drivers/scsi/libfc/fc_libfc.c - linux/torvalds/linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright(c) 2009 Intel Corporation. All rights reserved.
  *
  * Maintained at www.Open-FCoE.org
  */

 #include <linux/kernel.h>
 #include <linux/types.h>
 #include <linux/scatterlist.h>
 #include <linux/crc32.h>
 #include <linux/module.h>

 #include <scsi/libfc.h>
 #include <scsi/fc_encode.h>

 #include "fc_libfc.h"

 MODULE_AUTHOR("Open-FCoE.org");
 MODULE_DESCRIPTION("libfc");
 MODULE_LICENSE("GPL v2");

 unsigned int fc_debug_logging;
 module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO|S_IWUSR);
 MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");

 DEFINE_MUTEX(fc_prov_mutex);
 static LIST_HEAD(fc_local_ports);
 struct blocking_notifier_head fc_lport_notifier_head =
 		BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
 EXPORT_SYMBOL(fc_lport_notifier_head);

 /*
  * Providers which primarily send requests and PRLIs.
  */
 struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
 	[0] = &fc_rport_t0_prov,
 	[FC_TYPE_FCP] = &fc_rport_fcp_init,
 };

 /*
  * Providers which receive requests.
  */
 struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
 	[FC_TYPE_ELS] = &fc_lport_els_prov,
 };

 /**
  * libfc_init() - Initialize libfc.ko
  */
 static int __init libfc_init(void)
 {
 	int rc = 0;

 	rc = fc_setup_fcp();
 	if (rc)
 		return rc;

 	rc = fc_setup_exch_mgr();
 	if (rc)
 		goto destroy_pkt_cache;

 	rc = fc_setup_rport();
 	if (rc)
 		goto destroy_em;

 	return rc;
 destroy_em:
 	fc_destroy_exch_mgr();
 destroy_pkt_cache:
 	fc_destroy_fcp();
 	return rc;
 }
 module_init(libfc_init);

 /**
  * libfc_exit() - Tear down libfc.ko
  */
 static void __exit libfc_exit(void)
 {
 	fc_destroy_fcp();
 	fc_destroy_exch_mgr();
 	fc_destroy_rport();
 }
 module_exit(libfc_exit);

 /**
  * fc_copy_buffer_to_sglist() - This routine copies the data of a buffer
  *				into a scatter-gather list (SG list).
  *
  * @buf: pointer to the data buffer.
  * @len: the byte-length of the data buffer.
  * @sg: pointer to the pointer of the SG list.
  * @nents: pointer to the remaining number of entries in the SG list.
  * @offset: pointer to the current offset in the SG list.
  * @crc: pointer to the 32-bit crc value.
  *	 If crc is NULL, CRC is not calculated.
  */
 u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
 			     struct scatterlist *sg,
 			     u32 *nents, size_t *offset,
 			     u32 *crc)
 {
 	size_t remaining = len;
 	u32 copy_len = 0;

 	while (remaining > 0 && sg) {
 		size_t off, sg_bytes;
 		void *page_addr;

 		if (*offset >= sg->length) {
 			/*
 			 * Check for end and drop resources
 			 * from the last iteration.
 			 */
 			if (!(*nents))
 				break;
 			--(*nents);
 			*offset -= sg->length;
 			sg = sg_next(sg);
 			continue;
 		}
 		sg_bytes = min(remaining, sg->length - *offset);

 		/*
 		 * The scatterlist item may be bigger than PAGE_SIZE,
 		 * but we are limited to mapping PAGE_SIZE at a time.
 		 */
 		off = *offset + sg->offset;
 		sg_bytes = min(sg_bytes,
 			       (size_t)(PAGE_SIZE - (off & ~PAGE_MASK)));
 		page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT));
 		if (crc)
 			*crc = crc32(*crc, buf, sg_bytes);
 		memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
 		kunmap_atomic(page_addr);
 		buf += sg_bytes;
 		*offset += sg_bytes;
 		remaining -= sg_bytes;
 		copy_len += sg_bytes;
 	}
 	return copy_len;
 }

