text: /*
   * Copyright 2008-2010 Cisco Systems, Inc.  All rights reserved.
   * Copyright 2007 Nuova 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/kernel.h>
  #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_rq.h"
  
  static int vnic_rq_alloc_bufs(struct vnic_rq *rq)
  {
  	struct vnic_rq_buf *buf;
  	struct vnic_dev *vdev;
  	unsigned int i, j, count = rq->ring.desc_count;
  	unsigned int blks = VNIC_RQ_BUF_BLKS_NEEDED(count);
  
  	vdev = rq->vdev;
  
  	for (i = 0; i < blks; i++) {
  		rq->bufs[i] = kzalloc(VNIC_RQ_BUF_BLK_SZ(count), GFP_ATOMIC);
  		if (!rq->bufs[i]) {
  			pr_err("Failed to alloc rq_bufs\n");
  			return -ENOMEM;
  		}
  	}
  
  	for (i = 0; i < blks; i++) {
  		buf = rq->bufs[i];
  		for (j = 0; j < VNIC_RQ_BUF_BLK_ENTRIES(count); j++) {
  			buf->index = i * VNIC_RQ_BUF_BLK_ENTRIES(count) + j;
  			buf->desc = (u8 *)rq->ring.descs +
  				rq->ring.desc_size * buf->index;
  			if (buf->index + 1 == count) {
  				buf->next = rq->bufs[0];
  				break;
  			} else if (j + 1 == VNIC_RQ_BUF_BLK_ENTRIES(count)) {
  				buf->next = rq->bufs[i + 1];
  			} else {
  				buf->next = buf + 1;
  				buf++;
  			}
  		}
  	}
  
  	rq->to_use = rq->to_clean = rq->bufs[0];
  
  	return 0;
  }
  
  void vnic_rq_free(struct vnic_rq *rq)
  {
  	struct vnic_dev *vdev;
  	unsigned int i;
  
  	vdev = rq->vdev;
  
  	vnic_dev_free_desc_ring(vdev, &rq->ring);
  
  	for (i = 0; i < VNIC_RQ_BUF_BLKS_MAX; i++) {
  		if (rq->bufs[i]) {
  			kfree(rq->bufs[i]);
  			rq->bufs[i] = NULL;
  		}
  	}
  
  	rq->ctrl = NULL;
  }
  
  int vnic_rq_alloc(struct vnic_dev *vdev, struct vnic_rq *rq, unsigned int index,
  	unsigned int desc_count, unsigned int desc_size)
  {
  	int err;
  
  	rq->index = index;
  	rq->vdev = vdev;
  
  	rq->ctrl = vnic_dev_get_res(vdev, RES_TYPE_RQ, index);
  	if (!rq->ctrl) {
  		pr_err("Failed to hook RQ[%d] resource\n", index);
  		return -EINVAL;
  	}
  
  	vnic_rq_disable(rq);
  
  	err = vnic_dev_alloc_desc_ring(vdev, &rq->ring, desc_count, desc_size);
  	if (err)
  		return err;
  
  	err = vnic_rq_alloc_bufs(rq);
  	if (err) {
  		vnic_rq_free(rq);
  		return err;
  	}
  
  	return 0;
  }
  
  static void vnic_rq_init_start(struct vnic_rq *rq, 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 = rq->ring.desc_count;
  
  	paddr = (u64)rq->ring.base_addr | VNIC_PADDR_TARGET;
  	writeq(paddr, &rq->ctrl->ring_base);
  	iowrite32(count, &rq->ctrl->ring_size);
  	iowrite32(cq_index, &rq->ctrl->cq_index);
  	iowrite32(error_interrupt_enable, &rq->ctrl->error_interrupt_enable);
  	iowrite32(error_interrupt_offset, &rq->ctrl->error_interrupt_offset);
  	iowrite32(0, &rq->ctrl->dropped_packet_count);
  	iowrite32(0, &rq->ctrl->error_status);
  	iowrite32(fetch_index, &rq->ctrl->fetch_index);
  	iowrite32(posted_index, &rq->ctrl->posted_index);
  
  	rq->to_use = rq->to_clean =
  		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
  			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
  }
  
  void vnic_rq_init(struct vnic_rq *rq, unsigned int cq_index,
  	unsigned int error_interrupt_enable,
  	unsigned int error_interrupt_offset)
  {
  	u32 fetch_index;
  
  	/* Use current fetch_index as the ring starting point */
  	fetch_index = ioread32(&rq->ctrl->fetch_index);
  
  	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
  		/* Hardware surprise removal: reset fetch_index */
  		fetch_index = 0;
  	}
  
  	vnic_rq_init_start(rq, cq_index,
  		fetch_index, fetch_index,
  		error_interrupt_enable,
  		error_interrupt_offset);
  }
  
  unsigned int vnic_rq_error_status(struct vnic_rq *rq)
  {
  	return ioread32(&rq->ctrl->error_status);
  }
  
  void vnic_rq_enable(struct vnic_rq *rq)
  {
  	iowrite32(1, &rq->ctrl->enable);
  }
  
  int vnic_rq_disable(struct vnic_rq *rq)
  {
  	unsigned int wait;
  
  	iowrite32(0, &rq->ctrl->enable);
  
  	/* Wait for HW to ACK disable request */
  	for (wait = 0; wait < 1000; wait++) {
  		if (!(ioread32(&rq->ctrl->running)))
  			return 0;
  		udelay(10);
  	}
  
  	pr_err("Failed to disable RQ[%d]\n", rq->index);
  
  	return -ETIMEDOUT;
  }
  
  void vnic_rq_clean(struct vnic_rq *rq,
  	void (*buf_clean)(struct vnic_rq *rq, struct vnic_rq_buf *buf))
  {
  	struct vnic_rq_buf *buf;
  	u32 fetch_index;
  	unsigned int count = rq->ring.desc_count;
  
  	buf = rq->to_clean;
  
  	while (vnic_rq_desc_used(rq) > 0) {
  
  		(*buf_clean)(rq, buf);
  
  		buf = rq->to_clean = buf->next;
  		rq->ring.desc_avail++;
  	}
  
  	/* Use current fetch_index as the ring starting point */
  	fetch_index = ioread32(&rq->ctrl->fetch_index);
  
  	if (fetch_index == 0xFFFFFFFF) { /* check for hardware gone  */
  		/* Hardware surprise removal: reset fetch_index */
  		fetch_index = 0;
  	}
  	rq->to_use = rq->to_clean =
  		&rq->bufs[fetch_index / VNIC_RQ_BUF_BLK_ENTRIES(count)]
  			[fetch_index % VNIC_RQ_BUF_BLK_ENTRIES(count)];
  	iowrite32(fetch_index, &rq->ctrl->posted_index);
  
  	vnic_dev_clear_desc_ring(&rq->ring);
  }
  