[PATCH] blktrace: readahead support
[linux-2.6] / include / asm-ia64 / system.h
1 #ifndef _ASM_IA64_SYSTEM_H
2 #define _ASM_IA64_SYSTEM_H
3
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.
9  *
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>
14  */
15
16 #include <asm/kregs.h>
17 #include <asm/page.h>
18 #include <asm/pal.h>
19 #include <asm/percpu.h>
20
21 #define GATE_ADDR               RGN_BASE(RGN_GATE)
22
23 /*
24  * 0xa000000000000000+2*PERCPU_PAGE_SIZE
25  * - 0xa000000000000000+3*PERCPU_PAGE_SIZE remain unmapped (guard page)
26  */
27 #define KERNEL_START             (GATE_ADDR+0x100000000)
28 #define PERCPU_ADDR             (-PERCPU_PAGE_SIZE)
29
30 #ifndef __ASSEMBLY__
31
32 #include <linux/kernel.h>
33 #include <linux/types.h>
34
35 struct pci_vector_struct {
36         __u16 segment;  /* PCI Segment number */
37         __u16 bus;      /* PCI Bus number */
38         __u32 pci_id;   /* ACPI split 16 bits device, 16 bits function (see section 6.1.1) */
39         __u8 pin;       /* PCI PIN (0 = A, 1 = B, 2 = C, 3 = D) */
40         __u32 irq;      /* IRQ assigned */
41 };
42
43 extern struct ia64_boot_param {
44         __u64 command_line;             /* physical address of command line arguments */
45         __u64 efi_systab;               /* physical address of EFI system table */
46         __u64 efi_memmap;               /* physical address of EFI memory map */
47         __u64 efi_memmap_size;          /* size of EFI memory map */
48         __u64 efi_memdesc_size;         /* size of an EFI memory map descriptor */
49         __u32 efi_memdesc_version;      /* memory descriptor version */
50         struct {
51                 __u16 num_cols; /* number of columns on console output device */
52                 __u16 num_rows; /* number of rows on console output device */
53                 __u16 orig_x;   /* cursor's x position */
54                 __u16 orig_y;   /* cursor's y position */
55         } console_info;
56         __u64 fpswa;            /* physical address of the fpswa interface */
57         __u64 initrd_start;
58         __u64 initrd_size;
59 } *ia64_boot_param;
60
61 /*
62  * Macros to force memory ordering.  In these descriptions, "previous"
63  * and "subsequent" refer to program order; "visible" means that all
64  * architecturally visible effects of a memory access have occurred
65  * (at a minimum, this means the memory has been read or written).
66  *
67  *   wmb():     Guarantees that all preceding stores to memory-
68  *              like regions are visible before any subsequent
69  *              stores and that all following stores will be
70  *              visible only after all previous stores.
71  *   rmb():     Like wmb(), but for reads.
72  *   mb():      wmb()/rmb() combo, i.e., all previous memory
73  *              accesses are visible before all subsequent
74  *              accesses and vice versa.  This is also known as
75  *              a "fence."
76  *
77  * Note: "mb()" and its variants cannot be used as a fence to order
78  * accesses to memory mapped I/O registers.  For that, mf.a needs to
79  * be used.  However, we don't want to always use mf.a because (a)
80  * it's (presumably) much slower than mf and (b) mf.a is supported for
81  * sequential memory pages only.
82  */
83 #define mb()    ia64_mf()
84 #define rmb()   mb()
85 #define wmb()   mb()
86 #define read_barrier_depends()  do { } while(0)
87
88 #ifdef CONFIG_SMP
89 # define smp_mb()       mb()
90 # define smp_rmb()      rmb()
91 # define smp_wmb()      wmb()
92 # define smp_read_barrier_depends()     read_barrier_depends()
93 #else
94 # define smp_mb()       barrier()
95 # define smp_rmb()      barrier()
96 # define smp_wmb()      barrier()
97 # define smp_read_barrier_depends()     do { } while(0)
98 #endif
99
100 /*
101  * XXX check on these---I suspect what Linus really wants here is
102  * acquire vs release semantics but we can't discuss this stuff with
103  * Linus just yet.  Grrr...
