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Commit 71e7ae8e authored by Nicholas Bellinger's avatar Nicholas Bellinger
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usb-gadget/tcm: Conversion to percpu_ida tag pre-allocation 



This patch converts usb-gadget target to use percpu_ida tag
pre-allocation for struct usbg_cmd descriptor, in order to
avoid fast-path struct usbg_cmd memory allocations.

Note by default this is currently hardcoded to 128.

Tested-by: default avatarAndrzej Pietrasiewicz <andrzej.p@samsung.com>
Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Cc: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent 5f27edad

drivers/usb/gadget/function/f_tcm.c

+58 −39
Original line number Diff line number Diff line
@@ -1073,39 +1073,66 @@ static void usbg_cmd_work(struct work_struct *work) 
	usbg_cleanup_cmd(cmd);

}



static struct usbg_cmd *usbg_get_cmd(struct f_uas *fu,

		struct tcm_usbg_nexus *tv_nexus, u32 scsi_tag)

{

	struct se_session *se_sess = tv_nexus->tvn_se_sess;

	struct usbg_cmd *cmd;

	int tag;



	tag = percpu_ida_alloc(&se_sess->sess_tag_pool, GFP_ATOMIC);

	if (tag < 0)

		return ERR_PTR(-ENOMEM);



	cmd = &((struct usbg_cmd *)se_sess->sess_cmd_map)[tag];

	memset(cmd, 0, sizeof(*cmd));

	cmd->se_cmd.map_tag = tag;

	cmd->se_cmd.tag = cmd->tag = scsi_tag;

	cmd->fu = fu;



	return cmd;

}



static void usbg_release_cmd(struct se_cmd *);



static int usbg_submit_command(struct f_uas *fu,

		void *cmdbuf, unsigned int len)

{

	struct command_iu *cmd_iu = cmdbuf;

	struct usbg_cmd *cmd;

	struct usbg_tpg *tpg;

	struct tcm_usbg_nexus *tv_nexus;

	struct usbg_tpg *tpg = fu->tpg;

	struct tcm_usbg_nexus *tv_nexus = tpg->tpg_nexus;

	u32 cmd_len;

	u16 scsi_tag;



	if (cmd_iu->iu_id != IU_ID_COMMAND) {

		pr_err("Unsupported type %d\n", cmd_iu->iu_id);

		return -EINVAL;

	}



	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);

	if (!cmd)

		return -ENOMEM;

	tv_nexus = tpg->tpg_nexus;

	if (!tv_nexus) {

		pr_err("Missing nexus, ignoring command\n");

		return -EINVAL;

	}



	cmd->fu = fu;

	cmd_len = (cmd_iu->len & ~0x3) + 16;

	if (cmd_len > USBG_MAX_CMD)

		return -EINVAL;



	scsi_tag = be16_to_cpup(&cmd_iu->tag);

	cmd = usbg_get_cmd(fu, tv_nexus, scsi_tag);

	if (IS_ERR(cmd)) {

		pr_err("usbg_get_cmd failed\n");

		return -ENOMEM;

	}



	/* XXX until I figure out why I can't free in on complete */

	kref_init(&cmd->ref);

	kref_get(&cmd->ref);



	tpg = fu->tpg;

	cmd_len = (cmd_iu->len & ~0x3) + 16;

	if (cmd_len > USBG_MAX_CMD)

		goto err;



	memcpy(cmd->cmd_buf, cmd_iu->cdb, cmd_len);



	cmd->tag = be16_to_cpup(&cmd_iu->tag);

	cmd->se_cmd.tag = cmd->tag;

	if (fu->flags & USBG_USE_STREAMS) {

		if (cmd->tag > UASP_SS_EP_COMP_NUM_STREAMS)

			goto err;
@@ -1117,12 +1144,6 @@ static int usbg_submit_command(struct f_uas *fu, 
		cmd->stream = &fu->stream[0];

	}



	tv_nexus = tpg->tpg_nexus;

	if (!tv_nexus) {

		pr_err("Missing nexus, ignoring command\n");

		goto err;

