[PATCH 0/4] caif-u5500: CAIF shared memory/mailbox driver

[PATCH 0/4] caif-u5500: CAIF shared memory/mailbox driver

[Sjur Braendeland]

This patch-set introduces the CAIF protocol driver for shared memory
over mailbox for u5500.

It implements the driver for transporting CAIF frames between the DB5500
modem portion and host side for the u5500 architecture.

These patches depends on the patch-set "U5500 mailbox driver and
modem irq handler" submitted on the linux-arm-kernel list,
commit e81fcc97350755e021c85b816877ae292b8f28d0.

They applies cleanly on latest net-next-2.6 and linux-next git,
and depends on the CONFIG_U5500_MBX for compilation.

Please note that the size and address of the shared memory are specified as
module parameters: shm_total_size, shm_start.

Regards,
Sjur Braendeland

Amarnath Revanna (4):
  caif-u5500: Adding shared memory include
  caif-u5500: CAIF shared memory transport protocol
  caif-u5500: CAIF shared memory mailbox interface
  caif-u5500: Build config for CAIF shared mem driver

 drivers/net/caif/Kconfig          |    7 +
 drivers/net/caif/Makefile         |    4 +
 drivers/net/caif/caif_shm_u5500.c |  129 ++++++
 drivers/net/caif/caif_shmcore.c   |  792 +++++++++++++++++++++++++++++++++++++
 include/net/caif/caif_shm.h       |   26 ++
 5 files changed, 958 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/caif/caif_shm_u5500.c
 create mode 100644 drivers/net/caif/caif_shmcore.c
 create mode 100644 include/net/caif/caif_shm.h

[PATCH 1/4] caif-u5500: Adding shared memory include

[Sjur Braendeland]

From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---
 include/net/caif/caif_shm.h |   26 ++++++++++++++++++++++++++
 1 files changed, 26 insertions(+), 0 deletions(-)
 create mode 100644 include/net/caif/caif_shm.h

diff --git a/include/net/caif/caif_shm.h b/include/net/caif/caif_shm.h
new file mode 100644
index 0000000..5bcce55
--- /dev/null
+++ b/include/net/caif/caif_shm.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
+ * Author: Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef CAIF_SHM_H_
+#define CAIF_SHM_H_
+
+struct shmdev_layer {
+	u32 shm_base_addr;
+	u32 shm_total_sz;
+	u32 shm_id;
+	u32 shm_loopback;
+	void *hmbx;
+	int (*pshmdev_mbxsend) (u32 shm_id, u32 mbx_msg);
+	int (*pshmdev_mbxsetup) (void *pshmdrv_cb,
+				struct shmdev_layer *pshm_dev, void *pshm_drv);
+	struct net_device *pshm_netdev;
+};
+
+extern int caif_shmcore_probe(struct shmdev_layer *pshm_dev);
+extern void caif_shmcore_remove(struct net_device *pshm_netdev);
+
+#endif
-- 
1.6.3.3

[PATCH 2/4] caif-u5500: CAIF shared memory transport protocol

[Sjur Braendeland]

From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---
 drivers/net/caif/caif_shmcore.c |  792 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 792 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/caif/caif_shmcore.c

