alpha: fix RTC on marvel

Unlike other alphas, marvel doesn't have real PC-style CMOS clock hardware
- RTC accesses are emulated via PAL calls.  Unfortunately, for unknown
reason these calls work only on CPU #0.  So current implementation for
arbitrary CPU makes CMOS_READ/WRITE to be executed on CPU #0 via IPI.
However, for obvious reason this doesn't work with standard
get/set_rtc_time() functions, where a bunch of CMOS accesses is done with
disabled interrupts.

Solved by making the IPI calls for entire get/set_rtc_time() functions,
not for individual CMOS accesses.  Which is also a lot more effective
performance-wise.

The patch is largely based on the code from Jay Estabrook.
My changes:
- tweak asm-generic/rtc.h by adding a couple of #defines to
  avoid a massive code duplication in arch/alpha/include/asm/rtc.h;
- sys_marvel.c: fix get/set_rtc_time() return values (Jay's FIXMEs).

NOTE: this fixes *only* LIB_RTC drivers.  Legacy (CONFIG_RTC) driver
wont't work on marvel.  Actually I think that we should just disable
CONFIG_RTC on alpha (maybe in 2.6.30?), like most other arches - AFAIK,
all modern distributions use LIB_RTC anyway.

Signed-off-by: Ivan Kokshaysky <ink@jurassic.park.msu.ru>
Cc: Richard Henderson <rth@twiddle.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/arch/alpha/include/asm/machvec.h b/arch/alpha/include/asm/machvec.h
index a86c083..fea4ea7 100644 (file)
--- a/arch/alpha/include/asm/machvec.h
+++ b/arch/alpha/include/asm/machvec.h
@@ -21,6 +21,7 @@ struct pci_dev;
 struct pci_ops;
 struct pci_controller;
 struct _alpha_agp_info;
+struct rtc_time;
 
 struct alpha_machine_vector
 {
@@ -94,6 +95,9 @@ struct alpha_machine_vector
 
        struct _alpha_agp_info *(*agp_info)(void);
 
+       unsigned int (*rtc_get_time)(struct rtc_time *);
+       int (*rtc_set_time)(struct rtc_time *);
+
        const char *vector_name;
 
        /* NUMA information */

diff --git a/arch/alpha/include/asm/rtc.h b/arch/alpha/include/asm/rtc.h
index 4e854b1..1f7fba6 100644 (file)
--- a/arch/alpha/include/asm/rtc.h
+++ b/arch/alpha/include/asm/rtc.h
@@ -1,9 +1,15 @@
 #ifndef _ALPHA_RTC_H
 #define _ALPHA_RTC_H
 
-/*
- * Alpha uses the default access methods for the RTC.
- */
+#if defined(CONFIG_ALPHA_GENERIC)
+# define get_rtc_time          alpha_mv.rtc_get_time
+# define set_rtc_time          alpha_mv.rtc_set_time
+#else
+# if defined(CONFIG_ALPHA_MARVEL) && defined(CONFIG_SMP)
+#  define get_rtc_time         marvel_get_rtc_time
+#  define set_rtc_time         marvel_set_rtc_time
+# endif
+#endif
 
 #include <asm-generic/rtc.h>
 

diff --git a/arch/alpha/kernel/core_marvel.c b/arch/alpha/kernel/core_marvel.c
index 9cd8dca..e302dae 100644 (file)
--- a/arch/alpha/kernel/core_marvel.c
+++ b/arch/alpha/kernel/core_marvel.c
@@ -658,16 +658,8 @@ __marvel_rtc_io(u8 b, unsigned long addr, int write)
                rtc_access.data = bcd2bin(b);
                rtc_access.function = 0x48 + !write;    /* GET/PUT_TOY */
 
