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authorLinus Torvalds <torvalds@linux-foundation.org>2015-06-27 00:51:15 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2015-06-27 00:51:15 +0300
commitd87823813fe498fdd47894bd28e460a9dee8d771 (patch)
tree214eaf3babd0d61f08022fc1edd99a5128616548 /drivers/misc/mic/scif/scif_rb.h
parente382608254e06c8109f40044f5e693f2e04f3899 (diff)
parent3dc196eae1db548f05e53e5875ff87b8ff79f249 (diff)
downloadlinux-d87823813fe498fdd47894bd28e460a9dee8d771.tar.xz
Merge tag 'char-misc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc
Pull char/misc driver updates from Greg KH: "Here's the big char/misc driver pull request for 4.2-rc1. Lots of mei, extcon, coresight, uio, mic, and other driver updates in here. Full details in the shortlog. All of these have been in linux-next for some time with no reported problems" * tag 'char-misc-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc: (176 commits) mei: me: wait for power gating exit confirmation mei: reset flow control on the last client disconnection MAINTAINERS: mei: add mei_cl_bus.h to maintained file list misc: sram: sort and clean up included headers misc: sram: move reserved block logic out of probe function misc: sram: add private struct device and virt_base members misc: sram: report correct SRAM pool size misc: sram: bump error message level on unclean driver unbinding misc: sram: fix device node reference leak on error misc: sram: fix enabled clock leak on error path misc: mic: Fix reported static checker warning misc: mic: Fix randconfig build error by including errno.h uio: pruss: Drop depends on ARCH_DAVINCI_DA850 from config uio: pruss: Add CONFIG_HAS_IOMEM dependence uio: pruss: Include <linux/sizes.h> extcon: Redefine the unique id of supported external connectors without 'enum extcon' type char:xilinx_hwicap:buffer_icap - change 1/0 to true/false for bool type variable in function buffer_icap_set_configuration(). Drivers: hv: vmbus: Allocate ring buffer memory in NUMA aware fashion parport: check exclusive access before register w1: use correct lock on error in w1_seq_show() ...
Diffstat (limited to 'drivers/misc/mic/scif/scif_rb.h')
-rw-r--r--drivers/misc/mic/scif/scif_rb.h100
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diff --git a/drivers/misc/mic/scif/scif_rb.h b/drivers/misc/mic/scif/scif_rb.h
new file mode 100644
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+++ b/drivers/misc/mic/scif/scif_rb.h
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+/*
+ * Intel MIC Platform Software Stack (MPSS)
+ *
+ * This file is provided under a dual BSD/GPLv2 license. When using or
+ * redistributing this file, you may do so under either license.
+ *
+ * GPL LICENSE SUMMARY
+ *
+ * Copyright(c) 2014 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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.
+ *
+ * BSD LICENSE
+ *
+ * Copyright(c) 2014 Intel Corporation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * * Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in
+ * the documentation and/or other materials provided with the
+ * distribution.
+ * * Neither the name of Intel Corporation nor the names of its
+ * contributors may be used to endorse or promote products derived
+ * from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Intel SCIF driver.
+ */
+#ifndef SCIF_RB_H
+#define SCIF_RB_H
+/*
+ * This file describes a general purpose, byte based ring buffer. Writers to the
+ * ring buffer need to synchronize using a lock. The same is true for readers,
+ * although in practice, the ring buffer has a single reader. It is lockless
+ * between producer and consumer so it can handle being used across the PCIe
+ * bus. The ring buffer ensures that there are no reads across the PCIe bus for
+ * performance reasons. Two of these are used to form a single bidirectional
+ * queue-pair across PCIe.
+ */
+/*
+ * struct scif_rb - SCIF Ring Buffer
+ *
+ * @rb_base: The base of the memory used for storing RB messages
+ * @read_ptr: Pointer to the read offset
+ * @write_ptr: Pointer to the write offset
+ * @size: Size of the memory in rb_base
+ * @current_read_offset: Cached read offset for performance
+ * @current_write_offset: Cached write offset for performance
+ */
+struct scif_rb {
+ void *rb_base;
+ u32 *read_ptr;
+ u32 *write_ptr;
+ u32 size;
+ u32 current_read_offset;
+ u32 current_write_offset;
+};
+
+/* methods used by both */
+void scif_rb_init(struct scif_rb *rb, u32 *read_ptr, u32 *write_ptr,
+ void *rb_base, u8 size);
+/* writer only methods */
+/* write a new command, then scif_rb_commit() */
+int scif_rb_write(struct scif_rb *rb, void *msg, u32 size);
+/* after write(), then scif_rb_commit() */
+void scif_rb_commit(struct scif_rb *rb);
+/* query space available for writing to a RB. */
+u32 scif_rb_space(struct scif_rb *rb);
+
+/* reader only methods */
+/* read a new message from the ring buffer of size bytes */
+u32 scif_rb_get_next(struct scif_rb *rb, void *msg, u32 size);
+/* update the read pointer so that the space can be reused */
+void scif_rb_update_read_ptr(struct scif_rb *rb);
+/* count the number of bytes that can be read */
+u32 scif_rb_count(struct scif_rb *rb, u32 size);
+#endif