diff --git a/drivers/net/caif/caif_shmcore.c b/drivers/net/caif/caif_shmcore.c
new file mode 100644
index 0000000..8bb2614
--- /dev/null
+++ b/drivers/net/caif/caif_shmcore.c
@@ -0,0 +1,792 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
+ * Authors:  Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com,
+ *           Daniel Martensson / daniel.martensson@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":" __func__ "():" fmt
+
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+
+#include <net/caif/caif_device.h>
+#include <net/caif/caif_shm.h>
+
+#define NR_TX_BUF		6
+#define NR_RX_BUF		6
+#define TX_BUF_SZ		0x2000
+#define RX_BUF_SZ		0x2000
+
+#define CAIF_NEEDED_HEADROOM	32
+
+#define CAIF_FLOW_ON		1
+#define CAIF_FLOW_OFF		0
+
+#define LOW_WATERMARK		3
+#define HIGH_WATERMARK		4
+
+/* Maximum number of CAIF buffers per shared memory buffer. */
+#define SHM_MAX_FRMS_PER_BUF	10
+
+/*
+ * Size in bytes of the descriptor area
+ * (With end of descriptor signalling)
+ */
+#define SHM_CAIF_DESC_SIZE	((SHM_MAX_FRMS_PER_BUF + 1) * \
+					sizeof(struct shm_pck_desc))
+
+/*
+ * Offset to the first CAIF frame within a shared memory buffer.
+ * Aligned on 32 bytes.
+ */
+#define SHM_CAIF_FRM_OFS	(SHM_CAIF_DESC_SIZE + (SHM_CAIF_DESC_SIZE % 32))
+
+/* Number of bytes for CAIF shared memory header. */
+#define SHM_HDR_LEN		1
+
+/* Number of padding bytes for the complete CAIF frame. */
+#define SHM_FRM_PAD_LEN		4
+
+#define CAIF_MAX_MTU		4096
+
+#define SHM_SET_FULL(x)	(((x+1) & 0x0F) << 0)
+#define SHM_GET_FULL(x)	(((x >> 0) & 0x0F) - 1)
+
+#define SHM_SET_EMPTY(x)	(((x+1) & 0x0F) << 4)
+#define SHM_GET_EMPTY(x)	(((x >> 4) & 0x0F) - 1)
+
+#define SHM_FULL_MASK		(0x0F << 0)
+#define SHM_EMPTY_MASK		(0x0F << 4)
+
+struct shm_pck_desc {
+	/*
+	 * Offset from start of shared memory area to start of
+	 * shared memory CAIF frame.
+	 */
+	u32 frm_ofs;
+	u32 frm_len;
+};
+
+struct buf_list {
+	unsigned char *desc_vptr;
+	u32 phy_addr;
+	u32 index;
+	u32 len;
+	u32 frames;
+	u32 frm_ofs;
+	struct list_head list;
+};
+
+struct shm_caif_frm {
+	/* Number of bytes of padding before the CAIF frame. */
+	u8 hdr_ofs;
+};
+
+struct shmdrv_layer {
+	/* caif_dev_common must always be first in the structure*/
+	struct caif_dev_common cfdev;
+
+	u32 shm_tx_addr;
+	u32 shm_rx_addr;
+	u32 shm_base_addr;
+	u32 tx_empty_available;
+	spinlock_t lock;
+
+	struct list_head tx_empty_list;
+	struct list_head tx_pend_list;
+	struct list_head tx_full_list;
+	struct list_head rx_empty_list;
+	struct list_head rx_pend_list;
+	struct list_head rx_full_list;
+
+	struct workqueue_struct *pshm_tx_workqueue;
+	struct workqueue_struct *pshm_rx_workqueue;
+
+	struct work_struct shm_tx_work;
+	struct work_struct shm_rx_work;
+
+	struct sk_buff_head sk_qhead;
+	struct shmdev_layer *pshm_dev;
+};
+
+static int shm_netdev_open(struct net_device *shm_netdev)
+{
+	netif_wake_queue(shm_netdev);
+	return 0;
+}
+
+static int shm_netdev_close(struct net_device *shm_netdev)
+{
+	netif_stop_queue(shm_netdev);
+	return 0;
+}
+
+int caif_shmdrv_rx_cb(u32 mbx_msg, void *priv)
+{
+	struct buf_list *pbuf;
+	struct shmdrv_layer *pshm_drv;
+	struct list_head *pos;
+	u32 avail_emptybuff = 0;
+	unsigned long flags = 0;
+
+	pshm_drv = (struct shmdrv_layer *)priv;
+
+	/* Check for received buffers. */
+	if (mbx_msg & SHM_FULL_MASK) {
+		int idx;
+
+		if (!in_irq())
+			spin_lock_bh(&pshm_drv->lock);
+		else
+			spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check whether we have any outstanding buffers. */
+		if (list_empty(&pshm_drv->rx_empty_list)) {
+
+			/* Release spin lock. */
+			if (!in_irq())
+				spin_unlock_bh(&pshm_drv->lock);
+			else
+				spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* We print even in IRQ context... */
+			pr_warn("No empty Rx buffers to fill: "
+					"mbx_msg:%x\n", mbx_msg);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+
+		pbuf =
+			list_entry(pshm_drv->rx_empty_list.next,
+					struct buf_list, list);
+		idx = pbuf->index;
+
+		/* Check buffer synchronization. */
+		if (idx != SHM_GET_FULL(mbx_msg)) {
+
+			/* We print even in IRQ context... */
+			pr_warn(
+			"phyif_shm_mbx_msg_cb: RX full out of sync:"
+			" idx:%d, msg:%x SHM_GET_FULL(mbx_msg):%x\n",
+				idx, mbx_msg, SHM_GET_FULL(mbx_msg));
+
+			if (!in_irq())
+				spin_unlock_bh(&pshm_drv->lock);
+			else
+				spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+
+		list_del_init(&pbuf->list);
+		list_add_tail(&pbuf->list, &pshm_drv->rx_full_list);
+
+		if (!in_irq())
+			spin_unlock_bh(&pshm_drv->lock);
+		else
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+		/* Schedule RX work queue. */
+		if (!work_pending(&pshm_drv->shm_rx_work))
+			queue_work(pshm_drv->pshm_rx_workqueue,
+						&pshm_drv->shm_rx_work);
+	}
+
+	/* Check for emptied buffers. */
+	if (mbx_msg & SHM_EMPTY_MASK) {
+		int idx;
+
+		if (!in_irq())
+			spin_lock_bh(&pshm_drv->lock);
+		else
+			spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check whether we have any outstanding buffers. */
+		if (list_empty(&pshm_drv->tx_full_list)) {
+
+			/* We print even in IRQ context... */
+			pr_warn("No TX to empty: msg:%x\n", mbx_msg);
+
+			if (!in_irq())
+				spin_unlock_bh(&pshm_drv->lock);
+			else
+				spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+
+		pbuf =
+			list_entry(pshm_drv->tx_full_list.next,
+					struct buf_list, list);
+		idx = pbuf->index;
+
+		/* Check buffer synchronization. */
+		if (idx != SHM_GET_EMPTY(mbx_msg)) {
+
+			if (!in_irq())
+				spin_unlock_bh(&pshm_drv->lock);
+			else
+				spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* We print even in IRQ context... */
+			pr_warn("TX empty "
+				"out of sync:idx:%d, msg:%x\n", idx, mbx_msg);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+		list_del_init(&pbuf->list);
+
+		/* Reset buffer parameters. */
+		pbuf->frames = 0;
+		pbuf->frm_ofs = SHM_CAIF_FRM_OFS;
+
+		list_add_tail(&pbuf->list, &pshm_drv->tx_empty_list);
+
+		/* Check the available no. of buffers in the empty list */
+		list_for_each(pos, &pshm_drv->tx_empty_list)
+			avail_emptybuff++;
+
+		/* Check whether we have to wake up the transmitter. */
+		if ((avail_emptybuff > HIGH_WATERMARK) &&
+					(!pshm_drv->tx_empty_available)) {
+			pshm_drv->tx_empty_available = 1;
+			pshm_drv->cfdev.flowctrl
+					(pshm_drv->pshm_dev->pshm_netdev,
+								CAIF_FLOW_ON);
+
+			if (!in_irq())
+				spin_unlock_bh(&pshm_drv->lock);
+			else
+				spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* Schedule the work queue. if required */
+			if (!work_pending(&pshm_drv->shm_tx_work))
+				queue_work(pshm_drv->pshm_tx_workqueue,
+							&pshm_drv->shm_tx_work);
+		} else
+			if (!in_irq())
+				spin_unlock_bh(&pshm_drv->lock);
+			else
+				spin_unlock_irqrestore(&pshm_drv->lock, flags);
+	}
+
+	return 0;
+
+err_sync:
+	return -EIO;
+}
+
+static void shm_rx_work_func(struct work_struct *rx_work)
+{
+	struct shmdrv_layer *pshm_drv;
+	struct buf_list *pbuf;
+	unsigned long flags = 0;
+	struct sk_buff *skb;
+	char *p;
+	int ret;
+
+	pshm_drv = container_of(rx_work, struct shmdrv_layer, shm_rx_work);
+
+	while (1) {
+
+		struct shm_pck_desc *pck_desc;
+
+		if (!in_irq())
+			spin_lock_bh(&pshm_drv->lock);
+		else
+			spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check for received buffers. */
+		if (list_empty(&pshm_drv->rx_full_list)) {
+			if (!in_irq())
+				spin_unlock_bh(&pshm_drv->lock);
+			else
+				spin_unlock_irqrestore(&pshm_drv->lock, flags);
+			break;
+		}
+
+		pbuf =
+			list_entry(pshm_drv->rx_full_list.next, struct buf_list,
+					list);
+		list_del_init(&pbuf->list);
+
+		/* Retrieve pointer to start of the packet descriptor area. */
+		pck_desc = (struct shm_pck_desc *) pbuf->desc_vptr;
+
+		/*
+		 * Check whether descriptor contains a CAIF shared memory
+		 * frame.
+		 */
+		while (pck_desc->frm_ofs) {
+			unsigned int frm_buf_ofs;
+			unsigned int frm_pck_ofs;
+			unsigned int frm_pck_len;
+			/*
+			 * Check whether offset is within buffer limits
+			 * (lower).
+			 */
+			if (pck_desc->frm_ofs <
+				(pbuf->phy_addr - pshm_drv->shm_base_addr))
+				break;
+			/*
+			 * Check whether offset is within buffer limits
+			 * (higher).
+			 */
+			if (pck_desc->frm_ofs >
+				((pbuf->phy_addr - pshm_drv->shm_base_addr) +
+					pbuf->len))
+				break;
+
+			/* Calculate offset from start of buffer. */
+			frm_buf_ofs =
+				pck_desc->frm_ofs - (pbuf->phy_addr -
+						pshm_drv->shm_base_addr);
+
+			/*
+			 * Calculate offset and length of CAIF packet while
+			 * taking care of the shared memory header.
+			 */
+			frm_pck_ofs =
+				frm_buf_ofs + SHM_HDR_LEN +
+				(*(pbuf->desc_vptr + frm_buf_ofs));
+			frm_pck_len =
+				(pck_desc->frm_len - SHM_HDR_LEN -
+				(*(pbuf->desc_vptr + frm_buf_ofs)));
+
+			/* Check whether CAIF packet is within buffer limits */
+			if ((frm_pck_ofs + pck_desc->frm_len) > pbuf->len)
+				break;
+
+			/* Get a suitable CAIF packet and copy in data. */
+			skb = netdev_alloc_skb(pshm_drv->pshm_dev->pshm_netdev,
+							frm_pck_len + 1);
+			BUG_ON(skb == NULL);
+
+			p = skb_put(skb, frm_pck_len);
+			memcpy(p, pbuf->desc_vptr + frm_pck_ofs, frm_pck_len);
+
+			skb->protocol = htons(ETH_P_CAIF);
+			skb_reset_mac_header(skb);
+			skb->dev = pshm_drv->pshm_dev->pshm_netdev;
+
+			/* Push received packet up the stack. */
+			ret = netif_rx_ni(skb);
+
+			if (!ret) {
+				pshm_drv->pshm_dev->pshm_netdev->stats.
+								rx_packets++;
+				pshm_drv->pshm_dev->pshm_netdev->stats.
+						rx_bytes += pck_desc->frm_len;
+			} else
+				++pshm_drv->pshm_dev->pshm_netdev->stats.
+								rx_dropped;
+			/* Move to next packet descriptor. */
+			pck_desc++;
+		}
+
+		list_add_tail(&pbuf->list, &pshm_drv->rx_pend_list);
+
+		if (!in_irq())
+			spin_unlock_bh(&pshm_drv->lock);
+		else
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+	}
+
+	/* Schedule the work queue. if required */
+	if (!work_pending(&pshm_drv->shm_tx_work))
+		queue_work(pshm_drv->pshm_tx_workqueue, &pshm_drv->shm_tx_work);
+
+}
+
+static void shm_tx_work_func(struct work_struct *tx_work)
+{
+	u32 mbox_msg;
