[PATCH v5 05/12] intel-ipu3: css: Add dma buff pool utility functions

From: Yong Zhi <yong.zhi@intel.com>
To: linux-media@vger.kernel.org, sakari.ailus@linux.intel.com
Cc: jian.xu.zheng@intel.com, tfiga@chromium.org,
	rajmohan.mani@intel.com, tuukka.toivonen@intel.com,
	hyungwoo.yang@intel.com, chiranjeevi.rapolu@intel.com,
	jerry.w.hu@intel.com, Yong Zhi <yong.zhi@intel.com>
Subject: [PATCH v5 05/12] intel-ipu3: css: Add dma buff pool utility functions
Date: Fri,  1 Dec 2017 22:32:15 -0600	[thread overview]
Message-ID: <1512189142-19863-6-git-send-email-yong.zhi@intel.com> (raw)
In-Reply-To: <1512189142-19863-1-git-send-email-yong.zhi@intel.com>

The pools are used to store previous parameters set by
user with the parameter queue. Due to pipelining,
there needs to be multiple sets (up to four)
of parameters which are queued in a host-to-sp queue.

Signed-off-by: Yong Zhi <yong.zhi@intel.com>
---
 drivers/media/pci/intel/ipu3/ipu3-css-pool.c | 137 +++++++++++++++++++++++++++
 drivers/media/pci/intel/ipu3/ipu3-css-pool.h |   2 +-
 2 files changed, 138 insertions(+), 1 deletion(-)
 create mode 100644 drivers/media/pci/intel/ipu3/ipu3-css-pool.c

diff --git a/drivers/media/pci/intel/ipu3/ipu3-css-pool.c b/drivers/media/pci/intel/ipu3/ipu3-css-pool.c
new file mode 100644
index 000000000000..2f9cdda803de
--- /dev/null
+++ b/drivers/media/pci/intel/ipu3/ipu3-css-pool.c
@@ -0,0 +1,137 @@
+/*
+ * Copyright (c) 2017 Intel Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version
+ * 2 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.
+ */
+
+#include <linux/device.h>
+
+#include "ipu3-css-pool.h"
+#include "ipu3-dmamap.h"
+
+int ipu3_css_dma_buffer_resize(struct device *dev, struct ipu3_css_map *map,
+			       size_t size)
+{
+	if (map->size < size && map->vaddr) {
+		dev_warn(dev, "dma buffer is resized from %zu to %zu",
+			 map->size, size);
+
+		ipu3_dmamap_free(dev, map);
+		if (!ipu3_dmamap_alloc(dev, map, size))
+			return -ENOMEM;
+	}
+
+	return 0;
+}
+
+void ipu3_css_pool_cleanup(struct device *dev, struct ipu3_css_pool *pool)
+{
+	unsigned int i;
+
+	for (i = 0; i < IPU3_CSS_POOL_SIZE; i++)
+		ipu3_dmamap_free(dev, &pool->entry[i].param);
+}
+
+int ipu3_css_pool_init(struct device *dev, struct ipu3_css_pool *pool,
+		       size_t size)
+{
+	unsigned int i;
+
+	for (i = 0; i < IPU3_CSS_POOL_SIZE; i++) {
+		/*
+		 * entry[i].framenum is initialized to INT_MIN so that
+		 * ipu3_css_pool_check() can treat it as usesable slot.
+		 */
+		pool->entry[i].framenum = INT_MIN;
+
+		if (size == 0) {
+			pool->entry[i].param.vaddr = NULL;
+			continue;
+		}
+
+		if (!ipu3_dmamap_alloc(dev, &pool->entry[i].param, size))
+			goto fail;
+	}
+
+	pool->last = IPU3_CSS_POOL_SIZE;
+
+	return 0;
+
+fail:
+	ipu3_css_pool_cleanup(dev, pool);
+	return -ENOMEM;
+}
+
+/*
+ * Check that the following call to pool_get succeeds.
+ * Return negative on error.
+ */
+static int ipu3_css_pool_check(struct ipu3_css_pool *pool, long framenum)
+{
+	/* Get the oldest entry */
+	int n = (pool->last + 1) % IPU3_CSS_POOL_SIZE;
+	long diff = framenum - pool->entry[n].framenum;
+
+	/* if framenum wraps around and becomes smaller than entry n */
+	if (diff < 0)
+		diff += LONG_MAX;
+
+	/*
+	 * pool->entry[n].framenum stores the frame number where that
+	 * entry was allocated. If that was allocated more than POOL_SIZE
+	 * frames back, it is old enough that we know it is no more in
+	 * use by firmware.
+	 */
+	if (diff > IPU3_CSS_POOL_SIZE)
+		return n;
+
+	return -ENOSPC;
+}
+
+/*
+ * Allocate a new parameter from pool at frame number `framenum'.
+ * Release the oldest entry in the pool to make space for the new entry.
+ * Return negative on error.
+ */
+int ipu3_css_pool_get(struct ipu3_css_pool *pool, long framenum)
+{
+	int n = ipu3_css_pool_check(pool, framenum);
+
+	if (n < 0)
+		return n;
+
+	pool->entry[n].framenum = framenum;
+	pool->last = n;
+
+	return n;
+}
+
+/*
+ * Undo, for all practical purposes, the effect of pool_get().
+ */
+void ipu3_css_pool_put(struct ipu3_css_pool *pool)
+{
+	pool->entry[pool->last].framenum = INT_MIN;
+	pool->last = (pool->last + IPU3_CSS_POOL_SIZE - 1) % IPU3_CSS_POOL_SIZE;
+}
+
+const struct ipu3_css_map *
+ipu3_css_pool_last(struct ipu3_css_pool *pool, unsigned int n)
+{
+	static const struct ipu3_css_map null_map = { 0 };
+	int i = (pool->last + IPU3_CSS_POOL_SIZE - n) % IPU3_CSS_POOL_SIZE;
+
+	WARN_ON(n >= IPU3_CSS_POOL_SIZE);
+
+	if (pool->entry[i].framenum < 0)
+		return &null_map;
+
+	return &pool->entry[i].param;
+}
diff --git a/drivers/media/pci/intel/ipu3/ipu3-css-pool.h b/drivers/media/pci/intel/ipu3/ipu3-css-pool.h
index b60bcf2ad432..a94760a6de82 100644
--- a/drivers/media/pci/intel/ipu3/ipu3-css-pool.h
+++ b/drivers/media/pci/intel/ipu3/ipu3-css-pool.h
@@ -44,7 +44,7 @@ int ipu3_css_dma_buffer_resize(struct device *dev, struct ipu3_css_map *map,
 			       size_t size);
 void ipu3_css_pool_cleanup(struct device *dev, struct ipu3_css_pool *pool);
 int ipu3_css_pool_init(struct device *dev, struct ipu3_css_pool *pool,
-		       int size);
+		       size_t size);
 int ipu3_css_pool_get(struct ipu3_css_pool *pool, long framenum);
 void ipu3_css_pool_put(struct ipu3_css_pool *pool);
 const struct ipu3_css_map *ipu3_css_pool_last(struct ipu3_css_pool *pool,
-- 
2.7.4
