[S390] kernel: Add OS info memory interface

In order to allow kdump based stand-alone dump, some information has to be passed from the old kernel to the new dump kernel. This is done via a the struct "os_info" that contains the following fields: * crashkernel base and size * reipl block * vmcoreinfo * init function A pointer to os_info is stored at a well known storage location and the whole structure as well as all fields are secured with checksums. Signed-off-by: Michael Holzheu <[email protected]> Signed-off-by: Martin Schwidefsky <[email protected]>
MARV1S · Mar 11, 2012 · 4857d4b · 4857d4b
1 parent ad252ff
commit 4857d4b
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Showing 8 changed files with 304 additions and 20 deletions.
diff --git a/arch/s390/include/asm/lowcore.h b/arch/s390/include/asm/lowcore.h
@@ -154,7 +154,9 @@ struct _lowcore {
 	__u32	ipib;				/* 0x0e00 */
 	__u32	ipib_checksum;			/* 0x0e04 */
 	__u32	vmcore_info;			/* 0x0e08 */
-	__u8	pad_0x0e0c[0x0f00-0x0e0c];	/* 0x0e0c */
+	__u8	pad_0x0e0c[0x0e18-0x0e0c];	/* 0x0e0c */
+	__u32	os_info;			/* 0x0e18 */
+	__u8	pad_0x0e1c[0x0f00-0x0e1c];	/* 0x0e1c */
 
 	/* Extended facility list */
 	__u64	stfle_fac_list[32];		/* 0x0f00 */
@@ -301,7 +303,9 @@ struct _lowcore {
 	__u64	ipib;				/* 0x0e00 */
 	__u32	ipib_checksum;			/* 0x0e08 */
 	__u64	vmcore_info;			/* 0x0e0c */
-	__u8	pad_0x0e14[0x0f00-0x0e14];	/* 0x0e14 */
+	__u8	pad_0x0e14[0x0e18-0x0e14];	/* 0x0e14 */
+	__u64	os_info;			/* 0x0e18 */
+	__u8	pad_0x0e20[0x0f00-0x0e20];	/* 0x0e20 */
 
 	/* Extended facility list */
 	__u64	stfle_fac_list[32];		/* 0x0f00 */

diff --git a/arch/s390/include/asm/os_info.h b/arch/s390/include/asm/os_info.h
@@ -0,0 +1,50 @@
+/*
+ * OS info memory interface
+ *
+ * Copyright IBM Corp. 2012
+ * Author(s): Michael Holzheu <[email protected]>
+ */
+#ifndef _ASM_S390_OS_INFO_H
+#define _ASM_S390_OS_INFO_H
+
+#define OS_INFO_VERSION_MAJOR	1
+#define OS_INFO_VERSION_MINOR	1
+#define OS_INFO_MAGIC		0x4f53494e464f535aULL /* OSINFOSZ */
+
+#define OS_INFO_VMCOREINFO	0
+#define OS_INFO_REIPL_BLOCK	1
+#define OS_INFO_INIT_FN		2
+
+struct os_info_entry {
+	u64	addr;
+	u64	size;
+	u32	csum;
+} __packed;
+
+struct os_info {
+	u64	magic;
+	u32	csum;
+	u16	version_major;
+	u16	version_minor;
+	u64	crashkernel_addr;
+	u64	crashkernel_size;
+	struct os_info_entry entry[3];
+	u8	reserved[4004];
+} __packed;
+
+void os_info_init(void);
+void os_info_entry_add(int nr, void *ptr, u64 len);
+void os_info_crashkernel_add(unsigned long base, unsigned long size);
+u32 os_info_csum(struct os_info *os_info);
+
+#ifdef CONFIG_CRASH_DUMP
+void *os_info_old_entry(int nr, unsigned long *size);
+int copy_from_oldmem(void *dest, void *src, size_t count);
+#else
+static inline void *os_info_old_entry(int nr, unsigned long *size)
+{
+	return NULL;
+}
+#endif
+
+#endif /* _ASM_S390_OS_INFO_H */
diff --git a/arch/s390/kernel/Makefile b/arch/s390/kernel/Makefile
@@ -23,7 +23,7 @@ CFLAGS_sysinfo.o += -Iinclude/math-emu -Iarch/s390/math-emu -w
 obj-y	:=  bitmap.o traps.o time.o process.o base.o early.o setup.o vtime.o \
 	    processor.o sys_s390.o ptrace.o signal.o cpcmd.o ebcdic.o nmi.o \
 	    debug.o irq.o ipl.o dis.o diag.o mem_detect.o sclp.o vdso.o \
-	    sysinfo.o jump_label.o lgr.o
+	    sysinfo.o jump_label.o lgr.o os_info.o
 