+	unsigned int frmlen, avail_emptybuff, append = 0;
+	unsigned long flags = 0;
+	struct buf_list *pbuf = NULL;
+	struct shmdrv_layer *pshm_drv;
+	struct shm_caif_frm *frm;
+	struct sk_buff *skb;
+	struct shm_pck_desc *pck_desc;
+	struct list_head *pos;
+
+	pshm_drv = container_of(tx_work, struct shmdrv_layer, shm_tx_work);
+
+	do {
+		/* Initialize mailbox message. */
+		mbox_msg = 0x00;
+		avail_emptybuff = 0;
+
+		if (!in_irq())
+			spin_lock_bh(&pshm_drv->lock);
+		else
+			spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check for pending receive buffers. */
+		if (!list_empty(&pshm_drv->rx_pend_list)) {
+
+			pbuf = list_entry(pshm_drv->rx_pend_list.next,
+						struct buf_list, list);
+
+			list_del_init(&pbuf->list);
+			list_add_tail(&pbuf->list, &pshm_drv->rx_empty_list);
+			/*
+			 * Value index is never changed,
+			 * so read access should be safe.
+			 */
+			mbox_msg |= SHM_SET_EMPTY(pbuf->index);
+		}
+
+		skb = skb_peek(&pshm_drv->sk_qhead);
+
+		if (skb == NULL)
+			goto send_msg;
+
+		/* Check the available no. of buffers in the empty list */
+		list_for_each(pos, &pshm_drv->tx_empty_list)
+			avail_emptybuff++;
+
+		if ((avail_emptybuff < LOW_WATERMARK) &&
+					pshm_drv->tx_empty_available) {
+			/* Update blocking condition. */
+			pshm_drv->tx_empty_available = 0;
+			pshm_drv->cfdev.flowctrl
+					(pshm_drv->pshm_dev->pshm_netdev,
+					CAIF_FLOW_OFF);
+		}
+		/*
+		 * We simply return back to the caller if we do not have space
+		 * either in Tx pending list or Tx empty list. In this case,
+		 * we hold the received skb in the skb list, waiting to
+		 * be transmitted once Tx buffers become available
+		 */
+		if (list_empty(&pshm_drv->tx_empty_list))
+			goto send_msg;
+
+		/* Get the first free Tx buffer. */
+		pbuf = list_entry(pshm_drv->tx_empty_list.next,
+						struct buf_list, list);
+		do {
+			if (append) {
+				skb = skb_peek(&pshm_drv->sk_qhead);
+				if (skb == NULL)
+					break;
+			}
+
+			frm = (struct shm_caif_frm *)
+					(pbuf->desc_vptr + pbuf->frm_ofs);
+
+			frm->hdr_ofs = 0;
+			frmlen = 0;
+			frmlen += SHM_HDR_LEN + frm->hdr_ofs + skb->len;
+
+			/* Add tail padding if needed. */
+			if (frmlen % SHM_FRM_PAD_LEN)
+				frmlen += SHM_FRM_PAD_LEN -
+						(frmlen % SHM_FRM_PAD_LEN);
+
+			/*
+			 * Verify that packet, header and additional padding
+			 * can fit within the buffer frame area.
+			 */
+			if (frmlen >= (pbuf->len - pbuf->frm_ofs))
+				break;
+
+			if (!append) {
+				list_del_init(&pbuf->list);
+				append = 1;
+			}
+
+			skb = skb_dequeue(&pshm_drv->sk_qhead);
+			/* Copy in CAIF frame. */
+			skb_copy_bits(skb, 0, pbuf->desc_vptr +
+					pbuf->frm_ofs + SHM_HDR_LEN +
+						frm->hdr_ofs, skb->len);
+
+			pshm_drv->pshm_dev->pshm_netdev->stats.tx_packets++;
+			pshm_drv->pshm_dev->pshm_netdev->stats.tx_bytes +=
+									frmlen;
+			dev_kfree_skb(skb);
+
+			/* Fill in the shared memory packet descriptor area. */
+			pck_desc = (struct shm_pck_desc *) (pbuf->desc_vptr);
+			/* Forward to current frame. */
+			pck_desc += pbuf->frames;
+			pck_desc->frm_ofs = (pbuf->phy_addr -
+						pshm_drv->shm_base_addr) +
+								pbuf->frm_ofs;
+			pck_desc->frm_len = frmlen;
+			/* Terminate packet descriptor area. */
+			pck_desc++;
+			pck_desc->frm_ofs = 0;
+			/* Update buffer parameters. */
+			pbuf->frames++;
+			pbuf->frm_ofs += frmlen + (frmlen % 32);
+
+		} while (pbuf->frames < SHM_MAX_FRMS_PER_BUF);
+
+		/* Assign buffer as full. */
+		list_add_tail(&pbuf->list, &pshm_drv->tx_full_list);
+		append = 0;
+		mbox_msg |= SHM_SET_FULL(pbuf->index);
+send_msg:
+		if (!in_irq())
+			spin_unlock_bh(&pshm_drv->lock);
+		else
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+		if (mbox_msg)
+			pshm_drv->pshm_dev->pshmdev_mbxsend
+					(pshm_drv->pshm_dev->shm_id, mbox_msg);
+	} while (mbox_msg);
+}
+
+static int shm_netdev_tx(struct sk_buff *skb, struct net_device *shm_netdev)
+{
+	struct shmdrv_layer *pshm_drv;
+	unsigned long flags = 0;
+
+	pshm_drv = netdev_priv(shm_netdev);
+
+	if (!in_irq())
+		spin_lock_bh(&pshm_drv->lock);
+	else
+		spin_lock_irqsave(&pshm_drv->lock, flags);
+
+	skb_queue_tail(&pshm_drv->sk_qhead, skb);
+
+	if (!in_irq())
+		spin_unlock_bh(&pshm_drv->lock);
+	else
+		spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+	/* Schedule Tx work queue. for deferred processing of skbs*/
+	if (!work_pending(&pshm_drv->shm_tx_work))
+		queue_work(pshm_drv->pshm_tx_workqueue, &pshm_drv->shm_tx_work);
+
+	return 0;
+}
+
+static const struct net_device_ops netdev_ops = {
+	.ndo_open = shm_netdev_open,
+	.ndo_stop = shm_netdev_close,
+	.ndo_start_xmit = shm_netdev_tx,
+};
+
+static void shm_netdev_setup(struct net_device *pshm_netdev)
+{
+	struct shmdrv_layer *pshm_drv;
+	pshm_netdev->netdev_ops = &netdev_ops;
+
+	pshm_netdev->mtu = CAIF_MAX_MTU;
+	pshm_netdev->type = ARPHRD_CAIF;
+	pshm_netdev->hard_header_len = CAIF_NEEDED_HEADROOM;
+	pshm_netdev->tx_queue_len = 0;
+	pshm_netdev->destructor = free_netdev;
+
+	pshm_drv = netdev_priv(pshm_netdev);
+
+	/* Initialize structures in a clean state. */
+	memset(pshm_drv, 0, sizeof(struct shmdrv_layer));
+
+	pshm_drv->cfdev.link_select = CAIF_LINK_LOW_LATENCY;
+}
+
+int caif_shmcore_probe(struct shmdev_layer *pshm_dev)
+{
+	int result, j;
+	struct shmdrv_layer *pshm_drv = NULL;
+
+	pshm_dev->pshm_netdev = alloc_netdev(sizeof(struct shmdrv_layer),
+						"cfshm%d", shm_netdev_setup);
+	if (!pshm_dev->pshm_netdev)
+		return -ENOMEM;
+
+	pshm_drv = netdev_priv(pshm_dev->pshm_netdev);
+	pshm_drv->pshm_dev = pshm_dev;
+
+	/*
+	 * Initialization starts with the verification of the
+	 * availability of MBX driver by calling its setup function.
+	 * MBX driver must be available by this time for proper
+	 * functioning of SHM driver.
+	 */
+	if ((pshm_dev->pshmdev_mbxsetup
+				(caif_shmdrv_rx_cb, pshm_dev, pshm_drv)) != 0) {
+		pr_warn("Could not config. SHM Mailbox,"
+				" Bailing out.....\n");
+		free_netdev(pshm_dev->pshm_netdev);
+		return -ENODEV;
+	}
+
+	skb_queue_head_init(&pshm_drv->sk_qhead);
+
+	pr_info("SHM DEVICE[%d] PROBED BY DRIVER, NEW SHM DRIVER"
+			" INSTANCE AT pshm_drv =0x%p\n",
+			pshm_drv->pshm_dev->shm_id, pshm_drv);
+
+	if (pshm_dev->shm_total_sz <
+			(NR_TX_BUF * TX_BUF_SZ + NR_RX_BUF * RX_BUF_SZ)) {
+
+		pr_warn("ERROR, Amount of available"
+				" Phys. SHM cannot accomodate current SHM "
+				"driver configuration, Bailing out ...\n");
+		free_netdev(pshm_dev->pshm_netdev);
+		return -ENOMEM;
+	}
+
+	pshm_drv->shm_base_addr = pshm_dev->shm_base_addr;
+	pshm_drv->shm_tx_addr = pshm_drv->shm_base_addr;
+
+	if (pshm_dev->shm_loopback)
+		pshm_drv->shm_rx_addr = pshm_drv->shm_tx_addr;
+	else
+		pshm_drv->shm_rx_addr = pshm_dev->shm_base_addr +
+						(NR_TX_BUF * TX_BUF_SZ);
+
+	INIT_LIST_HEAD(&pshm_drv->tx_empty_list);
+	INIT_LIST_HEAD(&pshm_drv->tx_pend_list);
+	INIT_LIST_HEAD(&pshm_drv->tx_full_list);
+
+	INIT_LIST_HEAD(&pshm_drv->rx_empty_list);
+	INIT_LIST_HEAD(&pshm_drv->rx_pend_list);
+	INIT_LIST_HEAD(&pshm_drv->rx_full_list);
+
+	INIT_WORK(&pshm_drv->shm_tx_work, shm_tx_work_func);
+	INIT_WORK(&pshm_drv->shm_rx_work, shm_rx_work_func);
+
+	pshm_drv->pshm_tx_workqueue =
+				create_singlethread_workqueue("shm_tx_work");
+	pshm_drv->pshm_rx_workqueue =
+				create_singlethread_workqueue("shm_rx_work");
+
+	for (j = 0; j < NR_TX_BUF; j++) {
+		struct buf_list *tx_buf =
+				kmalloc(sizeof(struct buf_list), GFP_KERNEL);
+
+		if (tx_buf == NULL) {
+			pr_warn("ERROR, Could not"
+					" allocate dynamic mem. for tx_buf,"
+					" Bailing out ...\n");
+			free_netdev(pshm_dev->pshm_netdev);
+			return -ENOMEM;
+		}
+		tx_buf->index = j;
+		tx_buf->phy_addr = pshm_drv->shm_tx_addr + (TX_BUF_SZ * j);
+		tx_buf->len = TX_BUF_SZ;
+		tx_buf->frames = 0;
+		tx_buf->frm_ofs = SHM_CAIF_FRM_OFS;
+
+		if (pshm_dev->shm_loopback)
+			tx_buf->desc_vptr = (char *)tx_buf->phy_addr;
+		else
+			tx_buf->desc_vptr =
+					ioremap(tx_buf->phy_addr, TX_BUF_SZ);
+
+		list_add_tail(&tx_buf->list, &pshm_drv->tx_empty_list);
+	}
+
+	for (j = 0; j < NR_RX_BUF; j++) {
+		struct buf_list *rx_buf =
+				kmalloc(sizeof(struct buf_list), GFP_KERNEL);
+
+		if (rx_buf == NULL) {
+			pr_warn("ERROR, Could not"
+					" allocate dynamic mem.for rx_buf,"
+					" Bailing out ...\n");
+			free_netdev(pshm_dev->pshm_netdev);
+			return -ENOMEM;
+		}
+		rx_buf->index = j;
+		rx_buf->phy_addr = pshm_drv->shm_rx_addr + (RX_BUF_SZ * j);
+		rx_buf->len = RX_BUF_SZ;
+
+		if (pshm_dev->shm_loopback)
+			rx_buf->desc_vptr = (char *)rx_buf->phy_addr;
+		else
+			rx_buf->desc_vptr =
+					ioremap(rx_buf->phy_addr, RX_BUF_SZ);
+		list_add_tail(&rx_buf->list, &pshm_drv->rx_empty_list);
+	}
+
+	pshm_drv->tx_empty_available = 1;
+	result = register_netdev(pshm_dev->pshm_netdev);
+	if (result)
+		pr_warn("ERROR[%d], SHM could not, "
+			"register with NW FRMWK Bailing out ...\n", result);
+
+	return result;
+}
+
+void caif_shmcore_remove(struct net_device *pshm_netdev)
+{
+	struct buf_list *pbuf;
+	struct shmdrv_layer *pshm_drv = NULL;
+
+	pshm_drv = netdev_priv(pshm_netdev);
+
+	while (!(list_empty(&pshm_drv->tx_pend_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_pend_list.next,
+					struct buf_list, list);
+
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->tx_full_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_full_list.next,
+					struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->tx_empty_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_empty_list.next,
+					struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->rx_full_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_full_list.next,
+				struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->rx_pend_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_pend_list.next,
+				struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->rx_empty_list))) {
+		pbuf =
+			list_entry(pshm_drv->rx_empty_list.next,
+				struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	/* Destroy work queues. */
+	destroy_workqueue(pshm_drv->pshm_tx_workqueue);
+	destroy_workqueue(pshm_drv->pshm_rx_workqueue);
+
+	unregister_netdev(pshm_netdev);
+}
-- 
1.6.3.3

