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 #include <linux/pgtable.h>
  12
  13 #include <asm/lppaca.h>
  14 #include <asm/paca.h>
  15 #include <asm/sections.h>
  16 #include <asm/kexec.h>
  17 #include <asm/svm.h>
  18 #include <asm/ultravisor.h>
  19 #include <asm/rtas.h>
  20
  21 #include "setup.h"
  22
  23 #ifndef CONFIG_SMP
  24 #define boot_cpuid 0
  25 #endif
  26
  27 static void *__init alloc_paca_data(unsigned long size, unsigned long align,
  28                                 unsigned long limit, int cpu)
  29 {
  30         void *ptr;
  31         int nid;
  32
  33         /*
  34          * boot_cpuid paca is allocated very early before cpu_to_node is up.
  35          * Set bottom-up mode, because the boot CPU should be on node-0,
  36          * which will put its paca in the right place.
  37          */
  38         if (cpu == boot_cpuid) {
  39                 nid = NUMA_NO_NODE;
  40                 memblock_set_bottom_up(true);
  41         } else {
  42                 nid = early_cpu_to_node(cpu);
  43         }
  44
  45         ptr = memblock_alloc_try_nid(size, align, MEMBLOCK_LOW_LIMIT,
  46                                      limit, nid);
  47         if (!ptr)
  48                 panic("cannot allocate paca data");
  49
  50         if (cpu == boot_cpuid)
  51                 memblock_set_bottom_up(false);
  52
  53         return ptr;
  54 }
  55
  56 #ifdef CONFIG_PPC_PSERIES
  57
  58 #define LPPACA_SIZE 0x400
  59
  60 static void *__init alloc_shared_lppaca(unsigned long size, unsigned long limit,
  61                                         int cpu)
  62 {
  63         size_t shared_lppaca_total_size = PAGE_ALIGN(nr_cpu_ids * LPPACA_SIZE);
  64         static unsigned long shared_lppaca_size;
  65         static void *shared_lppaca;
  66         void *ptr;
  67
  68         if (!shared_lppaca) {
  69                 memblock_set_bottom_up(true);
  70
  71                 /*
  72                  * See Documentation/powerpc/ultravisor.rst for more details.
  73                  *
  74                  * UV/HV data sharing is in PAGE_SIZE granularity. In order to
  75                  * minimize the number of pages shared, align the allocation to
  76                  * PAGE_SIZE.
  77                  */
  78                 shared_lppaca =
  79                         memblock_alloc_try_nid(shared_lppaca_total_size,
  80                                                PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
  81                                                limit, NUMA_NO_NODE);
  82                 if (!shared_lppaca)
  83                         panic("cannot allocate shared data");
  84
  85                 memblock_set_bottom_up(false);
  86                 uv_share_page(PHYS_PFN(__pa(shared_lppaca)),
  87                               shared_lppaca_total_size >> PAGE_SHIFT);
  88         }
  89
  90         ptr = shared_lppaca + shared_lppaca_size;
  91         shared_lppaca_size += size;
  92
  93         /*
  94          * This is very early in boot, so no harm done if the kernel crashes at
  95          * this point.
  96          */
  97         BUG_ON(shared_lppaca_size > shared_lppaca_total_size);
  98
  99         return ptr;
 100 }
 101
 102 /*
 103  * See asm/lppaca.h for more detail.
 104  *
 105  * lppaca structures must must be 1kB in size, L1 cache line aligned,
 106  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
 107  * these requirements.
 108  */
 109 static inline void init_lppaca(struct lppaca *lppaca)
 110 {
 111         BUILD_BUG_ON(sizeof(struct lppaca) != 640);
 112
 113         *lppaca = (struct lppaca) {
 114                 .desc = cpu_to_be32(0xd397d781),        /* "LpPa" */
 115                 .size = cpu_to_be16(LPPACA_SIZE),
 116                 .fpregs_in_use = 1,
 117                 .slb_count = cpu_to_be16(64),
 118                 .vmxregs_in_use = 0,
 119                 .page_ins = 0, };
 120 };
 121
 122 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
 123 {
 124         struct lppaca *lp;
 125
 126         BUILD_BUG_ON(sizeof(struct lppaca) > LPPACA_SIZE);
 127
 128         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 129                 return NULL;
 130
 131         if (is_secure_guest())
 132                 lp = alloc_shared_lppaca(LPPACA_SIZE, limit, cpu);
 133         else
 134                 lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);
 135
 136         init_lppaca(lp);
 137
 138         return lp;
 139 }
 140 #endif /* CONFIG_PPC_PSERIES */
 141
 142 #ifdef CONFIG_PPC_BOOK3S_64
 143
 144 /*
 145  * 3 persistent SLBs are allocated here.  The buffer will be zero
 146  * initially, hence will all be invaild until we actually write them.
