diff options
| -rw-r--r-- | arch/i386/mm/highmem.c | 18 | ||||
| -rw-r--r-- | include/asm-i386/highmem.h | 1 | ||||
| -rw-r--r-- | include/linux/crash_dump.h | 13 | ||||
| -rw-r--r-- | include/linux/highmem.h | 1 | ||||
| -rw-r--r-- | kernel/Makefile | 1 | ||||
| -rw-r--r-- | kernel/crash_dump.c | 49 |
6 files changed, 83 insertions, 0 deletions
diff --git a/arch/i386/mm/highmem.c b/arch/i386/mm/highmem.c index 4b7aaf9..b6eb4dc 100644 --- a/arch/i386/mm/highmem.c +++ b/arch/i386/mm/highmem.c @@ -75,6 +75,24 @@ void kunmap_atomic(void *kvaddr, enum km_type type) preempt_check_resched(); } +/* This is the same as kmap_atomic() but can map memory that doesn't + * have a struct page associated with it. + */ +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type) +{ + enum fixed_addresses idx; + unsigned long vaddr; + + inc_preempt_count(); + + idx = type + KM_TYPE_NR*smp_processor_id(); + vaddr = __fix_to_virt(FIX_KMAP_BEGIN + idx); + set_pte(kmap_pte-idx, pfn_pte(pfn, kmap_prot)); + __flush_tlb_one(vaddr); + + return (void*) vaddr; +} + struct page *kmap_atomic_to_page(void *ptr) { unsigned long idx, vaddr = (unsigned long)ptr; diff --git a/include/asm-i386/highmem.h b/include/asm-i386/highmem.h index 1df42bf..0fd3313 100644 --- a/include/asm-i386/highmem.h +++ b/include/asm-i386/highmem.h @@ -70,6 +70,7 @@ void *kmap(struct page *page); void kunmap(struct page *page); void *kmap_atomic(struct page *page, enum km_type type); void kunmap_atomic(void *kvaddr, enum km_type type); +void *kmap_atomic_pfn(unsigned long pfn, enum km_type type); struct page *kmap_atomic_to_page(void *ptr); #define flush_cache_kmaps() do { } while (0) diff --git a/include/linux/crash_dump.h b/include/linux/crash_dump.h new file mode 100644 index 0000000..7d983b8 --- /dev/null +++ b/include/linux/crash_dump.h @@ -0,0 +1,13 @@ +#ifndef LINUX_CRASH_DUMP_H +#define LINUX_CRASH_DUMP_H + +#ifdef CONFIG_CRASH_DUMP +#include <linux/kexec.h> +#include <linux/smp_lock.h> +#include <linux/device.h> +#include <linux/proc_fs.h> + +extern ssize_t copy_oldmem_page(unsigned long, char *, size_t, + unsigned long, int); +#endif /* CONFIG_CRASH_DUMP */ +#endif /* LINUX_CRASHDUMP_H */ diff --git a/include/linux/highmem.h b/include/linux/highmem.h index 2a7e6c6..6bece92 100644 --- a/include/linux/highmem.h +++ b/include/linux/highmem.h @@ -28,6 +28,7 @@ static inline void *kmap(struct page *page) #define kmap_atomic(page, idx) page_address(page) #define kunmap_atomic(addr, idx) do { } while (0) +#define kmap_atomic_pfn(pfn, idx) page_address(pfn_to_page(pfn)) #define kmap_atomic_to_page(ptr) virt_to_page(ptr) #endif /* CONFIG_HIGHMEM */ diff --git a/kernel/Makefile b/kernel/Makefile index cfc8b0d..cb05cd0 100644 --- a/kernel/Makefile +++ b/kernel/Makefile @@ -28,6 +28,7 @@ obj-$(CONFIG_AUDITSYSCALL) += auditsc.o obj-$(CONFIG_KPROBES) += kprobes.o obj-$(CONFIG_SYSFS) += ksysfs.o obj-$(CONFIG_GENERIC_HARDIRQS) += irq/ +obj-$(CONFIG_CRASH_DUMP) += crash_dump.o obj-$(CONFIG_SECCOMP) += seccomp.o ifneq ($(CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER),y) diff --git a/kernel/crash_dump.c b/kernel/crash_dump.c new file mode 100644 index 0000000..5a1e6d5 --- /dev/null +++ b/kernel/crash_dump.c @@ -0,0 +1,49 @@ +/* + * kernel/crash_dump.c - Memory preserving reboot related code. + * + * Created by: Hariprasad Nellitheertha (hari@in.ibm.com) + * Copyright (C) IBM Corporation, 2004. All rights reserved + */ + +#include <linux/smp_lock.h> +#include <linux/errno.h> +#include <linux/proc_fs.h> +#include <linux/bootmem.h> +#include <linux/highmem.h> +#include <linux/crash_dump.h> + +#include <asm/io.h> +#include <asm/uaccess.h> + +/* + * 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 *page, *vaddr; + + if (!csize) + return 0; + + page = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!page) + return -ENOMEM; + + vaddr = kmap_atomic_pfn(pfn, KM_PTE0); + copy_page(page, vaddr); + kunmap_atomic(vaddr, KM_PTE0); + + if (userbuf) { + if (copy_to_user(buf, (page + offset), csize)) { + kfree(page); + return -EFAULT; + } + } else { + memcpy(buf, (page + offset), csize); + } + + kfree(page); + return csize; +} |