brcmfmac: Adding msgbuf protocol.

This patch will add the msgbuf protocol. This protocol is used by
the soon to be added new bus interface PCIe. Msgbuf is a protocol
where most data is and remains located on the host (driver) side
and transferred by DMA from and to device. Msgbuf is the protocol
which takes care of the signalling of the buffers between host and
device which identifies this DMA-able data.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 273 insertions, 0 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/commonring.c b/drivers/net/wireless/brcm80211/brcmfmac/commonring.c
new file mode 100644
index 000000000000..c6d65b8e1e15
--- /dev/null
+++ b/drivers/net/wireless/brcm80211/brcmfmac/commonring.c
@@ -0,0 +1,273 @@
+/* Copyright (c) 2014 Broadcom Corporation
+ *
+ * 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.
+ */
+
+#include <linux/types.h>
+#include <linux/netdevice.h>
+
+#include <brcmu_utils.h>
+#include <brcmu_wifi.h>
+
+#include "dhd.h"
+#include "commonring.h"
+
+
+/* dma flushing needs implementation for mips and arm platforms. Should
+ * be put in util. Note, this is not real flushing. It is virtual non
+ * cached memory. Only write buffers should have to be drained. Though
+ * this may be different depending on platform......
+ * SEE ALSO msgbuf.c
+ */
+#define brcmf_dma_flush(addr, len)
+#define brcmf_dma_invalidate_cache(addr, len)
+
+
+void brcmf_commonring_register_cb(struct brcmf_commonring *commonring,
+				  int (*cr_ring_bell)(void *ctx),
+				  int (*cr_update_rptr)(void *ctx),
+				  int (*cr_update_wptr)(void *ctx),
+				  int (*cr_write_rptr)(void *ctx),
+				  int (*cr_write_wptr)(void *ctx), void *ctx)
+{
+	commonring->cr_ring_bell = cr_ring_bell;
+	commonring->cr_update_rptr = cr_update_rptr;
+	commonring->cr_update_wptr = cr_update_wptr;
+	commonring->cr_write_rptr = cr_write_rptr;
+	commonring->cr_write_wptr = cr_write_wptr;
+	commonring->cr_ctx = ctx;
+}
+
+
+void brcmf_commonring_config(struct brcmf_commonring *commonring, u16 depth,
+			     u16 item_len, void *buf_addr)
+{
+	commonring->depth = depth;
+	commonring->item_len = item_len;
+	commonring->buf_addr = buf_addr;
+	if (!commonring->inited) {
+		spin_lock_init(&commonring->lock);
+		commonring->inited = true;
+	}
+	commonring->r_ptr = 0;
+	if (commonring->cr_write_rptr)
+		commonring->cr_write_rptr(commonring->cr_ctx);
+	commonring->w_ptr = 0;
+	if (commonring->cr_write_wptr)
+		commonring->cr_write_wptr(commonring->cr_ctx);
+	commonring->f_ptr = 0;
+}
+
+
+void brcmf_commonring_lock(struct brcmf_commonring *commonring)
+		__acquires(&commonring->lock)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&commonring->lock, flags);
+	commonring->flags = flags;
+}
+
+
+void brcmf_commonring_unlock(struct brcmf_commonring *commonring)
+		__releases(&commonring->lock)
+{
+	spin_unlock_irqrestore(&commonring->lock, commonring->flags);
+}
+
+
+bool brcmf_commonring_write_available(struct brcmf_commonring *commonring)
+{
+	u16 available;
+	bool retry = true;
+
+again:
+	if (commonring->r_ptr <= commonring->w_ptr)
+		available = commonring->depth - commonring->w_ptr +
+			    commonring->r_ptr;
+	else
+		available = commonring->r_ptr - commonring->w_ptr;
+
+	if (available > 1) {
+		if (!commonring->was_full)
+			return true;
+		if (available > commonring->depth / 8) {
+			commonring->was_full = false;
+			return true;
+		}
+		if (retry) {
+			if (commonring->cr_update_rptr)
+				commonring->cr_update_rptr(commonring->cr_ctx);
+			retry = false;
+			goto again;
+		}
+		return false;
+	}
+
+	if (retry) {
+		if (commonring->cr_update_rptr)
+			commonring->cr_update_rptr(commonring->cr_ctx);
