i2c: Kerneldoc for most I/O calls
[linux-ginger.git] / include / asm-ia64 / system.h
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1 #ifndef _ASM_IA64_SYSTEM_H
2 #define _ASM_IA64_SYSTEM_H
4 /*
5 * System defines. Note that this is included both from .c and .S
6 * files, so it does only defines, not any C code. This is based
7 * on information published in the Processor Abstraction Layer
8 * and the System Abstraction Layer manual.
10 * Copyright (C) 1998-2003 Hewlett-Packard Co
11 * David Mosberger-Tang <davidm@hpl.hp.com>
12 * Copyright (C) 1999 Asit Mallick <asit.k.mallick@intel.com>
13 * Copyright (C) 1999 Don Dugger <don.dugger@intel.com>
16 #include <asm/kregs.h>
17 #include <asm/page.h>
18 #include <asm/pal.h>
19 #include <asm/percpu.h>
21 #define GATE_ADDR RGN_BASE(RGN_GATE)
24 * 0xa000000000000000+2*PERCPU_PAGE_SIZE
25 * - 0xa000000000000000+3*PERCPU_PAGE_SIZE remain unmapped (guard page)
27 #define KERNEL_START (GATE_ADDR+__IA64_UL_CONST(0x100000000))
28 #define PERCPU_ADDR (-PERCPU_PAGE_SIZE)
30 #ifndef __ASSEMBLY__
32 #include <linux/kernel.h>
33 #include <linux/types.h>
35 #define AT_VECTOR_SIZE_ARCH 2 /* entries in ARCH_DLINFO */
37 struct pci_vector_struct {
38 __u16 segment; /* PCI Segment number */
39 __u16 bus; /* PCI Bus number */
40 __u32 pci_id; /* ACPI split 16 bits device, 16 bits function (see section 6.1.1) */
41 __u8 pin; /* PCI PIN (0 = A, 1 = B, 2 = C, 3 = D) */
42 __u32 irq; /* IRQ assigned */
45 extern struct ia64_boot_param {
46 __u64 command_line; /* physical address of command line arguments */
47 __u64 efi_systab; /* physical address of EFI system table */
48 __u64 efi_memmap; /* physical address of EFI memory map */
49 __u64 efi_memmap_size; /* size of EFI memory map */
50 __u64 efi_memdesc_size; /* size of an EFI memory map descriptor */
51 __u32 efi_memdesc_version; /* memory descriptor version */
52 struct {
53 __u16 num_cols; /* number of columns on console output device */
54 __u16 num_rows; /* number of rows on console output device */
55 __u16 orig_x; /* cursor's x position */
56 __u16 orig_y; /* cursor's y position */
57 } console_info;
58 __u64 fpswa; /* physical address of the fpswa interface */
59 __u64 initrd_start;
60 __u64 initrd_size;
61 } *ia64_boot_param;
64 * Macros to force memory ordering. In these descriptions, "previous"
65 * and "subsequent" refer to program order; "visible" means that all
66 * architecturally visible effects of a memory access have occurred
67 * (at a minimum, this means the memory has been read or written).
69 * wmb(): Guarantees that all preceding stores to memory-
70 * like regions are visible before any subsequent
71 * stores and that all following stores will be
72 * visible only after all previous stores.
73 * rmb(): Like wmb(), but for reads.
74 * mb(): wmb()/rmb() combo, i.e., all previous memory
75 * accesses are visible before all subsequent
76 * accesses and vice versa. This is also known as
77 * a "fence."
79 * Note: "mb()" and its variants cannot be used as a fence to order
80 * accesses to memory mapped I/O registers. For that, mf.a needs to
81 * be used. However, we don't want to always use mf.a because (a)
82 * it's (presumably) much slower than mf and (b) mf.a is supported for
83 * sequential memory pages only.