[PATCH 3/4] caif-u5500: CAIF shared memory mailbox interface

[Sjur Braendeland]

From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---
 drivers/net/caif/caif_shm_u5500.c |  129 +++++++++++++++++++++++++++++++++++++
 1 files changed, 129 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/caif/caif_shm_u5500.c

diff --git a/drivers/net/caif/caif_shm_u5500.c b/drivers/net/caif/caif_shm_u5500.c
new file mode 100644
index 0000000..1cd90da
--- /dev/null
+++ b/drivers/net/caif/caif_shm_u5500.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
+ * Author:  Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":" __func__ "():" fmt
+
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <mach/mbox.h>
+#include <net/caif/caif_shm.h>
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CAIF Shared Memory protocol driver");
+
+#define MAX_SHM_INSTANCES	1
+
+enum {
+	MBX_ACC0,
+	MBX_ACC1,
+	MBX_DSP
+};
+
+static struct shmdev_layer shmdev_lyr[MAX_SHM_INSTANCES];
+
+static unsigned int shm_start;
+static unsigned int shm_size;
+
+module_param(shm_size, uint  , 0440);
+MODULE_PARM_DESC(shm_total_size, "Start of SHM shared memory");
+
+module_param(shm_start, uint  , 0440);
+MODULE_PARM_DESC(shm_total_start, "Total Size of SHM shared memory");
+
+static int shmdev_send_msg(u32 dev_id, u32 mbx_msg)
+{
+	/* Always block until msg is written successfully */
+	mbox_send(shmdev_lyr[dev_id].hmbx, mbx_msg, true);
+	return 0;
+}
+
+static int shmdev_mbx_setup(void *pshmdrv_cb, struct shmdev_layer *pshm_dev,
+							 void *pshm_drv)
+{
+	/*
+	 * For UX5500, we have only 1 SHM instance which uses MBX0
+	 * for communication with the peer modem
+	 */
+	pshm_dev->hmbx = mbox_setup(MBX_ACC0, pshmdrv_cb, pshm_drv);
+
+	if (!pshm_dev->hmbx)
+		return -ENODEV;
+	else
+		return 0;
+}
+
+static int __init caif_shmdev_init(void)
+{
+	int i, result;
+
+	/* Loop is currently overkill, there is only one instance */
+	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+
+		shmdev_lyr[i].shm_base_addr = shm_start;
+		shmdev_lyr[i].shm_total_sz = shm_size;
+
+		if (((char *)shmdev_lyr[i].shm_base_addr == NULL)
+			       || (shmdev_lyr[i].shm_total_sz <= 0))	{
+			pr_warn("ERROR,"
+				"Shared memory Address and/or Size incorrect"
+				", Bailing out ...\n");
+			result = -EINVAL;
+			goto clean;
+		}
+
+		pr_info("SHM AREA (instance %d) STARTS"
+			" AT %p\n", i, (char *)shmdev_lyr[i].shm_base_addr);
+
+		shmdev_lyr[i].shm_id = i;
+		shmdev_lyr[i].pshmdev_mbxsend = shmdev_send_msg;
+		shmdev_lyr[i].pshmdev_mbxsetup = shmdev_mbx_setup;
+
+		/*
+		 * Finally, CAIF core module is called with details in place:
+		 * 1. SHM base address
+		 * 2. SHM size
+		 * 3. MBX handle
+		 */
+		result = caif_shmcore_probe(&shmdev_lyr[i]);
+		if (result) {
+			pr_warn("ERROR[%d],"
+				"Could not probe SHM core (instance %d)"
+				" Bailing out ...\n", result, i);
+			goto clean;
+		}
+	}
+
+	return 0;
+
+clean:
+	/*
+	 * For now, we assume that even if one instance of SHM fails, we bail
+	 * out of the driver support completely. For this, we need to release
+	 * any memory allocated and unregister any instance of SHM net device.
+	 */
+	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+		if (shmdev_lyr[i].pshm_netdev)
+			unregister_netdev(shmdev_lyr[i].pshm_netdev);
+	}
+	return result;
+}
+
+static void __exit caif_shmdev_exit(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+		caif_shmcore_remove(shmdev_lyr[i].pshm_netdev);
+		kfree((void *)shmdev_lyr[i].shm_base_addr);
+	}
+
+}
+
+module_init(caif_shmdev_init);
+module_exit(caif_shmdev_exit);
-- 
1.6.3.3

[PATCH 4/4] caif-u5500: Build config for CAIF shared mem driver

[Sjur Braendeland]

From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---
 drivers/net/caif/Kconfig  |    7 +++++++
 drivers/net/caif/Makefile |    4 ++++
 2 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/net/caif/Kconfig b/drivers/net/caif/Kconfig
index 75bfc3a..09ed3f4 100644
--- a/drivers/net/caif/Kconfig
+++ b/drivers/net/caif/Kconfig
@@ -31,3 +31,10 @@ config CAIF_SPI_SYNC
 	Putting the next command and length in the start of the frame can
 	help to synchronize to the next transfer in case of over or under-runs.
 	This option also needs to be enabled on the modem.
+
+config CAIF_SHM
+	tristate "CAIF shared memory protocol driver"
+	depends on CAIF && U5500_MBOX
+	default n
+	---help---
+	The CAIF shared memory protocol driver for the STE UX5500 platform.
diff --git a/drivers/net/caif/Makefile b/drivers/net/caif/Makefile
index 3a11d61..b38d987 100644
--- a/drivers/net/caif/Makefile
+++ b/drivers/net/caif/Makefile
@@ -8,3 +8,7 @@ obj-$(CONFIG_CAIF_TTY) += caif_serial.o
 # SPI slave physical interfaces module
 cfspi_slave-objs := caif_spi.o caif_spi_slave.o
 obj-$(CONFIG_CAIF_SPI_SLAVE) += cfspi_slave.o
+
+# Shared memory
+caif_shm-objs := caif_shmcore.o caif_shm_u5500.o
+obj-$(CONFIG_CAIF_SHM) += caif_shm.o
-- 
1.6.3.3

Re: [PATCH 2/4] caif-u5500: CAIF shared memory transport protocol

[David Miller]

From: Sjur Braendeland <sjur.brandeland@stericsson.com>
Date: Fri, 22 Oct 2010 21:03:53 +0200

> +		if (!in_irq())
> +			spin_lock_bh(&pshm_drv->lock);
> +		else
> +			spin_lock_irqsave(&pshm_drv->lock, flags);

You should never have contextual based locking schemes like this,
it's not just ugly it's also deadlock prone.

