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 #include <linux/numa.h>
  15
  16 #include <asm/lppaca.h>
  17 #include <asm/paca.h>
  18 #include <asm/sections.h>
  19 #include <asm/pgtable.h>
  20 #include <asm/kexec.h>
  21
  22 #include "setup.h"
  23
  24 #ifndef CONFIG_SMP
  25 #define boot_cpuid 0
  26 #endif
  27
  28 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
  29                                 unsigned long limit, int cpu)
  30 {
  31         void *ptr;
  32         int nid;
  33
  34         /*
  35          * boot_cpuid paca is allocated very early before cpu_to_node is up.
  36          * Set bottom-up mode, because the boot CPU should be on node-0,
  37          * which will put its paca in the right place.
  38          */
  39         if (cpu == boot_cpuid) {
  40                 nid = NUMA_NO_NODE;
  41                 memblock_set_bottom_up(true);
  42         } else {
  43                 nid = early_cpu_to_node(cpu);
  44         }
  45
  46         ptr = memblock_alloc_try_nid(size, align, MEMBLOCK_LOW_LIMIT,
  47                                      limit, nid);
  48         if (!ptr)
  49                 panic("cannot allocate paca data");
  50
  51         if (cpu == boot_cpuid)
  52                 memblock_set_bottom_up(false);
  53
  54         return ptr;
  55 }
  56
  57 #ifdef CONFIG_PPC_PSERIES
  58
  59 /*
  60  * See asm/lppaca.h for more detail.
  61  *
  62  * lppaca structures must must be 1kB in size, L1 cache line aligned,
  63  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
  64  * these requirements.
  65  */
  66 static inline void init_lppaca(struct lppaca *lppaca)
  67 {
  68         BUILD_BUG_ON(sizeof(struct lppaca) != 640);
  69
  70         *lppaca = (struct lppaca) {
  71                 .desc = cpu_to_be32(0xd397d781),        /* "LpPa" */
  72                 .size = cpu_to_be16(0x400),
  73                 .fpregs_in_use = 1,
  74                 .slb_count = cpu_to_be16(64),
  75                 .vmxregs_in_use = 0,
  76                 .page_ins = 0, };
  77 };
  78
  79 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
  80 {
  81         struct lppaca *lp;
  82         size_t size = 0x400;
  83
  84         BUILD_BUG_ON(size < sizeof(struct lppaca));
  85
  86         if (early_cpu_has_feature(CPU_FTR_HVMODE))
  87                 return NULL;
  88
  89         lp = alloc_paca_data(size, 0x400, limit, cpu);
  90         init_lppaca(lp);
  91
  92         return lp;
  93 }
  94 #endif /* CONFIG_PPC_BOOK3S */
  95
  96 #ifdef CONFIG_PPC_BOOK3S_64
  97
  98 /*
  99  * 3 persistent SLBs are allocated here.  The buffer will be zero
 100  * initially, hence will all be invaild until we actually write them.
 101  *
 102  * If you make the number of persistent SLB entries dynamic, please also
 103  * update PR KVM to flush and restore them accordingly.
 104  */
 105 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 106 {
 107         struct slb_shadow *s;
 108
 109         if (cpu != boot_cpuid) {
 110                 /*
 111                  * Boot CPU comes here before early_radix_enabled
 112                  * is parsed (e.g., for disable_radix). So allocate
 113                  * always and this will be fixed up in free_unused_pacas.
 114                  */
 115                 if (early_radix_enabled())
 116                         return NULL;
 117         }
 118
 119         s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
 120
 121         s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
 122         s->buffer_length = cpu_to_be32(sizeof(*s));
 123
 124         return s;
 125 }
 126
 127 #endif /* CONFIG_PPC_BOOK3S_64 */
 128
 129 /* The Paca is an array with one entry per processor.  Each contains an
 130  * lppaca, which contains the information shared between the
 131  * hypervisor and Linux.
 132  * On systems with hardware multi-threading, there are two threads
 133  * per processor.  The Paca array must contain an entry for each thread.
 134  * The VPD Areas will give a max logical processors = 2 * max physical
 135  * processors.  The processor VPD array needs one entry per physical
 136  * processor (not thread).
