* [PATCH 2/4] net: ll_temac: Prepare indirect register access for multicast support
2019-05-23 12:02 [PATCH 0/4] net: ll_temac: Fix and enable multicast support Esben Haabendal
2019-05-23 12:02 ` [PATCH 1/4] net: ll_temac: Do not make promiscuous mode sticky on multicast Esben Haabendal
@ 2019-05-23 12:02 ` Esben Haabendal
2019-05-23 12:02 ` [PATCH 3/4] net: ll_temac: Cleanup multicast filter on change Esben Haabendal
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: Esben Haabendal @ 2019-05-23 12:02 UTC (permalink / raw)
To: netdev
Cc: David S. Miller, Michal Simek, Andrew Lunn, YueHaibing,
Petr Štetiar, Dan Carpenter, Yang Wei, linux-arm-kernel,
linux-kernel
With .ndo_set_rx_mode/temac_set_multicast_list() being called in atomic
context (holding addr_list_lock), and temac_set_multicast_list() needing
to access temac indirect registers, the mutex used to synchronize indirect
register is a no-no.
Replace it with a spinlock, and avoid sleeping in
temac_indirect_busywait().
To avoid excessive holding of the lock, which is now a spinlock, the
temac_device_reset() function is changed to only hold the lock for short
periods. With timeouts, it could be holding the spinlock for more than
2 seconds.
Signed-off-by: Esben Haabendal <esben@geanix.com>
---
drivers/net/ethernet/xilinx/ll_temac.h | 5 +-
drivers/net/ethernet/xilinx/ll_temac_main.c | 240 ++++++++++++++++++--------
drivers/net/ethernet/xilinx/ll_temac_mdio.c | 20 +--
include/linux/platform_data/xilinx-ll-temac.h | 3 +-
4 files changed, 179 insertions(+), 89 deletions(-)
diff --git a/drivers/net/ethernet/xilinx/ll_temac.h b/drivers/net/ethernet/xilinx/ll_temac.h
index 1aeda08..276292b 100644
--- a/drivers/net/ethernet/xilinx/ll_temac.h
+++ b/drivers/net/ethernet/xilinx/ll_temac.h
@@ -361,7 +361,7 @@ struct temac_local {
/* For synchronization of indirect register access. Must be
* shared mutex between interfaces in same TEMAC block.
*/
- struct mutex *indirect_mutex;
+ spinlock_t *indirect_lock;
u32 options; /* Current options word */
int last_link;
unsigned int temac_features;
@@ -388,8 +388,9 @@ struct temac_local {
/* xilinx_temac.c */
int temac_indirect_busywait(struct temac_local *lp);
u32 temac_indirect_in32(struct temac_local *lp, int reg);
+u32 temac_indirect_in32_locked(struct temac_local *lp, int reg);
void temac_indirect_out32(struct temac_local *lp, int reg, u32 value);
-
+void temac_indirect_out32_locked(struct temac_local *lp, int reg, u32 value);
/* xilinx_temac_mdio.c */
int temac_mdio_setup(struct temac_local *lp, struct platform_device *pdev);
diff --git a/drivers/net/ethernet/xilinx/ll_temac_main.c b/drivers/net/ethernet/xilinx/ll_temac_main.c
index 05195ff..9d43be3 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_main.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_main.c
@@ -52,6 +52,7 @@
#include <linux/slab.h>
#include <linux/interrupt.h>
#include <linux/dma-mapping.h>
+#include <linux/processor.h>
#include <linux/platform_data/xilinx-ll-temac.h>
#include "ll_temac.h"
@@ -83,51 +84,118 @@ static void _temac_iow_le(struct temac_local *lp, int offset, u32 value)
return iowrite32(value, lp->regs + offset);
}
+static bool hard_acs_rdy(struct temac_local *lp)
+{
+ return temac_ior(lp, XTE_RDY0_OFFSET) & XTE_RDY0_HARD_ACS_RDY_MASK;
+}
+
+static bool hard_acs_rdy_or_timeout(struct temac_local *lp, ktime_t timeout)
+{
+ ktime_t cur = ktime_get();
+
+ return hard_acs_rdy(lp) || ktime_after(cur, timeout);
+}
+
+/* Poll for maximum 20 ms. This is similar to the 2 jiffies @ 100 Hz
+ * that was used before, and should cover MDIO bus speed down to 3200
+ * Hz.