[PATCHv2 1/4] caif-u5500: Adding shared memory include

[Sjur Braendeland]

From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---
 include/net/caif/caif_shm.h |   26 ++++++++++++++++++++++++++
 1 files changed, 26 insertions(+), 0 deletions(-)
 create mode 100644 include/net/caif/caif_shm.h

diff --git a/include/net/caif/caif_shm.h b/include/net/caif/caif_shm.h
new file mode 100644
index 0000000..5bcce55
--- /dev/null
+++ b/include/net/caif/caif_shm.h
@@ -0,0 +1,26 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
+ * Author: Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#ifndef CAIF_SHM_H_
+#define CAIF_SHM_H_
+
+struct shmdev_layer {
+	u32 shm_base_addr;
+	u32 shm_total_sz;
+	u32 shm_id;
+	u32 shm_loopback;
+	void *hmbx;
+	int (*pshmdev_mbxsend) (u32 shm_id, u32 mbx_msg);
+	int (*pshmdev_mbxsetup) (void *pshmdrv_cb,
+				struct shmdev_layer *pshm_dev, void *pshm_drv);
+	struct net_device *pshm_netdev;
+};
+
+extern int caif_shmcore_probe(struct shmdev_layer *pshm_dev);
+extern void caif_shmcore_remove(struct net_device *pshm_netdev);
+
+#endif
-- 
1.6.3.3

[PATCHv2 2/4] caif-u5500: CAIF shared memory transport protocol

[Sjur Braendeland]

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---

>> +             if (!in_irq())
>> +                     spin_lock_bh(&pshm_drv->lock);
>> +             else
>> +                     spin_lock_irqsave(&pshm_drv->lock, flags);
>
>You should never have contextual based locking schemes like this,
>it's not just ugly it's also deadlock prone.
Ok, thanks - I have fixed this.
Currently the code is running in IRQ context anyway.

 drivers/net/caif/caif_shmcore.c |  744 +++++++++++++++++++++++++++++++++++++++
 1 files changed, 744 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/caif/caif_shmcore.c