 /**
  * fc_fill_hdr() -  fill FC header fields based on request
  * @fp: reply frame containing header to be filled in
  * @in_fp: request frame containing header to use in filling in reply
  * @r_ctl: R_CTL value for header
  * @f_ctl: F_CTL value for header, with 0 pad
  * @seq_cnt: sequence count for the header, ignored if frame has a sequence
  * @parm_offset: parameter / offset value
  */
 void fc_fill_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
 		 enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset)
 {
 	struct fc_frame_header *fh;
 	struct fc_frame_header *in_fh;
 	struct fc_seq *sp;
 	u32 fill;

 	fh = __fc_frame_header_get(fp);
 	in_fh = __fc_frame_header_get(in_fp);

 	if (f_ctl & FC_FC_END_SEQ) {
 		fill = -fr_len(fp) & 3;
 		if (fill) {
 			/* TODO, this may be a problem with fragmented skb */
 			skb_put_zero(fp_skb(fp), fill);
 			f_ctl |= fill;
 		}
 		fr_eof(fp) = FC_EOF_T;
 	} else {
 		WARN_ON(fr_len(fp) % 4 != 0);	/* no pad to non last frame */
 		fr_eof(fp) = FC_EOF_N;
 	}

 	fh->fh_r_ctl = r_ctl;
 	memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id));
 	memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id));
 	fh->fh_type = in_fh->fh_type;
 	hton24(fh->fh_f_ctl, f_ctl);
 	fh->fh_ox_id = in_fh->fh_ox_id;
 	fh->fh_rx_id = in_fh->fh_rx_id;
 	fh->fh_cs_ctl = 0;
 	fh->fh_df_ctl = 0;
 	fh->fh_parm_offset = htonl(parm_offset);

 	sp = fr_seq(in_fp);
 	if (sp) {
 		fr_seq(fp) = sp;
 		fh->fh_seq_id = sp->id;
 		seq_cnt = sp->cnt;
 	} else {
 		fh->fh_seq_id = 0;
 	}
 	fh->fh_seq_cnt = ntohs(seq_cnt);
 	fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3;
 	fr_encaps(fp) = fr_encaps(in_fp);
 }
 EXPORT_SYMBOL(fc_fill_hdr);

 /**
  * fc_fill_reply_hdr() -  fill FC reply header fields based on request
  * @fp: reply frame containing header to be filled in
  * @in_fp: request frame containing header to use in filling in reply
  * @r_ctl: R_CTL value for reply
  * @parm_offset: parameter / offset value
  */
 void fc_fill_reply_hdr(struct fc_frame *fp, const struct fc_frame *in_fp,
 		       enum fc_rctl r_ctl, u32 parm_offset)
 {
 	struct fc_seq *sp;

 	sp = fr_seq(in_fp);
 	if (sp)
 		fr_seq(fp) = fc_seq_start_next(sp);
 	fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
 }
 EXPORT_SYMBOL(fc_fill_reply_hdr);

 /**
  * fc_fc4_conf_lport_params() - Modify "service_params" of specified lport
  * if there is service provider (target provider) registered with libfc
  * for specified "fc_ft_type"
  * @lport: Local port which service_params needs to be modified
  * @type: FC-4 type, such as FC_TYPE_FCP
  */
 void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type)
 {
 	struct fc4_prov *prov_entry;
 	BUG_ON(type >= FC_FC4_PROV_SIZE);
 	BUG_ON(!lport);
 	prov_entry = fc_passive_prov[type];
 	if (type == FC_TYPE_FCP) {
 		if (prov_entry && prov_entry->recv)
 			lport->service_params |= FCP_SPPF_TARG_FCN;
 	}
 }

 void fc_lport_iterate(void (*notify)(struct fc_lport *, void *), void *arg)
 {
 	struct fc_lport *lport;

 	mutex_lock(&fc_prov_mutex);
 	list_for_each_entry(lport, &fc_local_ports, lport_list)
 		notify(lport, arg);
 	mutex_unlock(&fc_prov_mutex);
 }
 EXPORT_SYMBOL(fc_lport_iterate);

 /**
  * fc_fc4_register_provider() - register FC-4 upper-level provider.
  * @type: FC-4 type, such as FC_TYPE_FCP
  * @prov: structure describing provider including ops vector.
  *
  * Returns 0 on success, negative error otherwise.
  */
 int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
 {
 	struct fc4_prov **prov_entry;
 	int ret = 0;

 	if (type >= FC_FC4_PROV_SIZE)
 		return -EINVAL;
 	mutex_lock(&fc_prov_mutex);
 	prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
 	if (*prov_entry)
 		ret = -EBUSY;
 	else
 		*prov_entry = prov;
 	mutex_unlock(&fc_prov_mutex);
 	return ret;
 }
 EXPORT_SYMBOL(fc_fc4_register_provider);