85 #define mb() ia64_mf()
86 #define rmb() mb()
87 #define wmb() mb()
88 #define read_barrier_depends() do { } while(0)
90 #ifdef CONFIG_SMP
91 # define smp_mb() mb()
92 # define smp_rmb() rmb()
93 # define smp_wmb() wmb()
94 # define smp_read_barrier_depends() read_barrier_depends()
95 #else
96 # define smp_mb() barrier()
97 # define smp_rmb() barrier()
98 # define smp_wmb() barrier()
99 # define smp_read_barrier_depends() do { } while(0)
100 #endif
103 * XXX check on this ---I suspect what Linus really wants here is
104 * acquire vs release semantics but we can't discuss this stuff with
105 * Linus just yet. Grrr...
107 #define set_mb(var, value) do { (var) = (value); mb(); } while (0)
109 #define safe_halt() ia64_pal_halt_light() /* PAL_HALT_LIGHT */
112 * The group barrier in front of the rsm & ssm are necessary to ensure
113 * that none of the previous instructions in the same group are
114 * affected by the rsm/ssm.
116 /* For spinlocks etc */
119 * - clearing psr.i is implicitly serialized (visible by next insn)
120 * - setting psr.i requires data serialization
121 * - we need a stop-bit before reading PSR because we sometimes
122 * write a floating-point register right before reading the PSR
123 * and that writes to PSR.mfl
125 #define __local_irq_save(x) \
126 do { \
127 ia64_stop(); \
128 (x) = ia64_getreg(_IA64_REG_PSR); \
129 ia64_stop(); \
130 ia64_rsm(IA64_PSR_I); \
131 } while (0)
133 #define __local_irq_disable() \
134 do { \
135 ia64_stop(); \
136 ia64_rsm(IA64_PSR_I); \
137 } while (0)
139 #define __local_irq_restore(x) ia64_intrin_local_irq_restore((x) & IA64_PSR_I)
141 #ifdef CONFIG_IA64_DEBUG_IRQ
143 extern unsigned long last_cli_ip;
145 # define __save_ip() last_cli_ip = ia64_getreg(_IA64_REG_IP)
147 # define local_irq_save(x) \
148 do { \
149 unsigned long __psr; \
151 __local_irq_save(__psr); \
152 if (__psr & IA64_PSR_I) \
153 __save_ip(); \
154 (x) = __psr; \
155 } while (0)
157 # define local_irq_disable() do { unsigned long __x; local_irq_save(__x); } while (0)
159 # define local_irq_restore(x) \
160 do { \
161 unsigned long __old_psr, __psr = (x); \
163 local_save_flags(__old_psr); \
164 __local_irq_restore(__psr); \
165 if ((__old_psr & IA64_PSR_I) && !(__psr & IA64_PSR_I)) \
166 __save_ip(); \
167 } while (0)
169 #else /* !CONFIG_IA64_DEBUG_IRQ */
170 # define local_irq_save(x) __local_irq_save(x)
171 # define local_irq_disable() __local_irq_disable()
172 # define local_irq_restore(x) __local_irq_restore(x)
173 #endif /* !CONFIG_IA64_DEBUG_IRQ */
175 #define local_irq_enable() ({ ia64_stop(); ia64_ssm(IA64_PSR_I); ia64_srlz_d(); })
176 #define local_save_flags(flags) ({ ia64_stop(); (flags) = ia64_getreg(_IA64_REG_PSR); })
178 #define irqs_disabled() \
179 ({ \
180 unsigned long __ia64_id_flags; \
181 local_save_flags(__ia64_id_flags); \
182 (__ia64_id_flags & IA64_PSR_I) == 0; \
185 #ifdef __KERNEL__
187 #ifdef CONFIG_IA32_SUPPORT
188 # define IS_IA32_PROCESS(regs) (ia64_psr(regs)->is != 0)
189 #else
190 # define IS_IA32_PROCESS(regs) 0
191 struct task_struct;
192 static inline void ia32_save_state(struct task_struct *t __attribute__((unused))){}
193 static inline void ia32_load_state(struct task_struct *t __attribute__((unused))){}
194 #endif
197 * Context switch from one thread to another. If the two threads have
198 * different address spaces, schedule() has already taken care of
199 * switching to the new address space by calling switch_mm().
