1 files changed, 366 insertions, 0 deletions
diff --git a/drivers/s390/char/zcore.c b/drivers/s390/char/zcore.c
new file mode 100644
index 000000000..76d3c50bf
--- /dev/null
+++ b/drivers/s390/char/zcore.c
@@ -0,0 +1,366 @@
+// SPDX-License-Identifier: GPL-1.0+
+/*
+ * zcore module to export memory content and register sets for creating system
+ * dumps on SCSI disks (zfcpdump). The "zcore/mem" debugfs file shows the same
+ * dump format as s390 standalone dumps.
+ *
+ * For more information please refer to Documentation/s390/zfcpdump.txt
+ *
+ * Copyright IBM Corp. 2003, 2008
+ * Author(s): Michael Holzheu
+ */
+
+#define KMSG_COMPONENT "zdump"
+#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
+
+#include <linux/init.h>
+#include <linux/slab.h>
+#include <linux/debugfs.h>
+#include <linux/memblock.h>
+
+#include <asm/asm-offsets.h>
+#include <asm/ipl.h>
+#include <asm/sclp.h>
+#include <asm/setup.h>
+#include <linux/uaccess.h>
+#include <asm/debug.h>
+#include <asm/processor.h>
+#include <asm/irqflags.h>
+#include <asm/checksum.h>
+#include <asm/os_info.h>
+#include <asm/switch_to.h>
+#include "sclp.h"
+
+#define TRACE(x...) debug_sprintf_event(zcore_dbf, 1, x)
+
+#define CHUNK_INFO_SIZE	34 /* 2 16-byte char, each followed by blank */
+
+enum arch_id {
+	ARCH_S390	= 0,
+	ARCH_S390X	= 1,
+};
+
+struct ipib_info {
+	unsigned long	ipib;
+	u32		checksum;
+}  __attribute__((packed));
+
+static struct debug_info *zcore_dbf;
+static int hsa_available;
+static struct dentry *zcore_dir;
+static struct dentry *zcore_memmap_file;
+static struct dentry *zcore_reipl_file;
+static struct dentry *zcore_hsa_file;
+static struct ipl_parameter_block *ipl_block;
+
+static char hsa_buf[PAGE_SIZE] __aligned(PAGE_SIZE);
+
+/*
+ * Copy memory from HSA to user memory (not reentrant):
+ *
+ * @dest:  User buffer where memory should be copied to
+ * @src:   Start address within HSA where data should be copied
+ * @count: Size of buffer, which should be copied
+ */
+int memcpy_hsa_user(void __user *dest, unsigned long src, size_t count)
+{
+	unsigned long offset, bytes;
+
+	if (!hsa_available)
+		return -ENODATA;
+
+	while (count) {
+		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
+			TRACE("sclp_sdias_copy() failed\n");
+			return -EIO;
+		}
+		offset = src % PAGE_SIZE;
+		bytes = min(PAGE_SIZE - offset, count);
+		if (copy_to_user(dest, hsa_buf + offset, bytes))
+			return -EFAULT;
+		src += bytes;
+		dest += bytes;
+		count -= bytes;
+	}
+	return 0;
+}
+
+/*
+ * Copy memory from HSA to kernel memory (not reentrant):
+ *
+ * @dest:  Kernel or user buffer where memory should be copied to
+ * @src:   Start address within HSA where data should be copied
+ * @count: Size of buffer, which should be copied
+ */
+int memcpy_hsa_kernel(void *dest, unsigned long src, size_t count)
+{
+	unsigned long offset, bytes;
+
+	if (!hsa_available)
+		return -ENODATA;
+
+	while (count) {
+		if (sclp_sdias_copy(hsa_buf, src / PAGE_SIZE + 2, 1)) {
+			TRACE("sclp_sdias_copy() failed\n");
+			return -EIO;
+		}
+		offset = src % PAGE_SIZE;