 obj-y	+= $(if $(CONFIG_64BIT),entry64.o,entry.o)
 obj-y	+= $(if $(CONFIG_64BIT),reipl64.o,reipl.o)

diff --git a/arch/s390/kernel/crash_dump.c b/arch/s390/kernel/crash_dump.c
@@ -14,6 +14,7 @@
 #include <linux/bootmem.h>
 #include <linux/elf.h>
 #include <asm/ipl.h>
+#include <asm/os_info.h>
 
 #define PTR_ADD(x, y) (((char *) (x)) + ((unsigned long) (y)))
 #define PTR_SUB(x, y) (((char *) (x)) - ((unsigned long) (y)))
@@ -51,7 +52,7 @@ ssize_t copy_oldmem_page(unsigned long pfn, char *buf,
 /*
  * Copy memory from old kernel
  */
-static int copy_from_oldmem(void *dest, void *src, size_t count)
+int copy_from_oldmem(void *dest, void *src, size_t count)
 {
 	unsigned long copied = 0;
 	int rc;
@@ -224,28 +225,44 @@ static void *nt_prpsinfo(void *ptr)
 }
 
 /*
- * Initialize vmcoreinfo note (new kernel)
+ * Get vmcoreinfo using lowcore->vmcore_info (new kernel)
  */
-static void *nt_vmcoreinfo(void *ptr)
+static void *get_vmcoreinfo_old(unsigned long *size)
 {
 	char nt_name[11], *vmcoreinfo;
 	Elf64_Nhdr note;
 	void *addr;
 
 	if (copy_from_oldmem(&addr, &S390_lowcore.vmcore_info, sizeof(addr)))
-		return ptr;
+		return NULL;
 	memset(nt_name, 0, sizeof(nt_name));
 	if (copy_from_oldmem(&note, addr, sizeof(note)))
-		return ptr;
+		return NULL;
 	if (copy_from_oldmem(nt_name, addr + sizeof(note), sizeof(nt_name) - 1))
-		return ptr;
+		return NULL;
 	if (strcmp(nt_name, "VMCOREINFO") != 0)
-		return ptr;
-	vmcoreinfo = kzalloc_panic(note.n_descsz + 1);
+		return NULL;
+	vmcoreinfo = kzalloc_panic(note.n_descsz);
 	if (copy_from_oldmem(vmcoreinfo, addr + 24, note.n_descsz))
+		return NULL;
+	*size = note.n_descsz;
+	return vmcoreinfo;
+}
+
+/*
+ * Initialize vmcoreinfo note (new kernel)
+ */
+static void *nt_vmcoreinfo(void *ptr)
+{
+	unsigned long size;
+	void *vmcoreinfo;
+
+	vmcoreinfo = os_info_old_entry(OS_INFO_VMCOREINFO, &size);
+	if (!vmcoreinfo)
+		vmcoreinfo = get_vmcoreinfo_old(&size);
+	if (!vmcoreinfo)
 		return ptr;
-	vmcoreinfo[note.n_descsz + 1] = 0;
-	return nt_init(ptr, 0, vmcoreinfo, note.n_descsz, "VMCOREINFO");
+	return nt_init(ptr, 0, vmcoreinfo, size, "VMCOREINFO");
 }
 
