From: Jon Mason <jon.mason@intel.com>
To: Greg KH <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org, netdev@vger.kernel.org,
Dave Jiang <dave.jiang@intel.com>,
Nicholas Bellinger <nab@linux-iscsi.org>
Subject: [PATCH 12/21] NTB: Remove reads across NTB
Date: Sat, 19 Jan 2013 02:02:26 -0700 [thread overview]
Message-ID: <1358586155-23322-13-git-send-email-jon.mason@intel.com> (raw)
In-Reply-To: <1358586155-23322-1-git-send-email-jon.mason@intel.com>
CPU reads across NTB are slow(er) and can hang the local system if an
ECC error is encountered on the remote. To work around the need for a
read, have the remote side write its current position in the rx buffer
to the local system's buffer and use that to see if there is room when
transmitting.
Signed-off-by: Jon Mason <jon.mason@intel.com>
---
drivers/ntb/ntb_transport.c | 137 ++++++++++++++++++++-----------------------
1 file changed, 63 insertions(+), 74 deletions(-)
diff --git a/drivers/ntb/ntb_transport.c b/drivers/ntb/ntb_transport.c
index 1bed1ba..69c58da 100644
--- a/drivers/ntb/ntb_transport.c
+++ b/drivers/ntb/ntb_transport.c
@@ -78,6 +78,10 @@ struct ntb_queue_entry {
unsigned int flags;
};
+struct ntb_rx_info {
+ unsigned int entry;
+};
+
struct ntb_transport_qp {
struct ntb_transport *transport;
struct ntb_device *ndev;
@@ -87,13 +91,16 @@ struct ntb_transport_qp {
bool qp_link;
u8 qp_num; /* Only 64 QP's are allowed. 0-63 */
+ struct ntb_rx_info *rx_info;
+ struct ntb_rx_info *remote_rx_info;
+
void (*tx_handler) (struct ntb_transport_qp *qp, void *qp_data,
void *data, int len);
struct list_head tx_free_q;
spinlock_t ntb_tx_free_q_lock;
- void *tx_mw_begin;
- void *tx_mw_end;
- void *tx_offset;
+ void *tx_mw;
+ unsigned int tx_index;
+ unsigned int tx_max_entry;
unsigned int tx_max_frame;
void (*rx_handler) (struct ntb_transport_qp *qp, void *qp_data,
@@ -103,9 +110,9 @@ struct ntb_transport_qp {
struct list_head rx_free_q;
spinlock_t ntb_rx_pend_q_lock;
spinlock_t ntb_rx_free_q_lock;
- void *rx_buff_begin;
- void *rx_buff_end;
- void *rx_offset;
+ void *rx_buff;
+ unsigned int rx_index;
+ unsigned int rx_max_entry;
unsigned int rx_max_frame;
void (*event_handler) (void *data, int status);
@@ -394,11 +401,11 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"rx_err_ver - \t%llu\n", qp->rx_err_ver);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "rx_buff_begin - %p\n", qp->rx_buff_begin);
+ "rx_buff - \t%p\n", qp->rx_buff);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "rx_offset - \t%p\n", qp->rx_offset);
+ "rx_index - \t%u\n", qp->rx_index);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "rx_buff_end - \t%p\n", qp->rx_buff_end);
+ "rx_max_entry - \t%u\n", qp->rx_max_entry);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_bytes - \t%llu\n", qp->tx_bytes);
@@ -407,11 +414,11 @@ static ssize_t debugfs_read(struct file *filp, char __user *ubuf, size_t count,
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"tx_ring_full - \t%llu\n", qp->tx_ring_full);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "tx_mw_begin - \t%p\n", qp->tx_mw_begin);
+ "tx_mw - \t%p\n", qp->tx_mw);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "tx_offset - \t%p\n", qp->tx_offset);
+ "tx_index - \t%u\n", qp->tx_index);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
- "tx_mw_end - \t%p\n", qp->tx_mw_end);
+ "tx_max_entry - \t%u\n", qp->tx_max_entry);
out_offset += snprintf(buf + out_offset, out_count - out_offset,
"\nQP Link %s\n", (qp->qp_link == NTB_LINK_UP) ?