104  */
105 #define set_mb(var, value)      do { (var) = (value); mb(); } while (0)
106 #define set_wmb(var, value)     do { (var) = (value); mb(); } while (0)
107
108 #define safe_halt()         ia64_pal_halt_light()    /* PAL_HALT_LIGHT */
109
110 /*
111  * The group barrier in front of the rsm & ssm are necessary to ensure
112  * that none of the previous instructions in the same group are
113  * affected by the rsm/ssm.
114  */
115 /* For spinlocks etc */
116
117 /*
118  * - clearing psr.i is implicitly serialized (visible by next insn)
119  * - setting psr.i requires data serialization
120  * - we need a stop-bit before reading PSR because we sometimes
121  *   write a floating-point register right before reading the PSR
122  *   and that writes to PSR.mfl
123  */
124 #define __local_irq_save(x)                     \
125 do {                                            \
126         ia64_stop();                            \
127         (x) = ia64_getreg(_IA64_REG_PSR);       \
128         ia64_stop();                            \
129         ia64_rsm(IA64_PSR_I);                   \
130 } while (0)
131
132 #define __local_irq_disable()                   \
133 do {                                            \
134         ia64_stop();                            \
135         ia64_rsm(IA64_PSR_I);                   \
136 } while (0)
137
138 #define __local_irq_restore(x)  ia64_intrin_local_irq_restore((x) & IA64_PSR_I)
139
140 #ifdef CONFIG_IA64_DEBUG_IRQ
141
142   extern unsigned long last_cli_ip;
143
144 # define __save_ip()            last_cli_ip = ia64_getreg(_IA64_REG_IP)
145
146 # define local_irq_save(x)                                      \
147 do {                                                            \
148         unsigned long psr;                                      \
149                                                                 \
150         __local_irq_save(psr);                                  \
151         if (psr & IA64_PSR_I)                                   \
152                 __save_ip();                                    \
153         (x) = psr;                                              \
154 } while (0)
155
156 # define local_irq_disable()    do { unsigned long x; local_irq_save(x); } while (0)
157
158 # define local_irq_restore(x)                                   \
159 do {                                                            \
160         unsigned long old_psr, psr = (x);                       \
161                                                                 \
162         local_save_flags(old_psr);                              \
163         __local_irq_restore(psr);                               \
164         if ((old_psr & IA64_PSR_I) && !(psr & IA64_PSR_I))      \
165                 __save_ip();                                    \
166 } while (0)
167
168 #else /* !CONFIG_IA64_DEBUG_IRQ */
169 # define local_irq_save(x)      __local_irq_save(x)
170 # define local_irq_disable()    __local_irq_disable()
171 # define local_irq_restore(x)   __local_irq_restore(x)
172 #endif /* !CONFIG_IA64_DEBUG_IRQ */
173
174 #define local_irq_enable()      ({ ia64_stop(); ia64_ssm(IA64_PSR_I); ia64_srlz_d(); })
175 #define local_save_flags(flags) ({ ia64_stop(); (flags) = ia64_getreg(_IA64_REG_PSR); })
176
177 #define irqs_disabled()                         \
178 ({                                              \
179         unsigned long __ia64_id_flags;          \
180         local_save_flags(__ia64_id_flags);      \
181         (__ia64_id_flags & IA64_PSR_I) == 0;    \
182 })
183
184 #ifdef __KERNEL__
185
186 #ifdef CONFIG_IA32_SUPPORT
187 # define IS_IA32_PROCESS(regs)  (ia64_psr(regs)->is != 0)
188 #else
189 # define IS_IA32_PROCESS(regs)          0
190 struct task_struct;
191 static inline void ia32_save_state(struct task_struct *t __attribute__((unused))){}
192 static inline void ia32_load_state(struct task_struct *t __attribute__((unused))){}
193 #endif
194
195 /*
196  * Context switch from one thread to another.  If the two threads have
197  * different address spaces, schedule() has already taken care of
198  * switching to the new address space by calling switch_mm().
