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 #include <asm/svm.h>
  18 #include <asm/ultravisor.h>
  19
  20 #include "setup.h"
  21
  22 #ifndef CONFIG_SMP
  23 #define boot_cpuid 0
  24 #endif
  25
  26 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
  27                                 unsigned long limit, int cpu)
  28 {
  29         void *ptr;
  30         int nid;
  31
  32         /*
  33          * boot_cpuid paca is allocated very early before cpu_to_node is up.
  34          * Set bottom-up mode, because the boot CPU should be on node-0,
  35          * which will put its paca in the right place.
  36          */
  37         if (cpu == boot_cpuid) {
  38                 nid = NUMA_NO_NODE;
  39                 memblock_set_bottom_up(true);
  40         } else {
  41                 nid = early_cpu_to_node(cpu);
  42         }
  43
  44         ptr = memblock_alloc_try_nid(size, align, MEMBLOCK_LOW_LIMIT,
  45                                      limit, nid);
  46         if (!ptr)
  47                 panic("cannot allocate paca data");
  48
  49         if (cpu == boot_cpuid)
  50                 memblock_set_bottom_up(false);
  51
  52         return ptr;
  53 }
  54
  55 #ifdef CONFIG_PPC_PSERIES
  56
  57 #define LPPACA_SIZE 0x400
  58
  59 static void *__init alloc_shared_lppaca(unsigned long size, unsigned long align,
  60                                         unsigned long limit, int cpu)
  61 {
  62         size_t shared_lppaca_total_size = PAGE_ALIGN(nr_cpu_ids * LPPACA_SIZE);
  63         static unsigned long shared_lppaca_size;
  64         static void *shared_lppaca;
  65         void *ptr;
  66
  67         if (!shared_lppaca) {
  68                 memblock_set_bottom_up(true);
  69
  70                 shared_lppaca =
  71                         memblock_alloc_try_nid(shared_lppaca_total_size,
  72                                                PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
  73                                                limit, NUMA_NO_NODE);
  74                 if (!shared_lppaca)
  75                         panic("cannot allocate shared data");
  76
  77                 memblock_set_bottom_up(false);
  78                 uv_share_page(PHYS_PFN(__pa(shared_lppaca)),
  79                               shared_lppaca_total_size >> PAGE_SHIFT);
  80         }
  81
  82         ptr = shared_lppaca + shared_lppaca_size;
  83         shared_lppaca_size += size;
  84
  85         /*
  86          * This is very early in boot, so no harm done if the kernel crashes at
  87          * this point.
  88          */
  89         BUG_ON(shared_lppaca_size >= shared_lppaca_total_size);
  90
  91         return ptr;
  92 }
  93
  94 /*
  95  * See asm/lppaca.h for more detail.
  96  *
  97  * lppaca structures must must be 1kB in size, L1 cache line aligned,
  98  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
  99  * these requirements.
 100  */
 101 static inline void init_lppaca(struct lppaca *lppaca)
 102 {
 103         BUILD_BUG_ON(sizeof(struct lppaca) != 640);
 104
 105         *lppaca = (struct lppaca) {
 106                 .desc = cpu_to_be32(0xd397d781),        /* "LpPa" */
 107                 .size = cpu_to_be16(LPPACA_SIZE),
 108                 .fpregs_in_use = 1,
 109                 .slb_count = cpu_to_be16(64),
 110                 .vmxregs_in_use = 0,
 111                 .page_ins = 0, };
 112 };
 113
 114 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
 115 {
 116         struct lppaca *lp;
 117
 118         BUILD_BUG_ON(sizeof(struct lppaca) > LPPACA_SIZE);
 119
 120         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 121                 return NULL;
 122
 123         if (is_secure_guest())
 124                 lp = alloc_shared_lppaca(LPPACA_SIZE, 0x400, limit, cpu);
 125         else
 126                 lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);
 127
 128         init_lppaca(lp);
 129
 130         return lp;
 131 }
 132 #endif /* CONFIG_PPC_PSERIES */
 133
 134 #ifdef CONFIG_PPC_BOOK3S_64
 135
 136 /*
 137  * 3 persistent SLBs are allocated here.  The buffer will be zero
 138  * initially, hence will all be invaild until we actually write them.
 139  *
 140  * If you make the number of persistent SLB entries dynamic, please also
 141  * update PR KVM to flush and restore them accordingly.
 142  */
 143 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 144 {
 145         struct slb_shadow *s;
 146
 147         if (cpu != boot_cpuid) {
 148                 /*
 149                  * Boot CPU comes here before early_radix_enabled
 150                  * is parsed (e.g., for disable_radix). So allocate
 151                  * always and this will be fixed up in free_unused_pacas.
 152                  */
 153                 if (early_radix_enabled())
 154                         return NULL;
 155         }
 156
 157         s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
 158
 159         s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
 160         s->buffer_length = cpu_to_be32(sizeof(*s));
 161
 162         return s;
 163 }
 164
 165 #endif /* CONFIG_PPC_BOOK3S_64 */
 166
 167 /* The Paca is an array with one entry per processor.  Each contains an
 168  * lppaca, which contains the information shared between the
 169  * hypervisor and Linux.
 170  * On systems with hardware multi-threading, there are two threads
 171  * per processor.  The Paca array must contain an entry for each thread.
 172  * The VPD Areas will give a max logical processors = 2 * max physical
 173  * processors.  The processor VPD array needs one entry per physical
 174  * processor (not thread).