@@ -465,7 +472,7 @@ static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
struct ntb_transport_qp *qp = &nt->qps[qp_num];
unsigned int rx_size, num_qps_mw;
u8 mw_num = QP_TO_MW(qp_num);
- void *offset;
+ unsigned int i;
WARN_ON(nt->mw[mw_num].virt_addr == 0);
@@ -474,18 +481,24 @@ static void ntb_transport_setup_qp_mw(struct ntb_transport *nt,
else
num_qps_mw = nt->max_qps / NTB_NUM_MW;
- rx_size = nt->mw[mw_num].size / num_qps_mw;
- qp->rx_buff_begin = nt->mw[mw_num].virt_addr +
- (qp_num / NTB_NUM_MW * rx_size);
- qp->rx_buff_end = qp->rx_buff_begin + rx_size;
- qp->rx_offset = qp->rx_buff_begin;
+ rx_size = (unsigned int) nt->mw[mw_num].size / num_qps_mw;
+ qp->remote_rx_info = nt->mw[mw_num].virt_addr +
+ (qp_num / NTB_NUM_MW * rx_size);
+ rx_size -= sizeof(struct ntb_rx_info);
+
+ qp->rx_buff = qp->remote_rx_info + sizeof(struct ntb_rx_info);
qp->rx_max_frame = min(transport_mtu, rx_size);
+ qp->rx_max_entry = rx_size / qp->rx_max_frame;
+ qp->rx_index = 0;
+
+ qp->remote_rx_info->entry = qp->rx_max_entry;
/* setup the hdr offsets with 0's */
- for (offset = qp->rx_buff_begin + qp->rx_max_frame -
- sizeof(struct ntb_payload_header);
- offset < qp->rx_buff_end; offset += qp->rx_max_frame)
+ for (i = 0; i < qp->rx_max_entry; i++) {
+ void *offset = qp->rx_buff + qp->rx_max_frame * (i + 1) -
+ sizeof(struct ntb_payload_header);
memset(offset, 0, sizeof(struct ntb_payload_header));
+ }
qp->rx_pkts = 0;
qp->tx_pkts = 0;
@@ -762,12 +775,15 @@ static void ntb_transport_init_queue(struct ntb_transport *nt,
else
num_qps_mw = nt->max_qps / NTB_NUM_MW;
- tx_size = ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
- qp->tx_mw_begin = ntb_get_mw_vbase(nt->ndev, mw_num) +
- (qp_num / NTB_NUM_MW * tx_size);
- qp->tx_mw_end = qp->tx_mw_begin + tx_size;
- qp->tx_offset = qp->tx_mw_begin;
+ tx_size = (unsigned int) ntb_get_mw_size(qp->ndev, mw_num) / num_qps_mw;
+ qp->rx_info = ntb_get_mw_vbase(nt->ndev, mw_num) +
+ (qp_num / NTB_NUM_MW * tx_size);
+ tx_size -= sizeof(struct ntb_rx_info);
+
+ qp->tx_mw = qp->rx_info + sizeof(struct ntb_rx_info);
qp->tx_max_frame = min(transport_mtu, tx_size);
+ qp->tx_max_entry = tx_size / qp->tx_max_frame;
+ qp->tx_index = 0;
if (nt->debugfs_dir) {
char debugfs_name[4];
@@ -894,21 +910,8 @@ void ntb_transport_free(void *transport)
static void ntb_rx_copy_task(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry, void *offset)
{
-
- struct ntb_payload_header *hdr;
-
- BUG_ON(offset < qp->rx_buff_begin ||
- offset + qp->rx_max_frame >= qp->rx_buff_end);
-
- hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
- entry->len = hdr->len;
-
memcpy(entry->buf, offset, entry->len);
- /* Ensure that the data is fully copied out before clearing the flag */
- wmb();
- hdr->flags = 0;
-
if (qp->rx_handler && qp->client_ready == NTB_LINK_UP)
qp->rx_handler(qp, qp->cb_data, entry->cb_data, entry->len);
@@ -921,10 +924,11 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