199  *
200  * Disabling access to the fph partition and the debug-register
201  * context switch MUST be done before calling ia64_switch_to() since a
202  * newly created thread returns directly to
203  * ia64_ret_from_syscall_clear_r8.
204  */
205 extern struct task_struct *ia64_switch_to (void *next_task);
206
207 struct task_struct;
208
209 extern void ia64_save_extra (struct task_struct *task);
210 extern void ia64_load_extra (struct task_struct *task);
211
212 #ifdef CONFIG_PERFMON
213   DECLARE_PER_CPU(unsigned long, pfm_syst_info);
214 # define PERFMON_IS_SYSWIDE() (__get_cpu_var(pfm_syst_info) & 0x1)
215 #else
216 # define PERFMON_IS_SYSWIDE() (0)
217 #endif
218
219 #define IA64_HAS_EXTRA_STATE(t)                                                 \
220         ((t)->thread.flags & (IA64_THREAD_DBG_VALID|IA64_THREAD_PM_VALID)       \
221          || IS_IA32_PROCESS(task_pt_regs(t)) || PERFMON_IS_SYSWIDE())
222
223 #define __switch_to(prev,next,last) do {                                                         \
224         if (IA64_HAS_EXTRA_STATE(prev))                                                          \
225                 ia64_save_extra(prev);                                                           \
226         if (IA64_HAS_EXTRA_STATE(next))                                                          \
227                 ia64_load_extra(next);                                                           \
228         ia64_psr(task_pt_regs(next))->dfh = !ia64_is_local_fpu_owner(next);                      \
229         (last) = ia64_switch_to((next));                                                         \
230 } while (0)
231
232 #ifdef CONFIG_SMP
233 /*
234  * In the SMP case, we save the fph state when context-switching away from a thread that
235  * modified fph.  This way, when the thread gets scheduled on another CPU, the CPU can
236  * pick up the state from task->thread.fph, avoiding the complication of having to fetch
237  * the latest fph state from another CPU.  In other words: eager save, lazy restore.
238  */
239 # define switch_to(prev,next,last) do {                                         \
240         if (ia64_psr(task_pt_regs(prev))->mfh && ia64_is_local_fpu_owner(prev)) {                               \
241                 ia64_psr(task_pt_regs(prev))->mfh = 0;                  \
242                 (prev)->thread.flags |= IA64_THREAD_FPH_VALID;                  \
243                 __ia64_save_fpu((prev)->thread.fph);                            \
244         }                                                                       \
245         __switch_to(prev, next, last);                                          \
246         /* "next" in old context is "current" in new context */                 \
247         if (unlikely((current->thread.flags & IA64_THREAD_MIGRATION) &&        \
248                      (task_cpu(current) !=                                     \
249                                       task_thread_info(current)->last_cpu))) { \
250                 platform_migrate(current);                                     \
251                 task_thread_info(current)->last_cpu = task_cpu(current);       \
252         }                                                                      \
253 } while (0)
254 #else
255 # define switch_to(prev,next,last)      __switch_to(prev, next, last)
256 #endif
257
258 #define __ARCH_WANT_UNLOCKED_CTXSW
259 #define ARCH_HAS_PREFETCH_SWITCH_STACK
260 #define ia64_platform_is(x) (strcmp(x, platform_name) == 0)
261
262 void cpu_idle_wait(void);
263 void sched_cacheflush(void);
264
265 #define arch_align_stack(x) (x)
266
267 void default_idle(void);
268
269 #endif /* __KERNEL__ */
270
271 #endif /* __ASSEMBLY__ */
272
273 #endif /* _ASM_IA64_SYSTEM_H */