 137  */
 138 struct paca_struct **paca_ptrs __read_mostly;
 139 EXPORT_SYMBOL(paca_ptrs);
 140
 141 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 142 {
 143 #ifdef CONFIG_PPC_PSERIES
 144         new_paca->lppaca_ptr = NULL;
 145 #endif
 146 #ifdef CONFIG_PPC_BOOK3E
 147         new_paca->kernel_pgd = swapper_pg_dir;
 148 #endif
 149         new_paca->lock_token = 0x8000;
 150         new_paca->paca_index = cpu;
 151         new_paca->kernel_toc = kernel_toc_addr();
 152         new_paca->kernelbase = (unsigned long) _stext;
 153         /* Only set MSR:IR/DR when MMU is initialized */
 154         new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 155         new_paca->hw_cpu_id = 0xffff;
 156         new_paca->kexec_state = KEXEC_STATE_NONE;
 157         new_paca->__current = &init_task;
 158         new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 159 #ifdef CONFIG_PPC_BOOK3S_64
 160         new_paca->slb_shadow_ptr = NULL;
 161 #endif
 162
 163 #ifdef CONFIG_PPC_BOOK3E
 164         /* For now -- if we have threads this will be adjusted later */
 165         new_paca->tcd_ptr = &new_paca->tcd;
 166 #endif
 167 }
 168
 169 /* Put the paca pointer into r13 and SPRG_PACA */
 170 void setup_paca(struct paca_struct *new_paca)
 171 {
 172         /* Setup r13 */
 173         local_paca = new_paca;
 174
 175 #ifdef CONFIG_PPC_BOOK3E
 176         /* On Book3E, initialize the TLB miss exception frames */
 177         mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
 178 #else
 179         /* In HV mode, we setup both HPACA and PACA to avoid problems
 180          * if we do a GET_PACA() before the feature fixups have been
 181          * applied
 182          */
 183         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 184                 mtspr(SPRN_SPRG_HPACA, local_paca);
 185 #endif
 186         mtspr(SPRN_SPRG_PACA, local_paca);
 187
 188 }
 189
 190 static int __initdata paca_nr_cpu_ids;
 191 static int __initdata paca_ptrs_size;
 192 static int __initdata paca_struct_size;
 193
 194 void __init allocate_paca_ptrs(void)
 195 {
 196         paca_nr_cpu_ids = nr_cpu_ids;
 197
 198         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 199         paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
 200         if (!paca_ptrs)
 201                 panic("Failed to allocate %d bytes for paca pointers\n",
 202                       paca_ptrs_size);
 203
 204         memset(paca_ptrs, 0x88, paca_ptrs_size);
 205 }
 206
 207 void __init allocate_paca(int cpu)
 208 {
 209         u64 limit;
 210         struct paca_struct *paca;
 211
 212         BUG_ON(cpu >= paca_nr_cpu_ids);
 213
 214 #ifdef CONFIG_PPC_BOOK3S_64
 215         /*
 216          * We access pacas in real mode, and cannot take SLB faults
 217          * on them when in virtual mode, so allocate them accordingly.
 218          */
 219         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 220 #else
 221         limit = ppc64_rma_size;
 222 #endif
 223
 224         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 225                                 limit, cpu);
 226         paca_ptrs[cpu] = paca;
 227
 228         initialise_paca(paca, cpu);
 229 #ifdef CONFIG_PPC_PSERIES
 230         paca->lppaca_ptr = new_lppaca(cpu, limit);
 231 #endif
 232 #ifdef CONFIG_PPC_BOOK3S_64
 233         paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 234 #endif
 235         paca_struct_size += sizeof(struct paca_struct);
 236 }
 237
 238 void __init free_unused_pacas(void)
 239 {
 240         int new_ptrs_size;
 241
 242         new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 243         if (new_ptrs_size < paca_ptrs_size)
 244                 memblock_free(__pa(paca_ptrs) + new_ptrs_size,
 245                                         paca_ptrs_size - new_ptrs_size);
 246
 247         paca_nr_cpu_ids = nr_cpu_ids;
 248         paca_ptrs_size = new_ptrs_size;
 249
 250 #ifdef CONFIG_PPC_BOOK3S_64
 251         if (early_radix_enabled()) {
 252                 /* Ugly fixup, see new_slb_shadow() */
 253                 memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
 254                                 sizeof(struct slb_shadow));
 255                 paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
 256         }
 257 #endif
 258
 259         printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 260                         paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 261 }
 262
 263 void copy_mm_to_paca(struct mm_struct *mm)
 264 {
 265 #ifdef CONFIG_PPC_BOOK3S
 266         mm_context_t *context = &mm->context;
 267
 268         get_paca()->mm_ctx_id = context->id;
 269 #ifdef CONFIG_PPC_MM_SLICES
 270         VM_BUG_ON(!mm->context.slb_addr_limit);
 271         get_paca()->mm_ctx_slb_addr_limit = mm->context.slb_addr_limit;
 272         memcpy(&get_paca()->mm_ctx_low_slices_psize,
 273                &context->low_slices_psize, sizeof(context->low_slices_psize));
 274         memcpy(&get_paca()->mm_ctx_high_slices_psize,
 275                &context->high_slices_psize, TASK_SLICE_ARRAY_SZ(mm));
 276 #else /* CONFIG_PPC_MM_SLICES */
 277         get_paca()->mm_ctx_user_psize = context->user_psize;
 278         get_paca()->mm_ctx_sllp = context->sllp;
 279 #endif
 280 #else /* !CONFIG_PPC_BOOK3S */
 281         return;
 282 #endif
 283 }