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/smp.h>
  11 #include <linux/export.h>
  12 #include <linux/memblock.h>
  13 #include <linux/sched/task.h>
  14
  15 #include <asm/lppaca.h>
  16 #include <asm/paca.h>
  17 #include <asm/sections.h>
  18 #include <asm/pgtable.h>
  19 #include <asm/kexec.h>
  20
  21 #include "setup.h"
  22
  23 #ifndef CONFIG_SMP
  24 #define boot_cpuid 0
  25 #endif
  26
  27 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
  28                                 unsigned long limit, int cpu)
  29 {
  30         unsigned long pa;
  31         int nid;
  32
  33         /*
  34          * boot_cpuid paca is allocated very early before cpu_to_node is up.
  35          * Set bottom-up mode, because the boot CPU should be on node-0,
  36          * which will put its paca in the right place.
  37          */
  38         if (cpu == boot_cpuid) {
  39                 nid = -1;
  40                 memblock_set_bottom_up(true);
  41         } else {
  42                 nid = early_cpu_to_node(cpu);
  43         }
  44
  45         pa = memblock_alloc_base_nid(size, align, limit, nid, MEMBLOCK_NONE);
  46         if (!pa) {
  47                 pa = memblock_alloc_base(size, align, limit);
  48                 if (!pa)
  49                         panic("cannot allocate paca data");
  50         }
  51
  52         if (cpu == boot_cpuid)
  53                 memblock_set_bottom_up(false);
  54
  55         return __va(pa);
  56 }
  57
  58 #ifdef CONFIG_PPC_PSERIES
  59
  60 /*
  61  * See asm/lppaca.h for more detail.
  62  *
  63  * lppaca structures must must be 1kB in size, L1 cache line aligned,
  64  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
  65  * these requirements.
  66  */
  67 static inline void init_lppaca(struct lppaca *lppaca)
  68 {
  69         BUILD_BUG_ON(sizeof(struct lppaca) != 640);
  70
  71         *lppaca = (struct lppaca) {
  72                 .desc = cpu_to_be32(0xd397d781),        /* "LpPa" */
  73                 .size = cpu_to_be16(0x400),
  74                 .fpregs_in_use = 1,
  75                 .slb_count = cpu_to_be16(64),
  76                 .vmxregs_in_use = 0,
  77                 .page_ins = 0, };
  78 };
  79
  80 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
  81 {
  82         struct lppaca *lp;
  83         size_t size = 0x400;
  84
  85         BUILD_BUG_ON(size < sizeof(struct lppaca));
  86
  87         if (early_cpu_has_feature(CPU_FTR_HVMODE))
  88                 return NULL;
  89
  90         lp = alloc_paca_data(size, 0x400, limit, cpu);
  91         init_lppaca(lp);
  92
  93         return lp;
  94 }
  95 #endif /* CONFIG_PPC_BOOK3S */
  96
  97 #ifdef CONFIG_PPC_BOOK3S_64
  98
  99 /*
 100  * 3 persistent SLBs are allocated here.  The buffer will be zero
 101  * initially, hence will all be invaild until we actually write them.
 102  *
 103  * If you make the number of persistent SLB entries dynamic, please also
 104  * update PR KVM to flush and restore them accordingly.
 105  */
 106 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 107 {
 108         struct slb_shadow *s;
 109
 110         if (cpu != boot_cpuid) {
 111                 /*
 112                  * Boot CPU comes here before early_radix_enabled
 113                  * is parsed (e.g., for disable_radix). So allocate
 114                  * always and this will be fixed up in free_unused_pacas.
 115                  */
 116                 if (early_radix_enabled())
 117                         return NULL;
 118         }
 119
 120         s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
 121         memset(s, 0, sizeof(*s));
 122
 123         s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
 124         s->buffer_length = cpu_to_be32(sizeof(*s));
 125
 126         return s;
 127 }
 128
 129 #endif /* CONFIG_PPC_BOOK3S_64 */
 130
 131 /* The Paca is an array with one entry per processor.  Each contains an
 132  * lppaca, which contains the information shared between the
 133  * hypervisor and Linux.
 134  * On systems with hardware multi-threading, there are two threads
 135  * per processor.  The Paca array must contain an entry for each thread.
 136  * The VPD Areas will give a max logical processors = 2 * max physical
 137  * processors.  The processor VPD array needs one entry per physical
 138  * processor (not thread).
