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
  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 limit,
  60                                         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                 /*
  71                  * See Documentation/arch/powerpc/ultravisor.rst for more details.
  72                  *
  73                  * UV/HV data sharing is in PAGE_SIZE granularity. In order to
  74                  * minimize the number of pages shared, align the allocation to
  75                  * PAGE_SIZE.
  76                  */
  77                 shared_lppaca =
  78                         memblock_alloc_try_nid(shared_lppaca_total_size,
  79                                                PAGE_SIZE, MEMBLOCK_LOW_LIMIT,
  80                                                limit, NUMA_NO_NODE);
  81                 if (!shared_lppaca)
  82                         panic("cannot allocate shared data");
  83
  84                 memblock_set_bottom_up(false);
  85                 uv_share_page(PHYS_PFN(__pa(shared_lppaca)),
  86                               shared_lppaca_total_size >> PAGE_SHIFT);
  87         }
  88
  89         ptr = shared_lppaca + shared_lppaca_size;
  90         shared_lppaca_size += size;
  91
  92         /*
  93          * This is very early in boot, so no harm done if the kernel crashes at
  94          * this point.
  95          */
  96         BUG_ON(shared_lppaca_size > shared_lppaca_total_size);
  97
  98         return ptr;
  99 }
 100
 101 /*
 102  * See asm/lppaca.h for more detail.
 103  *
 104  * lppaca structures must must be 1kB in size, L1 cache line aligned,
 105  * and not cross 4kB boundary. A 1kB size and 1kB alignment will satisfy
 106  * these requirements.
 107  */
 108 static inline void init_lppaca(struct lppaca *lppaca)
 109 {
 110         BUILD_BUG_ON(sizeof(struct lppaca) != 640);
 111
 112         *lppaca = (struct lppaca) {
 113                 .desc = cpu_to_be32(0xd397d781),        /* "LpPa" */
 114                 .size = cpu_to_be16(LPPACA_SIZE),
 115                 .fpregs_in_use = 1,
 116                 .slb_count = cpu_to_be16(64),
 117                 .vmxregs_in_use = 0,
 118                 .page_ins = 0, };
 119 };
 120
 121 static struct lppaca * __init new_lppaca(int cpu, unsigned long limit)
 122 {
 123         struct lppaca *lp;
 124
 125         BUILD_BUG_ON(sizeof(struct lppaca) > LPPACA_SIZE);
 126
 127         if (early_cpu_has_feature(CPU_FTR_HVMODE))
 128                 return NULL;
 129
 130         if (is_secure_guest())
 131                 lp = alloc_shared_lppaca(LPPACA_SIZE, limit, cpu);
 132         else
 133                 lp = alloc_paca_data(LPPACA_SIZE, 0x400, limit, cpu);
 134
 135         init_lppaca(lp);
 136
 137         return lp;
 138 }
 139 #endif /* CONFIG_PPC_PSERIES */
 140
 141 #ifdef CONFIG_PPC_64S_HASH_MMU
 142 /*
 143  * 3 persistent SLBs are allocated here.  The buffer will be zero
 144  * initially, hence will all be invaild until we actually write them.
 145  *
 146  * If you make the number of persistent SLB entries dynamic, please also
 147  * update PR KVM to flush and restore them accordingly.
 148  */
 149 static struct slb_shadow * __init new_slb_shadow(int cpu, unsigned long limit)
 150 {
 151         struct slb_shadow *s;
 152
 153         if (cpu != boot_cpuid) {
 154                 /*
 155                  * Boot CPU comes here before early_radix_enabled
 156                  * is parsed (e.g., for disable_radix). So allocate
 157                  * always and this will be fixed up in free_unused_pacas.
 158                  */
 159                 if (early_radix_enabled())
 160                         return NULL;
 161         }
 162
 163         s = alloc_paca_data(sizeof(*s), L1_CACHE_BYTES, limit, cpu);
 164
 165         s->persistent = cpu_to_be32(SLB_NUM_BOLTED);
 166         s->buffer_length = cpu_to_be32(sizeof(*s));
 167
 168         return s;
 169 }
 170 #endif /* CONFIG_PPC_64S_HASH_MMU */
 171
 172 /* The Paca is an array with one entry per processor.  Each contains an
 173  * lppaca, which contains the information shared between the
 174  * hypervisor and Linux.
 175  * On systems with hardware multi-threading, there are two threads
 176  * per processor.  The Paca array must contain an entry for each thread.
 177  * The VPD Areas will give a max logical processors = 2 * max physical
 178  * processors.  The processor VPD array needs one entry per physical
 179  * processor (not thread).