+ */
+#define HARD_ACS_RDY_POLL_NS (20 * NSEC_PER_MSEC)
+
+/**
+ * temac_indirect_busywait - Wait for current indirect register access
+ * to complete.
+ */
int temac_indirect_busywait(struct temac_local *lp)
{
- unsigned long end = jiffies + 2;
+ ktime_t timeout = ktime_add_ns(ktime_get(), HARD_ACS_RDY_POLL_NS);
- while (!(temac_ior(lp, XTE_RDY0_OFFSET) & XTE_RDY0_HARD_ACS_RDY_MASK)) {
- if (time_before_eq(end, jiffies)) {
- WARN_ON(1);
- return -ETIMEDOUT;
- }
- usleep_range(500, 1000);
- }
- return 0;
+ spin_until_cond(hard_acs_rdy_or_timeout(lp, timeout));
+ if (WARN_ON(!hard_acs_rdy(lp)))
+ return -ETIMEDOUT;
+ else
+ return 0;
}
/**
- * temac_indirect_in32
- *
- * lp->indirect_mutex must be held when calling this function
+ * temac_indirect_in32 - Indirect register read access. This function
+ * must be called without lp->indirect_lock being held.
*/
u32 temac_indirect_in32(struct temac_local *lp, int reg)
{
- u32 val;
+ unsigned long flags;
+ int val;
+
+ spin_lock_irqsave(lp->indirect_lock, flags);
+ val = temac_indirect_in32_locked(lp, reg);
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
+ return val;
+}
- if (temac_indirect_busywait(lp))
+/**
+ * temac_indirect_in32_locked - Indirect register read access. This
+ * function must be called with lp->indirect_lock being held. Use
+ * this together with spin_lock_irqsave/spin_lock_irqrestore to avoid
+ * repeated lock/unlock and to ensure uninterrupted access to indirect
+ * registers.
+ */
+u32 temac_indirect_in32_locked(struct temac_local *lp, int reg)
+{
+ /* This initial wait should normally not spin, as we always
+ * try to wait for indirect access to complete before
+ * releasing the indirect_lock.
+ */
+ if (WARN_ON(temac_indirect_busywait(lp)))
return -ETIMEDOUT;
+ /* Initiate read from indirect register */
temac_iow(lp, XTE_CTL0_OFFSET, reg);
- if (temac_indirect_busywait(lp))
+ /* Wait for indirect register access to complete. We really
+ * should not see timeouts, and could even end up causing
+ * problem for following indirect access, so let's make a bit
+ * of WARN noise.
+ */
+ if (WARN_ON(temac_indirect_busywait(lp)))
return -ETIMEDOUT;
- val = temac_ior(lp, XTE_LSW0_OFFSET);
-
- return val;
+ /* Value is ready now */
+ return temac_ior(lp, XTE_LSW0_OFFSET);
}
/**
- * temac_indirect_out32
- *
- * lp->indirect_mutex must be held when calling this function
+ * temac_indirect_out32 - Indirect register write access. This function
+ * must be called without lp->indirect_lock being held.
*/
void temac_indirect_out32(struct temac_local *lp, int reg, u32 value)
{
- if (temac_indirect_busywait(lp))
+ unsigned long flags;
+
+ spin_lock_irqsave(lp->indirect_lock, flags);
+ temac_indirect_out32_locked(lp, reg, value);
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
+}
+
+/**
+ * temac_indirect_out32_locked - Indirect register write access. This
+ * function must be called with lp->indirect_lock being held. Use
+ * this together with spin_lock_irqsave/spin_lock_irqrestore to avoid
+ * repeated lock/unlock and to ensure uninterrupted access to indirect
+ * registers.
+ */
+void temac_indirect_out32_locked(struct temac_local *lp, int reg, u32 value)
+{
+ /* As in temac_indirect_in32_locked(), we should normally not
+ * spin here. And if it happens, we actually end up silently
+ * ignoring the write request. Ouch.
