diff options
author | Al Viro <viro@zeniv.linux.org.uk> | 2008-08-17 21:05:42 -0400 |
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committer | H. Peter Anvin <hpa@zytor.com> | 2008-10-23 01:55:20 -0400 |
commit | bb8985586b7a906e116db835c64773b7a7d51663 (patch) | |
tree | de93ae58e88cc563d95cc124a73f3930594c6100 /arch/x86/include/asm/mc146818rtc.h | |
parent | 8ede0bdb63305d3353efd97e9af6210afb05734e (diff) |
x86, um: ... and asm-x86 move
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Diffstat (limited to 'arch/x86/include/asm/mc146818rtc.h')
-rw-r--r-- | arch/x86/include/asm/mc146818rtc.h | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mc146818rtc.h b/arch/x86/include/asm/mc146818rtc.h new file mode 100644 index 000000000000..a995f33176cd --- /dev/null +++ b/arch/x86/include/asm/mc146818rtc.h | |||
@@ -0,0 +1,104 @@ | |||
1 | /* | ||
2 | * Machine dependent access functions for RTC registers. | ||
3 | */ | ||
4 | #ifndef ASM_X86__MC146818RTC_H | ||
5 | #define ASM_X86__MC146818RTC_H | ||
6 | |||
7 | #include <asm/io.h> | ||
8 | #include <asm/system.h> | ||
9 | #include <asm/processor.h> | ||
10 | #include <linux/mc146818rtc.h> | ||
11 | |||
12 | #ifndef RTC_PORT | ||
13 | #define RTC_PORT(x) (0x70 + (x)) | ||
14 | #define RTC_ALWAYS_BCD 1 /* RTC operates in binary mode */ | ||
15 | #endif | ||
16 | |||
17 | #if defined(CONFIG_X86_32) && defined(__HAVE_ARCH_CMPXCHG) | ||
18 | /* | ||
19 | * This lock provides nmi access to the CMOS/RTC registers. It has some | ||
20 | * special properties. It is owned by a CPU and stores the index register | ||
21 | * currently being accessed (if owned). The idea here is that it works | ||
22 | * like a normal lock (normally). However, in an NMI, the NMI code will | ||
23 | * first check to see if its CPU owns the lock, meaning that the NMI | ||
24 | * interrupted during the read/write of the device. If it does, it goes ahead | ||
25 | * and performs the access and then restores the index register. If it does | ||
26 | * not, it locks normally. | ||
27 | * | ||
28 | * Note that since we are working with NMIs, we need this lock even in | ||
29 | * a non-SMP machine just to mark that the lock is owned. | ||
30 | * | ||
31 | * This only works with compare-and-swap. There is no other way to | ||
32 | * atomically claim the lock and set the owner. | ||
33 | */ | ||
34 | #include <linux/smp.h> | ||
35 | extern volatile unsigned long cmos_lock; | ||
36 | |||
37 | /* | ||
38 | * All of these below must be called with interrupts off, preempt | ||
39 | * disabled, etc. | ||
40 | */ | ||
41 | |||
42 | static inline void lock_cmos(unsigned char reg) | ||
43 | { | ||
44 | unsigned long new; | ||
45 | new = ((smp_processor_id() + 1) << 8) | reg; | ||
46 | for (;;) { | ||
47 | if (cmos_lock) { | ||
48 | cpu_relax(); | ||
49 | continue; | ||
50 | } | ||
51 | if (__cmpxchg(&cmos_lock, 0, new, sizeof(cmos_lock)) == 0) | ||
52 | return; | ||
53 | } | ||
54 | } | ||
55 | |||
56 | static inline void unlock_cmos(void) | ||
57 | { | ||
58 | cmos_lock = 0; | ||
59 | } | ||
60 | |||
61 | static inline int do_i_have_lock_cmos(void) | ||
62 | { | ||
63 | return (cmos_lock >> 8) == (smp_processor_id() + 1); | ||
64 | } | ||
65 | |||
66 | static inline unsigned char current_lock_cmos_reg(void) | ||
67 | { | ||
68 | return cmos_lock & 0xff; | ||
69 | } | ||
70 | |||
71 | #define lock_cmos_prefix(reg) \ | ||
72 | do { \ | ||
73 | unsigned long cmos_flags; \ | ||
74 | local_irq_save(cmos_flags); \ | ||
75 | lock_cmos(reg) | ||
76 | |||
77 | #define lock_cmos_suffix(reg) \ | ||
78 | unlock_cmos(); \ | ||
79 | local_irq_restore(cmos_flags); \ | ||
80 | } while (0) | ||
81 | #else | ||
82 | #define lock_cmos_prefix(reg) do {} while (0) | ||
83 | #define lock_cmos_suffix(reg) do {} while (0) | ||
84 | #define lock_cmos(reg) | ||
85 | #define unlock_cmos() | ||
86 | #define do_i_have_lock_cmos() 0 | ||
87 | #define current_lock_cmos_reg() 0 | ||
88 | #endif | ||
89 | |||
90 | /* | ||
91 | * The yet supported machines all access the RTC index register via | ||
92 | * an ISA port access but the way to access the date register differs ... | ||
93 | */ | ||
94 | #define CMOS_READ(addr) rtc_cmos_read(addr) | ||
95 | #define CMOS_WRITE(val, addr) rtc_cmos_write(val, addr) | ||
96 | unsigned char rtc_cmos_read(unsigned char addr); | ||
97 | void rtc_cmos_write(unsigned char val, unsigned char addr); | ||
98 | |||
99 | extern int mach_set_rtc_mmss(unsigned long nowtime); | ||
100 | extern unsigned long mach_get_cmos_time(void); | ||
101 | |||
102 | #define RTC_IRQ 8 | ||
103 | |||
104 | #endif /* ASM_X86__MC146818RTC_H */ | ||