diff options
-rw-r--r-- | exec.c | 71 |
1 files changed, 38 insertions, 33 deletions
@@ -2065,47 +2065,52 @@ void *address_space_map(AddressSpace *as, bool is_write) { hwaddr len = *plen; - hwaddr todo = 0; - hwaddr l, xlat; - MemoryRegion *mr; - ram_addr_t raddr = RAM_ADDR_MAX; - ram_addr_t rlen; - void *ret; + hwaddr done = 0; + hwaddr l, xlat, base; + MemoryRegion *mr, *this_mr; + ram_addr_t raddr; - while (len > 0) { - l = len; - mr = address_space_translate(as, addr, &xlat, &l, is_write); - - if (!memory_access_is_direct(mr, is_write)) { - if (todo || bounce.buffer) { - break; - } - bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, TARGET_PAGE_SIZE); - bounce.addr = addr; - bounce.len = l; - if (!is_write) { - address_space_read(as, addr, bounce.buffer, l); - } + if (len == 0) { + return NULL; + } - *plen = l; - return bounce.buffer; + l = len; + mr = address_space_translate(as, addr, &xlat, &l, is_write); + if (!memory_access_is_direct(mr, is_write)) { + if (bounce.buffer) { + return NULL; } - if (!todo) { - raddr = memory_region_get_ram_addr(mr) + xlat; - } else { - if (memory_region_get_ram_addr(mr) + xlat != raddr + todo) { - break; - } + bounce.buffer = qemu_memalign(TARGET_PAGE_SIZE, TARGET_PAGE_SIZE); + bounce.addr = addr; + bounce.len = l; + if (!is_write) { + address_space_read(as, addr, bounce.buffer, l); } + *plen = l; + return bounce.buffer; + } + + base = xlat; + raddr = memory_region_get_ram_addr(mr); + + for (;;) { len -= l; addr += l; - todo += l; + done += l; + if (len == 0) { + break; + } + + l = len; + this_mr = address_space_translate(as, addr, &xlat, &l, is_write); + if (this_mr != mr || xlat != base + done) { + break; + } } - rlen = todo; - ret = qemu_ram_ptr_length(raddr, &rlen); - *plen = rlen; - return ret; + + *plen = done; + return qemu_ram_ptr_length(raddr + base, plen); } /* Unmaps a memory region previously mapped by address_space_map(). |