[PATCH V2 1/2] powerpc/powernv: new function to access OPAL msglog

@@ -248,6 +248,7 @@ extern int opal_elog_init(void);
 extern void opal_platform_dump_init(void);
 extern void opal_sys_param_init(void);
 extern void opal_msglog_init(void);
+extern void opal_msglog_sysfs_init(void);
 extern int opal_async_comp_init(void);
 extern int opal_sensor_init(void);
 extern int opal_hmi_handler_init(void);

@@ -273,6 +274,8 @@ void opal_free_sg_list(struct opal_sg_list *sg);
 
 extern int opal_error_code(int rc);
 
+ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_OPAL_H */

@@ -31,26 +31,25 @@ struct memcons {
 	__be32 in_cons;
 };
 
-static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
-				struct bin_attribute *bin_attr, char *to,
-				loff_t pos, size_t count)
+static struct memcons *opal_memcons = NULL;
+
+ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count)
 {
-	struct memcons *mc = bin_attr->private;
 	const char *conbuf;
 	ssize_t ret;
 	size_t first_read = 0;
 	uint32_t out_pos, avail;
 
-	if (!mc)
+	if (!opal_memcons)
 		return -ENODEV;
 
-	out_pos = be32_to_cpu(ACCESS_ONCE(mc->out_pos));
+	out_pos = be32_to_cpu(ACCESS_ONCE(opal_memcons->out_pos));
 
 	/* Now we've read out_pos, put a barrier in before reading the new
 	 * data it points to in conbuf. */
 	smp_rmb();
 
-	conbuf = phys_to_virt(be64_to_cpu(mc->obuf_phys));
+	conbuf = phys_to_virt(be64_to_cpu(opal_memcons->obuf_phys));
 
 	/* When the buffer has wrapped, read from the out_pos marker to the end
 	 * of the buffer, and then read the remaining data as in the un-wrapped

@@ -58,7 +57,7 @@ static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
 	if (out_pos & MEMCONS_OUT_POS_WRAP) {
 
 		out_pos &= MEMCONS_OUT_POS_MASK;
-		avail = be32_to_cpu(mc->obuf_size) - out_pos;
+		avail = be32_to_cpu(opal_memcons->obuf_size) - out_pos;
 
 		ret = memory_read_from_buffer(to, count, &pos,
 				conbuf + out_pos, avail);

@@ -76,7 +75,7 @@ static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
 	}
 
 	/* Sanity check. The firmware should not do this to us. */
-	if (out_pos > be32_to_cpu(mc->obuf_size)) {
+	if (out_pos > be32_to_cpu(opal_memcons->obuf_size)) {
 		pr_err("OPAL: memory console corruption. Aborting read.\n");
 		return -EINVAL;
 	}

@@ -91,6 +90,13 @@ out:
 	return ret;
 }
 
+static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
+				struct bin_attribute *bin_attr, char *to,
+				loff_t pos, size_t count)
+{
+	return opal_msglog_copy(to, pos, count);
+}
+
 static struct bin_attribute opal_msglog_attr = {
 	.attr = {.name = "msglog", .mode = 0444},
 	.read = opal_msglog_read

@@ -117,8 +123,11 @@ void __init opal_msglog_init(void)
 		return;
 	}
 
-	opal_msglog_attr.private = mc;
+	opal_memcons = mc;
+}
 
+void __init opal_msglog_sysfs_init(void)
+{
 	if (sysfs_create_bin_file(opal_kobj, &opal_msglog_attr) != 0)
 		pr_warn("OPAL: sysfs file creation failed\n");
 }

@@ -724,6 +724,9 @@ static int __init opal_init(void)
 		of_node_put(leds);
 	}
 
+	/* Initialise OPAL message log interface */
+	opal_msglog_init();
+
 	/* Create "opal" kobject under /sys/firmware */
 	rc = opal_sysfs_init();
 	if (rc == 0) {

@@ -739,8 +742,8 @@ static int __init opal_init(void)
 		opal_platform_dump_init();
 		/* Setup system parameters interface */
 		opal_sys_param_init();
-		/* Setup message log interface. */
-		opal_msglog_init();
+		/* Setup message log sysfs interface. */
+		opal_msglog_sysfs_init();
 	}
 
 	/* Initialize platform devices: IPMI backend, PRD & flash interface */

@@ -47,6 +47,11 @@
 #include <asm/debug.h>
 #include <asm/hw_breakpoint.h>
 
+#ifdef CONFIG_PPC_POWERNV
+#include <asm/opal.h>
+#include <asm/firmware.h>
+#endif
+
 #ifdef CONFIG_PPC64
 #include <asm/hvcall.h>
 #include <asm/paca.h>

@@ -119,6 +124,11 @@ static void dump(void);
 static void prdump(unsigned long, long);
 static int ppc_inst_dump(unsigned long, long, int);
 static void dump_log_buf(void);
+
+#ifdef CONFIG_PPC_POWERNV
+static void dump_opal_msglog(void);
+#endif
+
 static void backtrace(struct pt_regs *);
 static void excprint(struct pt_regs *);
 static void prregs(struct pt_regs *);

