arch/powerpc/kernel/paca.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * c 2001 PPC 64 Team, IBM Corp
   4  */
   5
   6 #include <linux/smp.h>
   7 #include <linux/export.h>
   8 #include <linux/memblock.h>
   9 #include <linux/sched/task.h>
  10 #include <linux/numa.h>
  11
  12 #include <asm/lppaca.h>
  13 #include <asm/paca.h>
  14 #include <asm/sections.h>
  15 #include <asm/pgtable.h>
  16 #include <asm/kexec.h>
  17
  18 #include "setup.h"
  19
  20 #ifndef CONFIG_SMP
  21 #define boot_cpuid 0
  22 #endif
  23
  24 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
  25                                 unsigned long limit, int cpu)
  26 {
  27         void *ptr;
  28         int nid;
  29
  30         /*
  31          * boot_cpuid paca is allocated very early before cpu_to_node is up.
  32          * Set bottom-up mode, because the boot CPU should be on node-0,
  33          * which will put its paca in the right place.
  34          */
  35         if (cpu == boot_cpuid) {
  36                 nid = NUMA_NO_NODE;
  37                 memblock_set_bottom_up(true);
  38         } else {
  39                 nid = early_cpu_to_node(cpu);
  40         }
  41
  42         ptr = memblock_alloc_try_nid(size, align, MEMBLOCK_LOW_LIMIT,
  43                                      limit, nid);
  44         if (!ptr)
  45                 panic("cannot allocate paca data");
  46
  47         if (cpu == boot_cpuid)
  48                 memblock_set_bottom_up(false);
  49
  50         return ptr;
  51 }
  52
  53 #ifdef CONFIG_PPC_PSERIES
  54
  55 /*
  56  * See asm/lppaca.h for more detail.
  57  *
  58  * lppaca structures must must be 1kB in size, L1 cache line aligned,
  59  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
  60  * these requirements.
  61  */
  62 static inline void init_lppaca(struct lppaca *lppaca)
  63 {
  64         BUILD_BUG_ON(sizeof(struct lppaca) != 640);
  65
  66         *lppaca = (struct lppaca) {
  67                 .desc = cpu_to_be32(0xd397d781),        /* "LpPa" */
  68                 .size = cpu_to_be16(0x400),
  69                 .fpregs_in_use = 1,
  70                 .slb_count = cpu_to_be16(64),
  71                 .vmxregs_in_use = 0,
  72                 .page_ins = 0, };
  73 };
  74
  75 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
  76 {
  77         struct lppaca *lp;
  78         size_t size = 0x400;
  79
  80         BUILD_BUG_ON(size < sizeof(struct lppaca));
  81
  82         if (early_cpu_has_feature(CPU_FTR_HVMODE))
  83                 return NULL;
  84
  85         lp = alloc_paca_data(size, 0x400, limit, cpu);
  86         init_lppaca(lp);
  87
  88         return lp;
  89 }
  90 #endif /* CONFIG_PPC_BOOK3S */
  91
  92 #ifdef CONFIG_PPC_BOOK3S_64
  93
  94 /*
  95  * 3 persistent SLBs are allocated here.  The buffer will be zero
  96  * initially, hence will all be invaild until we actually write them.
  97  *
  98  * If you make the number of persistent SLB entries dynamic, please also
  99  * update PR KVM to flush and restore them accordingly.
 100  */
 101 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 102 {
 103         struct slb_shadow *s;
 104
 105         if (cpu != boot_cpuid) {
 106                 /*
 107                  * Boot CPU comes here before early_radix_enabled
 108                  * is parsed (e.g., for disable_radix). So allocate
 109                  * always and this will be fixed up in free_unused_pacas.
 110                  */
 111                 if (early_radix_enabled())
 112                         return NULL;
 113         }
 114
 115         s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
 116
 117         s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
 118         s->buffer_length = cpu_to_be32(sizeof(*s));
 119
 120         return s;
 121 }
 122
 123 #endif /* CONFIG_PPC_BOOK3S_64 */
 124
 125 /* The Paca is an array with one entry per processor.  Each contains an
 126  * lppaca, which contains the information shared between the
 127  * hypervisor and Linux.
 128  * On systems with hardware multi-threading, there are two threads
 129  * per processor.  The Paca array must contain an entry for each thread.
 130  * The VPD Areas will give a max logical processors = 2 * max physical
 131  * processors.  The processor VPD array needs one entry per physical
 132  * processor (not thread).