 147  *
 148  * If you make the number of persistent SLB entries dynamic, please also
 149  * update PR KVM to flush and restore them accordingly.
 150  */
 151 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 152 {
 153         struct slb_shadow *s;
 154
 155         if (cpu != boot_cpuid) {
 156                 /*
 157                  * Boot CPU comes here before early_radix_enabled
 158                  * is parsed (e.g., for disable_radix). So allocate
 159                  * always and this will be fixed up in free_unused_pacas.
 160                  */
 161                 if (early_radix_enabled())
 162                         return NULL;
 163         }
 164
 165         s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
 166
 167         s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
 168         s->buffer_length = cpu_to_be32(sizeof(*s));
 169
 170         return s;
 171 }
 172
 173 #endif /* CONFIG_PPC_BOOK3S_64 */
 174
 175 #ifdef CONFIG_PPC_PSERIES
 176 /**
 177  * new_rtas_args() - Allocates rtas args
 178  * @cpu:        CPU number
 179  * @limit:      Memory limit for this allocation
 180  *
 181  * Allocates a struct rtas_args and return it's pointer,
 182  * if not in Hypervisor mode
 183  *
 184  * Return:      Pointer to allocated rtas_args
 185  *              NULL if CPU in Hypervisor Mode
 186  */
 187 static struct rtas_args * __init new_rtas_args(int cpu, unsigned long limit)
 188 {
 189         limit = min_t(unsigned long, limit, RTAS_INSTANTIATE_MAX);
 190
 191         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 192                 return NULL;
 193
 194         return alloc_paca_data(sizeof(struct rtas_args), L1_CACHE_BYTES,
 195                                limit, cpu);
 196 }
 197 #endif /* CONFIG_PPC_PSERIES */
 198
 199 /* The Paca is an array with one entry per processor.  Each contains an
 200  * lppaca, which contains the information shared between the
 201  * hypervisor and Linux.
 202  * On systems with hardware multi-threading, there are two threads
 203  * per processor.  The Paca array must contain an entry for each thread.
 204  * The VPD Areas will give a max logical processors = 2 * max physical
 205  * processors.  The processor VPD array needs one entry per physical
 206  * processor (not thread).
 207  */
 208 struct paca_struct **paca_ptrs __read_mostly;
 209 EXPORT_SYMBOL(paca_ptrs);
 210
 211 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 212 {
 213 #ifdef CONFIG_PPC_PSERIES
 214         new_paca->lppaca_ptr = NULL;
 215 #endif
 216 #ifdef CONFIG_PPC_BOOK3E
 217         new_paca->kernel_pgd = swapper_pg_dir;
 218 #endif
 219         new_paca->lock_token = 0x8000;
 220         new_paca->paca_index = cpu;
 221         new_paca->kernel_toc = kernel_toc_addr();
 222         new_paca->kernelbase = (unsigned long) _stext;
 223         /* Only set MSR:IR/DR when MMU is initialized */
 224         new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 225         new_paca->hw_cpu_id = 0xffff;
 226         new_paca->kexec_state = KEXEC_STATE_NONE;
 227         new_paca->__current = &init_task;
 228         new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 229 #ifdef CONFIG_PPC_BOOK3S_64
 230         new_paca->slb_shadow_ptr = NULL;
 231 #endif
 232
 233 #ifdef CONFIG_PPC_BOOK3E
 234         /* For now -- if we have threads this will be adjusted later */
 235         new_paca->tcd_ptr = &new_paca->tcd;
 236 #endif
 237
 238 #ifdef CONFIG_PPC_PSERIES
 239         new_paca->rtas_args_reentrant = NULL;
 240 #endif
 241 }
 242
 243 /* Put the paca pointer into r13 and SPRG_PACA */
 244 void setup_paca(struct paca_struct *new_paca)
 245 {
 246         /* Setup r13 */
 247         local_paca = new_paca;
 248
 249 #ifdef CONFIG_PPC_BOOK3E
 250         /* On Book3E, initialize the TLB miss exception frames */
 251         mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
 252 #else
 253         /*
 254          * In HV mode, we setup both HPACA and PACA to avoid problems
 255          * if we do a GET_PACA() before the feature fixups have been
 256          * applied.