struct ntb_queue_entry *entry;
void *offset;
+ offset = qp->rx_buff + qp->rx_max_frame * qp->rx_index;
+ hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
+
entry = ntb_list_rm(&qp->ntb_rx_pend_q_lock, &qp->rx_pend_q);
if (!entry) {
- hdr = offset + qp->rx_max_frame -
- sizeof(struct ntb_payload_header);
dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
"no buffer - HDR ver %llu, len %d, flags %x\n",
hdr->ver, hdr->len, hdr->flags);
@@ -932,9 +936,6 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
return -ENOMEM;
}
- offset = qp->rx_offset;
- hdr = offset + qp->rx_max_frame - sizeof(struct ntb_payload_header);
-
if (!(hdr->flags & DESC_DONE_FLAG)) {
ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
&qp->rx_pend_q);
@@ -957,30 +958,20 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
&qp->rx_pend_q);
-
- /* Ensure that the data is fully copied out before clearing the
- * done flag
- */
- wmb();
- hdr->flags = 0;
goto out;
}
dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
- "rx offset %p, ver %llu - %d payload received, buf size %d\n",
- qp->rx_offset, hdr->ver, hdr->len, entry->len);
+ "rx offset %u, ver %llu - %d payload received, buf size %d\n",
+ qp->rx_index, hdr->ver, hdr->len, entry->len);
- if (hdr->len <= entry->len)
+ if (hdr->len <= entry->len) {
+ entry->len = hdr->len;
ntb_rx_copy_task(qp, entry, offset);
- else {
+ } else {
ntb_list_add(&qp->ntb_rx_pend_q_lock, &entry->entry,
&qp->rx_pend_q);
- /* Ensure that the data is fully copied out before clearing the
- * done flag
- */
- wmb();
- hdr->flags = 0;
qp->rx_err_oflow++;
dev_dbg(&ntb_query_pdev(qp->ndev)->dev,
"RX overflow! Wanted %d got %d\n",
@@ -991,9 +982,13 @@ static int ntb_process_rxc(struct ntb_transport_qp *qp)
qp->rx_pkts++;
out:
- qp->rx_offset += qp->rx_max_frame;
- if (qp->rx_offset + qp->rx_max_frame >= qp->rx_buff_end)
- qp->rx_offset = qp->rx_buff_begin;
+ /* Ensure that the data is fully copied out before clearing the flag */
+ wmb();
+ hdr->flags = 0;
+ qp->rx_info->entry = qp->rx_index;
+
+ qp->rx_index++;
+ qp->rx_index %= qp->rx_max_entry;
return 0;
}
@@ -1024,9 +1019,6 @@ static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
{
struct ntb_payload_header *hdr;
- BUG_ON(offset < qp->tx_mw_begin ||
- offset + qp->tx_max_frame >= qp->tx_mw_end);
-
memcpy_toio(offset, entry->buf, entry->len);
hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
@@ -1057,16 +1049,14 @@ static void ntb_tx_copy_task(struct ntb_transport_qp *qp,
static int ntb_process_tx(struct ntb_transport_qp *qp,
struct ntb_queue_entry *entry)
{
- struct ntb_payload_header *hdr;
void *offset;
- offset = qp->tx_offset;
- hdr = offset + qp->tx_max_frame - sizeof(struct ntb_payload_header);
+ offset = qp->tx_mw + qp->tx_max_frame * qp->tx_index;
- dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %p, entry len %d flags %x buff %p\n",
- qp->tx_pkts, offset, qp->tx_offset, entry->len, entry->flags,