 /**
  * fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
  * @type: FC-4 type, such as FC_TYPE_FCP
  * @prov: structure describing provider including ops vector.
  */
 void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
 {
 	BUG_ON(type >= FC_FC4_PROV_SIZE);
 	mutex_lock(&fc_prov_mutex);
 	if (prov->recv)
 		RCU_INIT_POINTER(fc_passive_prov[type], NULL);
 	else
 		RCU_INIT_POINTER(fc_active_prov[type], NULL);
 	mutex_unlock(&fc_prov_mutex);
 	synchronize_rcu();
 }
 EXPORT_SYMBOL(fc_fc4_deregister_provider);

 /**
  * fc_fc4_add_lport() - add new local port to list and run notifiers.
  * @lport:  The new local port.
  */
 void fc_fc4_add_lport(struct fc_lport *lport)
 {
 	mutex_lock(&fc_prov_mutex);
 	list_add_tail(&lport->lport_list, &fc_local_ports);
 	blocking_notifier_call_chain(&fc_lport_notifier_head,
 				     FC_LPORT_EV_ADD, lport);
 	mutex_unlock(&fc_prov_mutex);
 }

 /**
  * fc_fc4_del_lport() - remove local port from list and run notifiers.
  * @lport:  The new local port.
  */
 void fc_fc4_del_lport(struct fc_lport *lport)
 {
 	mutex_lock(&fc_prov_mutex);
 	list_del(&lport->lport_list);
 	blocking_notifier_call_chain(&fc_lport_notifier_head,
 				     FC_LPORT_EV_DEL, lport);
 	mutex_unlock(&fc_prov_mutex);
 }
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright(c) 2009 Intel Corporation. All rights reserved.
	*
	* Maintained at www.Open-FCoE.org
	*/

	#include <linux/kernel.h>
	#include <linux/types.h>
	#include <linux/scatterlist.h>
	#include <linux/crc32.h>
	#include <linux/module.h>

	#include <scsi/libfc.h>
	#include <scsi/fc_encode.h>

	#include "fc_libfc.h"

	MODULE_AUTHOR("Open-FCoE.org");
	MODULE_DESCRIPTION("libfc");
	MODULE_LICENSE("GPL v2");

	unsigned int fc_debug_logging;
	module_param_named(debug_logging, fc_debug_logging, int, S_IRUGO\|S_IWUSR);
	MODULE_PARM_DESC(debug_logging, "a bit mask of logging levels");

	DEFINE_MUTEX(fc_prov_mutex);
	static LIST_HEAD(fc_local_ports);
	struct blocking_notifier_head fc_lport_notifier_head =
	BLOCKING_NOTIFIER_INIT(fc_lport_notifier_head);
	EXPORT_SYMBOL(fc_lport_notifier_head);

	/*
	* Providers which primarily send requests and PRLIs.
	*/
	struct fc4_prov *fc_active_prov[FC_FC4_PROV_SIZE] = {
	[0] = &fc_rport_t0_prov,
	[FC_TYPE_FCP] = &fc_rport_fcp_init,
	};

	/*
	* Providers which receive requests.
	*/
	struct fc4_prov *fc_passive_prov[FC_FC4_PROV_SIZE] = {
	[FC_TYPE_ELS] = &fc_lport_els_prov,
	};

	/**
	* libfc_init() - Initialize libfc.ko
	*/
	static int __init libfc_init(void)
	{
	int rc = 0;

	rc = fc_setup_fcp();
	if (rc)
	return rc;

	rc = fc_setup_exch_mgr();
	if (rc)
	goto destroy_pkt_cache;

	rc = fc_setup_rport();
	if (rc)
	goto destroy_em;

	return rc;
	destroy_em:
	fc_destroy_exch_mgr();
	destroy_pkt_cache:
	fc_destroy_fcp();
	return rc;
	}
	module_init(libfc_init);

	/**
	* libfc_exit() - Tear down libfc.ko
	*/
	static void __exit libfc_exit(void)
	{
	fc_destroy_fcp();
	fc_destroy_exch_mgr();
	fc_destroy_rport();
	}
	module_exit(libfc_exit);