+ */
+ if (WARN_ON(temac_indirect_busywait(lp)))
return;
+ /* Initiate write to indirect register */
temac_iow(lp, XTE_LSW0_OFFSET, value);
temac_iow(lp, XTE_CTL0_OFFSET, CNTLREG_WRITE_ENABLE_MASK | reg);
- temac_indirect_busywait(lp);
+ /* As in temac_indirect_in32_locked(), we should not see timeouts
+ * here. And if it happens, we continue before the write has
+ * completed. Not good.
+ */
+ WARN_ON(temac_indirect_busywait(lp));
}
/**
@@ -343,20 +411,21 @@ static int temac_dma_bd_init(struct net_device *ndev)
static void temac_do_set_mac_address(struct net_device *ndev)
{
struct temac_local *lp = netdev_priv(ndev);
+ unsigned long flags;
/* set up unicast MAC address filter set its mac address */
- mutex_lock(lp->indirect_mutex);
- temac_indirect_out32(lp, XTE_UAW0_OFFSET,
- (ndev->dev_addr[0]) |
- (ndev->dev_addr[1] << 8) |
- (ndev->dev_addr[2] << 16) |
- (ndev->dev_addr[3] << 24));
+ spin_lock_irqsave(lp->indirect_lock, flags);
+ temac_indirect_out32_locked(lp, XTE_UAW0_OFFSET,
+ (ndev->dev_addr[0]) |
+ (ndev->dev_addr[1] << 8) |
+ (ndev->dev_addr[2] << 16) |
+ (ndev->dev_addr[3] << 24));
/* There are reserved bits in EUAW1
* so don't affect them Set MAC bits [47:32] in EUAW1 */
- temac_indirect_out32(lp, XTE_UAW1_OFFSET,
- (ndev->dev_addr[4] & 0x000000ff) |
- (ndev->dev_addr[5] << 8));
- mutex_unlock(lp->indirect_mutex);
+ temac_indirect_out32_locked(lp, XTE_UAW1_OFFSET,
+ (ndev->dev_addr[4] & 0x000000ff) |
+ (ndev->dev_addr[5] << 8));
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
}
static int temac_init_mac_address(struct net_device *ndev, const void *address)
@@ -382,42 +451,56 @@ static int temac_set_mac_address(struct net_device *ndev, void *p)
static void temac_set_multicast_list(struct net_device *ndev)
{
struct temac_local *lp = netdev_priv(ndev);
- u32 multi_addr_msw, multi_addr_lsw, val;
+ u32 multi_addr_msw, multi_addr_lsw;
int i;
+ unsigned long flags;
+ bool promisc_mode_disabled = false;
- mutex_lock(lp->indirect_mutex);
- if (ndev->flags & (IFF_ALLMULTI | IFF_PROMISC) ||
- netdev_mc_count(ndev) > MULTICAST_CAM_TABLE_NUM) {
+ if (ndev->flags & (IFF_PROMISC | IFF_ALLMULTI) ||
+ (netdev_mc_count(ndev) > MULTICAST_CAM_TABLE_NUM)) {
temac_indirect_out32(lp, XTE_AFM_OFFSET, XTE_AFM_EPPRM_MASK);
dev_info(&ndev->dev, "Promiscuous mode enabled.\n");
- } else if (!netdev_mc_empty(ndev)) {
+ return;
+ }
+
+ spin_lock_irqsave(lp->indirect_lock, flags);
+
+ if (!netdev_mc_empty(ndev)) {
struct netdev_hw_addr *ha;
i = 0;
netdev_for_each_mc_addr(ha, ndev) {
- if (i >= MULTICAST_CAM_TABLE_NUM)
+ if (WARN_ON(i >= MULTICAST_CAM_TABLE_NUM))
break;
multi_addr_msw = ((ha->addr[3] << 24) |
(ha->addr[2] << 16) |
(ha->addr[1] << 8) |
(ha->addr[0]));
- temac_indirect_out32(lp, XTE_MAW0_OFFSET,
- multi_addr_msw);
+ temac_indirect_out32_locked(lp, XTE_MAW0_OFFSET,
+ multi_addr_msw);
multi_addr_lsw = ((ha->addr[5] << 8) |
(ha->addr[4]) | (i << 16));
- temac_indirect_out32(lp, XTE_MAW1_OFFSET,
- multi_addr_lsw);
+ temac_indirect_out32_locked(lp, XTE_MAW1_OFFSET,
