2010-11-30 04:20:25

by Tomoya MORINAGA

[permalink] [raw]
Subject: [PATCH net-next-2.6 v6 05/20] can: EG20T PCH: Delete unnecessary spin_lock

Delete unnecessary spin_lock for accessing Message Object.
Since all message objects are divided into tx/rx area completely,
spin_lock processing is unnecessary.

Signed-off-by: Tomoya MORINAGA <[email protected]>
Acked-by: Marc Kleine-Budde <[email protected]>
---
drivers/net/can/pch_can.c | 34 ----------------------------------
1 files changed, 0 insertions(+), 34 deletions(-)

diff --git a/drivers/net/can/pch_can.c b/drivers/net/can/pch_can.c
index 8686d93..6437e60 100644
--- a/drivers/net/can/pch_can.c
+++ b/drivers/net/can/pch_can.c
@@ -71,7 +71,6 @@
#define PCH_REC 0x00007f00
#define PCH_TEC 0x000000ff

-
#define PCH_TX_OK BIT(3)
#define PCH_RX_OK BIT(4)
#define PCH_EPASSIV BIT(5)
@@ -178,7 +177,6 @@ struct pch_can_priv {
unsigned int int_enables;
unsigned int int_stat;
struct net_device *ndev;
- spinlock_t msgif_reg_lock; /* Message Interface Registers Access Lock*/
unsigned int msg_obj[PCH_TX_OBJ_END];
struct pch_can_regs __iomem *regs;
struct napi_struct napi;
@@ -309,7 +307,6 @@ static void pch_can_check_if_busy(u32 __iomem *creq_addr, u32 num)
static void pch_can_set_rxtx(struct pch_can_priv *priv, u32 buff_num,
u32 set, enum pch_ifreg dir)
{
- unsigned long flags;
u32 ie;

if (dir)
@@ -317,7 +314,6 @@ static void pch_can_set_rxtx(struct pch_can_priv *priv, u32 buff_num,
else
ie = PCH_IF_MCONT_RXIE;

- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
/* Reading the receive buffer data from RAM to Interface1 registers */
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[dir].creq, buff_num);
@@ -338,10 +334,8 @@ static void pch_can_set_rxtx(struct pch_can_priv *priv, u32 buff_num,
}

pch_can_check_if_busy(&priv->regs->ifregs[dir].creq, buff_num);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
}

-
static void pch_can_set_rx_all(struct pch_can_priv *priv, u32 set)
{
int i;
@@ -363,7 +357,6 @@ static void pch_can_set_tx_all(struct pch_can_priv *priv, u32 set)
static u32 pch_can_get_rxtx_ir(struct pch_can_priv *priv, u32 buff_num,
enum pch_ifreg dir)
{
- unsigned long flags;
u32 ie, enable;

if (dir)
@@ -371,7 +364,6 @@ static u32 pch_can_get_rxtx_ir(struct pch_can_priv *priv, u32 buff_num,
else
ie = PCH_IF_MCONT_TXIE;

- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[dir].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[dir].creq, buff_num);

@@ -381,7 +373,6 @@ static u32 pch_can_get_rxtx_ir(struct pch_can_priv *priv, u32 buff_num,
} else {
enable = 0;
}
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
return enable;
}

@@ -393,9 +384,6 @@ static int pch_can_int_pending(struct pch_can_priv *priv)
static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
u32 buffer_num, u32 set)
{
- unsigned long flags;
-
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[0].creq, buffer_num);
iowrite32(PCH_CMASK_RDWR | PCH_CMASK_CTRL,
@@ -407,15 +395,11 @@ static void pch_can_set_rx_buffer_link(struct pch_can_priv *priv,
pch_can_bit_set(&priv->regs->ifregs[0].mcont, PCH_IF_MCONT_EOB);

pch_can_check_if_busy(&priv->regs->ifregs[0].creq, buffer_num);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
}

static void pch_can_get_rx_buffer_link(struct pch_can_priv *priv,
u32 buffer_num, u32 *link)
{
- unsigned long flags;
-
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[0].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[0].creq, buffer_num);

