428 lines
10 KiB
C
428 lines
10 KiB
C
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/*******************************************************************************
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* SCSI RDMA Protocol lib functions
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*
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* Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org>
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* Copyright (C) 2016 Bryant G. Ly <bryantly@linux.vnet.ibm.com> IBM Corp.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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***********************************************************************/
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#define pr_fmt(fmt) "libsrp: " fmt
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#include <linux/printk.h>
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#include <linux/err.h>
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#include <linux/slab.h>
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#include <linux/kfifo.h>
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#include <linux/scatterlist.h>
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#include <linux/dma-mapping.h>
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#include <linux/module.h>
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#include <scsi/srp.h>
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#include <target/target_core_base.h>
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#include "libsrp.h"
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#include "ibmvscsi_tgt.h"
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static int srp_iu_pool_alloc(struct srp_queue *q, size_t max,
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struct srp_buf **ring)
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{
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struct iu_entry *iue;
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int i;
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q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL);
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if (!q->pool)
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return -ENOMEM;
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q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL);
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if (!q->items)
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goto free_pool;
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spin_lock_init(&q->lock);
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kfifo_init(&q->queue, (void *)q->pool, max * sizeof(void *));
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for (i = 0, iue = q->items; i < max; i++) {
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kfifo_in(&q->queue, (void *)&iue, sizeof(void *));
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iue->sbuf = ring[i];
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iue++;
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}
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return 0;
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free_pool:
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kfree(q->pool);
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return -ENOMEM;
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}
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static void srp_iu_pool_free(struct srp_queue *q)
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{
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kfree(q->items);
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kfree(q->pool);
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}
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static struct srp_buf **srp_ring_alloc(struct device *dev,
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size_t max, size_t size)
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{
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struct srp_buf **ring;
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int i;
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ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL);
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if (!ring)
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return NULL;
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for (i = 0; i < max; i++) {
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ring[i] = kzalloc(sizeof(*ring[i]), GFP_KERNEL);
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if (!ring[i])
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goto out;
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ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma,
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GFP_KERNEL);
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if (!ring[i]->buf)
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goto out;
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}
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return ring;
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out:
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for (i = 0; i < max && ring[i]; i++) {
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if (ring[i]->buf) {
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dma_free_coherent(dev, size, ring[i]->buf,
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ring[i]->dma);
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}
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kfree(ring[i]);
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}
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kfree(ring);
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return NULL;
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}
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static void srp_ring_free(struct device *dev, struct srp_buf **ring,
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size_t max, size_t size)
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{
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int i;
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for (i = 0; i < max; i++) {
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dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma);
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kfree(ring[i]);
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}
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kfree(ring);
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}
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int srp_target_alloc(struct srp_target *target, struct device *dev,
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size_t nr, size_t iu_size)
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{
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int err;
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spin_lock_init(&target->lock);
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target->dev = dev;
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target->srp_iu_size = iu_size;
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target->rx_ring_size = nr;
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target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size);
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if (!target->rx_ring)
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return -ENOMEM;
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err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring);
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if (err)
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goto free_ring;
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dev_set_drvdata(target->dev, target);
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return 0;
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free_ring:
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srp_ring_free(target->dev, target->rx_ring, nr, iu_size);
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return -ENOMEM;
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}
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void srp_target_free(struct srp_target *target)
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{
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dev_set_drvdata(target->dev, NULL);
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srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size,
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target->srp_iu_size);
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srp_iu_pool_free(&target->iu_queue);
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}
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struct iu_entry *srp_iu_get(struct srp_target *target)
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{
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struct iu_entry *iue = NULL;
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if (kfifo_out_locked(&target->iu_queue.queue, (void *)&iue,
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sizeof(void *),
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&target->iu_queue.lock) != sizeof(void *)) {
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WARN_ONCE(1, "unexpected fifo state");
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return NULL;
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}
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if (!iue)
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return iue;
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iue->target = target;