	}



	switch (cmd_iu->prio_attr & 0x7) {

	case UAS_HEAD_TAG:

		cmd->prio_attr = TCM_HEAD_TAG;
@@ -1148,7 +1169,7 @@ static int usbg_submit_command(struct f_uas *fu, 


	return 0;

err:

	kfree(cmd);

	usbg_release_cmd(&cmd->se_cmd);

	return -EINVAL;

}
@@ -1190,7 +1211,7 @@ static int bot_submit_command(struct f_uas *fu, 
{

	struct bulk_cb_wrap *cbw = cmdbuf;

	struct usbg_cmd *cmd;

	struct usbg_tpg *tpg;

	struct usbg_tpg *tpg = fu->tpg;

	struct tcm_usbg_nexus *tv_nexus;

	u32 cmd_len;
@@ -1207,28 +1228,25 @@ static int bot_submit_command(struct f_uas *fu, 
	if (cmd_len < 1 || cmd_len > 16)

		return -EINVAL;



	cmd = kzalloc(sizeof(*cmd), GFP_ATOMIC);

	if (!cmd)

		return -ENOMEM;

	tv_nexus = tpg->tpg_nexus;

	if (!tv_nexus) {

		pr_err("Missing nexus, ignoring command\n");

		return -ENODEV;

	}



	cmd->fu = fu;

	cmd = usbg_get_cmd(fu, tv_nexus, cbw->Tag);

	if (IS_ERR(cmd)) {

		pr_err("usbg_get_cmd failed\n");

		return -ENOMEM;

	}



	/* XXX until I figure out why I can't free in on complete */

	kref_init(&cmd->ref);

	kref_get(&cmd->ref);



	tpg = fu->tpg;



	memcpy(cmd->cmd_buf, cbw->CDB, cmd_len);



	cmd->bot_tag = cbw->Tag;



	tv_nexus = tpg->tpg_nexus;

	if (!tv_nexus) {

		pr_err("Missing nexus, ignoring command\n");

		goto err;

	}



	cmd->prio_attr = TCM_SIMPLE_TAG;

	cmd->unpacked_lun = cbw->Lun;

	cmd->is_read = cbw->Flags & US_BULK_FLAG_IN ? 1 : 0;
@@ -1239,9 +1257,6 @@ static int bot_submit_command(struct f_uas *fu, 
	queue_work(tpg->workqueue, &cmd->work);



	return 0;

err:

	kfree(cmd);

	return -EINVAL;

}



/* Start fabric.c code */
@@ -1294,8 +1309,10 @@ static void usbg_release_cmd(struct se_cmd *se_cmd) 
{

	struct usbg_cmd *cmd = container_of(se_cmd, struct usbg_cmd,

			se_cmd);

	struct se_session *se_sess = se_cmd->se_sess;



	kfree(cmd->data_buf);

	kfree(cmd);

	percpu_ida_free(&se_sess->sess_tag_pool, se_cmd->map_tag);

}



static int usbg_shutdown_session(struct se_session *se_sess)
@@ -1607,7 +1624,9 @@ static int tcm_usbg_make_nexus(struct usbg_tpg *tpg, char *name) 
		goto out_unlock;

	}



	tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg, 0, 0,

	tv_nexus->tvn_se_sess = target_alloc_session(&tpg->se_tpg,

						     USB_G_DEFAULT_SESSION_TAGS,

						     sizeof(struct usbg_cmd),

						     TARGET_PROT_NORMAL, name,

						     tv_nexus, usbg_alloc_sess_cb);

	if (IS_ERR(tv_nexus->tvn_se_sess)) {

drivers/usb/gadget/function/tcm.h

+2 −0
Original line number Diff line number Diff line
@@ -23,6 +23,8 @@ enum { 
#define USB_G_ALT_INT_BBB       0

#define USB_G_ALT_INT_UAS       1



#define USB_G_DEFAULT_SESSION_TAGS	128



struct tcm_usbg_nexus {

	struct se_session *tvn_se_sess;

};