hw/ppc/spapr_ovec.c

   1 /*
   2  * QEMU SPAPR Architecture Option Vector Helper Functions
   3  *
   4  * Copyright IBM Corp. 2016
   5  *
   6  * Authors:
   7  *  Bharata B Rao     <bharata@linux.vnet.ibm.com>
   8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
   9  *
  10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
  11  * See the COPYING file in the top-level directory.
  12  */
  13
  14 #include "qemu/osdep.h"
  15 #include "hw/ppc/spapr_ovec.h"
  16 #include "migration/vmstate.h"
  17 #include "qemu/bitmap.h"
  18 #include "exec/address-spaces.h"
  19 #include "qemu/error-report.h"
  20 #include "trace.h"
  21 #include <libfdt.h>
  22
  23 #define OV_MAXBYTES 256 /* not including length byte */
  24 #define OV_MAXBITS (OV_MAXBYTES * BITS_PER_BYTE)
  25
  26 /* we *could* work with bitmaps directly, but handling the bitmap privately
  27  * allows us to more safely make assumptions about the bitmap size and
  28  * simplify the calling code somewhat
  29  */
  30 struct SpaprOptionVector {
  31     unsigned long *bitmap;
  32     int32_t bitmap_size; /* only used for migration */
  33 };
  34
  35 const VMStateDescription vmstate_spapr_ovec = {
  36     .name = "spapr_option_vector",
  37     .version_id = 1,
  38     .minimum_version_id = 1,
  39     .fields = (VMStateField[]) {
  40         VMSTATE_BITMAP(bitmap, SpaprOptionVector, 1, bitmap_size),
  41         VMSTATE_END_OF_LIST()
  42     }
  43 };
  44
  45 SpaprOptionVector *spapr_ovec_new(void)
  46 {
  47     SpaprOptionVector *ov;
  48
  49     ov = g_new0(SpaprOptionVector, 1);
  50     ov->bitmap = bitmap_new(OV_MAXBITS);
  51     ov->bitmap_size = OV_MAXBITS;
  52
  53     return ov;
  54 }
  55
  56 SpaprOptionVector *spapr_ovec_clone(SpaprOptionVector *ov_orig)
  57 {
  58     SpaprOptionVector *ov;
  59
  60     g_assert(ov_orig);
  61
  62     ov = spapr_ovec_new();
  63     bitmap_copy(ov->bitmap, ov_orig->bitmap, OV_MAXBITS);
  64
  65     return ov;
  66 }
  67
  68 void spapr_ovec_intersect(SpaprOptionVector *ov,
  69                           SpaprOptionVector *ov1,
  70                           SpaprOptionVector *ov2)
  71 {
  72     g_assert(ov);
  73     g_assert(ov1);
  74     g_assert(ov2);
  75
  76     bitmap_and(ov->bitmap, ov1->bitmap, ov2->bitmap, OV_MAXBITS);
  77 }
  78
  79 /* returns true if ov1 has a subset of bits in ov2 */
  80 bool spapr_ovec_subset(SpaprOptionVector *ov1, SpaprOptionVector *ov2)
  81 {
  82     unsigned long *tmp = bitmap_new(OV_MAXBITS);
  83     bool result;
  84
  85     g_assert(ov1);
  86     g_assert(ov2);
  87
  88     bitmap_andnot(tmp, ov1->bitmap, ov2->bitmap, OV_MAXBITS);
  89     result = bitmap_empty(tmp, OV_MAXBITS);
  90
  91     g_free(tmp);
  92
  93     return result;
  94 }
  95
  96 void spapr_ovec_cleanup(SpaprOptionVector *ov)
  97 {
  98     if (ov) {
  99         g_free(ov->bitmap);
 100         g_free(ov);
 101     }
 102 }
 103
 104 void spapr_ovec_set(SpaprOptionVector *ov, long bitnr)
 105 {
 106     g_assert(ov);
 107     g_assert(bitnr < OV_MAXBITS);
 108
 109     set_bit(bitnr, ov->bitmap);
 110 }
 111
 112 void spapr_ovec_clear(SpaprOptionVector *ov, long bitnr)
 113 {
 114     g_assert(ov);
 115     g_assert(bitnr < OV_MAXBITS);
 116
 117     clear_bit(bitnr, ov->bitmap);
 118 }
 119
 120 bool spapr_ovec_test(SpaprOptionVector *ov, long bitnr)
 121 {
 122     g_assert(ov);
 123     g_assert(bitnr < OV_MAXBITS);
 124
 125     return test_bit(bitnr, ov->bitmap) ? true : false;
 126 }
 127
