/*
* Copy a number of bytes from or to the caller, to or from the intermediate
* buffer. If the given endpoint is SELF, a local memory copy must be made.
*/
static int
vnd_copy(iovec_s_t *iov, size_t iov_off, size_t bytes, endpoint_t endpt,
int do_write)
{
struct vscp_vec vvec[SCPVEC_NR], *vvp;
size_t off, chunk;
int count;
char *ptr;
assert(bytes > 0 && bytes <= VND_BUF_SIZE);
vvp = vvec;
count = 0;
for (off = 0; off < bytes; off += chunk) {
chunk = MIN(bytes - off, iov->iov_size - iov_off);
if (endpt == SELF) {
ptr = (char *) iov->iov_grant + iov_off;
if (do_write)
memcpy(&state.buf[off], ptr, chunk);
else
memcpy(ptr, &state.buf[off], chunk);
} else {
assert(count < SCPVEC_NR); /* SCPVEC_NR >= NR_IOREQS */
vvp->v_from = do_write ? endpt : SELF;
vvp->v_to = do_write ? SELF : endpt;
vvp->v_bytes = chunk;
vvp->v_gid = iov->iov_grant;
vvp->v_offset = iov_off;
vvp->v_addr = (vir_bytes) &state.buf[off];
vvp++;
count++;
}
iov_off += chunk;
if (iov_off == iov->iov_size) {
iov++;
iov_off = 0;
}
}
if (endpt != SELF)
return sys_vsafecopy(vvec, count);
else
return OK;
}
static int
sys_easy_vsafecopy_from(endpoint_t src_proc, iovec_s_t *iov, int count,
vir_bytes dst, size_t max, size_t *copied)
{
int i, r;
size_t left = max;
vir_bytes cur_off = 0;
struct vscp_vec vv[NR_IOREQS];
for (i = 0; i < count && left > 0; i++) {
vv[i].v_from = src_proc;
vv[i].v_to = SELF;
vv[i].v_gid = iov[i].iov_grant;
vv[i].v_offset = 0;
vv[i].v_addr = dst + cur_off;
vv[i].v_bytes = iov[i].iov_size;
/* More data in iov than the buffer can hold, this should be
* manageable by the caller.
*/
if (left - vv[i].v_bytes > left) {
printf("sys_easy_vsafecopy_from: buf too small!\n");
return ENOMEM;
}
left -= iov[i].iov_size;
cur_off += iov[i].iov_size;
}
/* Now that we prepared the vscp_vec, we can call vsafecopy() */
if ((r = sys_vsafecopy(vv, count)) != OK)
printf("sys_vsafecopy: failed: (%d)\n", r);
if (copied)
*copied = cur_off;
return OK;
}
/*===========================================================================*
* fbd_transfer_copy *
*===========================================================================*/
static ssize_t fbd_transfer_copy(int do_write, u64_t position,
endpoint_t endpt, iovec_t *iov, unsigned int count, size_t size,
int flags)
{
/* Interpose on the request. */
iovec_s_t iovec[NR_IOREQS];
struct vscp_vec vscp_vec[SCPVEC_NR];
cp_grant_id_t grant;
size_t off, len;
message m;
char *ptr;
int i, j, r;
ssize_t rsize;
assert(count > 0 && count <= SCPVEC_NR);
if (size > BUF_SIZE) {
printf("FBD: allocating memory for %d bytes\n", size);
ptr = alloc_contig(size, 0, NULL);
assert(ptr != NULL);
}
else ptr = fbd_buf;
/* For write operations, first copy in the data to write. */
if (do_write) {
for (i = off = 0; i < count; i++) {
len = iov[i].iov_size;
vscp_vec[i].v_from = endpt;
vscp_vec[i].v_to = SELF;
vscp_vec[i].v_gid = iov[i].iov_addr;
vscp_vec[i].v_offset = 0;
vscp_vec[i].v_addr = (vir_bytes) (ptr + off);
vscp_vec[i].v_bytes = len;
off += len;
}
if ((r = sys_vsafecopy(vscp_vec, i)) != OK)
panic("vsafecopy failed (%d)\n", r);
/* Trigger write hook. */
rule_io_hook(ptr, size, position, FBD_FLAG_WRITE);
}
/* Allocate grants for the data, in the same chunking as the original
* vector. This avoids performance fluctuations with bad hardware as
* observed with the filter driver.
*/
for (i = off = 0; i < count; i++) {
len = iov[i].iov_size;
iovec[i].iov_size = len;
iovec[i].iov_grant = cpf_grant_direct(driver_endpt,
(vir_bytes) (ptr + off), len,
do_write ? CPF_READ : CPF_WRITE);
assert(iovec[i].iov_grant != GRANT_INVALID);
off += len;
}
grant = cpf_grant_direct(driver_endpt, (vir_bytes) iovec,
count * sizeof(iovec[0]), CPF_READ);
assert(grant != GRANT_INVALID);
m.m_type = do_write ? BDEV_SCATTER : BDEV_GATHER;
m.m_lbdev_lblockdriver_msg.minor = driver_minor;
m.m_lbdev_lblockdriver_msg.count = count;
m.m_lbdev_lblockdriver_msg.grant = grant;
m.m_lbdev_lblockdriver_msg.flags = flags;
m.m_lbdev_lblockdriver_msg.id = 0;
m.m_lbdev_lblockdriver_msg.pos = position;
if ((r = ipc_sendrec(driver_endpt, &m)) != OK)
panic("ipc_sendrec to driver failed (%d)\n", r);
if (m.m_type != BDEV_REPLY)
panic("invalid reply from driver (%d)\n", m.m_type);
cpf_revoke(grant);
for (i = 0; i < count; i++)
cpf_revoke(iovec[i].iov_grant);
/* For read operations, finish by copying out the data read. */
if (!do_write) {
/* Trigger read hook. */
rule_io_hook(ptr, size, position, FBD_FLAG_READ);
/* Upon success, copy back whatever has been processed. */
rsize = m.m_lblockdriver_lbdev_reply.status;
for (i = j = off = 0; rsize > 0 && i < count; i++) {
len = MIN(rsize, iov[i].iov_size);
vscp_vec[j].v_from = SELF;
vscp_vec[j].v_to = endpt;
vscp_vec[j].v_gid = iov[i].iov_addr;
vscp_vec[j].v_offset = 0;
vscp_vec[j].v_addr = (vir_bytes) (ptr + off);
vscp_vec[j].v_bytes = len;
off += len;
rsize -= len;
j++;
}
if (j > 0 && (r = sys_vsafecopy(vscp_vec, j)) != OK)
panic("vsafecopy failed (%d)\n", r);
}
if (ptr != fbd_buf)
free_contig(ptr, size);
return m.m_lblockdriver_lbdev_reply.status;
}
