diff options
| -rw-r--r-- | exec.c | 68 |
1 files changed, 56 insertions, 12 deletions
@@ -1896,15 +1896,37 @@ static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write) return false; } -static inline int memory_access_size(MemoryRegion *mr, int l, hwaddr addr) +static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr) { - if (l >= 4 && (((addr & 3) == 0 || mr->ops->impl.unaligned))) { - return 4; + unsigned access_size_min = mr->ops->impl.min_access_size; + unsigned access_size_max = mr->ops->impl.max_access_size; + + /* Regions are assumed to support 1-4 byte accesses unless + otherwise specified. */ + if (access_size_min == 0) { + access_size_min = 1; + } + if (access_size_max == 0) { + access_size_max = 4; + } + + /* Bound the maximum access by the alignment of the address. */ + if (!mr->ops->impl.unaligned) { + unsigned align_size_max = addr & -addr; + if (align_size_max != 0 && align_size_max < access_size_max) { + access_size_max = align_size_max; + } } - if (l >= 2 && (((addr & 1) == 0) || mr->ops->impl.unaligned)) { - return 2; + + /* Don't attempt accesses larger than the maximum. */ + if (l > access_size_max) { + l = access_size_max; } - return 1; + /* ??? The users of this function are wrong, not supporting minimums larger + than the remaining length. C.f. memory.c:access_with_adjusted_size. */ + assert(l >= access_size_min); + + return l; } bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf, @@ -1926,18 +1948,29 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf, l = memory_access_size(mr, l, addr1); /* XXX: could force current_cpu to NULL to avoid potential bugs */ - if (l == 4) { + switch (l) { + case 8: + /* 64 bit write access */ + val = ldq_p(buf); + error |= io_mem_write(mr, addr1, val, 8); + break; + case 4: /* 32 bit write access */ val = ldl_p(buf); error |= io_mem_write(mr, addr1, val, 4); - } else if (l == 2) { + break; + case 2: /* 16 bit write access */ val = lduw_p(buf); error |= io_mem_write(mr, addr1, val, 2); - } else { + break; + case 1: /* 8 bit write access */ val = ldub_p(buf); error |= io_mem_write(mr, addr1, val, 1); + break; + default: + abort(); } } else { addr1 += memory_region_get_ram_addr(mr); @@ -1950,18 +1983,29 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf, if (!memory_access_is_direct(mr, is_write)) { /* I/O case */ l = memory_access_size(mr, l, addr1); - if (l == 4) { + switch (l) { + case 8: + /* 64 bit read access */ + error |= io_mem_read(mr, addr1, &val, 8); + stq_p(buf, val); + break; + case 4: /* 32 bit read access */ error |= io_mem_read(mr, addr1, &val, 4); stl_p(buf, val); - } else if (l == 2) { + break; + case 2: /* 16 bit read access */ error |= io_mem_read(mr, addr1, &val, 2); stw_p(buf, val); - } else { + break; + case 1: /* 8 bit read access */ error |= io_mem_read(mr, addr1, &val, 1); stb_p(buf, val); + break; + default: + abort(); } } else { /* RAM case */ |