snic: driver for Cisco SCSI HBA

Cisco has developed a new PCI HBA interface called sNIC, which stands for
SCSI NIC. This is a new storage feature supported on specialized network
adapter. The new PCI function provides a uniform host interface and abstracts
backend storage.

[jejb: fix up checkpatch errors]
Signed-off-by: Narsimhulu Musini <nmusini@cisco.com>
Signed-off-by: Sesidhar Baddela <sebaddel@cisco.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: James Bottomley <JBottomley@Odin.com>

1 files changed, 237 insertions, 0 deletions

diff --git a/drivers/scsi/snic/vnic_wq.c b/drivers/scsi/snic/vnic_wq.c
new file mode 100644
index 000000000000..1e91d432089e
--- /dev/null
+++ b/drivers/scsi/snic/vnic_wq.c
@@ -0,0 +1,237 @@
+/*
+ * Copyright 2014 Cisco Systems, Inc.  All rights reserved.
+ *
+ * This program is free software; you may redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; version 2 of the License.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
+ * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
+ * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
+ * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+ * SOFTWARE.
+ */
+
+#include <linux/errno.h>
+#include <linux/types.h>
+#include <linux/pci.h>
+#include <linux/delay.h>
+#include <linux/slab.h>
+#include "vnic_dev.h"
+#include "vnic_wq.h"
+
+static inline int vnic_wq_get_ctrl(struct vnic_dev *vdev, struct vnic_wq *wq,
+	unsigned int index, enum vnic_res_type res_type)
+{
+	wq->ctrl = svnic_dev_get_res(vdev, res_type, index);
+	if (!wq->ctrl)
+		return -EINVAL;
+
+	return 0;
+}
+
+static inline int vnic_wq_alloc_ring(struct vnic_dev *vdev, struct vnic_wq *wq,
+	unsigned int index, unsigned int desc_count, unsigned int desc_size)
+{
+	return svnic_dev_alloc_desc_ring(vdev, &wq->ring, desc_count,
+					 desc_size);
+}
+
+static int vnic_wq_alloc_bufs(struct vnic_wq *wq)
+{
+	struct vnic_wq_buf *buf;
+	unsigned int i, j, count = wq->ring.desc_count;
+	unsigned int blks = VNIC_WQ_BUF_BLKS_NEEDED(count);
+
+	for (i = 0; i < blks; i++) {
+		wq->bufs[i] = kzalloc(VNIC_WQ_BUF_BLK_SZ, GFP_ATOMIC);
+		if (!wq->bufs[i]) {
+			pr_err("Failed to alloc wq_bufs\n");
+
+			return -ENOMEM;
+		}
+	}
+
+	for (i = 0; i < blks; i++) {
+		buf = wq->bufs[i];
+		for (j = 0; j < VNIC_WQ_BUF_DFLT_BLK_ENTRIES; j++) {
+			buf->index = i * VNIC_WQ_BUF_DFLT_BLK_ENTRIES + j;
+			buf->desc = (u8 *)wq->ring.descs +
+				wq->ring.desc_size * buf->index;
+			if (buf->index + 1 == count) {
+				buf->next = wq->bufs[0];
+				break;
+			} else if (j + 1 == VNIC_WQ_BUF_DFLT_BLK_ENTRIES) {
+				buf->next = wq->bufs[i + 1];
+			} else {
+				buf->next = buf + 1;
+				buf++;
+			}
+		}
+	}
+
+	wq->to_use = wq->to_clean = wq->bufs[0];
+
+	return 0;
+}
+
+void svnic_wq_free(struct vnic_wq *wq)
+{
+	struct vnic_dev *vdev;
+	unsigned int i;
+
+	vdev = wq->vdev;
+
+	svnic_dev_free_desc_ring(vdev, &wq->ring);
+
+	for (i = 0; i < VNIC_WQ_BUF_BLKS_MAX; i++) {
+		kfree(wq->bufs[i]);
+		wq->bufs[i] = NULL;
+	}
+
+	wq->ctrl = NULL;
+
+}
+
+int vnic_wq_devcmd2_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