	/**
	* fc_copy_buffer_to_sglist() - This routine copies the data of a buffer
	* into a scatter-gather list (SG list).
	*
	* @buf: pointer to the data buffer.
	* @len: the byte-length of the data buffer.
	* @sg: pointer to the pointer of the SG list.
	* @nents: pointer to the remaining number of entries in the SG list.
	* @offset: pointer to the current offset in the SG list.
	* @crc: pointer to the 32-bit crc value.
	* If crc is NULL, CRC is not calculated.
	*/
	u32 fc_copy_buffer_to_sglist(void *buf, size_t len,
	struct scatterlist *sg,
	u32 nents, size_t offset,
	u32 *crc)
	{
	size_t remaining = len;
	u32 copy_len = 0;

	while (remaining > 0 && sg) {
	size_t off, sg_bytes;
	void *page_addr;

	if (*offset >= sg->length) {
	/*
	* Check for end and drop resources
	* from the last iteration.
	*/
	if (!(*nents))
	break;
	--(*nents);
	*offset -= sg->length;
	sg = sg_next(sg);
	continue;
	}
	sg_bytes = min(remaining, sg->length - *offset);

	/*
	* The scatterlist item may be bigger than PAGE_SIZE,
	* but we are limited to mapping PAGE_SIZE at a time.
	*/
	off = *offset + sg->offset;
	sg_bytes = min(sg_bytes,
	(size_t)(PAGE_SIZE - (off & ~PAGE_MASK)));
	page_addr = kmap_atomic(sg_page(sg) + (off >> PAGE_SHIFT));
	if (crc)
	crc = crc32(crc, buf, sg_bytes);
	memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
	kunmap_atomic(page_addr);
	buf += sg_bytes;
	*offset += sg_bytes;
	remaining -= sg_bytes;
	copy_len += sg_bytes;
	}
	return copy_len;
	}

	/**
	* fc_fill_hdr() - fill FC header fields based on request
	* @fp: reply frame containing header to be filled in
	* @in_fp: request frame containing header to use in filling in reply
	* @r_ctl: R_CTL value for header
	* @f_ctl: F_CTL value for header, with 0 pad
	* @seq_cnt: sequence count for the header, ignored if frame has a sequence
	* @parm_offset: parameter / offset value
	*/
	void fc_fill_hdr(struct fc_frame fp, const struct fc_frame in_fp,
	enum fc_rctl r_ctl, u32 f_ctl, u16 seq_cnt, u32 parm_offset)
	{
	struct fc_frame_header *fh;
	struct fc_frame_header *in_fh;
	struct fc_seq *sp;
	u32 fill;

	fh = __fc_frame_header_get(fp);
	in_fh = __fc_frame_header_get(in_fp);

	if (f_ctl & FC_FC_END_SEQ) {
	fill = -fr_len(fp) & 3;
	if (fill) {
	/* TODO, this may be a problem with fragmented skb */
	skb_put_zero(fp_skb(fp), fill);
	f_ctl \|= fill;
	}
	fr_eof(fp) = FC_EOF_T;
	} else {
	WARN_ON(fr_len(fp) % 4 != 0); /* no pad to non last frame */
	fr_eof(fp) = FC_EOF_N;
	}

	fh->fh_r_ctl = r_ctl;
	memcpy(fh->fh_d_id, in_fh->fh_s_id, sizeof(fh->fh_d_id));
	memcpy(fh->fh_s_id, in_fh->fh_d_id, sizeof(fh->fh_s_id));
	fh->fh_type = in_fh->fh_type;
	hton24(fh->fh_f_ctl, f_ctl);
	fh->fh_ox_id = in_fh->fh_ox_id;
	fh->fh_rx_id = in_fh->fh_rx_id;
	fh->fh_cs_ctl = 0;
	fh->fh_df_ctl = 0;
	fh->fh_parm_offset = htonl(parm_offset);

	sp = fr_seq(in_fp);
	if (sp) {
	fr_seq(fp) = sp;
	fh->fh_seq_id = sp->id;
	seq_cnt = sp->cnt;
	} else {
	fh->fh_seq_id = 0;
	}
	fh->fh_seq_cnt = ntohs(seq_cnt);
	fr_sof(fp) = seq_cnt ? FC_SOF_N3 : FC_SOF_I3;
	fr_encaps(fp) = fr_encaps(in_fp);
	}
	EXPORT_SYMBOL(fc_fill_hdr);