+		bytes = min(PAGE_SIZE - offset, count);
+		memcpy(dest, hsa_buf + offset, bytes);
+		src += bytes;
+		dest += bytes;
+		count -= bytes;
+	}
+	return 0;
+}
+
+static int __init init_cpu_info(void)
+{
+	struct save_area *sa;
+
+	/* get info for boot cpu from lowcore, stored in the HSA */
+	sa = save_area_boot_cpu();
+	if (!sa)
+		return -ENOMEM;
+	if (memcpy_hsa_kernel(hsa_buf, __LC_FPREGS_SAVE_AREA, 512) < 0) {
+		TRACE("could not copy from HSA\n");
+		return -EIO;
+	}
+	save_area_add_regs(sa, hsa_buf); /* vx registers are saved in smp.c */
+	return 0;
+}
+
+/*
+ * Release the HSA
+ */
+static void release_hsa(void)
+{
+	diag308(DIAG308_REL_HSA, NULL);
+	hsa_available = 0;
+}
+
+static ssize_t zcore_memmap_read(struct file *filp, char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	return simple_read_from_buffer(buf, count, ppos, filp->private_data,
+				       memblock.memory.cnt * CHUNK_INFO_SIZE);
+}
+
+static int zcore_memmap_open(struct inode *inode, struct file *filp)
+{
+	struct memblock_region *reg;
+	char *buf;
+	int i = 0;
+
+	buf = kcalloc(memblock.memory.cnt, CHUNK_INFO_SIZE, GFP_KERNEL);
+	if (!buf) {
+		return -ENOMEM;
+	}
+	for_each_memblock(memory, reg) {
+		sprintf(buf + (i++ * CHUNK_INFO_SIZE), "%016llx %016llx ",
+			(unsigned long long) reg->base,
+			(unsigned long long) reg->size);
+	}
+	filp->private_data = buf;
+	return nonseekable_open(inode, filp);
+}
+
+static int zcore_memmap_release(struct inode *inode, struct file *filp)
+{
+	kfree(filp->private_data);
+	return 0;
+}
+
+static const struct file_operations zcore_memmap_fops = {
+	.owner		= THIS_MODULE,
+	.read		= zcore_memmap_read,
+	.open		= zcore_memmap_open,
+	.release	= zcore_memmap_release,
+	.llseek		= no_llseek,
+};
+
+static ssize_t zcore_reipl_write(struct file *filp, const char __user *buf,
+				 size_t count, loff_t *ppos)
+{
+	if (ipl_block) {
+		diag308(DIAG308_SET, ipl_block);
+		diag308(DIAG308_LOAD_CLEAR, NULL);
+	}
+	return count;
+}
+
+static int zcore_reipl_open(struct inode *inode, struct file *filp)
+{
+	return nonseekable_open(inode, filp);
+}
+
+static int zcore_reipl_release(struct inode *inode, struct file *filp)
+{
+	return 0;
+}
+
+static const struct file_operations zcore_reipl_fops = {
+	.owner		= THIS_MODULE,
+	.write		= zcore_reipl_write,
+	.open		= zcore_reipl_open,
+	.release	= zcore_reipl_release,
+	.llseek		= no_llseek,
+};
+
+static ssize_t zcore_hsa_read(struct file *filp, char __user *buf,
+			      size_t count, loff_t *ppos)
+{
+	static char str[18];
+
+	if (hsa_available)
+		snprintf(str, sizeof(str), "%lx\n", sclp.hsa_size);
+	else
+		snprintf(str, sizeof(str), "0\n");
+	return simple_read_from_buffer(buf, count, ppos, str, strlen(str));
+}
+
+static ssize_t zcore_hsa_write(struct file *filp, const char __user *buf,
+			       size_t count, loff_t *ppos)
+{
+	char value;
+
+	if (*ppos != 0)
+		return -EPIPE;
+	if (copy_from_user(&value, buf, 1))
+		return -EFAULT;
+	if (value != '0')
+		return -EINVAL;
+	release_hsa();
+	return count;
+}
+
+static const struct file_operations zcore_hsa_fops = {
