powerpc/chrp: Use the same RTAS daemon as pSeries

The CHRP code has some fishy timer based code to scan the RTAS event
log, which uses a 1KB stack buffer and doesn't even use the results.

The pSeries code as a nicer daemon that allows userspace to read the
event log and basically uses the same RTAS interface

This patch moves rtasd.c out of platform/pseries and makes it usable
by CHRP, after removing the old crufty event log mechanism in there.

The nvram logging part of the daemon is still only available on 64-bit
since the underlying nvram management routines aren't currently shared.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/kernel/Makefile

@@ -46,6 +46,7 @@ procfs-y			:= proc_powerpc.o
 obj-$(CONFIG_PROC_FS)		+= $(procfs-y)
 rtaspci-$(CONFIG_PPC64)-$(CONFIG_PCI)	:= rtas_pci.o
 obj-$(CONFIG_PPC_RTAS)		+= rtas.o rtas-rtc.o $(rtaspci-y-y)
+obj-$(CONFIG_PPC_RTAS_DAEMON)	+= rtasd.o
 obj-$(CONFIG_RTAS_FLASH)	+= rtas_flash.o
 obj-$(CONFIG_RTAS_PROC)		+= rtas-proc.o
 obj-$(CONFIG_LPARCFG)		+= lparcfg.o

arch/powerpc/kernel/rtasd.c

@@ -39,6 +39,7 @@ static unsigned long rtas_log_start;
 static unsigned long rtas_log_size;
 
 static int surveillance_timeout = -1;
+
 static unsigned int rtas_error_log_max;
 static unsigned int rtas_error_log_buffer_max;
 
@@ -213,9 +214,11 @@ void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
 		return;
 	}
 
+#ifdef CONFIG_PPC64
 	/* Write error to NVRAM */
 	if (logging_enabled && !(err_type & ERR_FLAG_BOOT))
 		nvram_write_error_log(buf, len, err_type, error_log_cnt);
+#endif /* CONFIG_PPC64 */
 
 	/*
 	 * rtas errors can occur during boot, and we do want to capture
@@ -264,7 +267,6 @@ void pSeries_log_error(char *buf, unsigned int err_type, int fatal)
 
 }
 
-
 static int rtas_log_open(struct inode * inode, struct file * file)
 {
 	return 0;
@@ -300,6 +302,7 @@ static ssize_t rtas_log_read(struct file * file, char __user * buf,
 		return -ENOMEM;
 
 	spin_lock_irqsave(&rtasd_log_lock, s);
+
 	/* if it's 0, then we know we got the last one (the one in NVRAM) */
 	while (rtas_log_size == 0) {
 		if (file->f_flags & O_NONBLOCK) {
@@ -313,7 +316,9 @@ static ssize_t rtas_log_read(struct file * file, char __user * buf,
 			error = -ENODATA;
 			goto out;
 		}
+#ifdef CONFIG_PPC64
 		nvram_clear_error_log();
+#endif /* CONFIG_PPC64 */
 
 		spin_unlock_irqrestore(&rtasd_log_lock, s);
 		error = wait_event_interruptible(rtas_log_wait, rtas_log_size);
@@ -427,27 +432,38 @@ static void rtas_event_scan(struct work_struct *w)
 	put_online_cpus();
 }
 
-static void start_event_scan(void)
+#ifdef CONFIG_PPC64
+static void retreive_nvram_error_log(void)
 {
 	unsigned int err_type ;
 	int rc ;
 
-	printk(KERN_DEBUG "RTAS daemon started\n");
-	pr_debug("rtasd: will sleep for %d milliseconds\n",
-		 (30000 / rtas_event_scan_rate));
-
 	/* See if we have any error stored in NVRAM */
 	memset(logdata, 0, rtas_error_log_max);
 	rc = nvram_read_error_log(logdata, rtas_error_log_max,
 	                          &err_type, &error_log_cnt);
 	/* We can use rtas_log_buf now */
 	logging_enabled = 1;
-
 	if (!rc) {
 		if (err_type != ERR_FLAG_ALREADY_LOGGED) {
 			pSeries_log_error(logdata, err_type | ERR_FLAG_BOOT, 0);
 		}
 	}
+}
+#else /* CONFIG_PPC64 */
+static void retreive_nvram_error_log(void)
+{
+}
+#endif /* CONFIG_PPC64 */
+
+static void start_event_scan(void)
+{
+	printk(KERN_DEBUG "RTAS daemon started\n");
+	pr_debug("rtasd: will sleep for %d milliseconds\n",
+		 (30000 / rtas_event_scan_rate));
+
+	/* Retreive errors from nvram if any */
+	retreive_nvram_error_log();
 
 	schedule_delayed_work_on(first_cpu(cpu_online_map), &event_scan_work,
 				 event_scan_delay);
@@ -457,13 +473,13 @@ static int __init rtas_init(void)
 {
 	struct proc_dir_entry *entry;
 
-	if (!machine_is(pseries))
+	if (!machine_is(pseries) && !machine_is(chrp))
 		return 0;
 
 	/* No RTAS */
 	event_scan = rtas_token("event-scan");
 	if (event_scan == RTAS_UNKNOWN_SERVICE) {
-		printk(KERN_DEBUG "rtasd: no event-scan on system\n");
+		printk(KERN_INFO "rtasd: No event-scan on system\n");
 		return -ENODEV;
 	}
 
