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author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-04 20:04:37 -0400 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-08-04 20:04:37 -0400 |
commit | fdf1f7ff1bd7f1c6d1d5dc2b29b6b11a4f722276 (patch) | |
tree | 3608d840304d28ab26d7698631fa0a1000966a0c /drivers/scsi/ibmvscsi_tgt/libsrp.c | |
parent | a71e36045e1fd5813addad2fce878d96e2827d66 (diff) | |
parent | 291e3e51a34d2f546608bfd31f185151621135b7 (diff) | |
download | lwn-fdf1f7ff1bd7f1c6d1d5dc2b29b6b11a4f722276.tar.gz lwn-fdf1f7ff1bd7f1c6d1d5dc2b29b6b11a4f722276.zip |
Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending
Pull SCSI target updates from Nicholas Bellinger:
"The most notable item is IBM virtual SCSI target driver, that was
originally ported to target-core back in 2010 by Tomo-san, and has
been brought forward to v4.x code by Bryant Ly, Michael Cyr and co
over the last months.
Also included are two ORDERED task related bug-fixes Bryant + Michael
found along the way using ibmvscsis with AIX guests, plus a few
miscellaneous target-core + iscsi-target bug-fixes with associated
stable tags"
* 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
target: fix spelling mistake: "limitiation" -> "limitation"
target: Fix residual overflow handling in target_complete_cmd_with_length
tcm_fc: set and unset FCP_SPPF_TARG_FCN
iscsi-target: Fix panic when adding second TCP connection to iSCSI session
ibmvscsis: Initial commit of IBM VSCSI Tgt Driver
target: Fix ordered task CHECK_CONDITION early exception handling
target: Fix ordered task target_setup_cmd_from_cdb exception hang
target: Fix max_unmap_lba_count calc overflow
target: Fix race between iscsi-target connection shutdown + ABORT_TASK
target: Fix missing complete during ABORT_TASK + CMD_T_FABRIC_STOP
Diffstat (limited to 'drivers/scsi/ibmvscsi_tgt/libsrp.c')
-rw-r--r-- | drivers/scsi/ibmvscsi_tgt/libsrp.c | 427 |
1 files changed, 427 insertions, 0 deletions
diff --git a/drivers/scsi/ibmvscsi_tgt/libsrp.c b/drivers/scsi/ibmvscsi_tgt/libsrp.c new file mode 100644 index 000000000000..5a4cc28ca5ff --- /dev/null +++ b/drivers/scsi/ibmvscsi_tgt/libsrp.c @@ -0,0 +1,427 @@ +/******************************************************************************* + * SCSI RDMA Protocol lib functions + * + * Copyright (C) 2006 FUJITA Tomonori <tomof@acm.org> + * Copyright (C) 2016 Bryant G. Ly <bryantly@linux.vnet.ibm.com> IBM Corp. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + ***********************************************************************/ + +#define pr_fmt(fmt) "libsrp: " fmt + +#include <linux/printk.h> +#include <linux/err.h> +#include <linux/slab.h> +#include <linux/kfifo.h> +#include <linux/scatterlist.h> +#include <linux/dma-mapping.h> +#include <linux/module.h> +#include <scsi/srp.h> +#include <target/target_core_base.h> +#include "libsrp.h" +#include "ibmvscsi_tgt.h" + +static int srp_iu_pool_alloc(struct srp_queue *q, size_t max, + struct srp_buf **ring) +{ + struct iu_entry *iue; + int i; + + q->pool = kcalloc(max, sizeof(struct iu_entry *), GFP_KERNEL); + if (!q->pool) + return -ENOMEM; + q->items = kcalloc(max, sizeof(struct iu_entry), GFP_KERNEL); + if (!q->items) + goto free_pool; + + spin_lock_init(&q->lock); + kfifo_init(&q->queue, (void *)q->pool, max * sizeof(void *)); + + for (i = 0, iue = q->items; i < max; i++) { + kfifo_in(&q->queue, (void *)&iue, sizeof(void *)); + iue->sbuf = ring[i]; + iue++; + } + return 0; + +free_pool: + kfree(q->pool); + return -ENOMEM; +} + +static void srp_iu_pool_free(struct srp_queue *q) +{ + kfree(q->items); + kfree(q->pool); +} + +static struct srp_buf **srp_ring_alloc(struct device *dev, + size_t max, size_t size) +{ + struct srp_buf **ring; + int i; + + ring = kcalloc(max, sizeof(struct srp_buf *), GFP_KERNEL); + if (!ring) + return NULL; + + for (i = 0; i < max; i++) { + ring[i] = kzalloc(sizeof(*ring[i]), GFP_KERNEL); + if (!ring[i]) + goto out; + ring[i]->buf = dma_alloc_coherent(dev, size, &ring[i]->dma, + GFP_KERNEL); + if (!ring[i]->buf) + goto out; + } + return ring; + +out: + for (i = 0; i < max && ring[i]; i++) { + if (ring[i]->buf) { + dma_free_coherent(dev, size, ring[i]->buf, + ring[i]->dma); + } + kfree(ring[i]); + } + kfree(ring); + + return NULL; +} + +static void srp_ring_free(struct device *dev, struct srp_buf **ring, + size_t max, size_t size) +{ + int i; + + for (i = 0; i < max; i++) { + dma_free_coherent(dev, size, ring[i]->buf, ring[i]->dma); + kfree(ring[i]); + } + kfree(ring); +} + +int srp_target_alloc(struct srp_target *target, struct device *dev, + size_t nr, size_t iu_size) +{ + int err; + + spin_lock_init(&target->lock); + + target->dev = dev; + + target->srp_iu_size = iu_size; + target->rx_ring_size = nr; + target->rx_ring = srp_ring_alloc(target->dev, nr, iu_size); + if (!target->rx_ring) + return -ENOMEM; + err = srp_iu_pool_alloc(&target->iu_queue, nr, target->rx_ring); + if (err) + goto free_ring; + + dev_set_drvdata(target->dev, target); + return 0; + +free_ring: + srp_ring_free(target->dev, target->rx_ring, nr, iu_size); + return -ENOMEM; +} + +void srp_target_free(struct srp_target *target) +{ + dev_set_drvdata(target->dev, NULL); + srp_ring_free(target->dev, target->rx_ring, target->rx_ring_size, + target->srp_iu_size); + srp_iu_pool_free(&target->iu_queue); +} + +struct iu_entry *srp_iu_get(struct srp_target *target) +{ + struct iu_entry *iue = NULL; + + if (kfifo_out_locked(&target->iu_queue.queue, (void *)&iue, + sizeof(void *), + &target->iu_queue.lock) != sizeof(void *)) { + WARN_ONCE(1, "unexpected fifo state"); + return NULL; + } + if (!iue) + return iue; + iue->target = target; + iue->flags = 0; + return iue; +} + +void srp_iu_put(struct iu_entry *iue) +{ + kfifo_in_locked(&iue->target->iu_queue.queue, (void *)&iue, + sizeof(void *), &iue->target->iu_queue.lock); +} + +static int srp_direct_data(struct ibmvscsis_cmd *cmd, struct srp_direct_buf *md, + enum dma_data_direction dir, srp_rdma_t rdma_io, + int dma_map, int ext_desc) +{ + struct iu_entry *iue = NULL; + struct scatterlist *sg = NULL; + int err, nsg = 0, len; + + if (dma_map) { + iue = cmd->iue; + sg = cmd->se_cmd.t_data_sg; + nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents, + DMA_BIDIRECTIONAL); + if (!nsg) { + pr_err("fail to map %p %d\n", iue, + cmd->se_cmd.t_data_nents); + return 0; + } + len = min(cmd->se_cmd.data_length, be32_to_cpu(md->len)); + } else { + len = be32_to_cpu(md->len); + } + + err = rdma_io(cmd, sg, nsg, md, 1, dir, len); + + if (dma_map) + dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL); + + return err; +} + +static int srp_indirect_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd, + struct srp_indirect_buf *id, + enum dma_data_direction dir, srp_rdma_t rdma_io, + int dma_map, int ext_desc) +{ + struct iu_entry *iue = NULL; + struct srp_direct_buf *md = NULL; + struct scatterlist dummy, *sg = NULL; + dma_addr_t token = 0; + int err = 0; + int nmd, nsg = 0, len; + + if (dma_map || ext_desc) { + iue = cmd->iue; + sg = cmd->se_cmd.t_data_sg; + } + + nmd = be32_to_cpu(id->table_desc.len) / sizeof(struct srp_direct_buf); + + if ((dir == DMA_FROM_DEVICE && nmd == srp_cmd->data_in_desc_cnt) || + (dir == DMA_TO_DEVICE && nmd == srp_cmd->data_out_desc_cnt)) { + md = &id->desc_list[0]; + goto rdma; + } + + if (ext_desc && dma_map) { + md = dma_alloc_coherent(iue->target->dev, + be32_to_cpu(id->table_desc.len), + &token, GFP_KERNEL); + if (!md) { + pr_err("Can't get dma memory %u\n", + be32_to_cpu(id->table_desc.len)); + return -ENOMEM; + } + + sg_init_one(&dummy, md, be32_to_cpu(id->table_desc.len)); + sg_dma_address(&dummy) = token; + sg_dma_len(&dummy) = be32_to_cpu(id->table_desc.len); + err = rdma_io(cmd, &dummy, 1, &id->table_desc, 1, DMA_TO_DEVICE, + be32_to_cpu(id->table_desc.len)); + if (err) { + pr_err("Error copying indirect table %d\n", err); + goto free_mem; + } + } else { + pr_err("This command uses external indirect buffer\n"); + return -EINVAL; + } + +rdma: + if (dma_map) { + nsg = dma_map_sg(iue->target->dev, sg, cmd->se_cmd.t_data_nents, + DMA_BIDIRECTIONAL); + if (!nsg) { + pr_err("fail to map %p %d\n", iue, + cmd->se_cmd.t_data_nents); + err = -EIO; + goto free_mem; + } + len = min(cmd->se_cmd.data_length, be32_to_cpu(id->len)); + } else { + len = be32_to_cpu(id->len); + } + + err = rdma_io(cmd, sg, nsg, md, nmd, dir, len); + + if (dma_map) + dma_unmap_sg(iue->target->dev, sg, nsg, DMA_BIDIRECTIONAL); + +free_mem: + if (token && dma_map) { + dma_free_coherent(iue->target->dev, + be32_to_cpu(id->table_desc.len), md, token); + } + return err; +} + +static int data_out_desc_size(struct srp_cmd *cmd) +{ + int size = 0; + u8 fmt = cmd->buf_fmt >> 4; + + switch (fmt) { + case SRP_NO_DATA_DESC: + break; + case SRP_DATA_DESC_DIRECT: + size = sizeof(struct srp_direct_buf); + break; + case SRP_DATA_DESC_INDIRECT: + size = sizeof(struct srp_indirect_buf) + + sizeof(struct srp_direct_buf) * cmd->data_out_desc_cnt; + break; + default: + pr_err("client error. Invalid data_out_format %x\n", fmt); + break; + } + return size; +} + +/* + * TODO: this can be called multiple times for a single command if it + * has very long data. + */ +int srp_transfer_data(struct ibmvscsis_cmd *cmd, struct srp_cmd *srp_cmd, + srp_rdma_t rdma_io, int dma_map, int ext_desc) +{ + struct srp_direct_buf *md; + struct srp_indirect_buf *id; + enum dma_data_direction dir; + int offset, err = 0; + u8 format; + + if (!cmd->se_cmd.t_data_nents) + return 0; + + offset = srp_cmd->add_cdb_len & ~3; + + dir = srp_cmd_direction(srp_cmd); + if (dir == DMA_FROM_DEVICE) + offset += data_out_desc_size(srp_cmd); + + if (dir == DMA_TO_DEVICE) + format = srp_cmd->buf_fmt >> 4; + else + format = srp_cmd->buf_fmt & ((1U << 4) - 1); + + switch (format) { + case SRP_NO_DATA_DESC: + break; + case SRP_DATA_DESC_DIRECT: + md = (struct srp_direct_buf *)(srp_cmd->add_data + offset); + err = srp_direct_data(cmd, md, dir, rdma_io, dma_map, ext_desc); + break; + case SRP_DATA_DESC_INDIRECT: + id = (struct srp_indirect_buf *)(srp_cmd->add_data + offset); + err = srp_indirect_data(cmd, srp_cmd, id, dir, rdma_io, dma_map, + ext_desc); + break; + default: + pr_err("Unknown format %d %x\n", dir, format); + err = -EINVAL; + } + + return err; +} + +u64 srp_data_length(struct srp_cmd *cmd, enum dma_data_direction dir) +{ + struct srp_direct_buf *md; + struct srp_indirect_buf *id; + u64 len = 0; + uint offset = cmd->add_cdb_len & ~3; + u8 fmt; + + if (dir == DMA_TO_DEVICE) { + fmt = cmd->buf_fmt >> 4; + } else { + fmt = cmd->buf_fmt & ((1U << 4) - 1); + offset += data_out_desc_size(cmd); + } + + switch (fmt) { + case SRP_NO_DATA_DESC: + break; + case SRP_DATA_DESC_DIRECT: + md = (struct srp_direct_buf *)(cmd->add_data + offset); + 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"); |