include/asm-ppc64/paca.h

   1 #ifndef _PPC64_PACA_H
   2 #define _PPC64_PACA_H
   3
   4 /*
   5  * include/asm-ppc64/paca.h
   6  *
   7  * This control block defines the PACA which defines the processor
   8  * specific data for each logical processor on the system.
   9  * There are some pointers defined that are utilized by PLIC.
  10  *
  11  * C 2001 PPC 64 Team, IBM Corp
  12  *
  13  * This program is free software; you can redistribute it and/or
  14  * modify it under the terms of the GNU General Public License
  15  * as published by the Free Software Foundation; either version
  16  * 2 of the License, or (at your option) any later version.
  17  */
  18
  19 #include        <linux/config.h>
  20 #include        <asm/types.h>
  21 #include        <asm/lppaca.h>
  22 #include        <asm/iSeries/ItLpRegSave.h>
  23 #include        <asm/mmu.h>
  24
  25 register struct paca_struct *local_paca asm("r13");
  26 #define get_paca()      local_paca
  27
  28 struct task_struct;
  29
  30 /*
  31  * Defines the layout of the paca.
  32  *
  33  * This structure is not directly accessed by firmware or the service
  34  * processor except for the first two pointers that point to the
  35  * lppaca area and the ItLpRegSave area for this CPU.  Both the
  36  * lppaca and ItLpRegSave objects are currently contained within the
  37  * PACA but they do not need to be.
  38  */
  39 struct paca_struct {
  40         /*
  41          * Because hw_cpu_id, unlike other paca fields, is accessed
  42          * routinely from other CPUs (from the IRQ code), we stick to
  43          * read-only (after boot) fields in the first cacheline to
  44          * avoid cacheline bouncing.
  45          */
  46
  47         /*
  48          * MAGIC: These first two pointers can't be moved - they're
  49          * accessed by the firmware
  50          */
  51         struct lppaca *lppaca_ptr;      /* Pointer to LpPaca for PLIC */
  52         struct ItLpRegSave *reg_save_ptr; /* Pointer to LpRegSave for PLIC */
  53
  54         /*
  55          * MAGIC: the spinlock functions in arch/ppc64/lib/locks.c
  56          * load lock_token and paca_index with a single lwz
  57          * instruction.  They must travel together and be properly
  58          * aligned.
  59          */
  60         u16 lock_token;                 /* Constant 0x8000, used in locks */
  61         u16 paca_index;                 /* Logical processor number */
  62
  63         u32 default_decr;               /* Default decrementer value */
  64         u64 kernel_toc;                 /* Kernel TOC address */
  65         u64 stab_real;                  /* Absolute address of segment table */
  66         u64 stab_addr;                  /* Virtual address of segment table */
  67         void *emergency_sp;             /* pointer to emergency stack */
  68         s16 hw_cpu_id;                  /* Physical processor number */
  69         u8 cpu_start;                   /* At startup, processor spins until */
  70                                         /* this becomes non-zero. */
  71
  72         /*
  73          * Now, starting in cacheline 2, the exception save areas
  74          */
  75         u64 exgen[8] __attribute__((aligned(0x80))); /* used for most interrupts/exceptions */
  76         u64 exmc[8];            /* used for machine checks */
  77         u64 exslb[8];           /* used for SLB/segment table misses
  78                                  * on the linear mapping */
  79         mm_context_t context;
  80         u16 slb_cache[SLB_CACHE_ENTRIES];
  81         u16 slb_cache_ptr;
  82
  83         /*
  84          * then miscellaneous read-write fields
  85          */
  86         struct task_struct *__current;  /* Pointer to current */
  87         u64 kstack;                     /* Saved Kernel stack addr */
  88         u64 stab_rr;                    /* stab/slb round-robin counter */
  89         u64 next_jiffy_update_tb;       /* TB value for next jiffy update */
  90         u64 saved_r1;                   /* r1 save for RTAS calls */
  91         u64 saved_msr;                  /* MSR saved here by enter_rtas */
  92         u8 proc_enabled;                /* irq soft-enable flag */
  93
  94         /* not yet used */
  95         u64 exdsi[8];           /* used for linear mapping hash table misses */
  96
  97         /*
  98          * iSeries structure which the hypervisor knows about -
  99          * this structure should not cross a page boundary.
 100          * The vpa_init/register_vpa call is now known to fail if the
 101          * lppaca structure crosses a page boundary.
 102          * The lppaca is also used on POWER5 pSeries boxes.
 103          * The lppaca is 640 bytes long, and cannot readily change
 104          * since the hypervisor knows its layout, so a 1kB
 105          * alignment will suffice to ensure that it doesn't
 106          * cross a page boundary.
 107          */
 108         struct lppaca lppaca __attribute__((__aligned__(0x400)));
 109 #ifdef CONFIG_PPC_ISERIES
 110         struct ItLpRegSave reg_save;
 111 #endif
 112 };
 113
 114 extern struct paca_struct paca[];
 115
 116 #endif /* _PPC64_PACA_H */