powerpc: Fix event-scan code for 32-bit CHRP

On CHRP machines we are supposed to call into firmware (RTAS)
periodically, to give it a chance to check for errors and other
events.  Under ppc we had some special code in timer_interrupt
to do this, but that didn't get transferred over to arch/powerpc.
Instead, we use an array of timer_list structs, one per CPU,
and use add_timer_on to make sure each one gets called on the
appropriate CPU.

With this we can remove the heartbeat_* elements of the ppc_md
struct.

Signed-off-by: Paul Mackerras <paulus@samba.org>

diff --git a/arch/powerpc/platforms/chrp/chrp.h b/arch/powerpc/platforms/chrp/chrp.h
index 814f547..63f0aee 100644 (file)
--- a/arch/powerpc/platforms/chrp/chrp.h
+++ b/arch/powerpc/platforms/chrp/chrp.h
@@ -8,4 +8,4 @@ extern int chrp_set_rtc_time(struct rtc_time *);
 extern long chrp_time_init(void);
 
 extern void chrp_find_bridges(void);
-extern void chrp_event_scan(void);
+extern void chrp_event_scan(unsigned long);

diff --git a/arch/powerpc/platforms/chrp/setup.c b/arch/powerpc/platforms/chrp/setup.c
index 8bf4307..9c718bb 100644 (file)
--- a/arch/powerpc/platforms/chrp/setup.c
+++ b/arch/powerpc/platforms/chrp/setup.c
@@ -35,6 +35,7 @@
 #include <linux/root_dev.h>
 #include <linux/initrd.h>
 #include <linux/module.h>
+#include <linux/timer.h>
 
 #include <asm/io.h>
 #include <asm/pgtable.h>
@@ -61,6 +62,10 @@ EXPORT_SYMBOL(_chrp_type);
 
 struct mpic *chrp_mpic;
 
+/* Used for doing CHRP event-scans */
+DEFINE_PER_CPU(struct timer_list, heartbeat_timer);
+unsigned long event_scan_interval;
+
 /*
  * XXX this should be in xmon.h, but putting it there means xmon.h
  * has to include <linux/interrupt.h> (to get irqreturn_t), which
@@ -229,8 +234,6 @@ void __init chrp_setup_arch(void)
 {
        struct device_node *root = find_path_device ("/");
        char *machine = NULL;
-       struct device_node *device;
-       unsigned int *p = NULL;
 
        /* init to some ~sane value until calibrate_delay() runs */
        loops_per_jiffy = 50000000/HZ;
@@ -287,21 +290,6 @@ void __init chrp_setup_arch(void)
         */
        sio_init();
 
-       /* Get the event scan rate for the rtas so we know how
-        * often it expects a heartbeat. -- Cort
-        */
-       device = find_devices("rtas");
-       if (device)
-               p = (unsigned int *) get_property
-                       (device, "rtas-event-scan-rate", NULL);
-       if (p && *p) {
-               ppc_md.heartbeat = chrp_event_scan;
-               ppc_md.heartbeat_reset = HZ / (*p * 30) - 1;
-               ppc_md.heartbeat_count = 1;
-               printk("RTAS Event Scan Rate: %u (%lu jiffies)\n",
-                      *p, ppc_md.heartbeat_reset);
-       }
-
        pci_create_OF_bus_map();
 
        /*
@@ -312,7 +300,7 @@ void __init chrp_setup_arch(void)
 }
 
 void
-chrp_event_scan(void)
+chrp_event_scan(unsigned long unused)
 {
        unsigned char log[1024];
        int ret = 0;
@@ -320,7 +308,8 @@ chrp_event_scan(void)
        /* 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);
-       ppc_md.heartbeat_count = ppc_md.heartbeat_reset;
+       mod_timer(&__get_cpu_var(heartbeat_timer),
+                 jiffies + event_scan_interval);
 }
 
 /*
@@ -465,6 +454,9 @@ void __init chrp_init_IRQ(void)
 void __init
 chrp_init2(void)
 {
+       struct device_node *device;
+       unsigned int *p = NULL;
+
 #ifdef CONFIG_NVRAM
        chrp_nvram_init();
 #endif
@@ -476,6 +468,40 @@ 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 = find_devices("rtas");
+       if (device)
+               p = (unsigned int *) 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);
+       }
+
        if (ppc_md.progress)
                ppc_md.progress("  Have fun!    ", 0x7777);
 }

diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index 21c8dc9..758e47f 100644 (file)
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -176,10 +176,6 @@ struct machdep_calls {
           May be NULL. */
        void            (*init)(void);
 
-       void            (*heartbeat)(void);
-       unsigned long   heartbeat_reset;
-       unsigned long   heartbeat_count;
-
        void            (*setup_io_mappings)(void);
 
        void            (*early_serial_map)(void);