arch/powerpc/kernel/paca.c

   1 /*
   2  * c 2001 PPC 64 Team, IBM Corp
   3  *
   4  *      This program is free software; you can redistribute it and/or
   5  *      modify it under the terms of the GNU General Public License
   6  *      as published by the Free Software Foundation; either version
   7  *      2 of the License, or (at your option) any later version.
   8  */
   9
  10 #include <linux/threads.h>
  11 #include <linux/module.h>
  12
  13 #include <asm/lppaca.h>
  14 #include <asm/paca.h>
  15 #include <asm/sections.h>
  16
  17 /* This symbol is provided by the linker - let it fill in the paca
  18  * field correctly */
  19 extern unsigned long __toc_start;
  20
  21 /*
  22  * The structure which the hypervisor knows about - this structure
  23  * should not cross a page boundary.  The vpa_init/register_vpa call
  24  * is now known to fail if the lppaca structure crosses a page
  25  * boundary.  The lppaca is also used on legacy iSeries and POWER5
  26  * pSeries boxes.  The lppaca is 640 bytes long, and cannot readily
  27  * change since the hypervisor knows its layout, so a 1kB alignment
  28  * will suffice to ensure that it doesn't cross a page boundary.
  29  */
  30 struct lppaca lppaca[] = {
  31         [0 ... (NR_CPUS-1)] = {
  32                 .desc = 0xd397d781,     /* "LpPa" */
  33                 .size = sizeof(struct lppaca),
  34                 .dyn_proc_status = 2,
  35                 .decr_val = 0x00ff0000,
  36                 .fpregs_in_use = 1,
  37                 .end_of_quantum = 0xfffffffffffffffful,
  38                 .slb_count = 64,
  39                 .vmxregs_in_use = 0,
  40         },
  41 };
  42
  43 /*
  44  * 3 persistent SLBs are registered here.  The buffer will be zero
  45  * initially, hence will all be invaild until we actually write them.
  46  */
  47 struct slb_shadow slb_shadow[] __cacheline_aligned = {
  48         [0 ... (NR_CPUS-1)] = {
  49                 .persistent = SLB_NUM_BOLTED,
  50                 .buffer_length = sizeof(struct slb_shadow),
  51         },
  52 };
  53
  54 /* The Paca is an array with one entry per processor.  Each contains an
  55  * lppaca, which contains the information shared between the
  56  * hypervisor and Linux.
  57  * On systems with hardware multi-threading, there are two threads
  58  * per processor.  The Paca array must contain an entry for each thread.
  59  * The VPD Areas will give a max logical processors = 2 * max physical
  60  * processors.  The processor VPD array needs one entry per physical
  61  * processor (not thread).
  62  */
  63 struct paca_struct paca[NR_CPUS];
  64 EXPORT_SYMBOL(paca);
  65
  66 void __init initialise_pacas(void)
  67 {
  68         int cpu;
  69
  70         /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
  71          * of the TOC can be addressed using a single machine instruction.
  72          */
  73         unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
  74
  75         /* Can't use for_each_*_cpu, as they aren't functional yet */
  76         for (cpu = 0; cpu < NR_CPUS; cpu++) {
  77                 struct paca_struct *new_paca = &paca[cpu];
  78
  79                 new_paca->lppaca_ptr = &lppaca[cpu];
  80                 new_paca->lock_token = 0x8000;
  81                 new_paca->paca_index = cpu;
  82                 new_paca->kernel_toc = kernel_toc;
  83                 new_paca->kernelbase = (unsigned long) _stext;
  84                 new_paca->kernel_msr = MSR_KERNEL;
  85                 new_paca->hw_cpu_id = 0xffff;
  86                 new_paca->slb_shadow_ptr = &slb_shadow[cpu];
  87                 new_paca->__current = &init_task;
  88
  89         }
  90 }