 257          *
 258          * Normally you should test against CPU_FTR_HVMODE, but CPU features
 259          * are not yet set up when we first reach here.
 260          */
 261         if (mfmsr() & MSR_HV)
 262                 mtspr(SPRN_SPRG_HPACA, local_paca);
 263 #endif
 264         mtspr(SPRN_SPRG_PACA, local_paca);
 265
 266 }
 267
 268 static int __initdata paca_nr_cpu_ids;
 269 static int __initdata paca_ptrs_size;
 270 static int __initdata paca_struct_size;
 271
 272 void __init allocate_paca_ptrs(void)
 273 {
 274         paca_nr_cpu_ids = nr_cpu_ids;
 275
 276         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 277         paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
 278         if (!paca_ptrs)
 279                 panic("Failed to allocate %d bytes for paca pointers\n",
 280                       paca_ptrs_size);
 281
 282         memset(paca_ptrs, 0x88, paca_ptrs_size);
 283 }
 284
 285 void __init allocate_paca(int cpu)
 286 {
 287         u64 limit;
 288         struct paca_struct *paca;
 289
 290         BUG_ON(cpu >= paca_nr_cpu_ids);
 291
 292 #ifdef CONFIG_PPC_BOOK3S_64
 293         /*
 294          * We access pacas in real mode, and cannot take SLB faults
 295          * on them when in virtual mode, so allocate them accordingly.
 296          */
 297         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 298 #else
 299         limit = ppc64_rma_size;
 300 #endif
 301
 302         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 303                                 limit, cpu);
 304         paca_ptrs[cpu] = paca;
 305
 306         initialise_paca(paca, cpu);
 307 #ifdef CONFIG_PPC_PSERIES
 308         paca->lppaca_ptr = new_lppaca(cpu, limit);
 309 #endif
 310 #ifdef CONFIG_PPC_BOOK3S_64
 311         paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 312 #endif
 313 #ifdef CONFIG_PPC_PSERIES
 314         paca->rtas_args_reentrant = new_rtas_args(cpu, limit);
 315 #endif
 316         paca_struct_size += sizeof(struct paca_struct);
 317 }
 318
 319 void __init free_unused_pacas(void)
 320 {
 321         int new_ptrs_size;
 322
 323         new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 324         if (new_ptrs_size < paca_ptrs_size)
 325                 memblock_phys_free(__pa(paca_ptrs) + new_ptrs_size,
 326                                    paca_ptrs_size - new_ptrs_size);
 327
 328         paca_nr_cpu_ids = nr_cpu_ids;
 329         paca_ptrs_size = new_ptrs_size;
 330
 331 #ifdef CONFIG_PPC_BOOK3S_64
 332         if (early_radix_enabled()) {
 333                 /* Ugly fixup, see new_slb_shadow() */
 334                 memblock_phys_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
 335                                    sizeof(struct slb_shadow));
 336                 paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
 337         }
 338 #endif
 339
 340         printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 341                         paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 342 }
 343
 344 void copy_mm_to_paca(struct mm_struct *mm)
 345 {
 346 #ifdef CONFIG_PPC_BOOK3S
 347         mm_context_t *context = &mm->context;
 348
 349 #ifdef CONFIG_PPC_MM_SLICES
 350         VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
 351         memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
 352                LOW_SLICE_ARRAY_SZ);
 353         memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
 354                TASK_SLICE_ARRAY_SZ(context));
 355 #else /* CONFIG_PPC_MM_SLICES */
 356         get_paca()->mm_ctx_user_psize = context->user_psize;
 357         get_paca()->mm_ctx_sllp = context->sllp;
 358 #endif
 359 #else /* !CONFIG_PPC_BOOK3S */
 360         return;
 361 #endif
 362 }