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         unsigned long pa;
  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         pa = memblock_alloc_base_nid(size, align, limit, nid, MEMBLOCK_NONE);
  47         if (!pa) {
  48                 pa = memblock_alloc_base(size, align, limit);
  49                 if (!pa)
  50                         panic("cannot allocate paca data");
  51         }
  52
  53         if (cpu == boot_cpuid)
  54                 memblock_set_bottom_up(false);
  55
  56         return __va(pa);
  57 }
  58
  59 #ifdef CONFIG_PPC_PSERIES
  60
  61 /*
  62  * See asm/lppaca.h for more detail.
  63  *
  64  * lppaca structures must must be 1kB in size, L1 cache line aligned,
  65  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
  66  * these requirements.
  67  */
  68 static inline void init_lppaca(struct lppaca *lppaca)
  69 {
  70         BUILD_BUG_ON(sizeof(struct lppaca) != 640);
  71
  72         *lppaca = (struct lppaca) {
  73                 .desc = cpu_to_be32(0xd397d781),        /* "LpPa" */
  74                 .size = cpu_to_be16(0x400),
  75                 .fpregs_in_use = 1,
  76                 .slb_count = cpu_to_be16(64),
  77                 .vmxregs_in_use = 0,
  78                 .page_ins = 0, };
  79 };
  80
  81 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
  82 {
  83         struct lppaca *lp;
  84         size_t size = 0x400;
  85
  86         BUILD_BUG_ON(size < sizeof(struct lppaca));
  87
  88         if (early_cpu_has_feature(CPU_FTR_HVMODE))
  89                 return NULL;
  90
  91         lp = alloc_paca_data(size, 0x400, limit, cpu);
  92         init_lppaca(lp);
  93
  94         return lp;
  95 }
  96 #endif /* CONFIG_PPC_BOOK3S */
  97
  98 #ifdef CONFIG_PPC_BOOK3S_64
  99
 100 /*
 101  * 3 persistent SLBs are allocated here.  The buffer will be zero
 102  * initially, hence will all be invaild until we actually write them.
 103  *
 104  * If you make the number of persistent SLB entries dynamic, please also
 105  * update PR KVM to flush and restore them accordingly.
 106  */
 107 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 108 {
 109         struct slb_shadow *s;
 110
 111         if (cpu != boot_cpuid) {
 112                 /*
 113                  * Boot CPU comes here before early_radix_enabled
 114                  * is parsed (e.g., for disable_radix). So allocate
 115                  * always and this will be fixed up in free_unused_pacas.
 116                  */
 117                 if (early_radix_enabled())
 118                         return NULL;
 119         }
 120
 121         s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
 122         memset(s, 0, sizeof(*s));
 123
 124         s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
 125         s->buffer_length = cpu_to_be32(sizeof(*s));
 126
 127         return s;
 128 }
 129
 130 #endif /* CONFIG_PPC_BOOK3S_64 */
 131
 132 /* The Paca is an array with one entry per processor.  Each contains an
 133  * lppaca, which contains the information shared between the
 134  * hypervisor and Linux.
 135  * On systems with hardware multi-threading, there are two threads
 136  * per processor.  The Paca array must contain an entry for each thread.
 137  * The VPD Areas will give a max logical processors = 2 * max physical
 138  * processors.  The processor VPD array needs one entry per physical
 139  * processor (not thread).
 140  */
 141 struct paca_struct **paca_ptrs __read_mostly;
 142 EXPORT_SYMBOL(paca_ptrs);
 143
 144 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 145 {
 146 #ifdef CONFIG_PPC_PSERIES
 147         new_paca->lppaca_ptr = NULL;
 148 #endif
 149 #ifdef CONFIG_PPC_BOOK3E
 150         new_paca->kernel_pgd = swapper_pg_dir;
 151 #endif
 152         new_paca->lock_token = 0x8000;
 153         new_paca->paca_index = cpu;
 154         new_paca->kernel_toc = kernel_toc_addr();
 155         new_paca->kernelbase = (unsigned long) _stext;
 156         /* Only set MSR:IR/DR when MMU is initialized */
 157         new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 158         new_paca->hw_cpu_id = 0xffff;
 159         new_paca->kexec_state = KEXEC_STATE_NONE;
 160         new_paca->__current = &init_task;
 161         new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 162 #ifdef CONFIG_PPC_BOOK3S_64
 163         new_paca->slb_shadow_ptr = NULL;
 164 #endif
 165
 166 #ifdef CONFIG_PPC_BOOK3E
 167         /* For now -- if we have threads this will be adjusted later */
 168         new_paca->tcd_ptr = &new_paca->tcd;
 169 #endif
 170 }
 171
 172 /* Put the paca pointer into r13 and SPRG_PACA */
 173 void setup_paca(struct paca_struct *new_paca)
 174 {
 175         /* Setup r13 */
 176         local_paca = new_paca;
 177
 178 #ifdef CONFIG_PPC_BOOK3E
 179         /* On Book3E, initialize the TLB miss exception frames */
 180         mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
 181 #else
 182         /* In HV mode, we setup both HPACA and PACA to avoid problems
 183          * if we do a GET_PACA() before the feature fixups have been
 184          * applied
 185          */
 186         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 187                 mtspr(SPRN_SPRG_HPACA, local_paca);
 188 #endif
 189         mtspr(SPRN_SPRG_PACA, local_paca);
 190
 191 }
 192
 193 static int __initdata paca_nr_cpu_ids;
 194 static int __initdata paca_ptrs_size;
 195 static int __initdata paca_struct_size;
 196
 197 void __init allocate_paca_ptrs(void)
 198 {
 199         paca_nr_cpu_ids = nr_cpu_ids;
 200
 201         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 202         paca_ptrs = __va(memblock_phys_alloc(paca_ptrs_size, SMP_CACHE_BYTES));
 203         memset(paca_ptrs, 0x88, paca_ptrs_size);
 204 }
 205
 206 void __init allocate_paca(int cpu)
 207 {
 208         u64 limit;
 209         struct paca_struct *paca;
 210
 211         BUG_ON(cpu >= paca_nr_cpu_ids);
 212
 213 #ifdef CONFIG_PPC_BOOK3S_64
 214         /*
 215          * We access pacas in real mode, and cannot take SLB faults
 216          * on them when in virtual mode, so allocate them accordingly.
 217          */
 218         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 219 #else
 220         limit = ppc64_rma_size;
 221 #endif
 222
 223         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 224                                 limit, cpu);
 225         paca_ptrs[cpu] = paca;
 226         memset(paca, 0, sizeof(struct paca_struct));
 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 }