ia64/linux-2.6.18-xen.hg

view include/asm-i386/mc146818rtc.h @ 452:c7ed6fe5dca0

kexec: dont initialise regions in reserve_memory()

There is no need to initialise efi_memmap_res and boot_param_res in
reserve_memory() for the initial xen domain as it is done in
machine_kexec_setup_resources() using values from the kexec hypercall.

Signed-off-by: Simon Horman <horms@verge.net.au>
author Keir Fraser <keir.fraser@citrix.com>
date Thu Feb 28 10:55:18 2008 +0000 (2008-02-28)
parents 831230e53067
children
line source
1 /*
2 * Machine dependent access functions for RTC registers.
3 */
4 #ifndef _ASM_MC146818RTC_H
5 #define _ASM_MC146818RTC_H
7 #include <asm/io.h>
8 #include <asm/system.h>
9 #include <linux/mc146818rtc.h>
11 #ifndef RTC_PORT
12 #define RTC_PORT(x) (0x70 + (x))
13 #define RTC_ALWAYS_BCD 1 /* RTC operates in binary mode */
14 #endif
16 #ifdef __HAVE_ARCH_CMPXCHG
17 /*
18 * This lock provides nmi access to the CMOS/RTC registers. It has some
19 * special properties. It is owned by a CPU and stores the index register
20 * currently being accessed (if owned). The idea here is that it works
21 * like a normal lock (normally). However, in an NMI, the NMI code will
22 * first check to see if its CPU owns the lock, meaning that the NMI
23 * interrupted during the read/write of the device. If it does, it goes ahead
24 * and performs the access and then restores the index register. If it does
25 * not, it locks normally.
26 *
27 * Note that since we are working with NMIs, we need this lock even in
28 * a non-SMP machine just to mark that the lock is owned.
29 *
30 * This only works with compare-and-swap. There is no other way to
31 * atomically claim the lock and set the owner.
32 */
33 #include <linux/smp.h>
34 extern volatile unsigned long cmos_lock;
36 /*
37 * All of these below must be called with interrupts off, preempt
38 * disabled, etc.
39 */
41 static inline void lock_cmos(unsigned char reg)
42 {
43 unsigned long new;
44 new = ((smp_processor_id()+1) << 8) | reg;
45 for (;;) {
46 if (cmos_lock)
47 continue;
48 if (__cmpxchg(&cmos_lock, 0, new, sizeof(cmos_lock)) == 0)
49 return;
50 }
51 }
53 static inline void unlock_cmos(void)
54 {
55 cmos_lock = 0;
56 }
57 static inline int do_i_have_lock_cmos(void)
58 {
59 return (cmos_lock >> 8) == (smp_processor_id()+1);
60 }
61 static inline unsigned char current_lock_cmos_reg(void)
62 {
63 return cmos_lock & 0xff;
64 }
65 #define lock_cmos_prefix(reg) \
66 do { \
67 unsigned long cmos_flags; \
68 local_irq_save(cmos_flags); \
69 lock_cmos(reg)
70 #define lock_cmos_suffix(reg) \
71 unlock_cmos(); \
72 local_irq_restore(cmos_flags); \
73 } while (0)
74 #else
75 #define lock_cmos_prefix(reg) do {} while (0)
76 #define lock_cmos_suffix(reg) do {} while (0)
77 #define lock_cmos(reg)
78 #define unlock_cmos()
79 #define do_i_have_lock_cmos() 0
80 #define current_lock_cmos_reg() 0
81 #endif
83 /*
84 * The yet supported machines all access the RTC index register via
85 * an ISA port access but the way to access the date register differs ...
86 */
87 #define CMOS_READ(addr) rtc_cmos_read(addr)
88 #define CMOS_WRITE(val, addr) rtc_cmos_write(val, addr)
89 unsigned char rtc_cmos_read(unsigned char addr);
90 void rtc_cmos_write(unsigned char val, unsigned char addr);
92 #define RTC_IRQ 8
94 #endif /* _ASM_MC146818RTC_H */