qcacmn: Add support for WBUFF module

Introduce a new module WBUFF, which maintains a
pre-allocated pool of skbs for each registered
module and allocates skbs when requeted from
these pre-allocated pools.

The module exposes the following APIs:
 1) wbuff_module_init
 2) wbuff_module_deinit
 3) wbuff_module_register
 4) wbuff_module_deregister
 5) wbuff_buff_get
 6) wbuff_buff_put

Change-Id: Icab723ce29a9a364c822756dee78a0dae1006180
CRs-Fixed: 2313443

wbuff/inc/wbuff.h

@@ -0,0 +1,151 @@
+/*
+ * Copyright (c) 2018 The Linux Foundation. All rights reserved.
+ *
+ * Permission to use, copy, modify, and/or distribute this software for
+ * any purpose with or without fee is hereby granted, provided that the
+ * above copyright notice and this permission notice appear in all
+ * copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL
+ * WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE
+ * AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL
+ * DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR
+ * PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
+ * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+ * PERFORMANCE OF THIS SOFTWARE.
+ */
+
+/**
+ * DOC: wbuff.h
+ * wbuff buffer management APIs
+ */
+
+#ifndef _WBUFF_H
+#define _WBUFF_H
+
+#include <qdf_status.h>
+#include <qdf_nbuf.h>
+
+/* wbuff available pools */
+/* Pool of nbuf size 256 bytes */
+#define WBUFF_POOL_0 0
+/* Pool of nbuf size 512 bytes */
+#define WBUFF_POOL_1 1
+/* Pool of nbuf size 1024 bytes */
+#define WBUFF_POOL_2 2
+/* Pool of nbuf 2048 bytes */
+#define WBUFF_POOL_3 3
+
+/**
+ * struct wbuff_alloc_request - allocation structure for registering each
+ * pool for wbuff module.
+ * @slot: pool_slot identifier
+ * @size: number of buffers for @pool_slot
+ */
+struct wbuff_alloc_request {
+	uint8_t slot;
+	uint16_t size;
+};
+
+/* Opaque handle for wbuff */
+struct wbuff_mod_handle;
+
+#ifdef WLAN_FEATURE_WBUFF
+/**
+ * wbuff_module_init() - Initializes the wbuff module
+ *
+ * Return: QDF_STATUS_SUCCESS - init success
+ *         QDF_STATUS_E_NOSUPPORT - init failure
+ */
+QDF_STATUS wbuff_module_init(void);
+
+/**
+ * wbuff_module_deinit() - De-initializes the wbuff module
+ *
+ * Return: QDF_STATUS_SUCCESS - de-init success
+ *         QDF_STATUS_E_INVAL - de-init failure (wbuff not initialized)
+ */
+QDF_STATUS wbuff_module_deinit(void);
+
+/**
+ * wbuff_module_register() - Registers a module with wbuff
+ * @req: allocation request from registered module
+ * @num: number of pools required
+ * @reserve: nbuf headroom to start with
+ * @align: alignment for the nbuf
+ *
+ * Return: Handle if registration success
+ *         NULL if registration failure
+ */
+struct wbuff_mod_handle *
+wbuff_module_register(struct wbuff_alloc_request *req, uint8_t num,
+		      int reserve, int align);
+
+/**
+ * wbuff_module_deregister() - De-registers a module with wbuff
+ * @hdl: wbuff_handle corresponding to the module
+ *
+ * Return: QDF_STATUS_SUCCESS - deregistration success
+ *         QDF_STATUS_E_INVAL - deregistration failure
+ */
+QDF_STATUS wbuff_module_deregister(struct wbuff_mod_handle *hdl);
+
+/**
+ * wbuff_buff_get() - return buffer to the requester
+ * @handle: wbuff_handle corresponding to the module
+ * @len: length of buffer requested
+ *
+ * Return: Network buffer if success
+ *         NULL if failure
+ */
+qdf_nbuf_t wbuff_buff_get(struct wbuff_mod_handle *hdl, uint32_t len);
+
+/**
+ * wbuff_buff_put() - put the buffer back to wbuff pool
+ * @hdl: wbuff_handle corresponding to the module
+ * @buf: pointer to network buffer
+ *
+ * Return: NULL if success (buffer consumed)
+ *         @buf if failure (buffer not consumed)
+ */
+qdf_nbuf_t wbuff_buff_put(qdf_nbuf_t buf);
+
+#else
+
+static inline QDF_STATUS wbuff_module_init(void)
+{
+	return QDF_STATUS_E_NOSUPPORT;
+}
+
+static inline QDF_STATUS wbuff_module_deinit(void)
+{
+	return QDF_STATUS_E_NOSUPPORT;
+}
+
+static inline struct wbuff_mod_handle *
+wbuff_module_register(struct wbuff_alloc_request *req, uint8_t num,
+		      int reserve, int align)
+{
+	return NULL;
+}
+
+static inline QDF_STATUS wbuff_module_deregister(struct wbuff_mod_handle *hdl)
+{
+	return QDF_STATUS_E_NOSUPPORT;
+}
+
+static inline qdf_nbuf_t
+wbuff_buff_get(struct wbuff_mod_handle *hdl, uint32_t len)
+{
+	return NULL;
+}
+
+static inline qdf_nbuf_t
+wbuff_buff_put(qdf_nbuf_t buf)
+{
+	return buf;
+}
+
+#endif
+#endif /* _WBUFF_H */