+	.owner		= THIS_MODULE,
+	.write		= zcore_hsa_write,
+	.read		= zcore_hsa_read,
+	.open		= nonseekable_open,
+	.llseek		= no_llseek,
+};
+
+static int __init check_sdias(void)
+{
+	if (!sclp.hsa_size) {
+		TRACE("Could not determine HSA size\n");
+		return -ENODEV;
+	}
+	return 0;
+}
+
+/*
+ * Provide IPL parameter information block from either HSA or memory
+ * for future reipl
+ */
+static int __init zcore_reipl_init(void)
+{
+	struct ipib_info ipib_info;
+	int rc;
+
+	rc = memcpy_hsa_kernel(&ipib_info, __LC_DUMP_REIPL, sizeof(ipib_info));
+	if (rc)
+		return rc;
+	if (ipib_info.ipib == 0)
+		return 0;
+	ipl_block = (void *) __get_free_page(GFP_KERNEL);
+	if (!ipl_block)
+		return -ENOMEM;
+	if (ipib_info.ipib < sclp.hsa_size)
+		rc = memcpy_hsa_kernel(ipl_block, ipib_info.ipib, PAGE_SIZE);
+	else
+		rc = memcpy_real(ipl_block, (void *) ipib_info.ipib, PAGE_SIZE);
+	if (rc || (__force u32)csum_partial(ipl_block, ipl_block->hdr.len, 0) !=
+	    ipib_info.checksum) {
+		TRACE("Checksum does not match\n");
+		free_page((unsigned long) ipl_block);
+		ipl_block = NULL;
+	}
+	return 0;
+}
+
+static int __init zcore_init(void)
+{
+	unsigned char arch;
+	int rc;
+
+	if (ipl_info.type != IPL_TYPE_FCP_DUMP)
+		return -ENODATA;
+	if (OLDMEM_BASE)
+		return -ENODATA;
+
+	zcore_dbf = debug_register("zcore", 4, 1, 4 * sizeof(long));
+	debug_register_view(zcore_dbf, &debug_sprintf_view);
+	debug_set_level(zcore_dbf, 6);
+
+	TRACE("devno:  %x\n", ipl_info.data.fcp.dev_id.devno);
+	TRACE("wwpn:   %llx\n", (unsigned long long) ipl_info.data.fcp.wwpn);
+	TRACE("lun:    %llx\n", (unsigned long long) ipl_info.data.fcp.lun);
+
+	rc = sclp_sdias_init();
+	if (rc)
+		goto fail;
+
+	rc = check_sdias();
+	if (rc)
+		goto fail;
+	hsa_available = 1;
+
+	rc = memcpy_hsa_kernel(&arch, __LC_AR_MODE_ID, 1);
+	if (rc)
+		goto fail;
+
+	if (arch == ARCH_S390) {
+		pr_alert("The 64-bit dump tool cannot be used for a "
+			 "32-bit system\n");
+		rc = -EINVAL;
+		goto fail;
+	}
+
+	pr_alert("The dump process started for a 64-bit operating system\n");
+	rc = init_cpu_info();
+	if (rc)
+		goto fail;
+
+	rc = zcore_reipl_init();
+	if (rc)
+		goto fail;
+
+	zcore_dir = debugfs_create_dir("zcore" , NULL);
+	if (!zcore_dir) {
+		rc = -ENOMEM;
+		goto fail;
+	}
+	zcore_memmap_file = debugfs_create_file("memmap", S_IRUSR, zcore_dir,
+						NULL, &zcore_memmap_fops);
+	if (!zcore_memmap_file) {
+		rc = -ENOMEM;
+		goto fail_dir;
+	}
+	zcore_reipl_file = debugfs_create_file("reipl", S_IRUSR, zcore_dir,
+						NULL, &zcore_reipl_fops);
+	if (!zcore_reipl_file) {
+		rc = -ENOMEM;
+		goto fail_memmap_file;
+	}
+	zcore_hsa_file = debugfs_create_file("hsa", S_IRUSR|S_IWUSR, zcore_dir,
+					     NULL, &zcore_hsa_fops);
+	if (!zcore_hsa_file) {
+		rc = -ENOMEM;
+		goto fail_reipl_file;
+	}
+	return 0;
+
+fail_reipl_file:
+	debugfs_remove(zcore_reipl_file);
+fail_memmap_file:
+	debugfs_remove(zcore_memmap_file);
+fail_dir:
+	debugfs_remove(zcore_dir);
+fail:
+	diag308(DIAG308_REL_HSA, NULL);
+	return rc;
+}
+subsys_initcall(zcore_init);