201 * Disabling access to the fph partition and the debug-register
202 * context switch MUST be done before calling ia64_switch_to() since a
203 * newly created thread returns directly to
204 * ia64_ret_from_syscall_clear_r8.
206 extern struct task_struct *ia64_switch_to (void *next_task);
208 struct task_struct;
210 extern void ia64_save_extra (struct task_struct *task);
211 extern void ia64_load_extra (struct task_struct *task);
213 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
214 extern void ia64_account_on_switch (struct task_struct *prev, struct task_struct *next);
215 # define IA64_ACCOUNT_ON_SWITCH(p,n) ia64_account_on_switch(p,n)
216 #else
217 # define IA64_ACCOUNT_ON_SWITCH(p,n)
218 #endif
220 #ifdef CONFIG_PERFMON
221 DECLARE_PER_CPU(unsigned long, pfm_syst_info);
222 # define PERFMON_IS_SYSWIDE() (__get_cpu_var(pfm_syst_info) & 0x1)
223 #else
224 # define PERFMON_IS_SYSWIDE() (0)
225 #endif
227 #define IA64_HAS_EXTRA_STATE(t) \
228 ((t)->thread.flags & (IA64_THREAD_DBG_VALID|IA64_THREAD_PM_VALID) \
229 || IS_IA32_PROCESS(task_pt_regs(t)) || PERFMON_IS_SYSWIDE())
231 #define __switch_to(prev,next,last) do { \
232 IA64_ACCOUNT_ON_SWITCH(prev, next); \
233 if (IA64_HAS_EXTRA_STATE(prev)) \
234 ia64_save_extra(prev); \
235 if (IA64_HAS_EXTRA_STATE(next)) \
236 ia64_load_extra(next); \
237 ia64_psr(task_pt_regs(next))->dfh = !ia64_is_local_fpu_owner(next); \
238 (last) = ia64_switch_to((next)); \
239 } while (0)
241 #ifdef CONFIG_SMP
243 * In the SMP case, we save the fph state when context-switching away from a thread that
244 * modified fph. This way, when the thread gets scheduled on another CPU, the CPU can
245 * pick up the state from task->thread.fph, avoiding the complication of having to fetch
246 * the latest fph state from another CPU. In other words: eager save, lazy restore.
248 # define switch_to(prev,next,last) do { \
249 if (ia64_psr(task_pt_regs(prev))->mfh && ia64_is_local_fpu_owner(prev)) { \
250 ia64_psr(task_pt_regs(prev))->mfh = 0; \
251 (prev)->thread.flags |= IA64_THREAD_FPH_VALID; \
252 __ia64_save_fpu((prev)->thread.fph); \
254 __switch_to(prev, next, last); \
255 /* "next" in old context is "current" in new context */ \
256 if (unlikely((current->thread.flags & IA64_THREAD_MIGRATION) && \
257 (task_cpu(current) != \
258 task_thread_info(current)->last_cpu))) { \
259 platform_migrate(current); \
260 task_thread_info(current)->last_cpu = task_cpu(current); \
262 } while (0)
263 #else
264 # define switch_to(prev,next,last) __switch_to(prev, next, last)
265 #endif
267 #define __ARCH_WANT_UNLOCKED_CTXSW
268 #define ARCH_HAS_PREFETCH_SWITCH_STACK
269 #define ia64_platform_is(x) (strcmp(x, platform_name) == 0)
271 void cpu_idle_wait(void);
273 #define arch_align_stack(x) (x)
275 void default_idle(void);
277 #ifdef CONFIG_VIRT_CPU_ACCOUNTING
278 extern void account_system_vtime(struct task_struct *);
279 #endif
281 #endif /* __KERNEL__ */
283 #endif /* __ASSEMBLY__ */
285 #endif /* _ASM_IA64_SYSTEM_H */