-#ifdef CONFIG_SMP
-               if (smp_processor_id() != boot_cpuid)
-                       smp_call_function_single(boot_cpuid,
-                                                __marvel_access_rtc,
-                                                &rtc_access, 1);
-               else
-                       __marvel_access_rtc(&rtc_access);
-#else
                __marvel_access_rtc(&rtc_access);
-#endif
+
                ret = bin2bcd(rtc_access.data);
                break;
 

diff --git a/arch/alpha/kernel/machvec_impl.h b/arch/alpha/kernel/machvec_impl.h
index 466c9df..512685f 100644 (file)
--- a/arch/alpha/kernel/machvec_impl.h
+++ b/arch/alpha/kernel/machvec_impl.h
@@ -40,7 +40,10 @@
 #define CAT1(x,y)  x##y
 #define CAT(x,y)   CAT1(x,y)
 
-#define DO_DEFAULT_RTC .rtc_port = 0x70
+#define DO_DEFAULT_RTC \
+       .rtc_port = 0x70, \
+       .rtc_get_time = common_get_rtc_time, \
+       .rtc_set_time = common_set_rtc_time
 
 #define DO_EV4_MMU                                                     \
        .max_asn =                      EV4_MAX_ASN,                    \

diff --git a/arch/alpha/kernel/proto.h b/arch/alpha/kernel/proto.h
index 708d5ca..fe14c67 100644 (file)
--- a/arch/alpha/kernel/proto.h
+++ b/arch/alpha/kernel/proto.h
@@ -145,6 +145,8 @@ extern void smp_percpu_timer_interrupt(struct pt_regs *);
 extern irqreturn_t timer_interrupt(int irq, void *dev);
 extern void common_init_rtc(void);
 extern unsigned long est_cycle_freq;
+extern unsigned int common_get_rtc_time(struct rtc_time *time);
+extern int common_set_rtc_time(struct rtc_time *time);
 
 /* smc37c93x.c */
 extern void SMC93x_Init(void);

diff --git a/arch/alpha/kernel/sys_jensen.c b/arch/alpha/kernel/sys_jensen.c
index 2c3de97..e2516f9 100644 (file)
--- a/arch/alpha/kernel/sys_jensen.c
+++ b/arch/alpha/kernel/sys_jensen.c
@@ -261,6 +261,8 @@ struct alpha_machine_vector jensen_mv __initmv = {
        .machine_check          = jensen_machine_check,
        .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,
        .rtc_port               = 0x170,
+       .rtc_get_time           = common_get_rtc_time,
+       .rtc_set_time           = common_set_rtc_time,
 
        .nr_irqs                = 16,
        .device_interrupt       = jensen_device_interrupt,

diff --git a/arch/alpha/kernel/sys_marvel.c b/arch/alpha/kernel/sys_marvel.c
index 828449c..c5a1a24 100644 (file)
--- a/arch/alpha/kernel/sys_marvel.c
+++ b/arch/alpha/kernel/sys_marvel.c
@@ -23,6 +23,7 @@
 #include <asm/hwrpb.h>
 #include <asm/tlbflush.h>
 #include <asm/vga.h>
+#include <asm/rtc.h>
 
 #include "proto.h"
 #include "err_impl.h"
@@ -426,6 +427,57 @@ marvel_init_rtc(void)
        init_rtc_irq();
 }
 
