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authorMichael Holzheu <holzheu@linux.vnet.ibm.com>2013-09-11 23:24:54 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2013-09-12 00:59:15 +0200
commit6f79d33228fa7cf900826738a39f287cae96cd91 (patch)
tree219851a19eb86c91c77241cb00b3889719fdab23 /arch
parentvmcore: enable /proc/vmcore mmap for s390 (diff)
downloadlinux-6f79d33228fa7cf900826738a39f287cae96cd91.tar.xz
linux-6f79d33228fa7cf900826738a39f287cae96cd91.zip
s390/vmcore: use vmcore for zfcpdump
Modify the s390 copy_oldmem_page() and remap_oldmem_pfn_range() function for zfcpdump to read from the HSA memory if memory below HSA_SIZE bytes is requested. Otherwise real memory is used. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Cc: HATAYAMA Daisuke <d.hatayama@jp.fujitsu.com> Cc: Jan Willeke <willeke@de.ibm.com> Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/s390/Kconfig3
-rw-r--r--arch/s390/include/asm/sclp.h1
-rw-r--r--arch/s390/kernel/crash_dump.c122
3 files changed, 107 insertions, 19 deletions
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index fb2723e8ba65..3ec272859e1e 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -526,6 +526,7 @@ config CRASH_DUMP
bool "kernel crash dumps"
depends on 64BIT && SMP
select KEXEC
+ select ZFCPDUMP
help
Generate crash dump after being started by kexec.
Crash dump kernels are loaded in the main kernel with kexec-tools
@@ -536,7 +537,7 @@ config CRASH_DUMP
config ZFCPDUMP
def_bool n
prompt "zfcpdump support"
- select SMP
+ depends on SMP
help
Select this option if you want to build an zfcpdump enabled kernel.
Refer to <file:Documentation/s390/zfcpdump.txt> for more details on this.
diff --git a/arch/s390/include/asm/sclp.h b/arch/s390/include/asm/sclp.h
index 06a136136047..7dc7f9c63b65 100644
--- a/arch/s390/include/asm/sclp.h
+++ b/arch/s390/include/asm/sclp.h
@@ -56,5 +56,6 @@ bool sclp_has_linemode(void);
bool sclp_has_vt220(void);
int sclp_pci_configure(u32 fid);
int sclp_pci_deconfigure(u32 fid);
+int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode);
#endif /* _ASM_S390_SCLP_H */
diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
index 3e776158b330..c84f33d51f7b 100644
--- a/arch/s390/kernel/crash_dump.c
+++ b/arch/s390/kernel/crash_dump.c
@@ -16,6 +16,7 @@
#include <asm/os_info.h>
#include <asm/elf.h>
#include <asm/ipl.h>
+#include <asm/sclp.h>
#define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
#define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
@@ -69,22 +70,41 @@ static ssize_t copy_page_real(void *buf, void *src, size_t csize)
static void *elfcorehdr_newmem;
/*
- * Copy one page from "oldmem"
+ * Copy one page from zfcpdump "oldmem"
+ *
+ * For pages below ZFCPDUMP_HSA_SIZE memory from the HSA is copied. Otherwise
+ * real memory copy is used.
+ */
+static ssize_t copy_oldmem_page_zfcpdump(char *buf, size_t csize,
+ unsigned long src, int userbuf)
+{
+ int rc;
+
+ if (src < ZFCPDUMP_HSA_SIZE) {
+ rc = memcpy_hsa(buf, src, csize, userbuf);
+ } else {
+ if (userbuf)
+ rc = copy_to_user_real((void __force __user *) buf,
+ (void *) src, csize);
+ else
+ rc = memcpy_real(buf, (void *) src, csize);
+ }
+ return rc ? rc : csize;
+}
+
+/*
+ * Copy one page from kdump "oldmem"
*
* For the kdump reserved memory this functions performs a swap operation:
* - [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE] is mapped to [0 - OLDMEM_SIZE].