 133  */
 134 struct paca_struct **paca_ptrs __read_mostly;
 135 EXPORT_SYMBOL(paca_ptrs);
 136
 137 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 138 {
 139 #ifdef CONFIG_PPC_PSERIES
 140         new_paca->lppaca_ptr = NULL;
 141 #endif
 142 #ifdef CONFIG_PPC_BOOK3E
 143         new_paca->kernel_pgd = swapper_pg_dir;
 144 #endif
 145         new_paca->lock_token = 0x8000;
 146         new_paca->paca_index = cpu;
 147         new_paca->kernel_toc = kernel_toc_addr();
 148         new_paca->kernelbase = (unsigned long) _stext;
 149         /* Only set MSR:IR/DR when MMU is initialized */
 150         new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 151         new_paca->hw_cpu_id = 0xffff;
 152         new_paca->kexec_state = KEXEC_STATE_NONE;
 153         new_paca->__current = &init_task;
 154         new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 155 #ifdef CONFIG_PPC_BOOK3S_64
 156         new_paca->slb_shadow_ptr = NULL;
 157 #endif
 158
 159 #ifdef CONFIG_PPC_BOOK3E
 160         /* For now -- if we have threads this will be adjusted later */
 161         new_paca->tcd_ptr = &new_paca->tcd;
 162 #endif
 163 }
 164
 165 /* Put the paca pointer into r13 and SPRG_PACA */
 166 void setup_paca(struct paca_struct *new_paca)
 167 {
 168         /* Setup r13 */
 169         local_paca = new_paca;
 170
 171 #ifdef CONFIG_PPC_BOOK3E
 172         /* On Book3E, initialize the TLB miss exception frames */
 173         mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
 174 #else
 175         /* In HV mode, we setup both HPACA and PACA to avoid problems
 176          * if we do a GET_PACA() before the feature fixups have been
 177          * applied
 178          */
 179         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 180                 mtspr(SPRN_SPRG_HPACA, local_paca);
 181 #endif
 182         mtspr(SPRN_SPRG_PACA, local_paca);
 183
 184 }
 185
 186 static int __initdata paca_nr_cpu_ids;
 187 static int __initdata paca_ptrs_size;
 188 static int __initdata paca_struct_size;
 189
 190 void __init allocate_paca_ptrs(void)
 191 {
 192         paca_nr_cpu_ids = nr_cpu_ids;
 193
 194         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 195         paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
 196         if (!paca_ptrs)
 197                 panic("Failed to allocate %d bytes for paca pointers\n",
 198                       paca_ptrs_size);
 199
 200         memset(paca_ptrs, 0x88, paca_ptrs_size);
 201 }
 202
 203 void __init allocate_paca(int cpu)
 204 {
 205         u64 limit;
 206         struct paca_struct *paca;
 207
 208         BUG_ON(cpu >= paca_nr_cpu_ids);
 209
 210 #ifdef CONFIG_PPC_BOOK3S_64
 211         /*
 212          * We access pacas in real mode, and cannot take SLB faults
 213          * on them when in virtual mode, so allocate them accordingly.
 214          */
 215         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 216 #else
 217         limit = ppc64_rma_size;
 218 #endif
 219
 220         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 221                                 limit, cpu);
 222         paca_ptrs[cpu] = paca;
 223
 224         initialise_paca(paca, cpu);
 225 #ifdef CONFIG_PPC_PSERIES
 226         paca->lppaca_ptr = new_lppaca(cpu, limit);
 227 #endif
 228 #ifdef CONFIG_PPC_BOOK3S_64
 229         paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 230 #endif
 231         paca_struct_size += sizeof(struct paca_struct);
 232 }
 233
 234 void __init free_unused_pacas(void)
 235 {
 236         int new_ptrs_size;
 237
 238         new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 239         if (new_ptrs_size < paca_ptrs_size)
 240                 memblock_free(__pa(paca_ptrs) + new_ptrs_size,
 241                                         paca_ptrs_size - new_ptrs_size);
 242
 243         paca_nr_cpu_ids = nr_cpu_ids;
 244         paca_ptrs_size = new_ptrs_size;
 245
 246 #ifdef CONFIG_PPC_BOOK3S_64
 247         if (early_radix_enabled()) {
 248                 /* Ugly fixup, see new_slb_shadow() */
 249                 memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
 250                                 sizeof(struct slb_shadow));
 251                 paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
 252         }
 253 #endif
 254
 255         printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 256                         paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 257 }
 258
 259 void copy_mm_to_paca(struct mm_struct *mm)
 260 {
 261 #ifdef CONFIG_PPC_BOOK3S
 262         mm_context_t *context = &mm->context;
 263
 264         get_paca()->mm_ctx_id = context->id;
 265 #ifdef CONFIG_PPC_MM_SLICES
 266         VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
 267         get_paca()->mm_ctx_slb_addr_limit = mm_ctx_slb_addr_limit(context);
 268         memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
 269                LOW_SLICE_ARRAY_SZ);
 270         memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
 271                TASK_SLICE_ARRAY_SZ(context));
 272 #else /* CONFIG_PPC_MM_SLICES */
 273         get_paca()->mm_ctx_user_psize = context->user_psize;
 274         get_paca()->mm_ctx_sllp = context->sllp;
 275 #endif
 276 #else /* !CONFIG_PPC_BOOK3S */
 277         return;
 278 #endif
 279 }