diff --git a/drivers/net/caif/caif_shmcore.c b/drivers/net/caif/caif_shmcore.c
new file mode 100644
index 0000000..19f9c06
--- /dev/null
+++ b/drivers/net/caif/caif_shmcore.c
@@ -0,0 +1,744 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
+ * Authors:  Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com,
+ *           Daniel Martensson / daniel.martensson@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":" __func__ "():" fmt
+
+#include <linux/spinlock.h>
+#include <linux/sched.h>
+#include <linux/list.h>
+#include <linux/netdevice.h>
+#include <linux/if_arp.h>
+
+#include <net/caif/caif_device.h>
+#include <net/caif/caif_shm.h>
+
+#define NR_TX_BUF		6
+#define NR_RX_BUF		6
+#define TX_BUF_SZ		0x2000
+#define RX_BUF_SZ		0x2000
+
+#define CAIF_NEEDED_HEADROOM	32
+
+#define CAIF_FLOW_ON		1
+#define CAIF_FLOW_OFF		0
+
+#define LOW_WATERMARK		3
+#define HIGH_WATERMARK		4
+
+/* Maximum number of CAIF buffers per shared memory buffer. */
+#define SHM_MAX_FRMS_PER_BUF	10
+
+/*
+ * Size in bytes of the descriptor area
+ * (With end of descriptor signalling)
+ */
+#define SHM_CAIF_DESC_SIZE	((SHM_MAX_FRMS_PER_BUF + 1) * \
+					sizeof(struct shm_pck_desc))
+
+/*
+ * Offset to the first CAIF frame within a shared memory buffer.
+ * Aligned on 32 bytes.
+ */
+#define SHM_CAIF_FRM_OFS	(SHM_CAIF_DESC_SIZE + (SHM_CAIF_DESC_SIZE % 32))
+
+/* Number of bytes for CAIF shared memory header. */
+#define SHM_HDR_LEN		1
+
+/* Number of padding bytes for the complete CAIF frame. */
+#define SHM_FRM_PAD_LEN		4
+
+#define CAIF_MAX_MTU		4096
+
+#define SHM_SET_FULL(x)	(((x+1) & 0x0F) << 0)
+#define SHM_GET_FULL(x)	(((x >> 0) & 0x0F) - 1)
+
+#define SHM_SET_EMPTY(x)	(((x+1) & 0x0F) << 4)
+#define SHM_GET_EMPTY(x)	(((x >> 4) & 0x0F) - 1)
+
+#define SHM_FULL_MASK		(0x0F << 0)
+#define SHM_EMPTY_MASK		(0x0F << 4)
+
+struct shm_pck_desc {
+	/*
+	 * Offset from start of shared memory area to start of
+	 * shared memory CAIF frame.
+	 */
+	u32 frm_ofs;
+	u32 frm_len;
+};
+
+struct buf_list {
+	unsigned char *desc_vptr;
+	u32 phy_addr;
+	u32 index;
+	u32 len;
+	u32 frames;
+	u32 frm_ofs;
+	struct list_head list;
+};
+
+struct shm_caif_frm {
+	/* Number of bytes of padding before the CAIF frame. */
+	u8 hdr_ofs;
+};
+
+struct shmdrv_layer {
+	/* caif_dev_common must always be first in the structure*/
+	struct caif_dev_common cfdev;
+
+	u32 shm_tx_addr;
+	u32 shm_rx_addr;
+	u32 shm_base_addr;
+	u32 tx_empty_available;
+	spinlock_t lock;
+
+	struct list_head tx_empty_list;
+	struct list_head tx_pend_list;
+	struct list_head tx_full_list;
+	struct list_head rx_empty_list;
+	struct list_head rx_pend_list;
+	struct list_head rx_full_list;
+
+	struct workqueue_struct *pshm_tx_workqueue;
+	struct workqueue_struct *pshm_rx_workqueue;
+
+	struct work_struct shm_tx_work;
+	struct work_struct shm_rx_work;
+
+	struct sk_buff_head sk_qhead;
+	struct shmdev_layer *pshm_dev;
+};
+
+static int shm_netdev_open(struct net_device *shm_netdev)
+{
+	netif_wake_queue(shm_netdev);
+	return 0;
+}
+
+static int shm_netdev_close(struct net_device *shm_netdev)
+{
+	netif_stop_queue(shm_netdev);
+	return 0;
+}
+
+int caif_shmdrv_rx_cb(u32 mbx_msg, void *priv)
+{
+	struct buf_list *pbuf;
+	struct shmdrv_layer *pshm_drv;
+	struct list_head *pos;
+	u32 avail_emptybuff = 0;
+	unsigned long flags = 0;
+
+	pshm_drv = (struct shmdrv_layer *)priv;
+
+	/* Check for received buffers. */
+	if (mbx_msg & SHM_FULL_MASK) {
+		int idx;
+
+		spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check whether we have any outstanding buffers. */
+		if (list_empty(&pshm_drv->rx_empty_list)) {
+
+			/* Release spin lock. */
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* We print even in IRQ context... */
+			pr_warn("No empty Rx buffers to fill: "
+					"mbx_msg:%x\n", mbx_msg);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+
+		pbuf =
+			list_entry(pshm_drv->rx_empty_list.next,
+					struct buf_list, list);
+		idx = pbuf->index;
+
+		/* Check buffer synchronization. */
+		if (idx != SHM_GET_FULL(mbx_msg)) {
+
+			/* We print even in IRQ context... */
+			pr_warn(
+			"phyif_shm_mbx_msg_cb: RX full out of sync:"
+			" idx:%d, msg:%x SHM_GET_FULL(mbx_msg):%x\n",
+				idx, mbx_msg, SHM_GET_FULL(mbx_msg));
+
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+
+		list_del_init(&pbuf->list);
+		list_add_tail(&pbuf->list, &pshm_drv->rx_full_list);
+
+		spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+		/* Schedule RX work queue. */
+		if (!work_pending(&pshm_drv->shm_rx_work))
+			queue_work(pshm_drv->pshm_rx_workqueue,
+						&pshm_drv->shm_rx_work);
+	}
+
+	/* Check for emptied buffers. */
+	if (mbx_msg & SHM_EMPTY_MASK) {
+		int idx;
+
+		spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check whether we have any outstanding buffers. */
+		if (list_empty(&pshm_drv->tx_full_list)) {
+
+			/* We print even in IRQ context... */
+			pr_warn("No TX to empty: msg:%x\n", mbx_msg);
+
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+
+		pbuf =
+			list_entry(pshm_drv->tx_full_list.next,
+					struct buf_list, list);
+		idx = pbuf->index;
+
+		/* Check buffer synchronization. */
+		if (idx != SHM_GET_EMPTY(mbx_msg)) {
+
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* We print even in IRQ context... */
+			pr_warn("TX empty "
+				"out of sync:idx:%d, msg:%x\n", idx, mbx_msg);
+
+			/* Bail out. */
+			goto err_sync;
+		}
+		list_del_init(&pbuf->list);
+
+		/* Reset buffer parameters. */
+		pbuf->frames = 0;
+		pbuf->frm_ofs = SHM_CAIF_FRM_OFS;
+
+		list_add_tail(&pbuf->list, &pshm_drv->tx_empty_list);
+
+		/* Check the available no. of buffers in the empty list */
+		list_for_each(pos, &pshm_drv->tx_empty_list)
+			avail_emptybuff++;
+
+		/* Check whether we have to wake up the transmitter. */
+		if ((avail_emptybuff > HIGH_WATERMARK) &&
+					(!pshm_drv->tx_empty_available)) {
+			pshm_drv->tx_empty_available = 1;
+			pshm_drv->cfdev.flowctrl
+					(pshm_drv->pshm_dev->pshm_netdev,
+								CAIF_FLOW_ON);
+
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+			/* Schedule the work queue. if required */
+			if (!work_pending(&pshm_drv->shm_tx_work))
+				queue_work(pshm_drv->pshm_tx_workqueue,
+							&pshm_drv->shm_tx_work);
+		} else
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+	}
+
+	return 0;
+
+err_sync:
+	return -EIO;
+}
+
+static void shm_rx_work_func(struct work_struct *rx_work)
+{
+	struct shmdrv_layer *pshm_drv;
+	struct buf_list *pbuf;
+	unsigned long flags = 0;
+	struct sk_buff *skb;
+	char *p;
+	int ret;
+
+	pshm_drv = container_of(rx_work, struct shmdrv_layer, shm_rx_work);
+
+	while (1) {
+
+		struct shm_pck_desc *pck_desc;
+
+		spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check for received buffers. */
+		if (list_empty(&pshm_drv->rx_full_list)) {
+			spin_unlock_irqrestore(&pshm_drv->lock, flags);
+			break;
+		}
+
+		pbuf =
+			list_entry(pshm_drv->rx_full_list.next, struct buf_list,
+					list);
+		list_del_init(&pbuf->list);
+
+		/* Retrieve pointer to start of the packet descriptor area. */
+		pck_desc = (struct shm_pck_desc *) pbuf->desc_vptr;
+
+		/*
+		 * Check whether descriptor contains a CAIF shared memory
+		 * frame.
+		 */
+		while (pck_desc->frm_ofs) {
+			unsigned int frm_buf_ofs;
+			unsigned int frm_pck_ofs;
+			unsigned int frm_pck_len;
+			/*
+			 * Check whether offset is within buffer limits
+			 * (lower).
+			 */
+			if (pck_desc->frm_ofs <
+				(pbuf->phy_addr - pshm_drv->shm_base_addr))
+				break;
+			/*
+			 * Check whether offset is within buffer limits
+			 * (higher).
+			 */
+			if (pck_desc->frm_ofs >
+				((pbuf->phy_addr - pshm_drv->shm_base_addr) +
+					pbuf->len))
+				break;
+
+			/* Calculate offset from start of buffer. */
+			frm_buf_ofs =
+				pck_desc->frm_ofs - (pbuf->phy_addr -
+						pshm_drv->shm_base_addr);
+
+			/*
+			 * Calculate offset and length of CAIF packet while
+			 * taking care of the shared memory header.
+			 */
+			frm_pck_ofs =
+				frm_buf_ofs + SHM_HDR_LEN +
+				(*(pbuf->desc_vptr + frm_buf_ofs));
+			frm_pck_len =
+				(pck_desc->frm_len - SHM_HDR_LEN -
+				(*(pbuf->desc_vptr + frm_buf_ofs)));
+
+			/* Check whether CAIF packet is within buffer limits */
+			if ((frm_pck_ofs + pck_desc->frm_len) > pbuf->len)
+				break;
+
+			/* Get a suitable CAIF packet and copy in data. */
+			skb = netdev_alloc_skb(pshm_drv->pshm_dev->pshm_netdev,
+							frm_pck_len + 1);
+			BUG_ON(skb == NULL);
+
+			p = skb_put(skb, frm_pck_len);
+			memcpy(p, pbuf->desc_vptr + frm_pck_ofs, frm_pck_len);
+
+			skb->protocol = htons(ETH_P_CAIF);
+			skb_reset_mac_header(skb);
+			skb->dev = pshm_drv->pshm_dev->pshm_netdev;
+
+			/* Push received packet up the stack. */
+			ret = netif_rx_ni(skb);
+
+			if (!ret) {
+				pshm_drv->pshm_dev->pshm_netdev->stats.
+								rx_packets++;
+				pshm_drv->pshm_dev->pshm_netdev->stats.
+						rx_bytes += pck_desc->frm_len;
+			} else
+				++pshm_drv->pshm_dev->pshm_netdev->stats.
+								rx_dropped;
+			/* Move to next packet descriptor. */
+			pck_desc++;
+		}
+
+		list_add_tail(&pbuf->list, &pshm_drv->rx_pend_list);
+
+		spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+	}
+
+	/* Schedule the work queue. if required */
+	if (!work_pending(&pshm_drv->shm_tx_work))
+		queue_work(pshm_drv->pshm_tx_workqueue, &pshm_drv->shm_tx_work);
+
+}
+
+static void shm_tx_work_func(struct work_struct *tx_work)
+{
+	u32 mbox_msg;
+	unsigned int frmlen, avail_emptybuff, append = 0;
+	unsigned long flags = 0;
+	struct buf_list *pbuf = NULL;
+	struct shmdrv_layer *pshm_drv;
+	struct shm_caif_frm *frm;
+	struct sk_buff *skb;
+	struct shm_pck_desc *pck_desc;
+	struct list_head *pos;
+
