1 files changed, 247 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pseries/nvram.c b/arch/powerpc/platforms/pseries/nvram.c
new file mode 100644
index 000000000..69cedc1b3
--- /dev/null
+++ b/arch/powerpc/platforms/pseries/nvram.c
@@ -0,0 +1,247 @@
+/*
+ *  c 2001 PPC 64 Team, IBM Corp
+ *
+ *      This program is free software; you can redistribute it and/or
+ *      modify it under the terms of the GNU General Public License
+ *      as published by the Free Software Foundation; either version
+ *      2 of the License, or (at your option) any later version.
+ *
+ * /dev/nvram driver for PPC64
+ *
+ * This perhaps should live in drivers/char
+ */
+
+
+#include <linux/types.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/spinlock.h>
+#include <linux/slab.h>
+#include <linux/ctype.h>
+#include <linux/uaccess.h>
+#include <asm/nvram.h>
+#include <asm/rtas.h>
+#include <asm/prom.h>
+#include <asm/machdep.h>
+
+/* Max bytes to read/write in one go */
+#define NVRW_CNT 0x20
+
+static unsigned int nvram_size;
+static int nvram_fetch, nvram_store;
+static char nvram_buf[NVRW_CNT];	/* assume this is in the first 4GB */
+static DEFINE_SPINLOCK(nvram_lock);
+
+/* See clobbering_unread_rtas_event() */
+#define NVRAM_RTAS_READ_TIMEOUT 5		/* seconds */
+static time64_t last_unread_rtas_event;		/* timestamp */
+
+#ifdef CONFIG_PSTORE
+time64_t last_rtas_event;
+#endif
+
+static ssize_t pSeries_nvram_read(char *buf, size_t count, loff_t *index)
+{
+	unsigned int i;
+	unsigned long len;
+	int done;
+	unsigned long flags;
+	char *p = buf;
+
+
+	if (nvram_size == 0 || nvram_fetch == RTAS_UNKNOWN_SERVICE)
+		return -ENODEV;
+
+	if (*index >= nvram_size)
+		return 0;
+
+	i = *index;
+	if (i + count > nvram_size)
+		count = nvram_size - i;
+
+	spin_lock_irqsave(&nvram_lock, flags);
+
+	for (; count != 0; count -= len) {
+		len = count;
+		if (len > NVRW_CNT)
+			len = NVRW_CNT;
+		
+		if ((rtas_call(nvram_fetch, 3, 2, &done, i, __pa(nvram_buf),
+			       len) != 0) || len != done) {
+			spin_unlock_irqrestore(&nvram_lock, flags);
+			return -EIO;
+		}
+		
+		memcpy(p, nvram_buf, len);
+
+		p += len;
+		i += len;
+	}
+
+	spin_unlock_irqrestore(&nvram_lock, flags);
+	
+	*index = i;
+	return p - buf;
+}
+
+static ssize_t pSeries_nvram_write(char *buf, size_t count, loff_t *index)
+{
+	unsigned int i;
+	unsigned long len;
+	int done;
+	unsigned long flags;
+	const char *p = buf;
+
+	if (nvram_size == 0 || nvram_store == RTAS_UNKNOWN_SERVICE)
+		return -ENODEV;
+
+	if (*index >= nvram_size)
+		return 0;
+
+	i = *index;
+	if (i + count > nvram_size)
+		count = nvram_size - i;
+
+	spin_lock_irqsave(&nvram_lock, flags);
+
+	for (; count != 0; count -= len) {
+		len = count;
+		if (len > NVRW_CNT)
+			len = NVRW_CNT;
+
+		memcpy(nvram_buf, p, len);
+
+		if ((rtas_call(nvram_store, 3, 2, &done, i, __pa(nvram_buf),
+			       len) != 0) || len != done) {
+			spin_unlock_irqrestore(&nvram_lock, flags);
+			return -EIO;
+		}
+		
+		p += len;
+		i += len;
+	}
+	spin_unlock_irqrestore(&nvram_lock, flags);
+	
+	*index = i;
+	return p - buf;
+}
+
+static ssize_t pSeries_nvram_get_size(void)
+{
+	return nvram_size ? nvram_size : -ENODEV;
+}
+
+/* nvram_write_error_log
+ *
+ * We need to buffer the error logs into nvram to ensure that we have
+ * the failure information to decode.
