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 "trace.h" 20 #include <libfdt.h> 21 22 #define OV_MAXBYTES 256 /* not including length byte */ 23 #define OV_MAXBITS (OV_MAXBYTES * BITS_PER_BYTE) 24 25 /* we *could* work with bitmaps directly, but handling the bitmap privately 26 * allows us to more safely make assumptions about the bitmap size and 27 * simplify the calling code somewhat 28 */ 29 struct sPAPROptionVector { 30 unsigned long *bitmap; 31 int32_t bitmap_size; /* only used for migration */ 32 }; 33 34 const VMStateDescription vmstate_spapr_ovec = { 35 .name = "spapr_option_vector", 36 .version_id = 1, 37 .minimum_version_id = 1, 38 .fields = (VMStateField[]) { 39 VMSTATE_BITMAP(bitmap, sPAPROptionVector, 1, bitmap_size), 40 VMSTATE_END_OF_LIST() 41 } 42 }; 43 44 sPAPROptionVector *spapr_ovec_new(void) 45 { 46 sPAPROptionVector *ov; 47 48 ov = g_new0(sPAPROptionVector, 1); 49 ov->bitmap = bitmap_new(OV_MAXBITS); 50 ov->bitmap_size = OV_MAXBITS; 51 52 return ov; 53 } 54 55 sPAPROptionVector *spapr_ovec_clone(sPAPROptionVector *ov_orig) 56 { 57 sPAPROptionVector *ov; 58 59 g_assert(ov_orig); 60 61 ov = spapr_ovec_new(); 62 bitmap_copy(ov->bitmap, ov_orig->bitmap, OV_MAXBITS); 63 64 return ov; 65 } 66 67 void spapr_ovec_intersect(sPAPROptionVector *ov, 68 sPAPROptionVector *ov1, 69 sPAPROptionVector *ov2) 70 { 71 g_assert(ov); 72 g_assert(ov1); 73 g_assert(ov2); 74 75 bitmap_and(ov->bitmap, ov1->bitmap, ov2->bitmap, OV_MAXBITS); 76 } 77 78 /* returns true if options bits were removed, false otherwise */ 79 bool spapr_ovec_diff(sPAPROptionVector *ov, 80 sPAPROptionVector *ov_old, 81 sPAPROptionVector *ov_new) 82 { 83 unsigned long *change_mask = bitmap_new(OV_MAXBITS); 84 unsigned long *removed_bits = bitmap_new(OV_MAXBITS); 85 bool bits_were_removed = false; 86 87 g_assert(ov); 88 g_assert(ov_old); 89 g_assert(ov_new); 90 91 bitmap_xor(change_mask, ov_old->bitmap, ov_new->bitmap, OV_MAXBITS); 92 bitmap_and(ov->bitmap, ov_new->bitmap, change_mask, OV_MAXBITS); 93 bitmap_and(removed_bits, ov_old->bitmap, change_mask, OV_MAXBITS); 94 95 if (!bitmap_empty(removed_bits, OV_MAXBITS)) { 96 bits_were_removed = true; 97 } 98 99 g_free(change_mask); 100 g_free(removed_bits); 101 102 return bits_were_removed; 103 } 104 105 void spapr_ovec_cleanup(sPAPROptionVector *ov) 106 { 107 if (ov) { 108 g_free(ov->bitmap); 109 g_free(ov); 110 } 111 } 112 113 void spapr_ovec_set(sPAPROptionVector *ov, long bitnr) 114 { 115 g_assert(ov); 116 g_assert(bitnr < OV_MAXBITS); 117 118 set_bit(bitnr, ov->bitmap); 119 } 120 121 void spapr_ovec_clear(sPAPROptionVector *ov, long bitnr) 122 { 123 g_assert(ov); 124 g_assert(bitnr < OV_MAXBITS); 125 126 clear_bit(bitnr, ov->bitmap); 127 } 128 129 bool spapr_ovec_test(sPAPROptionVector *ov, long bitnr) 130 { 131 g_assert(ov); 132 g_assert(bitnr < OV_MAXBITS); 133 134 return test_bit(bitnr, ov->bitmap) ? true : false; 135 } 136 137 static void guest_byte_to_bitmap(uint8_t entry, unsigned