@@ -202,6 +212,10 @@ Commands:\n\
   df	dump float values\n\
   dd	dump double values\n\
   dl    dump the kernel log buffer\n"
+#ifdef CONFIG_PPC_POWERNV
+  "\
+  do    dump the OPAL message log\n"
+#endif
 #ifdef CONFIG_PPC64
   "\
   dp[#]	dump paca for current cpu, or cpu #\n\

@@ -2253,6 +2267,12 @@ dump(void)
 		last_cmd = "di\n";
 	} else if (c == 'l') {
 		dump_log_buf();
+	} else if (c == 'o') {
+#ifdef CONFIG_PPC_POWERNV
+		dump_opal_msglog();
+#else
+		printf("Machine is not running OPAL firmware.\n");
+#endif
 	} else if (c == 'r') {
 		scanhex(&ndump);
 		if (ndump == 0)

@@ -2395,6 +2415,46 @@ dump_log_buf(void)
 	catch_memory_errors = 0;
 }
 
+#ifdef CONFIG_PPC_POWERNV
+void
+dump_opal_msglog(void)
+{
+	unsigned char buf[128];
+	ssize_t res;
+	loff_t pos = 0;
+
+	if (!firmware_has_feature(FW_FEATURE_OPAL)) {
+		printf("Machine is not running OPAL firmware.\n");
+		return;
+	}
+
+	if (setjmp(bus_error_jmp) != 0) {
+		printf("Error dumping OPAL msglog!\n");
+		return;
+	}
+
+	catch_memory_errors = 1;
+	sync();
+
+	xmon_start_pagination();
+	while ((res = opal_msglog_copy(buf, pos, sizeof(buf) - 1))) {
+		if (res < 0) {
+			printf("Error dumping OPAL msglog! Error: %zd\n", res);
+			break;
+		}
+		buf[res] = '\0';
+		printf("%s", buf);
+		pos += res;
+	}
+	xmon_end_pagination();
+
+	sync();
+	/* wait a little while to see if we get a machine check */
+	__delay(200);
+	catch_memory_errors = 0;
+}
+#endif
+
 /*
  * Memory operations - move, set, print differences
  */

@@ -47,6 +47,11 @@
 #include <asm/debug.h>
 #include <asm/hw_breakpoint.h>
 
+#ifdef CONFIG_PPC_POWERNV
+#include <asm/opal.h>
+#include <asm/firmware.h>
+#endif
+
 #ifdef CONFIG_PPC64
 #include <asm/hvcall.h>
 #include <asm/paca.h>

@@ -119,6 +124,11 @@ static void dump(void);
 static void prdump(unsigned long, long);
 static int ppc_inst_dump(unsigned long, long, int);
 static void dump_log_buf(void);
+
+#ifdef CONFIG_PPC_POWERNV
+static void dump_opal_msglog(void);
+#endif
+
 static void backtrace(struct pt_regs *);
 static void excprint(struct pt_regs *);
 static void prregs(struct pt_regs *);

@@ -202,6 +212,10 @@ Commands:\n\
   df	dump float values\n\
   dd	dump double values\n\
   dl    dump the kernel log buffer\n"
+#ifdef CONFIG_PPC_POWERNV
+  "\
+  do    dump the OPAL message log\n"
+#endif
 #ifdef CONFIG_PPC64
   "\
   dp[#]	dump paca for current cpu, or cpu #\n\

@@ -2253,6 +2267,12 @@ dump(void)
 		last_cmd = "di\n";
 	} else if (c == 'l') {
 		dump_log_buf();
+	} else if (c == 'o') {
+#ifdef CONFIG_PPC_POWERNV
+		dump_opal_msglog();
+#else
+		printf("Machine is not running OPAL firmware.\n");
+#endif
 	} else if (c == 'r') {
 		scanhex(&ndump);
 		if (ndump == 0)

@@ -2395,6 +2415,46 @@ dump_log_buf(void)
 	catch_memory_errors = 0;
 }
 
+#ifdef CONFIG_PPC_POWERNV
+void
+dump_opal_msglog(void)
+{
+	unsigned char buf[128];
+	ssize_t res;
+	loff_t pos = 0;
+
+	if (!firmware_has_feature(FW_FEATURE_OPAL)) {
+		printf("Machine is not running OPAL firmware.\n");
+		return;
+	}
+
+	if (setjmp(bus_error_jmp) != 0) {
+		printf("Error dumping OPAL msglog!\n");
+		return;
+	}
+
+	catch_memory_errors = 1;
+	sync();
+
+	xmon_start_pagination();
+	while ((res = opal_msglog_copy(buf, pos, sizeof(buf) - 1))) {
+		if (res < 0) {
+			printf("Error dumping OPAL msglog! Error: %zd\n", res);
+			break;
+		}
+		buf[res] = '\0';
+		printf("%s", buf);
+		pos += res;
+	}
+	xmon_end_pagination();
+
+	sync();
+	/* wait a little while to see if we get a machine check */
+	__delay(200);
+	catch_memory_errors = 0;
+}
+#endif
+
 /*
  * Memory operations - move, set, print differences
  */

