[PATCH v2 3/3] s390/kdump: Use vmcore for zfcpdump
Michael Holzheu
holzheu at linux.vnet.ibm.com
Wed May 22 13:58:37 EDT 2013
From: Jan Willeke <willeke at de.ibm.com>
This patch modifies the s390 copy_oldmem_page() function for zfcpdump
to read from the HSA memory if memory below HSA_SIZE bytes is requested.
Otherwise from real memory is read.
Signed-off-by: Jan Willeke <willeke at de.ibm.com>
Signed-off-by: Michael Holzheu <holzheu at linux.vnet.ibm.com>
---
arch/s390/Kconfig | 3 +-
arch/s390/include/asm/sclp.h | 1 +
arch/s390/kernel/crash_dump.c | 74 ++++++++++++++++++++++++++++++++++---------
drivers/s390/char/zcore.c | 6 ++--
4 files changed, 65 insertions(+), 19 deletions(-)
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 2c9789d..a0d78f1 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -516,6 +516,7 @@ 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
@@ -526,7 +527,7 @@ 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 06a1361..7dc7f9c 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 4fe7fa7..40373b3 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)))
@@ -24,6 +25,25 @@
static size_t elfcorebuf_sz;
static char *elfcorebuf;
+/* 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)
+{
+ if (src < ZFCPDUMP_HSA_SIZE) {
+ if (memcpy_hsa(buf, src, csize, userbuf) < 0)
+ return -EINVAL;
+ } else {
+ if (userbuf)
+ copy_to_user_real((void __force __user *) buf,
+ (void *) src, csize);
+ else
+ memcpy_real(buf, (void *) src, csize);
+ }
+ return csize;
+}
+
/*
* Copy one page from "oldmem"
*
@@ -31,15 +51,10 @@ static char *elfcorebuf;
* - [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)
-{
- unsigned long src;
+static ssize_t copy_oldmem_page_kdump(char *buf, size_t csize,
+ unsigned long src, int userbuf)
- if (!csize)
- return 0;
-
- src = (pfn << PAGE_SHIFT) + offset;
+{
if (src < OLDMEM_SIZE)
src += OLDMEM_BASE;
else if (src > OLDMEM_BASE &&
@@ -54,6 +69,23 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
}
/*
+ * 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);
+}
+
+/*
* Copy memory from old kernel
*/
int copy_from_oldmem(void *dest, void *src, size_t count)
@@ -61,11 +93,21 @@ 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);
}
@@ -448,7 +490,9 @@ void arch_free_crash_header(void)
*/
static int setup_kdump_elfcorehdr(void)
{
- if (!OLDMEM_BASE || is_kdump_kernel())
+ if (!OLDMEM_BASE || (ipl_info.type != IPL_TYPE_FCP_DUMP))
+ return -EINVAL;
+ if (is_kdump_kernel())
return -EINVAL;
arch_vmcore_get_elf_hdr(&elfcorebuf, &elfcorebuf_sz);
elfcorehdr_addr = ELFCORE_ADDR_NEWMEM;
@@ -456,4 +500,4 @@ static int setup_kdump_elfcorehdr(void)
return 0;
}
-subsys_initcall(setup_kdump_elfcorehdr);
+subsys_initcall_sync(setup_kdump_elfcorehdr);
diff --git a/drivers/s390/char/zcore.c b/drivers/s390/char/zcore.c
index 9e5e146..794820a 100644
--- a/drivers/s390/char/zcore.c
+++ b/drivers/s390/char/zcore.c
@@ -30,8 +30,8 @@
#define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
-#define TO_USER 0
-#define TO_KERNEL 1
+#define TO_USER 1
+#define TO_KERNEL 0
#define CHUNK_INFO_SIZE 34 /* 2 16-byte char, each followed by blank */
enum arch_id {
@@ -73,7 +73,7 @@ static struct ipl_parameter_block *ipl_block;
* @count: Size of buffer, which should be copied
* @mode: Either TO_KERNEL or TO_USER
*/
-static int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)
+int memcpy_hsa(void *dest, unsigned long src, size_t count, int mode)
{
int offs, blk_num;
static char buf[PAGE_SIZE] __attribute__((__aligned__(PAGE_SIZE)));
--
1.8.1.6
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