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path: root/drivers/scsi/libfc/fc_libfc.c
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Diffstat (limited to 'drivers/scsi/libfc/fc_libfc.c')
-rw-r--r--drivers/scsi/libfc/fc_libfc.c134
1 files changed, 134 insertions, 0 deletions
diff --git a/drivers/scsi/libfc/fc_libfc.c b/drivers/scsi/libfc/fc_libfc.c
new file mode 100644
index 000000000000..39f4b6ab04b4
--- /dev/null
+++ b/drivers/scsi/libfc/fc_libfc.c
@@ -0,0 +1,134 @@
+/*
+ * Copyright(c) 2009 Intel Corporation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Maintained at www.Open-FCoE.org
+ */
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/scatterlist.h>
+#include <linux/crc32.h>
+
+#include <scsi/libfc.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");
+
+/**
+ * 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.
+ * @km_type: dedicated page table slot type for kmap_atomic.
+ * @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,
+ enum km_type km_type, 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),
+ km_type);
+ if (crc)
+ *crc = crc32(*crc, buf, sg_bytes);
+ memcpy((char *)page_addr + (off & ~PAGE_MASK), buf, sg_bytes);
+ kunmap_atomic(page_addr, km_type);
+ buf += sg_bytes;
+ *offset += sg_bytes;
+ remaining -= sg_bytes;
+ copy_len += sg_bytes;
+ }
+ return copy_len;
+}