 175  */
 176 struct paca_struct **paca_ptrs __read_mostly;
 177 EXPORT_SYMBOL(paca_ptrs);
 178
 179 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 180 {
 181 #ifdef CONFIG_PPC_PSERIES
 182         new_paca->lppaca_ptr = NULL;
 183 #endif
 184 #ifdef CONFIG_PPC_BOOK3E
 185         new_paca->kernel_pgd = swapper_pg_dir;
 186 #endif
 187         new_paca->lock_token = 0x8000;
 188         new_paca->paca_index = cpu;
 189         new_paca->kernel_toc = kernel_toc_addr();
 190         new_paca->kernelbase = (unsigned long) _stext;
 191         /* Only set MSR:IR/DR when MMU is initialized */
 192         new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 193         new_paca->hw_cpu_id = 0xffff;
 194         new_paca->kexec_state = KEXEC_STATE_NONE;
 195         new_paca->__current = &init_task;
 196         new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 197 #ifdef CONFIG_PPC_BOOK3S_64
 198         new_paca->slb_shadow_ptr = NULL;
 199 #endif
 200
 201 #ifdef CONFIG_PPC_BOOK3E
 202         /* For now -- if we have threads this will be adjusted later */
 203         new_paca->tcd_ptr = &new_paca->tcd;
 204 #endif
 205 }
 206
 207 /* Put the paca pointer into r13 and SPRG_PACA */
 208 void setup_paca(struct paca_struct *new_paca)
 209 {
 210         /* Setup r13 */
 211         local_paca = new_paca;
 212
 213 #ifdef CONFIG_PPC_BOOK3E
 214         /* On Book3E, initialize the TLB miss exception frames */
 215         mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
 216 #else
 217         /* In HV mode, we setup both HPACA and PACA to avoid problems
 218          * if we do a GET_PACA() before the feature fixups have been
 219          * applied
 220          */
 221         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 222                 mtspr(SPRN_SPRG_HPACA, local_paca);
 223 #endif
 224         mtspr(SPRN_SPRG_PACA, local_paca);
 225
 226 }
 227
 228 static int __initdata paca_nr_cpu_ids;
 229 static int __initdata paca_ptrs_size;
 230 static int __initdata paca_struct_size;
 231
 232 void __init allocate_paca_ptrs(void)
 233 {
 234         paca_nr_cpu_ids = nr_cpu_ids;
 235
 236         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 237         paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
 238         if (!paca_ptrs)
 239                 panic("Failed to allocate %d bytes for paca pointers\n",
 240                       paca_ptrs_size);
 241
 242         memset(paca_ptrs, 0x88, paca_ptrs_size);
 243 }
 244
 245 void __init allocate_paca(int cpu)
 246 {
 247         u64 limit;
 248         struct paca_struct *paca;
 249
 250         BUG_ON(cpu >= paca_nr_cpu_ids);
 251
 252 #ifdef CONFIG_PPC_BOOK3S_64
 253         /*
 254          * We access pacas in real mode, and cannot take SLB faults
 255          * on them when in virtual mode, so allocate them accordingly.
 256          */
 257         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 258 #else
 259         limit = ppc64_rma_size;
 260 #endif
 261
 262         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 263                                 limit, cpu);
 264         paca_ptrs[cpu] = paca;
 265
 266         initialise_paca(paca, cpu);
 267 #ifdef CONFIG_PPC_PSERIES
 268         paca->lppaca_ptr = new_lppaca(cpu, limit);
 269 #endif
 270 #ifdef CONFIG_PPC_BOOK3S_64
 271         paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 272 #endif
 273         paca_struct_size += sizeof(struct paca_struct);
 274 }
 275
 276 void __init free_unused_pacas(void)
 277 {
 278         int new_ptrs_size;
 279
 280         new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 281         if (new_ptrs_size < paca_ptrs_size)
 282                 memblock_free(__pa(paca_ptrs) + new_ptrs_size,
 283                                         paca_ptrs_size - new_ptrs_size);
 284
 285         paca_nr_cpu_ids = nr_cpu_ids;
 286         paca_ptrs_size = new_ptrs_size;
 287
 288 #ifdef CONFIG_PPC_BOOK3S_64
 289         if (early_radix_enabled()) {
 290                 /* Ugly fixup, see new_slb_shadow() */
 291                 memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
 292                                 sizeof(struct slb_shadow));
 293                 paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
 294         }
 295 #endif
 296
 297         printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 298                         paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 299 }
 300
 301 void copy_mm_to_paca(struct mm_struct *mm)
 302 {
 303 #ifdef CONFIG_PPC_BOOK3S
 304         mm_context_t *context = &mm->context;
 305
 306         get_paca()->mm_ctx_id = context->id;
 307 #ifdef CONFIG_PPC_MM_SLICES
 308         VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
 309         get_paca()->mm_ctx_slb_addr_limit = mm_ctx_slb_addr_limit(context);
 310         memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
 311                LOW_SLICE_ARRAY_SZ);
 312         memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
 313                TASK_SLICE_ARRAY_SZ(context));
 314 #else /* CONFIG_PPC_MM_SLICES */
 315         get_paca()->mm_ctx_user_psize = context->user_psize;
 316         get_paca()->mm_ctx_sllp = context->sllp;
 317 #endif
 318 #else /* !CONFIG_PPC_BOOK3S */
 319         return;
 320 #endif
 321 }