@@ -483,7 +499,7 @@ static int __init rtas_init(void)
 		return -ENOMEM;
 	}
 
-	entry = proc_create("ppc64/rtas/error_log", S_IRUSR, NULL,
+	entry = proc_create("powerpc/rtas/error_log", S_IRUSR, NULL,
 			    &proc_rtas_log_operations);
 	if (!entry)
 		printk(KERN_ERR "Failed to create error_log proc entry\n");
@@ -492,11 +508,16 @@ static int __init rtas_init(void)
 
 	return 0;
 }
+__initcall(rtas_init);
 
 static int __init surveillance_setup(char *str)
 {
 	int i;
 
+	/* We only do surveillance on pseries */
+	if (!machine_is(pseries))
+		return 0;
+
 	if (get_option(&str,&i)) {
 		if (i >= 0 && i <= 255)
 			surveillance_timeout = i;
@@ -504,6 +525,7 @@ static int __init surveillance_setup(char *str)
 
 	return 1;
 }
+__setup("surveillance=", surveillance_setup);
 
 static int __init rtasmsgs_setup(char *str)
 {
@@ -514,6 +536,4 @@ static int __init rtasmsgs_setup(char *str)
 
 	return 1;
 }
-__initcall(rtas_init);
-__setup("surveillance=", surveillance_setup);
 __setup("rtasmsgs=", rtasmsgs_setup);

arch/powerpc/platforms/Kconfig

@@ -86,6 +86,11 @@ config RTAS_ERROR_LOGGING
 	depends on PPC_RTAS
 	default n
 
+config PPC_RTAS_DAEMON
+	bool
+	depends on PPC_RTAS
+	default n
+
 config RTAS_PROC
 	bool "Proc interface to RTAS"
 	depends on PPC_RTAS

arch/powerpc/platforms/chrp/Kconfig

@@ -5,6 +5,8 @@ config PPC_CHRP
 	select PPC_I8259
 	select PPC_INDIRECT_PCI
 	select PPC_RTAS
+	select PPC_RTAS_DAEMON
+	select RTAS_ERROR_LOGGING
 	select PPC_MPC106
 	select PPC_UDBG_16550
 	select PPC_NATIVE

arch/powerpc/platforms/chrp/setup.c

@@ -364,19 +364,6 @@ void __init chrp_setup_arch(void)
 	if (ppc_md.progress) ppc_md.progress("Linux/PPC "UTS_RELEASE"\n", 0x0);
 }
 
-void
-chrp_event_scan(unsigned long unused)
-{
-	unsigned char log[1024];
-	int ret = 0;
-
-	/* XXX: we should loop until the hardware says no more error logs -- Cort */
-	rtas_call(rtas_token("event-scan"), 4, 1, &ret, 0xffffffff, 0,
-		  __pa(log), 1024);
-	mod_timer(&__get_cpu_var(heartbeat_timer),
-		  jiffies + event_scan_interval);
-}
-
 static void chrp_8259_cascade(unsigned int irq, struct irq_desc *desc)
 {
 	unsigned int cascade_irq = i8259_irq();
@@ -568,9 +555,6 @@ void __init chrp_init_IRQ(void)
 void __init
 chrp_init2(void)
 {
-	struct device_node *device;
-	const unsigned int *p = NULL;
-
 #ifdef CONFIG_NVRAM
 	chrp_nvram_init();
 #endif
@@ -582,40 +566,6 @@ chrp_init2(void)
 	request_region(0x80,0x10,"dma page reg");
 	request_region(0xc0,0x20,"dma2");
 
-	/* Get the event scan rate for the rtas so we know how
-	 * often it expects a heartbeat. -- Cort
-	 */
-	device = of_find_node_by_name(NULL, "rtas");
-	if (device)
-		p = of_get_property(device, "rtas-event-scan-rate", NULL);
-	if (p && *p) {
-		/*
-		 * Arrange to call chrp_event_scan at least *p times
-		 * per minute.  We use 59 rather than 60 here so that
-		 * the rate will be slightly higher than the minimum.
-		 * This all assumes we don't do hotplug CPU on any
-		 * machine that needs the event scans done.
-		 */
-		unsigned long interval, offset;
-		int cpu, ncpus;
-		struct timer_list *timer;
-
-		interval = HZ * 59 / *p;
-		offset = HZ;
-		ncpus = num_online_cpus();
-		event_scan_interval = ncpus * interval;
-		for (cpu = 0; cpu < ncpus; ++cpu) {
-			timer = &per_cpu(heartbeat_timer, cpu);
-			setup_timer(timer, chrp_event_scan, 0);
-			timer->expires = jiffies + offset;
-			add_timer_on(timer, cpu);
-			offset += interval;
-		}
-		printk("RTAS Event Scan Rate: %u (%lu jiffies)\n",
-		       *p, interval);
-	}
-	of_node_put(device);
-
 	if (ppc_md.progress)
 		ppc_md.progress("  Have fun!    ", 0x7777);
 }

arch/powerpc/platforms/pseries/Kconfig

@@ -4,6 +4,7 @@ config PPC_PSERIES
 	select MPIC
 	select PPC_I8259
 	select PPC_RTAS
+	select PPC_RTAS_DAEMON
 	select RTAS_ERROR_LOGGING
 	select PPC_UDBG_16550
 	select PPC_NATIVE

arch/powerpc/platforms/pseries/Makefile

@@ -7,7 +7,7 @@ EXTRA_CFLAGS		+= -DDEBUG
 endif
 
 obj-y			:= lpar.o hvCall.o nvram.o reconfig.o \
-			   setup.o iommu.o ras.o rtasd.o \
+			   setup.o iommu.o ras.o \
 			   firmware.o power.o
 obj-$(CONFIG_SMP)	+= smp.o
 obj-$(CONFIG_XICS)	+= xics.o