long *bitmap, 138 long bitmap_offset) 139 { 140 int i; 141 142 for (i = 0; i < BITS_PER_BYTE; i++) { 143 if (entry & (1 << (BITS_PER_BYTE - 1 - i))) { 144 bitmap_set(bitmap, bitmap_offset + i, 1); 145 } 146 } 147 } 148 149 static uint8_t guest_byte_from_bitmap(unsigned long *bitmap, long bitmap_offset) 150 { 151 uint8_t entry = 0; 152 int i; 153 154 for (i = 0; i < BITS_PER_BYTE; i++) { 155 if (test_bit(bitmap_offset + i, bitmap)) { 156 entry |= (1 << (BITS_PER_BYTE - 1 - i)); 157 } 158 } 159 160 return entry; 161 } 162 163 static target_ulong vector_addr(target_ulong table_addr, int vector) 164 { 165 uint16_t vector_count, vector_len; 166 int i; 167 168 vector_count = ldub_phys(&address_space_memory, table_addr) + 1; 169 if (vector > vector_count) { 170 return 0; 171 } 172 table_addr++; /* skip nr option vectors */ 173 174 for (i = 0; i < vector - 1; i++) { 175 vector_len = ldub_phys(&address_space_memory, table_addr) + 1; 176 table_addr += vector_len + 1; /* bit-vector + length byte */ 177 } 178 return table_addr; 179 } 180 181 sPAPROptionVector *spapr_ovec_parse_vector(target_ulong table_addr, int vector) 182 { 183 sPAPROptionVector *ov; 184 target_ulong addr; 185 uint16_t vector_len; 186 int i; 187 188 g_assert(table_addr); 189 g_assert(vector >= 1); /* vector numbering starts at 1 */ 190 191 addr = vector_addr(table_addr, vector); 192 if (!addr) { 193 /* specified vector isn't present */ 194 return NULL; 195 } 196 197 vector_len = ldub_phys(&address_space_memory, addr++) + 1; 198 g_assert(vector_len <= OV_MAXBYTES); 199 ov = spapr_ovec_new(); 200 201 for (i = 0; i < vector_len; i++) { 202 uint8_t entry = ldub_phys(&address_space_memory, addr + i); 203 if (entry) { 204 trace_spapr_ovec_parse_vector(vector, i + 1, vector_len, entry); 205 guest_byte_to_bitmap(entry, ov->bitmap, i * BITS_PER_BYTE); 206 } 207 } 208 209 return ov; 210 } 211 212 int spapr_ovec_populate_dt(void *fdt, int fdt_offset, 213 sPAPROptionVector *ov, const char *name) 214 { 215 uint8_t vec[OV_MAXBYTES + 1]; 216 uint16_t vec_len; 217 unsigned long lastbit; 218 int i; 219 220 g_assert(ov); 221 222 lastbit = find_last_bit(ov->bitmap, OV_MAXBITS); 223 /* if no bits are set, include at least 1 byte of the vector so we can 224 * still encoded this in the device tree while abiding by the same 225 * encoding/sizing expected in ibm,client-architecture-support 226 */ 227 vec_len = (lastbit == OV_MAXBITS) ? 1 : lastbit / BITS_PER_BYTE + 1; 228 g_assert(vec_len <= OV_MAXBYTES); 229 /* guest expects vector len encoded as vec_len - 1, since the length byte 230 * is assumed and not included, and the first byte of the vector 231 * is assumed as well 232 */ 233 vec[0] = vec_len - 1; 234 235 for (i = 1; i < vec_len + 1; i++) { 236 vec[i] = guest_byte_from_bitmap(ov->bitmap, (i - 1) * BITS_PER_BYTE); 237 if (vec[i]) { 238 trace_spapr_ovec_populate_dt(i, vec_len, vec[i]); 239 } 240 } 241 242 return fdt_setprop(fdt, fdt_offset, name, vec, vec_len + 1); 243 } 244