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 #include <asm/pgtable.h>
  17
  18 /* This symbol is provided by the linker - let it fill in the paca
  19  * field correctly */
  20 extern unsigned long __toc_start;
  21
  22 #ifdef CONFIG_PPC_BOOK3S
  23
  24 /*
  25  * The structure which the hypervisor knows about - this structure
  26  * should not cross a page boundary.  The vpa_init/register_vpa call
  27  * is now known to fail if the lppaca structure crosses a page
  28  * boundary.  The lppaca is also used on legacy iSeries and POWER5
  29  * pSeries boxes.  The lppaca is 640 bytes long, and cannot readily
  30  * change since the hypervisor knows its layout, so a 1kB alignment
  31  * will suffice to ensure that it doesn't cross a page boundary.
  32  */
  33 struct lppaca lppaca[] = {
  34         [0 ... (NR_CPUS-1)] = {
  35                 .desc = 0xd397d781,     /* "LpPa" */
  36                 .size = sizeof(struct lppaca),
  37                 .dyn_proc_status = 2,
  38                 .decr_val = 0x00ff0000,
  39                 .fpregs_in_use = 1,
  40                 .end_of_quantum = 0xfffffffffffffffful,
  41                 .slb_count = 64,
  42                 .vmxregs_in_use = 0,
  43                 .page_ins = 0,
  44         },
  45 };
  46
  47 #endif /* CONFIG_PPC_BOOK3S */
  48
  49 #ifdef CONFIG_PPC_STD_MMU_64
  50
  51 /*
  52  * 3 persistent SLBs are registered here.  The buffer will be zero
  53  * initially, hence will all be invaild until we actually write them.
  54  */
  55 struct slb_shadow slb_shadow[] __cacheline_aligned = {
  56         [0 ... (NR_CPUS-1)] = {
  57                 .persistent = SLB_NUM_BOLTED,
  58                 .buffer_length = sizeof(struct slb_shadow),
  59         },
  60 };
  61
  62 #endif /* CONFIG_PPC_STD_MMU_64 */
  63
  64 /* The Paca is an array with one entry per processor.  Each contains an
  65  * lppaca, which contains the information shared between the
  66  * hypervisor and Linux.
  67  * On systems with hardware multi-threading, there are two threads
  68  * per processor.  The Paca array must contain an entry for each thread.
  69  * The VPD Areas will give a max logical processors = 2 * max physical
  70  * processors.  The processor VPD array needs one entry per physical
  71  * processor (not thread).
  72  */
  73 struct paca_struct paca[NR_CPUS];
  74 EXPORT_SYMBOL(paca);
  75
  76 void __init initialise_pacas(void)
  77 {
  78         int cpu;
  79
  80         /* The TOC register (GPR2) points 32kB into the TOC, so that 64kB
  81          * of the TOC can be addressed using a single machine instruction.
  82          */
  83         unsigned long kernel_toc = (unsigned long)(&__toc_start) + 0x8000UL;
  84
  85         /* Can't use for_each_*_cpu, as they aren't functional yet */
  86         for (cpu = 0; cpu < NR_CPUS; cpu++) {
  87                 struct paca_struct *new_paca = &paca[cpu];
  88
  89 #ifdef CONFIG_PPC_BOOK3S
  90                 new_paca->lppaca_ptr = &lppaca[cpu];
  91 #else
  92                 new_paca->kernel_pgd = swapper_pg_dir;
  93 #endif
  94                 new_paca->lock_token = 0x8000;
  95                 new_paca->paca_index = cpu;
  96                 new_paca->kernel_toc = kernel_toc;
  97                 new_paca->kernelbase = (unsigned long) _stext;
  98                 new_paca->kernel_msr = MSR_KERNEL;
  99                 new_paca->hw_cpu_id = 0xffff;
 100                 new_paca->__current = &init_task;
 101 #ifdef CONFIG_PPC_STD_MMU_64
 102                 new_paca->slb_shadow_ptr = &slb_shadow[cpu];
 103 #endif /* CONFIG_PPC_STD_MMU_64 */
 104
 105         }
 106 }