+	pshm_drv = container_of(tx_work, struct shmdrv_layer, shm_tx_work);
+
+	do {
+		/* Initialize mailbox message. */
+		mbox_msg = 0x00;
+		avail_emptybuff = 0;
+
+		spin_lock_irqsave(&pshm_drv->lock, flags);
+
+		/* Check for pending receive buffers. */
+		if (!list_empty(&pshm_drv->rx_pend_list)) {
+
+			pbuf = list_entry(pshm_drv->rx_pend_list.next,
+						struct buf_list, list);
+
+			list_del_init(&pbuf->list);
+			list_add_tail(&pbuf->list, &pshm_drv->rx_empty_list);
+			/*
+			 * Value index is never changed,
+			 * so read access should be safe.
+			 */
+			mbox_msg |= SHM_SET_EMPTY(pbuf->index);
+		}
+
+		skb = skb_peek(&pshm_drv->sk_qhead);
+
+		if (skb == NULL)
+			goto send_msg;
+
+		/* Check the available no. of buffers in the empty list */
+		list_for_each(pos, &pshm_drv->tx_empty_list)
+			avail_emptybuff++;
+
+		if ((avail_emptybuff < LOW_WATERMARK) &&
+					pshm_drv->tx_empty_available) {
+			/* Update blocking condition. */
+			pshm_drv->tx_empty_available = 0;
+			pshm_drv->cfdev.flowctrl
+					(pshm_drv->pshm_dev->pshm_netdev,
+					CAIF_FLOW_OFF);
+		}
+		/*
+		 * We simply return back to the caller if we do not have space
+		 * either in Tx pending list or Tx empty list. In this case,
+		 * we hold the received skb in the skb list, waiting to
+		 * be transmitted once Tx buffers become available
+		 */
+		if (list_empty(&pshm_drv->tx_empty_list))
+			goto send_msg;
+
+		/* Get the first free Tx buffer. */
+		pbuf = list_entry(pshm_drv->tx_empty_list.next,
+						struct buf_list, list);
+		do {
+			if (append) {
+				skb = skb_peek(&pshm_drv->sk_qhead);
+				if (skb == NULL)
+					break;
+			}
+
+			frm = (struct shm_caif_frm *)
+					(pbuf->desc_vptr + pbuf->frm_ofs);
+
+			frm->hdr_ofs = 0;
+			frmlen = 0;
+			frmlen += SHM_HDR_LEN + frm->hdr_ofs + skb->len;
+
+			/* Add tail padding if needed. */
+			if (frmlen % SHM_FRM_PAD_LEN)
+				frmlen += SHM_FRM_PAD_LEN -
+						(frmlen % SHM_FRM_PAD_LEN);
+
+			/*
+			 * Verify that packet, header and additional padding
+			 * can fit within the buffer frame area.
+			 */
+			if (frmlen >= (pbuf->len - pbuf->frm_ofs))
+				break;
+
+			if (!append) {
+				list_del_init(&pbuf->list);
+				append = 1;
+			}
+
+			skb = skb_dequeue(&pshm_drv->sk_qhead);
+			/* Copy in CAIF frame. */
+			skb_copy_bits(skb, 0, pbuf->desc_vptr +
+					pbuf->frm_ofs + SHM_HDR_LEN +
+						frm->hdr_ofs, skb->len);
+
+			pshm_drv->pshm_dev->pshm_netdev->stats.tx_packets++;
+			pshm_drv->pshm_dev->pshm_netdev->stats.tx_bytes +=
+									frmlen;
+			dev_kfree_skb(skb);
+
+			/* Fill in the shared memory packet descriptor area. */
+			pck_desc = (struct shm_pck_desc *) (pbuf->desc_vptr);
+			/* Forward to current frame. */
+			pck_desc += pbuf->frames;
+			pck_desc->frm_ofs = (pbuf->phy_addr -
+						pshm_drv->shm_base_addr) +
+								pbuf->frm_ofs;
+			pck_desc->frm_len = frmlen;
+			/* Terminate packet descriptor area. */
+			pck_desc++;
+			pck_desc->frm_ofs = 0;
+			/* Update buffer parameters. */
+			pbuf->frames++;
+			pbuf->frm_ofs += frmlen + (frmlen % 32);
+
+		} while (pbuf->frames < SHM_MAX_FRMS_PER_BUF);
+
+		/* Assign buffer as full. */
+		list_add_tail(&pbuf->list, &pshm_drv->tx_full_list);
+		append = 0;
+		mbox_msg |= SHM_SET_FULL(pbuf->index);
+send_msg:
+		spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+		if (mbox_msg)
+			pshm_drv->pshm_dev->pshmdev_mbxsend
+					(pshm_drv->pshm_dev->shm_id, mbox_msg);
+	} while (mbox_msg);
+}
+
+static int shm_netdev_tx(struct sk_buff *skb, struct net_device *shm_netdev)
+{
+	struct shmdrv_layer *pshm_drv;
+	unsigned long flags = 0;
+
+	pshm_drv = netdev_priv(shm_netdev);
+
+	spin_lock_irqsave(&pshm_drv->lock, flags);
+
+	skb_queue_tail(&pshm_drv->sk_qhead, skb);
+
+	spin_unlock_irqrestore(&pshm_drv->lock, flags);
+
+	/* Schedule Tx work queue. for deferred processing of skbs*/
+	if (!work_pending(&pshm_drv->shm_tx_work))
+		queue_work(pshm_drv->pshm_tx_workqueue, &pshm_drv->shm_tx_work);
+
+	return 0;
+}
+
+static const struct net_device_ops netdev_ops = {
+	.ndo_open = shm_netdev_open,
+	.ndo_stop = shm_netdev_close,
+	.ndo_start_xmit = shm_netdev_tx,
+};
+
+static void shm_netdev_setup(struct net_device *pshm_netdev)
+{
+	struct shmdrv_layer *pshm_drv;
+	pshm_netdev->netdev_ops = &netdev_ops;
+
+	pshm_netdev->mtu = CAIF_MAX_MTU;
+	pshm_netdev->type = ARPHRD_CAIF;
+	pshm_netdev->hard_header_len = CAIF_NEEDED_HEADROOM;
+	pshm_netdev->tx_queue_len = 0;
+	pshm_netdev->destructor = free_netdev;
+
+	pshm_drv = netdev_priv(pshm_netdev);
+
+	/* Initialize structures in a clean state. */
+	memset(pshm_drv, 0, sizeof(struct shmdrv_layer));
+
+	pshm_drv->cfdev.link_select = CAIF_LINK_LOW_LATENCY;
+}
+
+int caif_shmcore_probe(struct shmdev_layer *pshm_dev)
+{
+	int result, j;
+	struct shmdrv_layer *pshm_drv = NULL;
+
+	pshm_dev->pshm_netdev = alloc_netdev(sizeof(struct shmdrv_layer),
+						"cfshm%d", shm_netdev_setup);
+	if (!pshm_dev->pshm_netdev)
+		return -ENOMEM;
+
+	pshm_drv = netdev_priv(pshm_dev->pshm_netdev);
+	pshm_drv->pshm_dev = pshm_dev;
+
+	/*
+	 * Initialization starts with the verification of the
+	 * availability of MBX driver by calling its setup function.
+	 * MBX driver must be available by this time for proper
+	 * functioning of SHM driver.
+	 */
+	if ((pshm_dev->pshmdev_mbxsetup
+				(caif_shmdrv_rx_cb, pshm_dev, pshm_drv)) != 0) {
+		pr_warn("Could not config. SHM Mailbox,"
+				" Bailing out.....\n");
+		free_netdev(pshm_dev->pshm_netdev);
+		return -ENODEV;
+	}
+
+	skb_queue_head_init(&pshm_drv->sk_qhead);
+
+	pr_info("SHM DEVICE[%d] PROBED BY DRIVER, NEW SHM DRIVER"
+			" INSTANCE AT pshm_drv =0x%p\n",
+			pshm_drv->pshm_dev->shm_id, pshm_drv);
+
+	if (pshm_dev->shm_total_sz <
+			(NR_TX_BUF * TX_BUF_SZ + NR_RX_BUF * RX_BUF_SZ)) {
+
+		pr_warn("ERROR, Amount of available"
+				" Phys. SHM cannot accomodate current SHM "
+				"driver configuration, Bailing out ...\n");
+		free_netdev(pshm_dev->pshm_netdev);
+		return -ENOMEM;
+	}
+
+	pshm_drv->shm_base_addr = pshm_dev->shm_base_addr;
+	pshm_drv->shm_tx_addr = pshm_drv->shm_base_addr;
+
+	if (pshm_dev->shm_loopback)
+		pshm_drv->shm_rx_addr = pshm_drv->shm_tx_addr;
+	else
+		pshm_drv->shm_rx_addr = pshm_dev->shm_base_addr +
+						(NR_TX_BUF * TX_BUF_SZ);
+
+	INIT_LIST_HEAD(&pshm_drv->tx_empty_list);
+	INIT_LIST_HEAD(&pshm_drv->tx_pend_list);
+	INIT_LIST_HEAD(&pshm_drv->tx_full_list);
+
+	INIT_LIST_HEAD(&pshm_drv->rx_empty_list);
+	INIT_LIST_HEAD(&pshm_drv->rx_pend_list);
+	INIT_LIST_HEAD(&pshm_drv->rx_full_list);
+
+	INIT_WORK(&pshm_drv->shm_tx_work, shm_tx_work_func);
+	INIT_WORK(&pshm_drv->shm_rx_work, shm_rx_work_func);
+
+	pshm_drv->pshm_tx_workqueue =
+				create_singlethread_workqueue("shm_tx_work");
+	pshm_drv->pshm_rx_workqueue =
+				create_singlethread_workqueue("shm_rx_work");
+
+	for (j = 0; j < NR_TX_BUF; j++) {
+		struct buf_list *tx_buf =
+				kmalloc(sizeof(struct buf_list), GFP_KERNEL);
+
+		if (tx_buf == NULL) {
+			pr_warn("ERROR, Could not"
+					" allocate dynamic mem. for tx_buf,"
+					" Bailing out ...\n");
+			free_netdev(pshm_dev->pshm_netdev);
+			return -ENOMEM;
+		}
+		tx_buf->index = j;
+		tx_buf->phy_addr = pshm_drv->shm_tx_addr + (TX_BUF_SZ * j);
+		tx_buf->len = TX_BUF_SZ;
+		tx_buf->frames = 0;
+		tx_buf->frm_ofs = SHM_CAIF_FRM_OFS;
+
+		if (pshm_dev->shm_loopback)
+			tx_buf->desc_vptr = (char *)tx_buf->phy_addr;
+		else
+			tx_buf->desc_vptr =
+					ioremap(tx_buf->phy_addr, TX_BUF_SZ);
+
+		list_add_tail(&tx_buf->list, &pshm_drv->tx_empty_list);
+	}
+
+	for (j = 0; j < NR_RX_BUF; j++) {
+		struct buf_list *rx_buf =
+				kmalloc(sizeof(struct buf_list), GFP_KERNEL);
+
+		if (rx_buf == NULL) {
+			pr_warn("ERROR, Could not"
+					" allocate dynamic mem.for rx_buf,"
+					" Bailing out ...\n");
+			free_netdev(pshm_dev->pshm_netdev);
+			return -ENOMEM;
+		}
+		rx_buf->index = j;
+		rx_buf->phy_addr = pshm_drv->shm_rx_addr + (RX_BUF_SZ * j);
+		rx_buf->len = RX_BUF_SZ;
+
+		if (pshm_dev->shm_loopback)
+			rx_buf->desc_vptr = (char *)rx_buf->phy_addr;
+		else
+			rx_buf->desc_vptr =
+					ioremap(rx_buf->phy_addr, RX_BUF_SZ);
+		list_add_tail(&rx_buf->list, &pshm_drv->rx_empty_list);
+	}
+
+	pshm_drv->tx_empty_available = 1;
+	result = register_netdev(pshm_dev->pshm_netdev);
+	if (result)
+		pr_warn("ERROR[%d], SHM could not, "
+			"register with NW FRMWK Bailing out ...\n", result);
+
+	return result;
+}
+
+void caif_shmcore_remove(struct net_device *pshm_netdev)
+{
+	struct buf_list *pbuf;
+	struct shmdrv_layer *pshm_drv = NULL;
+
+	pshm_drv = netdev_priv(pshm_netdev);
+
+	while (!(list_empty(&pshm_drv->tx_pend_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_pend_list.next,
+					struct buf_list, list);
+
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->tx_full_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_full_list.next,
+					struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->tx_empty_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_empty_list.next,
+					struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->rx_full_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_full_list.next,
+				struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->rx_pend_list))) {
+		pbuf =
+			list_entry(pshm_drv->tx_pend_list.next,
+				struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	while (!(list_empty(&pshm_drv->rx_empty_list))) {
+		pbuf =
+			list_entry(pshm_drv->rx_empty_list.next,
+				struct buf_list, list);
+		list_del(&pbuf->list);
+		kfree(pbuf);
+	}
+
+	/* Destroy work queues. */
+	destroy_workqueue(pshm_drv->pshm_tx_workqueue);
+	destroy_workqueue(pshm_drv->pshm_rx_workqueue);
+
+	unregister_netdev(pshm_netdev);
+}
-- 
1.6.3.3