* - [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
*/
-ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
- size_t csize, unsigned long offset, int userbuf)
+static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
+ unsigned long src, int userbuf)
+
{
- unsigned long src;
int rc;
- if (!csize)
- return 0;
-
- src = (pfn << PAGE_SHIFT) + offset;
if (src < OLDMEM_SIZE)
src += OLDMEM_BASE;
else if (src > OLDMEM_BASE &&
@@ -95,17 +115,35 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
(void *) src, csize);
else
rc = copy_page_real(buf, (void *) src, csize);
- return (rc == 0) ? csize : rc;
+ return (rc == 0) ? rc : csize;
}
/*
- * Remap "oldmem"
+ * Copy one page from "oldmem"
+ */
+ssize_t copy_oldmem_page(unsigned long pfn, char *buf, size_t csize,
+ unsigned long offset, int userbuf)
+{
+ unsigned long src;
+
+ if (!csize)
+ return 0;
+ src = (pfn << PAGE_SHIFT) + offset;
+ if (OLDMEM_BASE)
+ return copy_oldmem_page_kdump(buf, csize, src, userbuf);
+ else
+ return copy_oldmem_page_zfcpdump(buf, csize, src, userbuf);
+}
+
+/*
+ * Remap "oldmem" for kdump
*
* For the kdump reserved memory this functions performs a swap operation:
* [0 - OLDMEM_SIZE] is mapped to [OLDMEM_BASE - OLDMEM_BASE + OLDMEM_SIZE]
*/
-int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
- unsigned long pfn, unsigned long size, pgprot_t prot)
+static int remap_oldmem_pfn_range_kdump(struct vm_area_struct *vma,
+ unsigned long from, unsigned long pfn,
+ unsigned long size, pgprot_t prot)
{
unsigned long size_old;
int rc;
@@ -125,6 +163,43 @@ int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
}
/*
+ * Remap "oldmem" for zfcpdump
+ *
+ * We only map available memory above ZFCPDUMP_HSA_SIZE. Memory below
+ * ZFCPDUMP_HSA_SIZE is read on demand using the copy_oldmem_page() function.
+ */
+static int remap_oldmem_pfn_range_zfcpdump(struct vm_area_struct *vma,
+ unsigned long from,
+ unsigned long pfn,
+ unsigned long size, pgprot_t prot)
+{
+ unsigned long size_hsa;
+
+ if (pfn < ZFCPDUMP_HSA_SIZE >> PAGE_SHIFT) {
+ size_hsa = min(size, ZFCPDUMP_HSA_SIZE - (pfn << PAGE_SHIFT));
+ if (size == size_hsa)
+ return 0;
+ size -= size_hsa;
+ from += size_hsa;
+ pfn += size_hsa >> PAGE_SHIFT;
+ }
+ return remap_pfn_range(vma, from, pfn, size, prot);
+}
+
+/*
+ * Remap "oldmem" for kdump or zfcpdump
+ */
+int remap_oldmem_pfn_range(struct vm_area_struct *vma, unsigned long from,
+ unsigned long pfn, unsigned long size, pgprot_t prot)
+{
+ if (OLDMEM_BASE)
+ return remap_oldmem_pfn_range_kdump(vma, from, pfn, size, prot);
+ else
+ return remap_oldmem_pfn_range_zfcpdump(vma, from, pfn, size,
+ prot);
+}
+
+/*
* Copy memory from old kernel
*/
int copy_from_oldmem(void *dest, void *src, size_t count)
@@ -132,11 +207,21 @@ int copy_from_oldmem(void *dest, void *src, size_t count)
unsigned long copied = 0;
int rc;
- if ((unsigned long) src < OLDMEM_SIZE) {
- copied = min(count, OLDMEM_SIZE - (unsigned long) src);
- rc = memcpy_real(dest, src + OLDMEM_BASE, copied);
- if (rc)
- return rc;
+ if (OLDMEM_BASE) {
+ if ((unsigned long) src < OLDMEM_SIZE) {
+ copied = min(count, OLDMEM_SIZE - (unsigned long) src);
+ rc = memcpy_real(dest, src + OLDMEM_BASE, copied);
+ if (rc)
+ return rc;
+ }
+ } else {
+ if ((unsigned long) src < ZFCPDUMP_HSA_SIZE) {
+ copied = min(count,
+ ZFCPDUMP_HSA_SIZE - (unsigned long) src);
+ rc = memcpy_hsa(dest, (unsigned long) src, copied, 0);
+ if (rc)
+ return rc;
+ }
}
return memcpy_real(dest + copied, src + copied, count - copied);
}
@@ -466,7 +551,8 @@ int elfcorehdr_alloc(unsigned long long *addr, unsigned long long *size)
u32 alloc_size;
u64 hdr_off;
- if (!OLDMEM_BASE)
+ /* If we are not in kdump or zfcpdump mode return */
+ if (!OLDMEM_BASE && ipl_info.type != IPL_TYPE_FCP_DUMP)
return 0;
/* If elfcorehdr= has been passed via cmdline, we use that one */
if (elfcorehdr_addr != ELFCORE_ADDR_MAX)