root/arch/powerpc/kernel/paca.c

DEFINITIONS

1. alloc_paca_data
2. alloc_shared_lppaca
3. init_lppaca
4. new_lppaca
5. new_slb_shadow
6. initialise_paca
7. setup_paca
8. allocate_paca_ptrs
9. allocate_paca
10. free_unused_pacas
11. copy_mm_to_paca

   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 __nostackprotector 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 __nostackprotector 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         /*
 218          * In HV mode, we setup both HPACA and PACA to avoid problems
 219          * if we do a GET_PACA() before the feature fixups have been
 220          * applied.
 221          *
 222          * Normally you should test against CPU_FTR_HVMODE, but CPU features
 223          * are not yet set up when we first reach here.
 224          */
 225         if (mfmsr() & MSR_HV)
 226                 mtspr(SPRN_SPRG_HPACA, local_paca);
 227 #endif
 228         mtspr(SPRN_SPRG_PACA, local_paca);
 229 
 230 }
 231 
 232 static int __initdata paca_nr_cpu_ids;
 233 static int __initdata paca_ptrs_size;
 234 static int __initdata paca_struct_size;
 235 
 236 void __init allocate_paca_ptrs(void)
 237 {
 238         paca_nr_cpu_ids = nr_cpu_ids;
 239 
 240         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 241         paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
 242         if (!paca_ptrs)
 243                 panic("Failed to allocate %d bytes for paca pointers\n",
 244                       paca_ptrs_size);
 245 
 246         memset(paca_ptrs, 0x88, paca_ptrs_size);
 247 }
 248 
 249 void __init allocate_paca(int cpu)
 250 {
 251         u64 limit;
 252         struct paca_struct *paca;
 253 
 254         BUG_ON(cpu >= paca_nr_cpu_ids);
 255 
 256 #ifdef CONFIG_PPC_BOOK3S_64
 257         /*
 258          * We access pacas in real mode, and cannot take SLB faults
 259          * on them when in virtual mode, so allocate them accordingly.
 260          */
 261         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 262 #else
 263         limit = ppc64_rma_size;
 264 #endif
 265 
 266         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 267                                 limit, cpu);
 268         paca_ptrs[cpu] = paca;
 269 
 270         initialise_paca(paca, cpu);
 271 #ifdef CONFIG_PPC_PSERIES
 272         paca->lppaca_ptr = new_lppaca(cpu, limit);
 273 #endif
 274 #ifdef CONFIG_PPC_BOOK3S_64
 275         paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 276 #endif
 277         paca_struct_size += sizeof(struct paca_struct);
 278 }
 279 
 280 void __init free_unused_pacas(void)
 281 {
 282         int new_ptrs_size;
 283 
 284         new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 285         if (new_ptrs_size < paca_ptrs_size)
 286                 memblock_free(__pa(paca_ptrs) + new_ptrs_size,
 287                                         paca_ptrs_size - new_ptrs_size);
 288 
 289         paca_nr_cpu_ids = nr_cpu_ids;
 290         paca_ptrs_size = new_ptrs_size;
 291 
 292 #ifdef CONFIG_PPC_BOOK3S_64
 293         if (early_radix_enabled()) {
 294                 /* Ugly fixup, see new_slb_shadow() */
 295                 memblock_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
 296                                 sizeof(struct slb_shadow));
 297                 paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
 298         }
 299 #endif
 300 
 301         printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 302                         paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 303 }
 304 
 305 void copy_mm_to_paca(struct mm_struct *mm)
 306 {
 307 #ifdef CONFIG_PPC_BOOK3S
 308         mm_context_t *context = &mm->context;
 309 
 310         get_paca()->mm_ctx_id = context->id;
 311 #ifdef CONFIG_PPC_MM_SLICES
 312         VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
 313         get_paca()->mm_ctx_slb_addr_limit = mm_ctx_slb_addr_limit(context);
 314         memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
 315                LOW_SLICE_ARRAY_SZ);
 316         memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
 317                TASK_SLICE_ARRAY_SZ(context));
 318 #else /* CONFIG_PPC_MM_SLICES */
 319         get_paca()->mm_ctx_user_psize = context->user_psize;
 320         get_paca()->mm_ctx_sllp = context->sllp;
 321 #endif
 322 #else /* !CONFIG_PPC_BOOK3S */
 323         return;
 324 #endif
 325 }