diff options
Diffstat (limited to 'hw/ide/ahci.c')
| -rw-r--r-- | hw/ide/ahci.c | 27 |
1 files changed, 25 insertions, 2 deletions
diff --git a/hw/ide/ahci.c b/hw/ide/ahci.c index b4b65c100a..0d6a2d8b4c 100644 --- a/hw/ide/ahci.c +++ b/hw/ide/ahci.c @@ -331,8 +331,7 @@ static void ahci_port_write(AHCIState *s, int port, int offset, uint32_t val) } } -static uint64_t ahci_mem_read(void *opaque, hwaddr addr, - unsigned size) +static uint64_t ahci_mem_read_32(void *opaque, hwaddr addr) { AHCIState *s = opaque; uint32_t val = 0; @@ -368,6 +367,30 @@ static uint64_t ahci_mem_read(void *opaque, hwaddr addr, } +/** + * AHCI 1.3 section 3 ("HBA Memory Registers") + * Support unaligned 8/16/32 bit reads, and 64 bit aligned reads. + * Caller is responsible for masking unwanted higher order bytes. + */ +static uint64_t ahci_mem_read(void *opaque, hwaddr addr, unsigned size) +{ + hwaddr aligned = addr & ~0x3; + int ofst = addr - aligned; + uint64_t lo = ahci_mem_read_32(opaque, aligned); + uint64_t hi; + + /* if < 8 byte read does not cross 4 byte boundary */ + if (ofst + size <= 4) { + return lo >> (ofst * 8); + } + g_assert_cmpint(size, >, 1); + + /* If the 64bit read is unaligned, we will produce undefined + * results. AHCI does not support unaligned 64bit reads. */ + hi = ahci_mem_read_32(opaque, aligned + 4); + return (hi << 32 | lo) >> (ofst * 8); +} + static void ahci_mem_write(void *opaque, hwaddr addr, uint64_t val, unsigned size) |