+ */
+int nvram_write_error_log(char * buff, int length,
+                          unsigned int err_type, unsigned int error_log_cnt)
+{
+	int rc = nvram_write_os_partition(&rtas_log_partition, buff, length,
+						err_type, error_log_cnt);
+	if (!rc) {
+		last_unread_rtas_event = ktime_get_real_seconds();
+#ifdef CONFIG_PSTORE
+		last_rtas_event = ktime_get_real_seconds();
+#endif
+	}
+
+	return rc;
+}
+
+/* nvram_read_error_log
+ *
+ * Reads nvram for error log for at most 'length'
+ */
+int nvram_read_error_log(char *buff, int length,
+			unsigned int *err_type, unsigned int *error_log_cnt)
+{
+	return nvram_read_partition(&rtas_log_partition, buff, length,
+						err_type, error_log_cnt);
+}
+
+/* This doesn't actually zero anything, but it sets the event_logged
+ * word to tell that this event is safely in syslog.
+ */
+int nvram_clear_error_log(void)
+{
+	loff_t tmp_index;
+	int clear_word = ERR_FLAG_ALREADY_LOGGED;
+	int rc;
+
+	if (rtas_log_partition.index == -1)
+		return -1;
+
+	tmp_index = rtas_log_partition.index;
+	
+	rc = ppc_md.nvram_write((char *)&clear_word, sizeof(int), &tmp_index);
+	if (rc <= 0) {
+		printk(KERN_ERR "nvram_clear_error_log: Failed nvram_write (%d)\n", rc);
+		return rc;
+	}
+	last_unread_rtas_event = 0;
+
+	return 0;
+}
+
+/*
+ * Are we using the ibm,rtas-log for oops/panic reports?  And if so,
+ * would logging this oops/panic overwrite an RTAS event that rtas_errd
+ * hasn't had a chance to read and process?  Return 1 if so, else 0.
+ *
+ * We assume that if rtas_errd hasn't read the RTAS event in
+ * NVRAM_RTAS_READ_TIMEOUT seconds, it's probably not going to.
+ */
+int clobbering_unread_rtas_event(void)
+{
+	return (oops_log_partition.index == rtas_log_partition.index
+		&& last_unread_rtas_event
+		&& ktime_get_real_seconds() - last_unread_rtas_event <=
+						NVRAM_RTAS_READ_TIMEOUT);
+}
+
+static int __init pseries_nvram_init_log_partitions(void)
+{
+	int rc;
+
+	/* Scan nvram for partitions */
+	nvram_scan_partitions();
+
+	rc = nvram_init_os_partition(&rtas_log_partition);
+	nvram_init_oops_partition(rc == 0);
+	return 0;
+}
+machine_arch_initcall(pseries, pseries_nvram_init_log_partitions);
+
+int __init pSeries_nvram_init(void)
+{
+	struct device_node *nvram;
+	const __be32 *nbytes_p;
+	unsigned int proplen;
+
+	nvram = of_find_node_by_type(NULL, "nvram");
+	if (nvram == NULL)
+		return -ENODEV;
+
+	nbytes_p = of_get_property(nvram, "#bytes", &proplen);
+	if (nbytes_p == NULL || proplen != sizeof(unsigned int)) {
+		of_node_put(nvram);
+		return -EIO;
+	}
+
+	nvram_size = be32_to_cpup(nbytes_p);
+
+	nvram_fetch = rtas_token("nvram-fetch");
+	nvram_store = rtas_token("nvram-store");
+	printk(KERN_INFO "PPC64 nvram contains %d bytes\n", nvram_size);
+	of_node_put(nvram);
+
+	ppc_md.nvram_read	= pSeries_nvram_read;
+	ppc_md.nvram_write	= pSeries_nvram_write;
+	ppc_md.nvram_size	= pSeries_nvram_get_size;
+
+	return 0;
+}
+