+struct marvel_rtc_time {
+       struct rtc_time *time;
+       int retval;
+};
+
+#ifdef CONFIG_SMP
+static void
+smp_get_rtc_time(void *data)
+{
+       struct marvel_rtc_time *mrt = data;
+       mrt->retval = __get_rtc_time(mrt->time);
+}
+
+static void
+smp_set_rtc_time(void *data)
+{
+       struct marvel_rtc_time *mrt = data;
+       mrt->retval = __set_rtc_time(mrt->time);
+}
+#endif
+
+static unsigned int
+marvel_get_rtc_time(struct rtc_time *time)
+{
+#ifdef CONFIG_SMP
+       struct marvel_rtc_time mrt;
+
+       if (smp_processor_id() != boot_cpuid) {
+               mrt.time = time;
+               smp_call_function_single(boot_cpuid, smp_get_rtc_time, &mrt, 1);
+               return mrt.retval;
+       }
+#endif
+       return __get_rtc_time(time);
+}
+
+static int
+marvel_set_rtc_time(struct rtc_time *time)
+{
+#ifdef CONFIG_SMP
+       struct marvel_rtc_time mrt;
+
+       if (smp_processor_id() != boot_cpuid) {
+               mrt.time = time;
+               smp_call_function_single(boot_cpuid, smp_set_rtc_time, &mrt, 1);
+               return mrt.retval;
+       }
+#endif
+       return __set_rtc_time(time);
+}
+
 static void
 marvel_smp_callin(void)
 {
@@ -466,7 +518,9 @@ marvel_smp_callin(void)
 struct alpha_machine_vector marvel_ev7_mv __initmv = {
        .vector_name            = "MARVEL/EV7",
        DO_EV7_MMU,
-       DO_DEFAULT_RTC,
+       .rtc_port               = 0x70,
+       .rtc_get_time           = marvel_get_rtc_time,
+       .rtc_set_time           = marvel_set_rtc_time,
        DO_MARVEL_IO,
        .machine_check          = marvel_machine_check,
        .max_isa_dma_address    = ALPHA_MAX_ISA_DMA_ADDRESS,

diff --git a/arch/alpha/kernel/time.c b/arch/alpha/kernel/time.c
index e6a2314..b04e2cb 100644 (file)
--- a/arch/alpha/kernel/time.c
+++ b/arch/alpha/kernel/time.c
@@ -46,6 +46,7 @@
 #include <asm/io.h>
 #include <asm/hwrpb.h>
 #include <asm/8253pit.h>
+#include <asm/rtc.h>
 
 #include <linux/mc146818rtc.h>
 #include <linux/time.h>
@@ -180,6 +181,15 @@ common_init_rtc(void)
        init_rtc_irq();
 }
 
+unsigned int common_get_rtc_time(struct rtc_time *time)
+{
+       return __get_rtc_time(time);
+}
+
+int common_set_rtc_time(struct rtc_time *time)
+{
+       return __set_rtc_time(time);
+}
 
 /* Validate a computed cycle counter result against the known bounds for
    the given processor core.  There's too much brokenness in the way of

diff --git a/include/asm-generic/rtc.h b/include/asm-generic/rtc.h
index 89061c1..763e3b0 100644 (file)
--- a/include/asm-generic/rtc.h
+++ b/include/asm-generic/rtc.h
@@ -42,7 +42,7 @@ static inline unsigned char rtc_is_updating(void)
        return uip;
 }
 
-static inline unsigned int get_rtc_time(struct rtc_time *time)
+static inline unsigned int __get_rtc_time(struct rtc_time *time)
 {
        unsigned char ctrl;
        unsigned long flags;
@@ -108,8 +108,12 @@ static inline unsigned int get_rtc_time(struct rtc_time *time)
        return RTC_24H;
 }
 
+#ifndef get_rtc_time
+#define get_rtc_time   __get_rtc_time
+#endif
+
 /* Set the current date and time in the real time clock. */
-static inline int set_rtc_time(struct rtc_time *time)
+static inline int __set_rtc_time(struct rtc_time *time)
 {
        unsigned long flags;
        unsigned char mon, day, hrs, min, sec;
@@ -190,11 +194,15 @@ static inline int set_rtc_time(struct rtc_time *time)
        return 0;
 }
 
+#ifndef set_rtc_time
+#define set_rtc_time   __set_rtc_time
+#endif
+
 static inline unsigned int get_rtc_ss(void)
 {
        struct rtc_time h;
 
-       get_rtc_time(&h);
+       __get_rtc_time(&h);
        return h.tm_sec;
 }