+ multi_addr_lsw);
i++;
}
} else {
- val = temac_indirect_in32(lp, XTE_AFM_OFFSET);
- temac_indirect_out32(lp, XTE_AFM_OFFSET,
- val & ~XTE_AFM_EPPRM_MASK);
- temac_indirect_out32(lp, XTE_MAW0_OFFSET, 0);
- temac_indirect_out32(lp, XTE_MAW1_OFFSET, 0);
- dev_info(&ndev->dev, "Promiscuous mode disabled.\n");
+ temac_indirect_out32_locked(lp, XTE_MAW0_OFFSET, 0);
+ temac_indirect_out32_locked(lp, XTE_MAW1_OFFSET, i << 16);
+ }
}
- mutex_unlock(lp->indirect_mutex);
+
+ /* Enable address filter block if currently disabled */
+ if (temac_indirect_in32_locked(lp, XTE_AFM_OFFSET)
+ & XTE_AFM_EPPRM_MASK) {
+ temac_indirect_out32_locked(lp, XTE_AFM_OFFSET, 0);
+ promisc_mode_disabled = true;
+ }
+
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
+
+ if (promisc_mode_disabled)
+ dev_info(&ndev->dev, "Promiscuous mode disabled.\n");
}
static struct temac_option {
@@ -508,17 +591,19 @@ static u32 temac_setoptions(struct net_device *ndev, u32 options)
struct temac_local *lp = netdev_priv(ndev);
struct temac_option *tp = &temac_options[0];
int reg;
+ unsigned long flags;
- mutex_lock(lp->indirect_mutex);
+ spin_lock_irqsave(lp->indirect_lock, flags);
while (tp->opt) {
- reg = temac_indirect_in32(lp, tp->reg) & ~tp->m_or;
- if (options & tp->opt)
+ reg = temac_indirect_in32_locked(lp, tp->reg) & ~tp->m_or;
+ if (options & tp->opt) {
reg |= tp->m_or;
- temac_indirect_out32(lp, tp->reg, reg);
+ temac_indirect_out32_locked(lp, tp->reg, reg);
+ }
tp++;
}
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
lp->options |= options;
- mutex_unlock(lp->indirect_mutex);
return 0;
}
@@ -529,6 +614,7 @@ static void temac_device_reset(struct net_device *ndev)
struct temac_local *lp = netdev_priv(ndev);
u32 timeout;
u32 val;
+ unsigned long flags;
/* Perform a software reset */
@@ -537,7 +623,6 @@ static void temac_device_reset(struct net_device *ndev)
dev_dbg(&ndev->dev, "%s()\n", __func__);
- mutex_lock(lp->indirect_mutex);
/* Reset the receiver and wait for it to finish reset */
temac_indirect_out32(lp, XTE_RXC1_OFFSET, XTE_RXC1_RXRST_MASK);
timeout = 1000;
@@ -563,8 +648,11 @@ static void temac_device_reset(struct net_device *ndev)
}
/* Disable the receiver */
- val = temac_indirect_in32(lp, XTE_RXC1_OFFSET);
- temac_indirect_out32(lp, XTE_RXC1_OFFSET, val & ~XTE_RXC1_RXEN_MASK);
+ spin_lock_irqsave(lp->indirect_lock, flags);
+ val = temac_indirect_in32_locked(lp, XTE_RXC1_OFFSET);
+ temac_indirect_out32_locked(lp, XTE_RXC1_OFFSET,
+ val & ~XTE_RXC1_RXEN_MASK);
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
/* Reset Local Link (DMA) */
lp->dma_out(lp, DMA_CONTROL_REG, DMA_CONTROL_RST);
@@ -584,12 +672,12 @@ static void temac_device_reset(struct net_device *ndev)
"temac_device_reset descriptor allocation failed\n");
}
- temac_indirect_out32(lp, XTE_RXC0_OFFSET, 0);
- temac_indirect_out32(lp, XTE_RXC1_OFFSET, 0);
- temac_indirect_out32(lp, XTE_TXC_OFFSET, 0);
- temac_indirect_out32(lp, XTE_FCC_OFFSET, XTE_FCC_RXFLO_MASK);
-
- mutex_unlock(lp->indirect_mutex);
+ spin_lock_irqsave(lp->indirect_lock, flags);
