diff options
Diffstat (limited to 'drivers/vme/bridges/vme_tsi148.c')
| -rw-r--r-- | drivers/vme/bridges/vme_tsi148.c | 85 |
1 files changed, 83 insertions, 2 deletions
diff --git a/drivers/vme/bridges/vme_tsi148.c b/drivers/vme/bridges/vme_tsi148.c index f6385f7a66d9..880d9242e349 100644 --- a/drivers/vme/bridges/vme_tsi148.c +++ b/drivers/vme/bridges/vme_tsi148.c @@ -1263,12 +1263,55 @@ static ssize_t tsi148_master_read(struct vme_master_resource *image, void *buf, u32 aspace, cycle, dwidth; struct vme_bus_error *vme_err = NULL; struct vme_bridge *tsi148_bridge; + void *addr = image->kern_base + offset; + unsigned int done = 0; + unsigned int count32; tsi148_bridge = image->parent; spin_lock(&image->lock); - memcpy_fromio(buf, image->kern_base + offset, (unsigned int)count); + /* The following code handles VME address alignment. We cannot use + * memcpy_xxx directly here because it may cut small data transfers in + * to 8-bit cycles, thus making D16 cycle impossible. + * On the other hand, the bridge itself assures that the maximum data + * cycle configured for the transfer is used and splits it + * automatically for non-aligned addresses, so we don't want the + * overhead of needlessly forcing small transfers for the entire cycle. + */ + if ((uintptr_t)addr & 0x1) { + *(u8 *)buf = ioread8(addr); + done += 1; + if (done == count) + goto out; + } + if ((uintptr_t)addr & 0x2) { + if ((count - done) < 2) { + *(u8 *)(buf + done) = ioread8(addr + done); + done += 1; + goto out; + } else { + *(u16 *)(buf + done) = ioread16(addr + done); + done += 2; + } + } + + count32 = (count - done) & ~0x3; + if (count32 > 0) { + memcpy_fromio(buf + done, addr + done, count32); + done += count32; + } + + if ((count - done) & 0x2) { + *(u16 *)(buf + done) = ioread16(addr + done); + done += 2; + } + if ((count - done) & 0x1) { + *(u8 *)(buf + done) = ioread8(addr + done); + done += 1; + } + +out: retval = count; if (!err_chk) @@ -1301,6 +1344,9 @@ static ssize_t tsi148_master_write(struct vme_master_resource *image, void *buf, int retval = 0, enabled; unsigned long long vme_base, size; u32 aspace, cycle, dwidth; + void *addr = image->kern_base + offset; + unsigned int done = 0; + unsigned int count32; struct vme_bus_error *vme_err = NULL; struct vme_bridge *tsi148_bridge; @@ -1312,7 +1358,42 @@ static ssize_t tsi148_master_write(struct vme_master_resource *image, void *buf, spin_lock(&image->lock); - memcpy_toio(image->kern_base + offset, buf, (unsigned int)count); + /* Here we apply for the same strategy we do in master_read + * function in order to assure D16 cycle when required. + */ + if ((uintptr_t)addr & 0x1) { + iowrite8(*(u8 *)buf, addr); + done += 1; + if (done == count) + goto out; + } + if ((uintptr_t)addr & 0x2) { + if ((count - done) < 2) { + iowrite8(*(u8 *)(buf + done), addr + done); + done += 1; + goto out; + } else { + iowrite16(*(u16 *)(buf + done), addr + done); + done += 2; + } + } + + count32 = (count - done) & ~0x3; + if (count32 > 0) { + memcpy_toio(addr + done, buf + done, count32); + done += count32; + } + + if ((count - done) & 0x2) { + iowrite16(*(u16 *)(buf + done), addr + done); + done += 2; + } + if ((count - done) & 0x1) { + iowrite8(*(u8 *)(buf + done), addr + done); + done += 1; + } + +out: retval = count; /* |