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iue->flags = 0;
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return iue;
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}
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void srp_iu_put(struct iu_entry *iue)
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{
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kfifo_in_locked(&iue->target->iu_queue.queue, (void *)&iue,
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sizeof(void *), &iue->target->iu_queue.lock);
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}
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static int srp_direct_data(struct ibmvscsis_cmd *cmd, struct srp_direct_buf *md,
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enum dma_data_direction dir, srp_rdma_t rdma_io,
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int dma_map, int ext_desc)
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{
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struct iu_entry *iue = NULL;
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struct scatterlist *sg = NULL;
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int err, nsg = 0, len;
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if (dma_map) {
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iue = cmd->iue;
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sg = cmd->se_cmd.t_data_sg;
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nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents,
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DMA_BIDIRECTIONAL);
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if (!nsg) {
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pr_err("fail to map %p %d\n", iue,
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cmd->se_cmd.t_data_nents);
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return 0;
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}
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len = min(cmd->se_cmd.data_length, be32_to_cpu(md->len));
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} else {
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len = be32_to_cpu(md->len);
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}
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err = rdma_io(cmd, sg, nsg, md, 1, dir, len);
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if (dma_map)
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dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
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return err;
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}
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static int srp_indirect_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd,
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struct srp_indirect_buf *id,
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enum dma_data_direction dir, srp_rdma_t rdma_io,
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int dma_map, int ext_desc)
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{
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struct iu_entry *iue = NULL;
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struct srp_direct_buf *md = NULL;
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struct scatterlist dummy, *sg = NULL;
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dma_addr_t token = 0;
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int err = 0;
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int nmd, nsg = 0, len;
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if (dma_map || ext_desc) {
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iue = cmd->iue;
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sg = cmd->se_cmd.t_data_sg;
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}
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nmd = be32_to_cpu(id->table_desc.len) / sizeof(struct srp_direct_buf);
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if ((dir == DMA_FROM_DEVICE && nmd == srp_cmd->data_in_desc_cnt) ||
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(dir == DMA_TO_DEVICE && nmd == srp_cmd->data_out_desc_cnt)) {
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md = &id->desc_list[0];
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goto rdma;
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}
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if (ext_desc && dma_map) {
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md = dma_alloc_coherent(iue->target->dev,
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be32_to_cpu(id->table_desc.len),
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&token, GFP_KERNEL);
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if (!md) {
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pr_err("Can't get dma memory %u\n",
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be32_to_cpu(id->table_desc.len));
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return -ENOMEM;
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}
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sg_init_one(&dummy, md, be32_to_cpu(id->table_desc.len));
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sg_dma_address(&dummy) = token;
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sg_dma_len(&dummy) = be32_to_cpu(id->table_desc.len);
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err = rdma_io(cmd, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE,
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be32_to_cpu(id->table_desc.len));
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if (err) {
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pr_err("Error copying indirect table %d\n", err);
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goto free_mem;
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}
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} else {
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pr_err("This command uses external indirect buffer\n");
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return -EINVAL;
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}
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rdma:
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if (dma_map) {
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nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents,
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DMA_BIDIRECTIONAL);
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if (!nsg) {
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pr_err("fail to map %p %d\n", iue,
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cmd->se_cmd.t_data_nents);
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err = -EIO;
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goto free_mem;
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}
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len = min(cmd->se_cmd.data_length, be32_to_cpu(id->len));
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} else {
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len = be32_to_cpu(id->len);
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}
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err = rdma_io(cmd, sg, nsg, md, nmd, dir, len);
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if (dma_map)
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dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL);
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free_mem:
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if (token && dma_map) {
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dma_free_coherent(iue->target->dev,
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be32_to_cpu(id->table_desc.len), md, token);
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}
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return err;
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}
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static int data_out_desc_size(struct srp_cmd *cmd)
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{
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int size = 0;
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u8 fmt = cmd->buf_fmt >> 4;
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switch (fmt) {
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case SRP_NO_DATA_DESC:
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break;
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case SRP_DATA_DESC_DIRECT:
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size = sizeof(struct srp_direct_buf);
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break;
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case SRP_DATA_DESC_INDIRECT:
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size = sizeof(struct srp_indirect_buf) +
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sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt;
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break;
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default:
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pr_err("client error. Invalid data_out_format %x\n", fmt);
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break;
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}
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return size;
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}
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/*
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* TODO: this can be called multiple times for a single command if it
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* has very long data.