 180  */
 181 struct paca_struct **paca_ptrs __read_mostly;
 182 EXPORT_SYMBOL(paca_ptrs);
 183
 184 void __init initialise_paca(struct paca_struct *new_paca, int cpu)
 185 {
 186 #ifdef CONFIG_PPC_PSERIES
 187         new_paca->lppaca_ptr = NULL;
 188 #endif
 189 #ifdef CONFIG_PPC_BOOK3E_64
 190         new_paca->kernel_pgd = swapper_pg_dir;
 191 #endif
 192         new_paca->lock_token = 0x8000;
 193         new_paca->paca_index = cpu;
 194 #ifndef CONFIG_PPC_KERNEL_PCREL
 195         new_paca->kernel_toc = kernel_toc_addr();
 196 #endif
 197         new_paca->kernelbase = (unsigned long) _stext;
 198         /* Only set MSR:IR/DR when MMU is initialized */
 199         new_paca->kernel_msr = MSR_KERNEL & ~(MSR_IR | MSR_DR);
 200         new_paca->hw_cpu_id = 0xffff;
 201         new_paca->kexec_state = KEXEC_STATE_NONE;
 202         new_paca->__current = &init_task;
 203         new_paca->data_offset = 0xfeeeeeeeeeeeeeeeULL;
 204 #ifdef CONFIG_PPC_64S_HASH_MMU
 205         new_paca->slb_shadow_ptr = NULL;
 206 #endif
 207
 208 #ifdef CONFIG_PPC_BOOK3E_64
 209         /* For now -- if we have threads this will be adjusted later */
 210         new_paca->tcd_ptr = &new_paca->tcd;
 211 #endif
 212 }
 213
 214 /* Put the paca pointer into r13 and SPRG_PACA */
 215 void setup_paca(struct paca_struct *new_paca)
 216 {
 217         /* Setup r13 */
 218         local_paca = new_paca;
 219
 220 #ifdef CONFIG_PPC_BOOK3E_64
 221         /* On Book3E, initialize the TLB miss exception frames */
 222         mtspr(SPRN_SPRG_TLB_EXFRAME, local_paca->extlb);
 223 #else
 224         /*
 225          * In HV mode, we setup both HPACA and PACA to avoid problems
 226          * if we do a GET_PACA() before the feature fixups have been
 227          * applied.
 228          *
 229          * Normally you should test against CPU_FTR_HVMODE, but CPU features
 230          * are not yet set up when we first reach here.
 231          */
 232         if (mfmsr() & MSR_HV)
 233                 mtspr(SPRN_SPRG_HPACA, local_paca);
 234 #endif
 235         mtspr(SPRN_SPRG_PACA, local_paca);
 236
 237 }
 238
 239 static int __initdata paca_nr_cpu_ids;
 240 static int __initdata paca_ptrs_size;
 241 static int __initdata paca_struct_size;
 242
 243 void __init allocate_paca_ptrs(void)
 244 {
 245         paca_nr_cpu_ids = nr_cpu_ids;
 246
 247         paca_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 248         paca_ptrs = memblock_alloc_raw(paca_ptrs_size, SMP_CACHE_BYTES);
 249         if (!paca_ptrs)
 250                 panic("Failed to allocate %d bytes for paca pointers\n",
 251                       paca_ptrs_size);
 252
 253         memset(paca_ptrs, 0x88, paca_ptrs_size);
 254 }
 255
 256 void __init allocate_paca(int cpu)
 257 {
 258         u64 limit;
 259         struct paca_struct *paca;
 260
 261         BUG_ON(cpu >= paca_nr_cpu_ids);
 262
 263 #ifdef CONFIG_PPC_BOOK3S_64
 264         /*
 265          * We access pacas in real mode, and cannot take SLB faults
 266          * on them when in virtual mode, so allocate them accordingly.
 267          */
 268         limit = min(ppc64_bolted_size(), ppc64_rma_size);
 269 #else
 270         limit = ppc64_rma_size;
 271 #endif
 272
 273         paca = alloc_paca_data(sizeof(struct paca_struct), L1_CACHE_BYTES,
 274                                 limit, cpu);
 275         paca_ptrs[cpu] = paca;
 276
 277         initialise_paca(paca, cpu);
 278 #ifdef CONFIG_PPC_PSERIES
 279         paca->lppaca_ptr = new_lppaca(cpu, limit);
 280 #endif
 281 #ifdef CONFIG_PPC_64S_HASH_MMU
 282         paca->slb_shadow_ptr = new_slb_shadow(cpu, limit);
 283 #endif
 284         paca_struct_size += sizeof(struct paca_struct);
 285 }
 286
 287 void __init free_unused_pacas(void)
 288 {
 289         int new_ptrs_size;
 290
 291         new_ptrs_size = sizeof(struct paca_struct *) * nr_cpu_ids;
 292         if (new_ptrs_size < paca_ptrs_size)
 293                 memblock_phys_free(__pa(paca_ptrs) + new_ptrs_size,
 294                                    paca_ptrs_size - new_ptrs_size);
 295
 296         paca_nr_cpu_ids = nr_cpu_ids;
 297         paca_ptrs_size = new_ptrs_size;
 298
 299 #ifdef CONFIG_PPC_64S_HASH_MMU
 300         if (early_radix_enabled()) {
 301                 /* Ugly fixup, see new_slb_shadow() */
 302                 memblock_phys_free(__pa(paca_ptrs[boot_cpuid]->slb_shadow_ptr),
 303                                    sizeof(struct slb_shadow));
 304                 paca_ptrs[boot_cpuid]->slb_shadow_ptr = NULL;
 305         }
 306 #endif
 307
 308         printk(KERN_DEBUG "Allocated %u bytes for %u pacas\n",
 309                         paca_ptrs_size + paca_struct_size, nr_cpu_ids);
 310 }
 311
 312 #ifdef CONFIG_PPC_64S_HASH_MMU
 313 void copy_mm_to_paca(struct mm_struct *mm)
 314 {
 315         mm_context_t *context = &mm->context;
 316
 317         VM_BUG_ON(!mm_ctx_slb_addr_limit(context));
 318         memcpy(&get_paca()->mm_ctx_low_slices_psize, mm_ctx_low_slices(context),
 319                LOW_SLICE_ARRAY_SZ);
 320         memcpy(&get_paca()->mm_ctx_high_slices_psize, mm_ctx_high_slices(context),
 321                TASK_SLICE_ARRAY_SZ(context));
 322 }
 323 #endif /* CONFIG_PPC_64S_HASH_MMU */