 139  */
 140 struct paca_struct **paca_ptrs __read_mostly;
 141 EXPORT_SYMBOL(paca_ptrs);
 142
 143 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 144 {
 145 #ifdef CONFIG_PPC_PSERIES
 146         new_paca->lppaca_ptr = NULL;
 147 #endif
 148 #ifdef CONFIG_PPC_BOOK3E
 149         new_paca->kernel_pgd = swapper_pg_dir;
 150 #endif
 151         new_paca->lock_token = 0x8000;
 152         new_paca->paca_index = cpu;
 153         new_paca->kernel_toc = kernel_toc_addr();
 154         new_paca->kernelbase = (unsigned long) _stext;
 155         /* Only set MSR:IR/DR when MMU is initialized */
 156         new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 157         new_paca->hw_cpu_id = 0xffff;
 158         new_paca->kexec_state = KEXEC_STATE_NONE;
 159         new_paca->__current = &init_task;
 160         new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 161 #ifdef CONFIG_PPC_BOOK3S_64
 162         new_paca->slb_shadow_ptr = NULL;
 163 #endif
 164
 165 #ifdef CONFIG_PPC_BOOK3E
 166         /* For now -- if we have threads this will be adjusted later */
 167         new_paca->tcd_ptr = &new_paca->tcd;
 168 #endif
 169 }
 170
 171 /* Put the paca pointer into r13 and SPRG_PACA */
 172 void setup_paca(struct paca_struct *new_paca)
 173 {
 174         /* Setup r13 */
 175         local_paca = new_paca;
 176
 177 #ifdef CONFIG_PPC_BOOK3E
 178         /* On Book3E, initialize the TLB miss exception frames */
 179         mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
 180 #else
 181         /* In HV mode, we setup both HPACA and PACA to avoid problems
 182          * if we do a GET_PACA() before the feature fixups have been
 183          * applied
 184          */
 185         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 186                 mtspr(SPRN_SPRG_HPACA, local_paca);
 187 #endif
 188         mtspr(SPRN_SPRG_PACA, local_paca);
 189
 190 }
 191
 192 static int __initdata paca_nr_cpu_ids;
 193 static int __initdata paca_ptrs_size;
 194 static int __initdata paca_struct_size;
 195
 196 void __init allocate_paca_ptrs(void)
 197 {
 198         paca_nr_cpu_ids = nr_cpu_ids;
 199
 200         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 201         paca_ptrs = __va(memblock_phys_alloc(paca_ptrs_size, SMP_CACHE_BYTES));
 202         memset(paca_ptrs, 0x88, paca_ptrs_size);
 203 }
 204
 205 void __init allocate_paca(int cpu)
 206 {
 207         u64 limit;
 208         struct paca_struct *paca;
 209
 210         BUG_ON(cpu >= paca_nr_cpu_ids);
 211
 212 #ifdef CONFIG_PPC_BOOK3S_64
 213         /*
 214          * We access pacas in real mode, and cannot take SLB faults
 215          * on them when in virtual mode, so allocate them accordingly.
 216          */
 217         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 218 #else
 219         limit = ppc64_rma_size;
 220 #endif
 221
 222         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 223                                 limit, cpu);
 224         paca_ptrs[cpu] = paca;
 225         memset(paca, 0, sizeof(struct paca_struct));
 226
 227         initialise_paca(paca, cpu);
 228 #ifdef CONFIG_PPC_PSERIES
 229         paca->lppaca_ptr = new_lppaca(cpu, limit);
 230 #endif
 231 #ifdef CONFIG_PPC_BOOK3S_64
 232         paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 233 #endif
 234         paca_struct_size += sizeof(struct paca_struct);
 235 }
 236
 237 void __init free_unused_pacas(void)
 238 {
 239         int new_ptrs_size;
 240
 241         new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 242         if (new_ptrs_size < paca_ptrs_size)
 243                 memblock_free(__pa(paca_ptrs) + new_ptrs_size,
 244                                         paca_ptrs_size - new_ptrs_size);
 245
 246         paca_nr_cpu_ids = nr_cpu_ids;
 247         paca_ptrs_size = new_ptrs_size;
 248
 249 #ifdef CONFIG_PPC_BOOK3S_64
 250         if (early_radix_enabled()) {
 251                 /* Ugly fixup, see new_slb_shadow() */
 252                 memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
 253                                 sizeof(struct slb_shadow));
 254                 paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
 255         }
 256 #endif
 257
 258         printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 259                         paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 260 }
 261
 262 void copy_mm_to_paca(struct mm_struct *mm)
 263 {
 264 #ifdef CONFIG_PPC_BOOK3S
 265         mm_context_t *context = &mm->context;
 266
 267         get_paca()->mm_ctx_id = context->id;
 268 #ifdef CONFIG_PPC_MM_SLICES
 269         VM_BUG_ON(!mm->context.slb_addr_limit);
 270         get_paca()->mm_ctx_slb_addr_limit = mm->context.slb_addr_limit;
 271         memcpy(&get_paca()->mm_ctx_low_slices_psize,
 272                &context->low_slices_psize, sizeof(context->low_slices_psize));
 273         memcpy(&get_paca()->mm_ctx_high_slices_psize,
 274                &context->high_slices_psize, TASK_SLICE_ARRAY_SZ(mm));
 275 #else /* CONFIG_PPC_MM_SLICES */
 276         get_paca()->mm_ctx_user_psize = context->user_psize;
 277         get_paca()->mm_ctx_sllp = context->sllp;
 278 #endif
 279 #else /* !CONFIG_PPC_BOOK3S */
 280         return;
 281 #endif
 282 }