Skip to content

Commit

Permalink
vmci: simplify qp_dequeue_locked()
Browse files Browse the repository at this point in the history 
* no need for callback argument - it's always the same one
* fold __qp_memcpy_from_queue() into its only caller, get rid of dead code
* pass struct iov_iter * without casting to void *
* don't pass buf_size at all - it's always iov_iter_count(to)

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
  • Loading branch information
Al Viro committed Dec 3, 2017
1 parent ce3d6e7 commit 53f58d8
Showing 1 changed file with 18 additions and 53 deletions.
71 changes: 18 additions & 53 deletions drivers/misc/vmw_vmci/vmci_queue_pair.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -142,9 +142,6 @@
typedef int vmci_memcpy_to_queue_func(struct vmci_queue *queue,
u64 queue_offset, const void *src,
size_t src_offset, size_t size);
typedef int vmci_memcpy_from_queue_func(void *dest, size_t dest_offset,
const struct vmci_queue *queue,
u64 queue_offset, size_t size);

/* The Kernel specific component of the struct vmci_queue structure. */
struct vmci_queue_kern_if {
Expand Down Expand Up @@ -411,11 +408,9 @@ static int __qp_memcpy_to_queue(struct vmci_queue *queue,
* by traversing the offset -> page translation structure for the queue.
* Assumes that offset + size does not wrap around in the queue.
*/
static int __qp_memcpy_from_queue(void *dest,
const struct vmci_queue *queue,
u64 queue_offset,
size_t size,
bool is_iovec)
static int qp_memcpy_from_queue_iter(struct iov_iter *to,
const struct vmci_queue *queue,
u64 queue_offset, size_t size)
{
struct vmci_queue_kern_if *kernel_if = queue->kernel_if;
size_t bytes_copied = 0;
Expand All @@ -427,6 +422,7 @@ static int __qp_memcpy_from_queue(void *dest,
(queue_offset + bytes_copied) & (PAGE_SIZE - 1);
void *va;
size_t to_copy;
int err;

if (kernel_if->host)
va = kmap(kernel_if->u.h.page[page_index]);
Expand All @@ -440,21 +436,12 @@ static int __qp_memcpy_from_queue(void *dest,
else
to_copy = size - bytes_copied;

if (is_iovec) {
struct iov_iter *to = dest;
int err;

err = copy_to_iter((u8 *)va + page_offset, to_copy, to);
if (err != to_copy) {
if (kernel_if->host)
kunmap(kernel_if->u.h.page[page_index]);
return VMCI_ERROR_INVALID_ARGS;
}
} else {
memcpy((u8 *)dest + bytes_copied,
(u8 *)va + page_offset, to_copy);
err = copy_to_iter((u8 *)va + page_offset, to_copy, to);
if (err != to_copy) {
if (kernel_if->host)
kunmap(kernel_if->u.h.page[page_index]);
return VMCI_ERROR_INVALID_ARGS;
}

bytes_copied += to_copy;
if (kernel_if->host)
kunmap(kernel_if->u.h.page[page_index]);
Expand Down Expand Up @@ -591,21 +578,6 @@ static int qp_memcpy_to_queue_iov(struct vmci_queue *queue,
return __qp_memcpy_to_queue(queue, queue_offset, msg, size, true);
}

/*
* Copies to a given iovec from a VMCI Queue.
*/
static int qp_memcpy_from_queue_iov(void *dest,
size_t dest_offset,
const struct vmci_queue *queue,
u64 queue_offset, size_t size)
{
/*
* We ignore dest_offset because dest is really a struct iovec * and
* will maintain offset internally.
*/
return __qp_memcpy_from_queue(dest, queue, queue_offset, size, true);
}

/*
* Allocates kernel VA space of specified size plus space for the queue
* and kernel interface. This is different from the guest queue allocator,
Expand Down Expand Up @@ -2679,11 +2651,10 @@ static ssize_t qp_enqueue_locked(struct vmci_queue *produce_q,
static ssize_t qp_dequeue_locked(struct vmci_queue *produce_q,
struct vmci_queue *consume_q,
const u64 consume_q_size,
void *buf,
size_t buf_size,
vmci_memcpy_from_queue_func memcpy_from_queue,
struct iov_iter *to,
bool update_consumer)
{
size_t buf_size = iov_iter_count(to);
s64 buf_ready;
u64 head;
size_t read;
Expand All @@ -2705,15 +2676,15 @@ static ssize_t qp_dequeue_locked(struct vmci_queue *produce_q,
read = (size_t) (buf_ready > buf_size ? buf_size : buf_ready);
head = vmci_q_header_consumer_head(produce_q->q_header);
if (likely(head + read < consume_q_size)) {
result = memcpy_from_queue(buf, 0, consume_q, head, read);
result = qp_memcpy_from_queue_iter(to, consume_q, head, read);
} else {
/* Head pointer wraps around. */

const size_t tmp = (size_t) (consume_q_size - head);

result = memcpy_from_queue(buf, 0, consume_q, head, tmp);
result = qp_memcpy_from_queue_iter(to, consume_q, head, tmp);
if (result >= VMCI_SUCCESS)
result = memcpy_from_queue(buf, tmp, consume_q, 0,
result = qp_memcpy_from_queue_iter(to, consume_q, 0,
read - tmp);

}
Expand Down Expand Up @@ -3162,8 +3133,7 @@ ssize_t vmci_qpair_dequeue(struct vmci_qp *qpair,
result = qp_dequeue_locked(qpair->produce_q,
qpair->consume_q,
qpair->consume_q_size,
&to, buf_size,
qp_memcpy_from_queue_iov, true);
&to, true);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3208,8 +3178,7 @@ ssize_t vmci_qpair_peek(struct vmci_qp *qpair,
result = qp_dequeue_locked(qpair->produce_q,
qpair->consume_q,
qpair->consume_q_size,
&to, buf_size,
qp_memcpy_from_queue_iov, false);
&to, false);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3292,9 +3261,7 @@ ssize_t vmci_qpair_dequev(struct vmci_qp *qpair,
result = qp_dequeue_locked(qpair->produce_q,
qpair->consume_q,
qpair->consume_q_size,
&msg->msg_iter, msg_data_left(msg),
qp_memcpy_from_queue_iov,
true);
&msg->msg_iter, true);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down Expand Up @@ -3336,9 +3303,7 @@ ssize_t vmci_qpair_peekv(struct vmci_qp *qpair,
result = qp_dequeue_locked(qpair->produce_q,
qpair->consume_q,
qpair->consume_q_size,
&msg->msg_iter, msg_data_left(msg),
qp_memcpy_from_queue_iov,
false);
&msg->msg_iter, false);

if (result == VMCI_ERROR_QUEUEPAIR_NOT_READY &&
!qp_wait_for_ready_queue(qpair))
Expand Down

0 comments on commit 53f58d8

Please sign in to comment.