@@ -248,6 +248,7 @@ extern int opal_elog_init(void);
 extern void opal_platform_dump_init(void);
 extern void opal_sys_param_init(void);
 extern void opal_msglog_init(void);
+extern void opal_msglog_sysfs_init(void);
 extern int opal_async_comp_init(void);
 extern int opal_sensor_init(void);
 extern int opal_hmi_handler_init(void);

@@ -273,6 +274,8 @@ void opal_free_sg_list(struct opal_sg_list *sg);
 
 extern int opal_error_code(int rc);
 
+ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count);
+
 #endif /* __ASSEMBLY__ */
 
 #endif /* _ASM_POWERPC_OPAL_H */

@@ -31,26 +31,25 @@ struct memcons {
 	__be32 in_cons;
 };
 
-static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
-				struct bin_attribute *bin_attr, char *to,
-				loff_t pos, size_t count)
+static struct memcons *opal_memcons = NULL;
+
+ssize_t opal_msglog_copy(char *to, loff_t pos, size_t count)
 {
-	struct memcons *mc = bin_attr->private;
 	const char *conbuf;
 	ssize_t ret;
 	size_t first_read = 0;
 	uint32_t out_pos, avail;
 
-	if (!mc)
+	if (!opal_memcons)
 		return -ENODEV;
 
-	out_pos = be32_to_cpu(ACCESS_ONCE(mc->out_pos));
+	out_pos = be32_to_cpu(ACCESS_ONCE(opal_memcons->out_pos));
 
 	/* Now we've read out_pos, put a barrier in before reading the new
 	 * data it points to in conbuf. */
 	smp_rmb();
 
-	conbuf = phys_to_virt(be64_to_cpu(mc->obuf_phys));
+	conbuf = phys_to_virt(be64_to_cpu(opal_memcons->obuf_phys));
 
 	/* When the buffer has wrapped, read from the out_pos marker to the end
 	 * of the buffer, and then read the remaining data as in the un-wrapped

@@ -58,7 +57,7 @@ static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
 	if (out_pos & MEMCONS_OUT_POS_WRAP) {
 
 		out_pos &= MEMCONS_OUT_POS_MASK;
-		avail = be32_to_cpu(mc->obuf_size) - out_pos;
+		avail = be32_to_cpu(opal_memcons->obuf_size) - out_pos;
 
 		ret = memory_read_from_buffer(to, count, &pos,
 				conbuf + out_pos, avail);

@@ -76,7 +75,7 @@ static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
 	}
 
 	/* Sanity check. The firmware should not do this to us. */
-	if (out_pos > be32_to_cpu(mc->obuf_size)) {
+	if (out_pos > be32_to_cpu(opal_memcons->obuf_size)) {
 		pr_err("OPAL: memory console corruption. Aborting read.\n");
 		return -EINVAL;
 	}

@@ -91,6 +90,13 @@ out:
 	return ret;
 }
 
+static ssize_t opal_msglog_read(struct file *file, struct kobject *kobj,
+				struct bin_attribute *bin_attr, char *to,
+				loff_t pos, size_t count)
+{
+	return opal_msglog_copy(to, pos, count);
+}
+
 static struct bin_attribute opal_msglog_attr = {
 	.attr = {.name = "msglog", .mode = 0444},
 	.read = opal_msglog_read

@@ -117,8 +123,16 @@ void __init opal_msglog_init(void)
 		return;
 	}
 
-	opal_msglog_attr.private = mc;
+	opal_memcons = mc;
+}
 
+void __init opal_msglog_sysfs_init(void)
+{
+	if (!opal_memcons) {
+		pr_warn("OPAL: message log initialisation failed, not creating sysfs entry\n");
+		return;
+	}
+	
 	if (sysfs_create_bin_file(opal_kobj, &opal_msglog_attr) != 0)
 		pr_warn("OPAL: sysfs file creation failed\n");
 }

@@ -724,6 +724,9 @@ static int __init opal_init(void)
 		of_node_put(leds);
 	}
 
+	/* Initialise OPAL message log interface */
+	opal_msglog_init();
+
 	/* Create "opal" kobject under /sys/firmware */
 	rc = opal_sysfs_init();
 	if (rc == 0) {

@@ -739,8 +742,8 @@ static int __init opal_init(void)
 		opal_platform_dump_init();
 		/* Setup system parameters interface */
 		opal_sys_param_init();
-		/* Setup message log interface. */
-		opal_msglog_init();
+		/* Setup message log sysfs interface. */
+		opal_msglog_sysfs_init();
 	}
 
 	/* Initialize platform devices: IPMI backend, PRD & flash interface */