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 #include <linux/config.h>
  16
  17 #include <asm/kregs.h>
  18 #include <asm/page.h>
  19 #include <asm/pal.h>
  20 #include <asm/percpu.h>
  21
  22 #define GATE_ADDR               __IA64_UL_CONST(0xa000000000000000)
  23 /*
  24  * 0xa000000000000000+2*PERCPU_PAGE_SIZE
  25  * - 0xa000000000000000+3*PERCPU_PAGE_SIZE remain unmapped (guard page)
  26  */
  27 #define KERNEL_START             __IA64_UL_CONST(0xa000000100000000)
  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 #define prepare_to_switch()    do { } while(0)
 187
 188 #ifdef CONFIG_IA32_SUPPORT
 189 # define IS_IA32_PROCESS(regs)  (ia64_psr(regs)->is != 0)
 190 #else
 191 # define IS_IA32_PROCESS(regs)          0
 192 struct task_struct;
 193 static inline void ia32_save_state(struct task_struct *t __attribute__((unused))){}
 194 static inline void ia32_load_state(struct task_struct *t __attribute__((unused))){}
 195 #endif
 196
 197 /*
 198  * Context switch from one thread to another.  If the two threads have
 199  * different address spaces, schedule() has already taken care of
 200  * switching to the new address space by calling switch_mm().
 201  *
 202  * Disabling access to the fph partition and the debug-register
 203  * context switch MUST be done before calling ia64_switch_to() since a
 204  * newly created thread returns directly to
 205  * ia64_ret_from_syscall_clear_r8.
 206  */
 207 extern struct task_struct *ia64_switch_to (void *next_task);
 208
 209 struct task_struct;
 210
 211 extern void ia64_save_extra (struct task_struct *task);
 212 extern void ia64_load_extra (struct task_struct *task);
 213
 214 #ifdef CONFIG_PERFMON
 215   DECLARE_PER_CPU(unsigned long, pfm_syst_info);
 216 # define PERFMON_IS_SYSWIDE() (__get_cpu_var(pfm_syst_info) & 0x1)
 217 #else
 218 # define PERFMON_IS_SYSWIDE() (0)
 219 #endif
 220
 221 #define IA64_HAS_EXTRA_STATE(t)                                                 \
 222         ((t)->thread.flags & (IA64_THREAD_DBG_VALID|IA64_THREAD_PM_VALID)       \
 223          || IS_IA32_PROCESS(ia64_task_regs(t)) || PERFMON_IS_SYSWIDE())
 224
 225 #define __switch_to(prev,next,last) do {                                                         \
 226         if (IA64_HAS_EXTRA_STATE(prev))                                                          \
 227                 ia64_save_extra(prev);                                                           \
 228         if (IA64_HAS_EXTRA_STATE(next))                                                          \
 229                 ia64_load_extra(next);                                                           \
 230         ia64_psr(ia64_task_regs(next))->dfh = !ia64_is_local_fpu_owner(next);                    \
 231         (last) = ia64_switch_to((next));                                                         \
 232 } while (0)
 233
 234 #ifdef CONFIG_SMP
 235 /*
 236  * In the SMP case, we save the fph state when context-switching away from a thread that
 237  * modified fph.  This way, when the thread gets scheduled on another CPU, the CPU can
 238  * pick up the state from task->thread.fph, avoiding the complication of having to fetch
 239  * the latest fph state from another CPU.  In other words: eager save, lazy restore.
 240  */
 241 # define switch_to(prev,next,last) do {                                         \
 242         if (ia64_psr(ia64_task_regs(prev))->mfh && ia64_is_local_fpu_owner(prev)) {                             \
 243                 ia64_psr(ia64_task_regs(prev))->mfh = 0;                        \
 244                 (prev)->thread.flags |= IA64_THREAD_FPH_VALID;                  \
 245                 __ia64_save_fpu((prev)->thread.fph);                            \
 246         }                                                                       \
 247         __switch_to(prev, next, last);                                          \
 248 } while (0)
 249 #else
 250 # define switch_to(prev,next,last)      __switch_to(prev, next, last)
 251 #endif
 252
 253 /*
 254  * On IA-64, we don't want to hold the runqueue's lock during the low-level context-switch,
 255  * because that could cause a deadlock.  Here is an example by Erich Focht:
 256  *
 257  * Example:
 258  * CPU#0:
 259  * schedule()
 260  *    -> spin_lock_irq(&rq->lock)
 261  *    -> context_switch()
 262  *       -> wrap_mmu_context()
 263  *          -> read_lock(&tasklist_lock)
 264  *
 265  * CPU#1:
 266  * sys_wait4() or release_task() or forget_original_parent()
 267  *    -> write_lock(&tasklist_lock)
 268  *    -> do_notify_parent()
 269  *       -> wake_up_parent()
 270  *          -> try_to_wake_up()
 271  *             -> spin_lock_irq(&parent_rq->lock)
 272  *
 273  * If the parent's rq happens to be on CPU#0, we'll wait for the rq->lock
 274  * of that CPU which will not be released, because there we wait for the
 275  * tasklist_lock to become available.
 276  */
 277 #define prepare_arch_switch(rq, next)           \
 278 do {                                            \
 279         spin_lock(&(next)->switch_lock);        \
 280         spin_unlock(&(rq)->lock);               \
 281 } while (0)
 282 #define finish_arch_switch(rq, prev)    spin_unlock_irq(&(prev)->switch_lock)
 283 #define task_running(rq, p)             ((rq)->curr == (p) || spin_is_locked(&(p)->switch_lock))
 284
 285 #define ia64_platform_is(x) (strcmp(x, platform_name) == 0)
 286
 287 #endif /* __KERNEL__ */
 288
 289 #endif /* __ASSEMBLY__ */
 290
 291 #endif /* _ASM_IA64_SYSTEM_H */