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 "qemu/bitmap.h"
  17 #include "exec/address-spaces.h"
  18 #include "qemu/error-report.h"
  19 #include "sysemu/qtest.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 options bits were removed, false otherwise */
  80 bool spapr_ovec_diff(sPAPROptionVector *ov,
  81                      sPAPROptionVector *ov_old,
  82                      sPAPROptionVector *ov_new)
  83 {
  84     unsigned long *change_mask = bitmap_new(OV_MAXBITS);
  85     unsigned long *removed_bits = bitmap_new(OV_MAXBITS);
  86     bool bits_were_removed = false;
  87
  88     g_assert(ov);
  89     g_assert(ov_old);
  90     g_assert(ov_new);
  91
  92     bitmap_xor(change_mask, ov_old->bitmap, ov_new->bitmap, OV_MAXBITS);
  93     bitmap_and(ov->bitmap, ov_new->bitmap, change_mask, OV_MAXBITS);
  94     bitmap_and(removed_bits, ov_old->bitmap, change_mask, OV_MAXBITS);
  95
  96     if (!bitmap_empty(removed_bits, OV_MAXBITS)) {
  97         bits_were_removed = true;
  98     }
  99
 100     g_free(change_mask);
 101     g_free(removed_bits);
 102
 103     return bits_were_removed;
 104 }
 105
 106 void spapr_ovec_cleanup(sPAPROptionVector *ov)
 107 {
 108     if (ov) {
 109         g_free(ov->bitmap);
 110         g_free(ov);
 111     }
 112 }
 113
 114 void spapr_ovec_set(sPAPROptionVector *ov, long bitnr)
 115 {
 116     g_assert(ov);
 117     g_assert(bitnr < OV_MAXBITS);
 118
 119     set_bit(bitnr, ov->bitmap);
 120 }
 121
 122 void spapr_ovec_clear(sPAPROptionVector *ov, long bitnr)
 123 {
 124     g_assert(ov);
 125     g_assert(bitnr < OV_MAXBITS);
 126
 127     clear_bit(bitnr, ov->bitmap);
 128 }
 129
 130 bool spapr_ovec_test(sPAPROptionVector *ov, long bitnr)
 131 {
 132     g_assert(ov);
 133     g_assert(bitnr < OV_MAXBITS);
 134
 135     /* support memory unplug for qtest */
 136     if (qtest_enabled() && bitnr == OV5_HP_EVT) {
 137         return true;
 138     }
 139
 140     return test_bit(bitnr, ov->bitmap) ? true : false;
 141 }
 142
 143 static void guest_byte_to_bitmap(uint8_t entry, unsigned long *bitmap,
 144                                  long bitmap_offset)
 145 {
 146     int i;
 147
 148     for (i = 0; i < BITS_PER_BYTE; i++) {
 149         if (entry & (1 << (BITS_PER_BYTE - 1 - i))) {
 150             bitmap_set(bitmap, bitmap_offset + i, 1);
 151         }
 152     }
 153 }
 154
 155 static uint8_t guest_byte_from_bitmap(unsigned long *bitmap, long bitmap_offset)
 156 {
 157     uint8_t entry = 0;
 158     int i;
 159
 160     for (i = 0; i < BITS_PER_BYTE; i++) {
 161         if (test_bit(bitmap_offset + i, bitmap)) {
 162             entry |= (1 << (BITS_PER_BYTE - 1 - i));
 163         }
 164     }
 165
 166     return entry;
 167 }
 168
 169 static target_ulong vector_addr(target_ulong table_addr, int vector)
 170 {
 171     uint16_t vector_count, vector_len;
 172     int i;
 173
 174     vector_count = ldub_phys(&address_space_memory, table_addr) + 1;
 175     if (vector > vector_count) {
 176         return 0;
 177     }
 178     table_addr++; /* skip nr option vectors */
 179
 180     for (i = 0; i < vector - 1; i++) {
 181         vector_len = ldub_phys(&address_space_memory, table_addr) + 1;
 182         table_addr += vector_len + 1; /* bit-vector + length byte */
 183     }
 184     return table_addr;
 185 }
 186
 187 sPAPROptionVector *spapr_ovec_parse_vector(target_ulong table_addr, int vector)
 188 {
 189     sPAPROptionVector *ov;
 190     target_ulong addr;
 191     uint16_t vector_len;
 192     int i;
 193
 194     g_assert(table_addr);
 195     g_assert(vector >= 1);      /* vector numbering starts at 1 */
 196
 197     addr = vector_addr(table_addr, vector);
 198     if (!addr) {
 199         /* specified vector isn't present */
 200         return NULL;
 201     }
 202
 203     vector_len = ldub_phys(&address_space_memory, addr++) + 1;
 204     g_assert(vector_len <= OV_MAXBYTES);
 205     ov = spapr_ovec_new();
 206
 207     for (i = 0; i < vector_len; i++) {
 208         uint8_t entry = ldub_phys(&address_space_memory, addr + i);
 209         if (entry) {
 210             trace_spapr_ovec_parse_vector(vector, i + 1, vector_len, entry);
 211             guest_byte_to_bitmap(entry, ov->bitmap, i * BITS_PER_BYTE);
 212         }
 213     }
 214
 215     return ov;
 216 }
 217
 218 int spapr_ovec_populate_dt(void *fdt, int fdt_offset,
 219                            sPAPROptionVector *ov, const char *name)
 220 {
 221     uint8_t vec[OV_MAXBYTES + 1];
 222     uint16_t vec_len;
 223     unsigned long lastbit;
 224     int i;
 225
 226     g_assert(ov);
 227
 228     lastbit = find_last_bit(ov->bitmap, OV_MAXBITS);
 229     /* if no bits are set, include at least 1 byte of the vector so we can
 230      * still encoded this in the device tree while abiding by the same
 231      * encoding/sizing expected in ibm,client-architecture-support
 232      */
 233     vec_len = (lastbit == OV_MAXBITS) ? 1 : lastbit / BITS_PER_BYTE + 1;
 234     g_assert(vec_len <= OV_MAXBYTES);
 235     /* guest expects vector len encoded as vec_len - 1, since the length byte
 236      * is assumed and not included, and the first byte of the vector
 237      * is assumed as well
 238      */
 239     vec[0] = vec_len - 1;
 240
 241     for (i = 1; i < vec_len + 1; i++) {
 242         vec[i] = guest_byte_from_bitmap(ov->bitmap, (i - 1) * BITS_PER_BYTE);
 243         if (vec[i]) {
 244             trace_spapr_ovec_populate_dt(i, vec_len, vec[i]);
 245         }
 246     }
 247
 248     return fdt_setprop(fdt, fdt_offset, name, vec, vec_len + 1);
 249 }