+ dev_dbg(&ntb_query_pdev(qp->ndev)->dev, "%lld - offset %p, tx %u, entry len %d flags %x buff %p\n",
+ qp->tx_pkts, offset, qp->tx_index, entry->len, entry->flags,
entry->buf);
- if (hdr->flags) {
+ if (qp->tx_index == qp->remote_rx_info->entry) {
qp->tx_ring_full++;
return -EAGAIN;
}
@@ -1082,9 +1072,8 @@ static int ntb_process_tx(struct ntb_transport_qp *qp,
ntb_tx_copy_task(qp, entry, offset);
- qp->tx_offset += qp->tx_max_frame;
- if (qp->tx_offset + qp->tx_max_frame >= qp->tx_mw_end)
- qp->tx_offset = qp->tx_mw_begin;
+ qp->tx_index++;
+ qp->tx_index %= qp->tx_max_entry;
qp->tx_pkts++;
--
1.7.9.5
next prev parent reply other threads:[~2013-01-19 9:10 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-01-19 9:02 [PATCH 0/21] NTB and ntb_netdev patches Jon Mason
2013-01-19 9:02 ` [PATCH 01/21] NTB: correct missing readq/writeq errors Jon Mason
2013-01-20 23:40 ` Greg KH
2013-01-21 17:38 ` Jon Mason
2013-01-21 18:23 ` Greg KH
2013-01-21 20:34 ` Ben Hutchings
2013-01-21 20:47 ` Greg KH
2013-01-19 9:02 ` [PATCH 02/21] NTB: Handle ntb client device probes without present hardware Jon Mason
2013-01-19 9:02 ` [PATCH 03/21] NTB: correct memory barrier Jon Mason
2013-01-19 9:02 ` [PATCH 04/21] NTB: separate transmit and receive windows Jon Mason
2013-01-19 9:02 ` [PATCH 05/21] NTB: No sleeping in interrupt context Jon Mason
2013-01-19 9:02 ` [PATCH 06/21] NTB: use simple_open for debugfs Jon Mason
2013-01-19 9:02 ` [PATCH 07/21] NTB: zero PCI driver data Jon Mason
2013-01-20 23:41 ` Greg KH
2013-01-19 9:02 ` [PATCH 08/21] NTB: declare unused variables Jon Mason
2013-01-20 23:42 ` Greg KH
2013-01-21 17:50 ` Jon Mason
2013-01-21 18:25 ` Greg KH
2013-01-19 9:02 ` [PATCH 09/21] NTB: namespacecheck cleanups Jon Mason
2013-01-19 9:02 ` [PATCH 10/21] NTB: whitespace cleanups Jon Mason
2013-01-19 9:02 ` [PATCH 11/21] NTB: correct stack usage warning in debugfs_read Jon Mason
2013-01-19 9:02 ` Jon Mason [this message]
2013-01-19 9:02 ` [PATCH 13/21] NTB: Out of free receive entries issue Jon Mason
2013-01-19 9:02 ` [PATCH 14/21] NTB: Fix Sparse Warnings Jon Mason
2013-01-20 23:45 ` Greg KH
2013-01-21 21:13 ` Jon Mason
2013-01-21 21:37 ` Greg KH
2013-01-21 22:28 ` Jon Mason
2013-01-19 9:02 ` [PATCH 15/21] NTB: Update Version Jon Mason
2013-01-20 23:47 ` Greg KH
2013-01-21 17:57 ` Jon Mason
2013-01-21 18:26 ` Greg KH
2013-01-19 9:02 ` [PATCH 16/21] ntb_netdev: remove init/exit from probe/remove Jon Mason
2013-01-19 9:02 ` [PATCH 17/21] ntb_netdev: correct skb leak Jon Mason
2013-01-19 9:02 ` [PATCH 18/21] ntb_netdev: remove tx timeout Jon Mason
2013-01-19 9:02 ` [PATCH 19/21] ntb_netdev: declare unused variables and fix missing initializer Jon Mason
2013-01-20 23:47 ` Greg KH
2013-01-19 9:02 ` [PATCH 20/21] ntb_netdev: improve logging Jon Mason
2013-01-19 18:51 ` Joe Perches
2013-01-19 9:02 ` [PATCH 21/21] ntb_netdev: Update Version Jon Mason
2013-01-20 23:48 ` [PATCH 0/21] NTB and ntb_netdev patches Greg KH
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