 /*

diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
@@ -28,6 +28,7 @@
 #include <asm/sclp.h>
 #include <asm/checksum.h>
 #include <asm/debug.h>
+#include <asm/os_info.h>
 #include "entry.h"
 
 #define IPL_PARM_BLOCK_VERSION 0
@@ -951,6 +952,13 @@ static struct attribute_group reipl_nss_attr_group = {
 	.attrs = reipl_nss_attrs,
 };
 
+static void set_reipl_block_actual(struct ipl_parameter_block *reipl_block)
+{
+	reipl_block_actual = reipl_block;
+	os_info_entry_add(OS_INFO_REIPL_BLOCK, reipl_block_actual,
+			  reipl_block->hdr.len);
+}
+
 /* reipl type */
 
 static int reipl_set_type(enum ipl_type type)
@@ -966,7 +974,7 @@ static int reipl_set_type(enum ipl_type type)
 			reipl_method = REIPL_METHOD_CCW_VM;
 		else
 			reipl_method = REIPL_METHOD_CCW_CIO;
-		reipl_block_actual = reipl_block_ccw;
+		set_reipl_block_actual(reipl_block_ccw);
 		break;
 	case IPL_TYPE_FCP:
 		if (diag308_set_works)
@@ -975,7 +983,7 @@ static int reipl_set_type(enum ipl_type type)
 			reipl_method = REIPL_METHOD_FCP_RO_VM;
 		else
 			reipl_method = REIPL_METHOD_FCP_RO_DIAG;
-		reipl_block_actual = reipl_block_fcp;
+		set_reipl_block_actual(reipl_block_fcp);
 		break;
 	case IPL_TYPE_FCP_DUMP:
 		reipl_method = REIPL_METHOD_FCP_DUMP;
@@ -985,7 +993,7 @@ static int reipl_set_type(enum ipl_type type)
 			reipl_method = REIPL_METHOD_NSS_DIAG;
 		else
 			reipl_method = REIPL_METHOD_NSS;
-		reipl_block_actual = reipl_block_nss;
+		set_reipl_block_actual(reipl_block_nss);
 		break;
 	case IPL_TYPE_UNKNOWN:
 		reipl_method = REIPL_METHOD_DEFAULT;
@@ -1257,6 +1265,29 @@ static int __init reipl_fcp_init(void)
 	return 0;
 }
 
+static int __init reipl_type_init(void)
+{
+	enum ipl_type reipl_type = ipl_info.type;
+	struct ipl_parameter_block *reipl_block;
+	unsigned long size;
+
+	reipl_block = os_info_old_entry(OS_INFO_REIPL_BLOCK, &size);
+	if (!reipl_block)
+		goto out;
+	/*
+	 * If we have an OS info reipl block, this will be used
+	 */
+	if (reipl_block->hdr.pbt == DIAG308_IPL_TYPE_FCP) {
+		memcpy(reipl_block_fcp, reipl_block, size);
+		reipl_type = IPL_TYPE_FCP;
+	} else if (reipl_block->hdr.pbt == DIAG308_IPL_TYPE_CCW) {
+		memcpy(reipl_block_ccw, reipl_block, size);
+		reipl_type = IPL_TYPE_CCW;
+	}
+out:
+	return reipl_set_type(reipl_type);
+}
+
 static int __init reipl_init(void)
 {
 	int rc;
@@ -1278,10 +1309,7 @@ static int __init reipl_init(void)
 	rc = reipl_nss_init();
 	if (rc)
 		return rc;
-	rc = reipl_set_type(ipl_info.type);
-	if (rc)
-		return rc;
-	return 0;
+	return reipl_type_init();
 }
 
 static struct shutdown_action __refdata reipl_action = {