@@ -423,7 +407,6 @@ static void pch_can_get_rx_buffer_link(struct pch_can_priv *priv,
*link = PCH_DISABLE;
else
*link = PCH_ENABLE;
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
}

static void pch_can_clear_buffers(struct pch_can_priv *priv)
@@ -468,9 +451,6 @@ static void pch_can_clear_buffers(struct pch_can_priv *priv)
static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)
{
int i;
- unsigned long flags;
-
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);

for (i = PCH_RX_OBJ_START; i <= PCH_RX_OBJ_END; i++) {
iowrite32(PCH_CMASK_RX_TX_GET,
@@ -529,7 +509,6 @@ static void pch_can_config_rx_tx_buffers(struct pch_can_priv *priv)

pch_can_check_if_busy(&priv->regs->ifregs[1].creq, i);
}
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
}

static void pch_can_init(struct pch_can_priv *priv)
@@ -845,7 +824,6 @@ static int pch_can_rx_poll(struct napi_struct *napi, int quota)
u32 int_stat;
int rcv_pkts = 0;
u32 reg_stat;
- unsigned long flags;

int_stat = pch_can_int_pending(priv);
if (!int_stat)
@@ -860,12 +838,10 @@ INT_STAT:
}

if (reg_stat & PCH_TX_OK) {
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET,
&priv->regs->ifregs[1].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[1].creq,
ioread32(&priv->regs->intr));
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
pch_can_bit_clear(&priv->regs->stat, PCH_TX_OK);
}

@@ -879,22 +855,18 @@ INT_STAT:

MSG_OBJ:
if ((int_stat >= PCH_RX_OBJ_START) && (int_stat <= PCH_RX_OBJ_END)) {
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
rcv_pkts = pch_can_rx_normal(ndev, int_stat);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
if (rcv_pkts < 0)
return 0;
} else if ((int_stat >= PCH_TX_OBJ_START) &&
(int_stat <= PCH_TX_OBJ_END)) {
/* Handle transmission interrupt */
can_get_echo_skb(ndev, int_stat - PCH_RX_OBJ_END - 1);
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
iowrite32(PCH_CMASK_RX_TX_GET | PCH_CMASK_CLRINTPND,
&priv->regs->ifregs[1].cmask);
dlc = ioread32(&priv->regs->ifregs[1].mcont) &
PCH_IF_MCONT_DLC;
pch_can_check_if_busy(&priv->regs->ifregs[1].creq, int_stat);
- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
if (dlc > 8)
dlc = 8;
stats->tx_bytes += dlc;
@@ -1042,7 +1014,6 @@ static int pch_close(struct net_device *ndev)
static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
{
int i, j;
- unsigned long flags;
struct pch_can_priv *priv = netdev_priv(ndev);
struct can_frame *cf = (struct can_frame *)skb->data;
int tx_buffer_avail = 0;
@@ -1061,9 +1032,6 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)
priv->tx_obj++;
}

- /* Attaining the lock. */
- spin_lock_irqsave(&priv->msgif_reg_lock, flags);
-
/* Reading the Msg Obj from the Msg RAM to the Interface register. */
iowrite32(PCH_CMASK_RX_TX_GET, &priv->regs->ifregs[1].cmask);
pch_can_check_if_busy(&priv->regs->ifregs[1].creq, tx_buffer_avail);
@@ -1115,8 +1083,6 @@ static netdev_tx_t pch_xmit(struct sk_buff *skb, struct net_device *ndev)

pch_can_check_if_busy(&priv->regs->ifregs[1].creq, tx_buffer_avail);

- spin_unlock_irqrestore(&priv->msgif_reg_lock, flags);
-
return NETDEV_TX_OK;
}

--
1.6.0.6


2010-12-02 21:13:37

by David Miller

[permalink] [raw]
Subject: Re: [PATCH net-next-2.6 v6 05/20] can: EG20T PCH: Delete unnecessary spin_lock

From: Tomoya MORINAGA <[email protected]>
Date: Tue, 30 Nov 2010 13:19:52 +0900

> Delete unnecessary spin_lock for accessing Message Object.
> Since all message objects are divided into tx/rx area completely,
> spin_lock processing is unnecessary.
>
> Signed-off-by: Tomoya MORINAGA <[email protected]>
> Acked-by: Marc Kleine-Budde <[email protected]>

Applied.