	/**
	* fc_fill_reply_hdr() - fill FC reply header fields based on request
	* @fp: reply frame containing header to be filled in
	* @in_fp: request frame containing header to use in filling in reply
	* @r_ctl: R_CTL value for reply
	* @parm_offset: parameter / offset value
	*/
	void fc_fill_reply_hdr(struct fc_frame fp, const struct fc_frame in_fp,
	enum fc_rctl r_ctl, u32 parm_offset)
	{
	struct fc_seq *sp;

	sp = fr_seq(in_fp);
	if (sp)
	fr_seq(fp) = fc_seq_start_next(sp);
	fc_fill_hdr(fp, in_fp, r_ctl, FC_FCTL_RESP, 0, parm_offset);
	}
	EXPORT_SYMBOL(fc_fill_reply_hdr);

	/**
	* fc_fc4_conf_lport_params() - Modify "service_params" of specified lport
	* if there is service provider (target provider) registered with libfc
	* for specified "fc_ft_type"
	* @lport: Local port which service_params needs to be modified
	* @type: FC-4 type, such as FC_TYPE_FCP
	*/
	void fc_fc4_conf_lport_params(struct fc_lport *lport, enum fc_fh_type type)
	{
	struct fc4_prov *prov_entry;
	BUG_ON(type >= FC_FC4_PROV_SIZE);
	BUG_ON(!lport);
	prov_entry = fc_passive_prov[type];
	if (type == FC_TYPE_FCP) {
	if (prov_entry && prov_entry->recv)
	lport->service_params \|= FCP_SPPF_TARG_FCN;
	}
	}

	void fc_lport_iterate(void (notify)(struct fc_lport , void ), void arg)
	{
	struct fc_lport *lport;

	mutex_lock(&fc_prov_mutex);
	list_for_each_entry(lport, &fc_local_ports, lport_list)
	notify(lport, arg);
	mutex_unlock(&fc_prov_mutex);
	}
	EXPORT_SYMBOL(fc_lport_iterate);

	/**
	* fc_fc4_register_provider() - register FC-4 upper-level provider.
	* @type: FC-4 type, such as FC_TYPE_FCP
	* @prov: structure describing provider including ops vector.
	*
	* Returns 0 on success, negative error otherwise.
	*/
	int fc_fc4_register_provider(enum fc_fh_type type, struct fc4_prov *prov)
	{
	struct fc4_prov **prov_entry;
	int ret = 0;

	if (type >= FC_FC4_PROV_SIZE)
	return -EINVAL;
	mutex_lock(&fc_prov_mutex);
	prov_entry = (prov->recv ? fc_passive_prov : fc_active_prov) + type;
	if (*prov_entry)
	ret = -EBUSY;
	else
	*prov_entry = prov;
	mutex_unlock(&fc_prov_mutex);
	return ret;
	}
	EXPORT_SYMBOL(fc_fc4_register_provider);

	/**
	* fc_fc4_deregister_provider() - deregister FC-4 upper-level provider.
	* @type: FC-4 type, such as FC_TYPE_FCP
	* @prov: structure describing provider including ops vector.
	*/
	void fc_fc4_deregister_provider(enum fc_fh_type type, struct fc4_prov *prov)
	{
	BUG_ON(type >= FC_FC4_PROV_SIZE);
	mutex_lock(&fc_prov_mutex);
	if (prov->recv)
	RCU_INIT_POINTER(fc_passive_prov[type], NULL);
	else
	RCU_INIT_POINTER(fc_active_prov[type], NULL);
	mutex_unlock(&fc_prov_mutex);
	synchronize_rcu();
	}
	EXPORT_SYMBOL(fc_fc4_deregister_provider);

	/**
	* fc_fc4_add_lport() - add new local port to list and run notifiers.
	* @lport: The new local port.
	*/
	void fc_fc4_add_lport(struct fc_lport *lport)
	{
	mutex_lock(&fc_prov_mutex);
	list_add_tail(&lport->lport_list, &fc_local_ports);
	blocking_notifier_call_chain(&fc_lport_notifier_head,
	FC_LPORT_EV_ADD, lport);
	mutex_unlock(&fc_prov_mutex);
	}

	/**
	* fc_fc4_del_lport() - remove local port from list and run notifiers.
	* @lport: The new local port.
	*/
	void fc_fc4_del_lport(struct fc_lport *lport)
	{
	mutex_lock(&fc_prov_mutex);
	list_del(&lport->lport_list);
	blocking_notifier_call_chain(&fc_lport_notifier_head,
	FC_LPORT_EV_DEL, lport);
	mutex_unlock(&fc_prov_mutex);
	}