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*/
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int srp_transfer_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd,
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srp_rdma_t rdma_io, int dma_map, int ext_desc)
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{
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struct srp_direct_buf *md;
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struct srp_indirect_buf *id;
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enum dma_data_direction dir;
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int offset, err = 0;
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u8 format;
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if (!cmd->se_cmd.t_data_nents)
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return 0;
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offset = srp_cmd->add_cdb_len & ~3;
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dir = srp_cmd_direction(srp_cmd);
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if (dir == DMA_FROM_DEVICE)
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offset += data_out_desc_size(srp_cmd);
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if (dir == DMA_TO_DEVICE)
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format = srp_cmd->buf_fmt >> 4;
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else
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format = srp_cmd->buf_fmt & ((1U << 4) - 1);
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switch (format) {
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case SRP_NO_DATA_DESC:
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break;
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case SRP_DATA_DESC_DIRECT:
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md = (struct srp_direct_buf *)(srp_cmd->add_data + offset);
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err = srp_direct_data(cmd, md, dir, rdma_io, dma_map, ext_desc);
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break;
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case SRP_DATA_DESC_INDIRECT:
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id = (struct srp_indirect_buf *)(srp_cmd->add_data + offset);
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err = srp_indirect_data(cmd, srp_cmd, id, dir, rdma_io, dma_map,
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ext_desc);
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break;
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default:
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pr_err("Unknown format %d %x\n", dir, format);
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err = -EINVAL;
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}
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return err;
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}
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u64 srp_data_length(struct srp_cmd *cmd, enum dma_data_direction dir)
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{
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struct srp_direct_buf *md;
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struct srp_indirect_buf *id;
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u64 len = 0;
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uint offset = cmd->add_cdb_len & ~3;
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u8 fmt;
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if (dir == DMA_TO_DEVICE) {
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fmt = cmd->buf_fmt >> 4;
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} else {
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fmt = cmd->buf_fmt & ((1U << 4) - 1);
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offset += data_out_desc_size(cmd);
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}
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switch (fmt) {
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case SRP_NO_DATA_DESC:
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break;
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case SRP_DATA_DESC_DIRECT:
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md = (struct srp_direct_buf *)(cmd->add_data + offset);
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|
|
len = be32_to_cpu(md->len);
|
||
|
|
break;
|
||
|
|
case SRP_DATA_DESC_INDIRECT:
|
||
|
|
id = (struct srp_indirect_buf *)(cmd->add_data + offset);
|
||
|
|
len = be32_to_cpu(id->len);
|
||
|
|
break;
|
||
|
|
default:
|
||
|
|
pr_err("invalid data format %x\n", fmt);
|
||
|
|
break;
|
||
|
|
}
|
||
|
|
return len;
|
||
|
|
}
|
||
|
|
|
||
|
|
int srp_get_desc_table(struct srp_cmd *srp_cmd, enum dma_data_direction *dir,
|
||
|
|
u64 *data_len)
|
||
|
|
{
|
||
|
|
struct srp_indirect_buf *idb;
|
||
|
|
struct srp_direct_buf *db;
|
||
|
|
uint add_cdb_offset;
|
||
|
|
int rc;
|
||
|
|
|
||
|
|
/*
|
||
|
|
* The pointer computations below will only be compiled correctly
|
||
|
|
* if srp_cmd::add_data is declared as s8*, u8*, s8[] or u8[], so check
|
||
|
|
* whether srp_cmd::add_data has been declared as a byte pointer.
|
||
|
|
*/
|
||
|
|
BUILD_BUG_ON(!__same_type(srp_cmd->add_data[0], (s8)0)
|
||
|
|
&& !__same_type(srp_cmd->add_data[0], (u8)0));
|
||
|
|
|
||
|
|
BUG_ON(!dir);
|
||
|
|
BUG_ON(!data_len);
|
||
|
|
|
||
|
|
rc = 0;
|
||
|
|
*data_len = 0;
|
||
|
|
|
||
|
|
*dir = DMA_NONE;
|
||
|
|
|
||
|
|
if (srp_cmd->buf_fmt & 0xf)
|
||
|
|
*dir = DMA_FROM_DEVICE;
|
||
|
|
else if (srp_cmd->buf_fmt >> 4)
|
||
|
|
*dir = DMA_TO_DEVICE;
|
||
|
|
|
||
|
|
add_cdb_offset = srp_cmd->add_cdb_len & ~3;
|
||
|
|
if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_DIRECT) ||
|
||
|
|
((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_DIRECT)) {
|
||
|
|
db = (struct srp_direct_buf *)(srp_cmd->add_data
|
||
|
|
+ add_cdb_offset);
|
||
|
|
*data_len = be32_to_cpu(db->len);
|
||
|
|
} else if (((srp_cmd->buf_fmt & 0xf) == SRP_DATA_DESC_INDIRECT) ||
|
||
|
|
((srp_cmd->buf_fmt >> 4) == SRP_DATA_DESC_INDIRECT)) {
|
||
|
|
idb = (struct srp_indirect_buf *)(srp_cmd->add_data
|
||
|
|
+ add_cdb_offset);
|
||
|
|
|
||
|
|
*data_len = be32_to_cpu(idb->len);
|
||
|
|
}
|
||
|
|
return rc;
|
||
|
|
}
|
||
|
|
|
||
|
|
MODULE_DESCRIPTION("SCSI RDMA Protocol lib functions");
|
||
|
|
MODULE_AUTHOR("FUJITA Tomonori");
|
||
|
|
MODULE_LICENSE("GPL");
|