 128 static void guest_byte_to_bitmap(uint8_t entry, unsigned long *bitmap,
 129                                  long bitmap_offset)
 130 {
 131     int i;
 132
 133     for (i = 0; i < BITS_PER_BYTE; i++) {
 134         if (entry & (1 << (BITS_PER_BYTE - 1 - i))) {
 135             bitmap_set(bitmap, bitmap_offset + i, 1);
 136         }
 137     }
 138 }
 139
 140 static uint8_t guest_byte_from_bitmap(unsigned long *bitmap, long bitmap_offset)
 141 {
 142     uint8_t entry = 0;
 143     int i;
 144
 145     for (i = 0; i < BITS_PER_BYTE; i++) {
 146         if (test_bit(bitmap_offset + i, bitmap)) {
 147             entry |= (1 << (BITS_PER_BYTE - 1 - i));
 148         }
 149     }
 150
 151     return entry;
 152 }
 153
 154 static target_ulong vector_addr(target_ulong table_addr, int vector)
 155 {
 156     uint16_t vector_count, vector_len;
 157     int i;
 158
 159     vector_count = ldub_phys(&address_space_memory, table_addr) + 1;
 160     if (vector > vector_count) {
 161         return 0;
 162     }
 163     table_addr++; /* skip nr option vectors */
 164
 165     for (i = 0; i < vector - 1; i++) {
 166         vector_len = ldub_phys(&address_space_memory, table_addr) + 1;
 167         table_addr += vector_len + 1; /* bit-vector + length byte */
 168     }
 169     return table_addr;
 170 }
 171
 172 SpaprOptionVector *spapr_ovec_parse_vector(target_ulong table_addr, int vector)
 173 {
 174     SpaprOptionVector *ov;
 175     target_ulong addr;
 176     uint16_t vector_len;
 177     int i;
 178
 179     g_assert(table_addr);
 180     g_assert(vector >= 1);      /* vector numbering starts at 1 */
 181
 182     addr = vector_addr(table_addr, vector);
 183     if (!addr) {
 184         /* specified vector isn't present */
 185         return NULL;
 186     }
 187
 188     vector_len = ldub_phys(&address_space_memory, addr++) + 1;
 189     g_assert(vector_len <= OV_MAXBYTES);
 190     ov = spapr_ovec_new();
 191
 192     for (i = 0; i < vector_len; i++) {
 193         uint8_t entry = ldub_phys(&address_space_memory, addr + i);
 194         if (entry) {
 195             trace_spapr_ovec_parse_vector(vector, i + 1, vector_len, entry);
 196             guest_byte_to_bitmap(entry, ov->bitmap, i * BITS_PER_BYTE);
 197         }
 198     }
 199
 200     return ov;
 201 }
 202
 203 int spapr_dt_ovec(void *fdt, int fdt_offset,
 204                   SpaprOptionVector *ov, const char *name)
 205 {
 206     uint8_t vec[OV_MAXBYTES + 1];
 207     uint16_t vec_len;
 208     unsigned long lastbit;
 209     int i;
 210
 211     g_assert(ov);
 212
 213     lastbit = find_last_bit(ov->bitmap, OV_MAXBITS);
 214     /* if no bits are set, include at least 1 byte of the vector so we can
 215      * still encoded this in the device tree while abiding by the same
 216      * encoding/sizing expected in ibm,client-architecture-support
 217      */
 218     vec_len = (lastbit == OV_MAXBITS) ? 1 : lastbit / BITS_PER_BYTE + 1;
 219     g_assert(vec_len <= OV_MAXBYTES);
 220     /* guest expects vector len encoded as vec_len - 1, since the length byte
 221      * is assumed and not included, and the first byte of the vector
 222      * is assumed as well
 223      */
 224     vec[0] = vec_len - 1;
 225
 226     for (i = 1; i < vec_len + 1; i++) {
 227         vec[i] = guest_byte_from_bitmap(ov->bitmap, (i - 1) * BITS_PER_BYTE);
 228         if (vec[i]) {
 229             trace_spapr_ovec_populate_dt(i, vec_len, vec[i]);
 230         }
 231     }
 232
 233     return fdt_setprop(fdt, fdt_offset, name, vec, vec_len + 1);
 234 }