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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /drivers/scsi/fnic/cq_desc.h
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'drivers/scsi/fnic/cq_desc.h')
-rw-r--r--drivers/scsi/fnic/cq_desc.h66
1 files changed, 66 insertions, 0 deletions
diff --git a/drivers/scsi/fnic/cq_desc.h b/drivers/scsi/fnic/cq_desc.h
new file mode 100644
index 000000000..0eb4ba277
--- /dev/null
+++ b/drivers/scsi/fnic/cq_desc.h
@@ -0,0 +1,66 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2008 Cisco Systems, Inc. All rights reserved.
+ * Copyright 2007 Nuova Systems, Inc. All rights reserved.
+ */
+#ifndef _CQ_DESC_H_
+#define _CQ_DESC_H_
+
+/*
+ * Completion queue descriptor types
+ */
+enum cq_desc_types {
+ CQ_DESC_TYPE_WQ_ENET = 0,
+ CQ_DESC_TYPE_DESC_COPY = 1,
+ CQ_DESC_TYPE_WQ_EXCH = 2,
+ CQ_DESC_TYPE_RQ_ENET = 3,
+ CQ_DESC_TYPE_RQ_FCP = 4,
+};
+
+/* Completion queue descriptor: 16B
+ *
+ * All completion queues have this basic layout. The
+ * type_specfic area is unique for each completion
+ * queue type.
+ */
+struct cq_desc {
+ __le16 completed_index;
+ __le16 q_number;
+ u8 type_specfic[11];
+ u8 type_color;
+};
+
+#define CQ_DESC_TYPE_BITS 4
+#define CQ_DESC_TYPE_MASK ((1 << CQ_DESC_TYPE_BITS) - 1)
+#define CQ_DESC_COLOR_MASK 1
+#define CQ_DESC_COLOR_SHIFT 7
+#define CQ_DESC_Q_NUM_BITS 10
+#define CQ_DESC_Q_NUM_MASK ((1 << CQ_DESC_Q_NUM_BITS) - 1)
+#define CQ_DESC_COMP_NDX_BITS 12
+#define CQ_DESC_COMP_NDX_MASK ((1 << CQ_DESC_COMP_NDX_BITS) - 1)
+
+static inline void cq_desc_dec(const struct cq_desc *desc_arg,
+ u8 *type, u8 *color, u16 *q_number, u16 *completed_index)
+{
+ const struct cq_desc *desc = desc_arg;
+ const u8 type_color = desc->type_color;
+
+ *color = (type_color >> CQ_DESC_COLOR_SHIFT) & CQ_DESC_COLOR_MASK;
+
+ /*
+ * Make sure color bit is read from desc *before* other fields
+ * are read from desc. Hardware guarantees color bit is last
+ * bit (byte) written. Adding the rmb() prevents the compiler
+ * and/or CPU from reordering the reads which would potentially
+ * result in reading stale values.
+ */
+
+ rmb();
+
+ *type = type_color & CQ_DESC_TYPE_MASK;
+ *q_number = le16_to_cpu(desc->q_number) & CQ_DESC_Q_NUM_MASK;
+ *completed_index = le16_to_cpu(desc->completed_index) &
+ CQ_DESC_COMP_NDX_MASK;
+}
+
+#endif /* _CQ_DESC_H_ */