+	unsigned int desc_count, unsigned int desc_size)
+{
+	int err;
+
+	wq->index = 0;
+	wq->vdev = vdev;
+
+	err = vnic_wq_get_ctrl(vdev, wq, 0, RES_TYPE_DEVCMD2);
+	if (err) {
+		pr_err("Failed to get devcmd2 resource\n");
+
+		return err;
+	}
+
+	svnic_wq_disable(wq);
+
+	err = vnic_wq_alloc_ring(vdev, wq, 0, desc_count, desc_size);
+	if (err)
+		return err;
+
+	return 0;
+}
+
+int svnic_wq_alloc(struct vnic_dev *vdev, struct vnic_wq *wq,
+	unsigned int index, unsigned int desc_count, unsigned int desc_size)
+{
+	int err;
+
+	wq->index = index;
+	wq->vdev = vdev;
+
+	err = vnic_wq_get_ctrl(vdev, wq, index, RES_TYPE_WQ);
+	if (err) {
+		pr_err("Failed to hook WQ[%d] resource\n", index);
+
+		return err;
+	}
+
+	svnic_wq_disable(wq);
+
+	err = vnic_wq_alloc_ring(vdev, wq, index, desc_count, desc_size);
+	if (err)
+		return err;
+
+	err = vnic_wq_alloc_bufs(wq);
+	if (err) {
+		svnic_wq_free(wq);
+
+		return err;
+	}
+
+	return 0;
+}
+
+void vnic_wq_init_start(struct vnic_wq *wq, unsigned int cq_index,
+	unsigned int fetch_index, unsigned int posted_index,
+	unsigned int error_interrupt_enable,
+	unsigned int error_interrupt_offset)
+{
+	u64 paddr;
+	unsigned int count = wq->ring.desc_count;
+
+	paddr = (u64)wq->ring.base_addr | VNIC_PADDR_TARGET;
+	writeq(paddr, &wq->ctrl->ring_base);
+	iowrite32(count, &wq->ctrl->ring_size);
+	iowrite32(fetch_index, &wq->ctrl->fetch_index);
+	iowrite32(posted_index, &wq->ctrl->posted_index);
+	iowrite32(cq_index, &wq->ctrl->cq_index);
+	iowrite32(error_interrupt_enable, &wq->ctrl->error_interrupt_enable);
+	iowrite32(error_interrupt_offset, &wq->ctrl->error_interrupt_offset);
+	iowrite32(0, &wq->ctrl->error_status);
+
+	wq->to_use = wq->to_clean =
+		&wq->bufs[fetch_index / VNIC_WQ_BUF_BLK_ENTRIES(count)]
+			[fetch_index % VNIC_WQ_BUF_BLK_ENTRIES(count)];
+}
+
+void svnic_wq_init(struct vnic_wq *wq, unsigned int cq_index,
+	unsigned int error_interrupt_enable,
+	unsigned int error_interrupt_offset)
+{
+	vnic_wq_init_start(wq, cq_index, 0, 0, error_interrupt_enable,
+			   error_interrupt_offset);
+}
+
+unsigned int svnic_wq_error_status(struct vnic_wq *wq)
+{
+	return ioread32(&wq->ctrl->error_status);
+}
+
+void svnic_wq_enable(struct vnic_wq *wq)
+{
+	iowrite32(1, &wq->ctrl->enable);
+}
+
+int svnic_wq_disable(struct vnic_wq *wq)
+{
+	unsigned int wait;
+
+	iowrite32(0, &wq->ctrl->enable);
+
+	/* Wait for HW to ACK disable request */
+	for (wait = 0; wait < 100; wait++) {
+		if (!(ioread32(&wq->ctrl->running)))
+			return 0;
+		udelay(1);
+	}
+
+	pr_err("Failed to disable WQ[%d]\n", wq->index);
+
+	return -ETIMEDOUT;
+}
+
+void svnic_wq_clean(struct vnic_wq *wq,
+	void (*buf_clean)(struct vnic_wq *wq, struct vnic_wq_buf *buf))
+{
+	struct vnic_wq_buf *buf;
+
+	BUG_ON(ioread32(&wq->ctrl->enable));
+
+	buf = wq->to_clean;
+
+	while (svnic_wq_desc_used(wq) > 0) {
+
+		(*buf_clean)(wq, buf);
+
+		buf = wq->to_clean = buf->next;
+		wq->ring.desc_avail++;
+	}
+
+	wq->to_use = wq->to_clean = wq->bufs[0];
+
+	iowrite32(0, &wq->ctrl->fetch_index);
+	iowrite32(0, &wq->ctrl->posted_index);
+	iowrite32(0, &wq->ctrl->error_status);
+
+	svnic_dev_clear_desc_ring(&wq->ring);
+}