[PATCHv2 3/4] caif-u5500: CAIF shared memory mailbox interface

[Sjur Braendeland]

From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---
 drivers/net/caif/caif_shm_u5500.c |  129 +++++++++++++++++++++++++++++++++++++
 1 files changed, 129 insertions(+), 0 deletions(-)
 create mode 100644 drivers/net/caif/caif_shm_u5500.c

diff --git a/drivers/net/caif/caif_shm_u5500.c b/drivers/net/caif/caif_shm_u5500.c
new file mode 100644
index 0000000..1cd90da
--- /dev/null
+++ b/drivers/net/caif/caif_shm_u5500.c
@@ -0,0 +1,129 @@
+/*
+ * Copyright (C) ST-Ericsson AB 2010
+ * Contact: Sjur Brendeland / sjur.brandeland@stericsson.com
+ * Author:  Amarnath Revanna / amarnath.bangalore.revanna@stericsson.com
+ * License terms: GNU General Public License (GPL) version 2
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ":" __func__ "():" fmt
+
+#include <linux/version.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/netdevice.h>
+#include <mach/mbox.h>
+#include <net/caif/caif_shm.h>
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("CAIF Shared Memory protocol driver");
+
+#define MAX_SHM_INSTANCES	1
+
+enum {
+	MBX_ACC0,
+	MBX_ACC1,
+	MBX_DSP
+};
+
+static struct shmdev_layer shmdev_lyr[MAX_SHM_INSTANCES];
+
+static unsigned int shm_start;
+static unsigned int shm_size;
+
+module_param(shm_size, uint  , 0440);
+MODULE_PARM_DESC(shm_total_size, "Start of SHM shared memory");
+
+module_param(shm_start, uint  , 0440);
+MODULE_PARM_DESC(shm_total_start, "Total Size of SHM shared memory");
+
+static int shmdev_send_msg(u32 dev_id, u32 mbx_msg)
+{
+	/* Always block until msg is written successfully */
+	mbox_send(shmdev_lyr[dev_id].hmbx, mbx_msg, true);
+	return 0;
+}
+
+static int shmdev_mbx_setup(void *pshmdrv_cb, struct shmdev_layer *pshm_dev,
+							 void *pshm_drv)
+{
+	/*
+	 * For UX5500, we have only 1 SHM instance which uses MBX0
+	 * for communication with the peer modem
+	 */
+	pshm_dev->hmbx = mbox_setup(MBX_ACC0, pshmdrv_cb, pshm_drv);
+
+	if (!pshm_dev->hmbx)
+		return -ENODEV;
+	else
+		return 0;
+}
+
+static int __init caif_shmdev_init(void)
+{
+	int i, result;
+
+	/* Loop is currently overkill, there is only one instance */
+	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+
+		shmdev_lyr[i].shm_base_addr = shm_start;
+		shmdev_lyr[i].shm_total_sz = shm_size;
+
+		if (((char *)shmdev_lyr[i].shm_base_addr == NULL)
+			       || (shmdev_lyr[i].shm_total_sz <= 0))	{
+			pr_warn("ERROR,"
+				"Shared memory Address and/or Size incorrect"
+				", Bailing out ...\n");
+			result = -EINVAL;
+			goto clean;
+		}
+
+		pr_info("SHM AREA (instance %d) STARTS"
+			" AT %p\n", i, (char *)shmdev_lyr[i].shm_base_addr);
+
+		shmdev_lyr[i].shm_id = i;
+		shmdev_lyr[i].pshmdev_mbxsend = shmdev_send_msg;
+		shmdev_lyr[i].pshmdev_mbxsetup = shmdev_mbx_setup;
+
+		/*
+		 * Finally, CAIF core module is called with details in place:
+		 * 1. SHM base address
+		 * 2. SHM size
+		 * 3. MBX handle
+		 */
+		result = caif_shmcore_probe(&shmdev_lyr[i]);
+		if (result) {
+			pr_warn("ERROR[%d],"
+				"Could not probe SHM core (instance %d)"
+				" Bailing out ...\n", result, i);
+			goto clean;
+		}
+	}
+
+	return 0;
+
+clean:
+	/*
+	 * For now, we assume that even if one instance of SHM fails, we bail
+	 * out of the driver support completely. For this, we need to release
+	 * any memory allocated and unregister any instance of SHM net device.
+	 */
+	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+		if (shmdev_lyr[i].pshm_netdev)
+			unregister_netdev(shmdev_lyr[i].pshm_netdev);
+	}
+	return result;
+}
+
+static void __exit caif_shmdev_exit(void)
+{
+	int i;
+
+	for (i = 0; i < MAX_SHM_INSTANCES; i++) {
+		caif_shmcore_remove(shmdev_lyr[i].pshm_netdev);
+		kfree((void *)shmdev_lyr[i].shm_base_addr);
+	}
+
+}
+
+module_init(caif_shmdev_init);
+module_exit(caif_shmdev_exit);
-- 
1.6.3.3

[PATCHv2 4/4] caif-u5500: Build config for CAIF shared mem driver

[Sjur Braendeland]

From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>

Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
---
 drivers/net/caif/Kconfig  |    7 +++++++
 drivers/net/caif/Makefile |    4 ++++
 2 files changed, 11 insertions(+), 0 deletions(-)

diff --git a/drivers/net/caif/Kconfig b/drivers/net/caif/Kconfig
index 75bfc3a..09ed3f4 100644
--- a/drivers/net/caif/Kconfig
+++ b/drivers/net/caif/Kconfig
@@ -31,3 +31,10 @@ config CAIF_SPI_SYNC
 	Putting the next command and length in the start of the frame can
 	help to synchronize to the next transfer in case of over or under-runs.
 	This option also needs to be enabled on the modem.
+
+config CAIF_SHM
+	tristate "CAIF shared memory protocol driver"
+	depends on CAIF && U5500_MBOX
+	default n
+	---help---
+	The CAIF shared memory protocol driver for the STE UX5500 platform.
diff --git a/drivers/net/caif/Makefile b/drivers/net/caif/Makefile
index 3a11d61..b38d987 100644
--- a/drivers/net/caif/Makefile
+++ b/drivers/net/caif/Makefile
@@ -8,3 +8,7 @@ obj-$(CONFIG_CAIF_TTY) += caif_serial.o
 # SPI slave physical interfaces module
 cfspi_slave-objs := caif_spi.o caif_spi_slave.o
 obj-$(CONFIG_CAIF_SPI_SLAVE) += cfspi_slave.o
+
+# Shared memory
+caif_shm-objs := caif_shmcore.o caif_shm_u5500.o
+obj-$(CONFIG_CAIF_SHM) += caif_shm.o
-- 
1.6.3.3

Re: [PATCHv2 4/4] caif-u5500: Build config for CAIF shared mem driver

[David Miller]

From: Sjur Braendeland <sjur.brandeland@stericsson.com>
Date: Wed, 27 Oct 2010 20:34:42 +0200

> From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>
> 
> Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>

Applied.

Re: [PATCHv2 3/4] caif-u5500: CAIF shared memory mailbox interface

[David Miller]

From: Sjur Braendeland <sjur.brandeland@stericsson.com>
Date: Wed, 27 Oct 2010 20:34:41 +0200

> From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>
> 
> Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>

Applied.

Re: [PATCHv2 2/4] caif-u5500: CAIF shared memory transport protocol

[David Miller]

From: Sjur Braendeland <sjur.brandeland@stericsson.com>
Date: Wed, 27 Oct 2010 20:34:40 +0200

> Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>

Applied.

Re: [PATCHv2 1/4] caif-u5500: Adding shared memory include

[David Miller]

From: Sjur Braendeland <sjur.brandeland@stericsson.com>
Date: Wed, 27 Oct 2010 20:34:39 +0200

> From: Amarnath Revanna <amarnath.bangalore.revanna@stericsson.com>
> 
> Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>

Applied.