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author | Ivan Kokshaysky <ink@jurassic.park.msu.ru> | 2009-01-15 22:51:19 +0100 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-01-16 01:39:40 +0100 |
commit | 5f7dc5d75076fd1c1fc6bc09f2467509d20db24a (patch) | |
tree | c105f8463607381acd7d02bdda75641b3f497e37 /arch/alpha/kernel/sys_marvel.c | |
parent | alpha: nautilus - fix hang on boot (diff) | |
download | linux-5f7dc5d75076fd1c1fc6bc09f2467509d20db24a.tar.xz linux-5f7dc5d75076fd1c1fc6bc09f2467509d20db24a.zip |
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>
Diffstat (limited to 'arch/alpha/kernel/sys_marvel.c')
-rw-r--r-- | arch/alpha/kernel/sys_marvel.c | 56 |
1 files changed, 55 insertions, 1 deletions
diff --git a/arch/alpha/kernel/sys_marvel.c b/arch/alpha/kernel/sys_marvel.c index 828449cd2636..c5a1a2438c67 100644 --- 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, |