+		retry = false;
+		goto again;
+	}
+
+	commonring->was_full = true;
+	return false;
+}
+
+
+void *brcmf_commonring_reserve_for_write(struct brcmf_commonring *commonring)
+{
+	void *ret_ptr;
+	u16 available;
+	bool retry = true;
+
+again:
+	if (commonring->r_ptr <= commonring->w_ptr)
+		available = commonring->depth - commonring->w_ptr +
+			    commonring->r_ptr;
+	else
+		available = commonring->r_ptr - commonring->w_ptr;
+
+	if (available > 1) {
+		ret_ptr = commonring->buf_addr +
+			  (commonring->w_ptr * commonring->item_len);
+		commonring->w_ptr++;
+		if (commonring->w_ptr == commonring->depth)
+			commonring->w_ptr = 0;
+		return ret_ptr;
+	}
+
+	if (retry) {
+		if (commonring->cr_update_rptr)
+			commonring->cr_update_rptr(commonring->cr_ctx);
+		retry = false;
+		goto again;
+	}
+
+	commonring->was_full = true;
+	return NULL;
+}
+
+
+void *
+brcmf_commonring_reserve_for_write_multiple(struct brcmf_commonring *commonring,
+					    u16 n_items, u16 *alloced)
+{
+	void *ret_ptr;
+	u16 available;
+	bool retry = true;
+
+again:
+	if (commonring->r_ptr <= commonring->w_ptr)
+		available = commonring->depth - commonring->w_ptr +
+			    commonring->r_ptr;
+	else
+		available = commonring->r_ptr - commonring->w_ptr;
+
+	if (available > 1) {
+		ret_ptr = commonring->buf_addr +
+			  (commonring->w_ptr * commonring->item_len);
+		*alloced = min_t(u16, n_items, available - 1);
+		if (*alloced + commonring->w_ptr > commonring->depth)
+			*alloced = commonring->depth - commonring->w_ptr;
+		commonring->w_ptr += *alloced;
+		if (commonring->w_ptr == commonring->depth)
+			commonring->w_ptr = 0;
+		return ret_ptr;
+	}
+
+	if (retry) {
+		if (commonring->cr_update_rptr)
+			commonring->cr_update_rptr(commonring->cr_ctx);
+		retry = false;
+		goto again;
+	}
+
+	commonring->was_full = true;
+	return NULL;
+}
+
+
+int brcmf_commonring_write_complete(struct brcmf_commonring *commonring)
+{
+	void *address;
+
+	address = commonring->buf_addr;
+	address += (commonring->f_ptr * commonring->item_len);
+	if (commonring->f_ptr > commonring->w_ptr) {
+		brcmf_dma_flush(address,
+				(commonring->depth - commonring->f_ptr) *
+				commonring->item_len);
+		address = commonring->buf_addr;
+		commonring->f_ptr = 0;
+	}
+	brcmf_dma_flush(address, (commonring->w_ptr - commonring->f_ptr) *
+			commonring->item_len);
+
+	commonring->f_ptr = commonring->w_ptr;
+
+	if (commonring->cr_write_wptr)
+		commonring->cr_write_wptr(commonring->cr_ctx);
+	if (commonring->cr_ring_bell)
+		return commonring->cr_ring_bell(commonring->cr_ctx);
+
+	return -EIO;
+}
+
+
+void brcmf_commonring_write_cancel(struct brcmf_commonring *commonring,
+				   u16 n_items)
+{
+	if (commonring->w_ptr == 0)
+		commonring->w_ptr = commonring->depth - n_items;
+	else
+		commonring->w_ptr -= n_items;
+}
+
+
+void *brcmf_commonring_get_read_ptr(struct brcmf_commonring *commonring,
+				    u16 *n_items)
+{
+	void *ret_addr;
+
+	if (commonring->cr_update_wptr)
+		commonring->cr_update_wptr(commonring->cr_ctx);
+
+	*n_items = (commonring->w_ptr >= commonring->r_ptr) ?
+				(commonring->w_ptr - commonring->r_ptr) :
+				(commonring->depth - commonring->r_ptr);
+
+	if (*n_items == 0)
+		return NULL;
+
+	ret_addr = commonring->buf_addr +
+		   (commonring->r_ptr * commonring->item_len);
+
+	commonring->r_ptr += *n_items;
+	if (commonring->r_ptr == commonring->depth)
+		commonring->r_ptr = 0;
+
+	brcmf_dma_invalidate_cache(ret_addr, *n_ items * commonring->item_len);
+
+	return ret_addr;
+}
+
+
+int brcmf_commonring_read_complete(struct brcmf_commonring *commonring)
+{
+	if (commonring->cr_write_rptr)
+		return commonring->cr_write_rptr(commonring->cr_ctx);
+
+	return -EIO;
+}