efSAnton Blanchard rtas_start = be32_to_cpup(basep); 138a29e30efSAnton Blanchard rtas_end = rtas_start + be32_to_cpup(sizep); 139d72e063bSAnton Blanchard } 140d72e063bSAnton Blanchard 141d72e063bSAnton Blanchard for (addr = begin; addr < end; addr += PAGE_SIZE) { 142d72e063bSAnton Blanchard /* Does this page overlap with the RTAS region? */ 143d72e063bSAnton Blanchard if (addr <= rtas_end && ((addr + PAGE_SIZE) > rtas_start)) 144d72e063bSAnton Blanchard continue; 145d72e063bSAnton Blanchard 1465d585e5cSJiang Liu free_reserved_page(pfn_to_page(addr >> PAGE_SHIFT)); 147d72e063bSAnton Blanchard } 148d72e063bSAnton Blanchard } 149d72e063bSAnton Blanchard #endif 150