From 52ef2743f16cca9884a9dfd3a8bb013b8e136e4a Mon Sep 17 00:00:00 2001 From: Bodo Stroesser Date: Thu, 10 Sep 2020 17:50:39 +0200 Subject: scsi: target: tcmu: Join tcmu_cmd_get_data_length() and tcmu_cmd_get_block_cnt() Simplify code by joining tcmu_cmd_get_data_length() and tcmu_cmd_get_block_cnt() into tcmu_cmd_set_block_cnts(). The new function sets tcmu_cmd->dbi_cnt and also the new field tcmu_cmd->dbi_bidi_cnt which is needed for further enhancements in following patches. Simplify some code by using tcmu_cmd->dbi(_bidi)_cnt instead of calculation from length. Please note: The calculation of the number of dbis needed for bidi was wrong. It was based on the length of the first bidi sg only. I changed it to correctly sum up entire length of all bidi sgs. Link: https://lore.kernel.org/r/20200910155041.17654-2-bstroesser@ts.fujitsu.com Acked-by: Mike Christie Signed-off-by: Bodo Stroesser Signed-off-by: Martin K. Petersen --- drivers/target/target_core_user.c | 53 +++++++++++++++++---------------------- 1 file changed, 23 insertions(+), 30 deletions(-) (limited to 'drivers/target') diff --git a/drivers/target/target_core_user.c b/drivers/target/target_core_user.c index 9775670351c6..411172d772b4 100644 --- a/drivers/target/target_core_user.c +++ b/drivers/target/target_core_user.c @@ -177,6 +177,7 @@ struct tcmu_cmd { /* Can't use se_cmd when cleaning up expired cmds, because if cmd has been completed then accessing se_cmd is off limits */ uint32_t dbi_cnt; + uint32_t dbi_bidi_cnt; uint32_t dbi_cur; uint32_t *dbi; @@ -558,25 +559,20 @@ static inline void tcmu_free_cmd(struct tcmu_cmd *tcmu_cmd) kmem_cache_free(tcmu_cmd_cache, tcmu_cmd); } -static inline size_t tcmu_cmd_get_data_length(struct tcmu_cmd *tcmu_cmd) +static inline void tcmu_cmd_set_block_cnts(struct tcmu_cmd *cmd) { - struct se_cmd *se_cmd = tcmu_cmd->se_cmd; - size_t data_length = round_up(se_cmd->data_length, DATA_BLOCK_SIZE); + int i, len; + struct se_cmd *se_cmd = cmd->se_cmd; + + cmd->dbi_cnt = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE); if (se_cmd->se_cmd_flags & SCF_BIDI) { BUG_ON(!(se_cmd->t_bidi_data_sg && se_cmd->t_bidi_data_nents)); - data_length += round_up(se_cmd->t_bidi_data_sg->length, - DATA_BLOCK_SIZE); + for (i = 0, len = 0; i < se_cmd->t_bidi_data_nents; i++) + len += se_cmd->t_bidi_data_sg[i].length; + cmd->dbi_bidi_cnt = DIV_ROUND_UP(len, DATA_BLOCK_SIZE); + cmd->dbi_cnt += cmd->dbi_bidi_cnt; } - - return data_length; -} - -static inline uint32_t tcmu_cmd_get_block_cnt(struct tcmu_cmd *tcmu_cmd) -{ - size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd); - - return data_length / DATA_BLOCK_SIZE; } static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd) @@ -593,8 +589,7 @@ static struct tcmu_cmd *tcmu_alloc_cmd(struct se_cmd *se_cmd) tcmu_cmd->se_cmd = se_cmd; tcmu_cmd->tcmu_dev = udev; - tcmu_cmd_reset_dbi_cur(tcmu_cmd); - tcmu_cmd->dbi_cnt = tcmu_cmd_get_block_cnt(tcmu_cmd); + tcmu_cmd_set_block_cnts(tcmu_cmd); tcmu_cmd->dbi = kcalloc(tcmu_cmd->dbi_cnt, sizeof(uint32_t), GFP_NOIO); if (!tcmu_cmd->dbi) { @@ -767,13 +762,12 @@ static void gather_data_area(struct tcmu_dev *udev, struct tcmu_cmd *cmd, data_sg = se_cmd->t_data_sg; data_nents = se_cmd->t_data_nents; } else { - /* * For bidi case, the first count blocks are for Data-Out * buffer blocks, and before gathering the Data-In buffer - * the Data-Out buffer blocks should be discarded. + * the Data-Out buffer blocks should be skipped. */ - count = DIV_ROUND_UP(se_cmd->data_length, DATA_BLOCK_SIZE); + count = cmd->dbi_cnt - cmd->dbi_bidi_cnt; data_sg = se_cmd->t_bidi_data_sg; data_nents = se_cmd->t_bidi_data_nents; @@ -827,11 +821,9 @@ static inline size_t spc_bitmap_free(unsigned long *bitmap, uint32_t thresh) * Called with ring lock held. */ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd, - size_t cmd_size, size_t data_needed) + size_t cmd_size) { struct tcmu_mailbox *mb = udev->mb_addr; - uint32_t blocks_needed = (data_needed + DATA_BLOCK_SIZE - 1) - / DATA_BLOCK_SIZE; size_t space, cmd_needed; u32 cmd_head; @@ -855,23 +847,23 @@ static bool is_ring_space_avail(struct tcmu_dev *udev, struct tcmu_cmd *cmd, return false; } - if (!data_needed) + if (!cmd || !cmd->dbi_cnt) return true; /* try to check and get the data blocks as needed */ space = spc_bitmap_free(udev->data_bitmap, udev->dbi_thresh); - if ((space * DATA_BLOCK_SIZE) < data_needed) { + if (space < cmd->dbi_cnt) { unsigned long blocks_left = (udev->max_blocks - udev->dbi_thresh) + space; - if (blocks_left < blocks_needed) { + if (blocks_left < cmd->dbi_cnt) { pr_debug("no data space: only %lu available, but ask for %zu\n", blocks_left * DATA_BLOCK_SIZE, - data_needed); + cmd->dbi_cnt * DATA_BLOCK_SIZE); return false; } - udev->dbi_thresh += blocks_needed; + udev->dbi_thresh += cmd->dbi_cnt; if (udev->dbi_thresh > udev->max_blocks) udev->dbi_thresh = udev->max_blocks; } @@ -990,7 +982,8 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err) uint32_t cmd_head; uint64_t cdb_off; bool copy_to_data_area; - size_t data_length = tcmu_cmd_get_data_length(tcmu_cmd); + /* size of data buffer needed */ + size_t data_length = (size_t)tcmu_cmd->dbi_cnt * DATA_BLOCK_SIZE; *scsi_err = TCM_NO_SENSE; @@ -1031,7 +1024,7 @@ static int queue_cmd_ring(struct tcmu_cmd *tcmu_cmd, sense_reason_t *scsi_err) return -1; } - if (!is_ring_space_avail(udev, tcmu_cmd, command_size, data_length)) { + if (!is_ring_space_avail(udev, tcmu_cmd, command_size)) { /* * Don't leave commands partially setup because the unmap * thread might need the blocks to make forward progress. @@ -1145,7 +1138,7 @@ queue_tmr_ring(struct tcmu_dev *udev, struct tcmu_tmr *tmr) cmd_size = round_up(sizeof(*entry) + id_list_sz, TCMU_OP_ALIGN_SIZE); if (!list_empty(&udev->tmr_queue) || - !is_ring_space_avail(udev, NULL, cmd_size, 0)) { + !is_ring_space_avail(udev, NULL, cmd_size)) { list_add_tail(&tmr->queue_entry, &udev->tmr_queue); pr_debug("adding tmr %p on dev %s to TMR ring space wait queue\n", tmr, udev->name); 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