+ temac_indirect_out32_locked(lp, XTE_RXC0_OFFSET, 0);
+ temac_indirect_out32_locked(lp, XTE_RXC1_OFFSET, 0);
+ temac_indirect_out32_locked(lp, XTE_TXC_OFFSET, 0);
+ temac_indirect_out32_locked(lp, XTE_FCC_OFFSET, XTE_FCC_RXFLO_MASK);
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
/* Sync default options with HW
* but leave receiver and transmitter disabled. */
@@ -613,13 +701,14 @@ static void temac_adjust_link(struct net_device *ndev)
struct phy_device *phy = ndev->phydev;
u32 mii_speed;
int link_state;
+ unsigned long flags;
/* hash together the state values to decide if something has changed */
link_state = phy->speed | (phy->duplex << 1) | phy->link;
- mutex_lock(lp->indirect_mutex);
if (lp->last_link != link_state) {
- mii_speed = temac_indirect_in32(lp, XTE_EMCFG_OFFSET);
+ spin_lock_irqsave(lp->indirect_lock, flags);
+ mii_speed = temac_indirect_in32_locked(lp, XTE_EMCFG_OFFSET);
mii_speed &= ~XTE_EMCFG_LINKSPD_MASK;
switch (phy->speed) {
@@ -629,11 +718,12 @@ static void temac_adjust_link(struct net_device *ndev)
}
/* Write new speed setting out to TEMAC */
- temac_indirect_out32(lp, XTE_EMCFG_OFFSET, mii_speed);
+ temac_indirect_out32_locked(lp, XTE_EMCFG_OFFSET, mii_speed);
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
+
lp->last_link = link_state;
phy_print_status(phy);
}
- mutex_unlock(lp->indirect_mutex);
}
#ifdef CONFIG_64BIT
@@ -1095,17 +1185,17 @@ static int temac_probe(struct platform_device *pdev)
/* Setup mutex for synchronization of indirect register access */
if (pdata) {
- if (!pdata->indirect_mutex) {
+ if (!pdata->indirect_lock) {
dev_err(&pdev->dev,
- "indirect_mutex missing in platform_data\n");
+ "indirect_lock missing in platform_data\n");
return -EINVAL;
}
- lp->indirect_mutex = pdata->indirect_mutex;
+ lp->indirect_lock = pdata->indirect_lock;
} else {
- lp->indirect_mutex = devm_kmalloc(&pdev->dev,
- sizeof(*lp->indirect_mutex),
- GFP_KERNEL);
- mutex_init(lp->indirect_mutex);
+ lp->indirect_lock = devm_kmalloc(&pdev->dev,
+ sizeof(*lp->indirect_lock),
+ GFP_KERNEL);
+ spin_lock_init(lp->indirect_lock);
}
/* map device registers */
diff --git a/drivers/net/ethernet/xilinx/ll_temac_mdio.c b/drivers/net/ethernet/xilinx/ll_temac_mdio.c
index a466732..6fd2dea 100644
--- a/drivers/net/ethernet/xilinx/ll_temac_mdio.c
+++ b/drivers/net/ethernet/xilinx/ll_temac_mdio.c
@@ -25,14 +25,15 @@ static int temac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
{
struct temac_local *lp = bus->priv;
u32 rc;
+ unsigned long flags;
/* Write the PHY address to the MIIM Access Initiator register.
* When the transfer completes, the PHY register value will appear
* in the LSW0 register */
- mutex_lock(lp->indirect_mutex);
+ spin_lock_irqsave(lp->indirect_lock, flags);
temac_iow(lp, XTE_LSW0_OFFSET, (phy_id << 5) | reg);
- rc = temac_indirect_in32(lp, XTE_MIIMAI_OFFSET);
- mutex_unlock(lp->indirect_mutex);
+ rc = temac_indirect_in32_locked(lp, XTE_MIIMAI_OFFSET);
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
dev_dbg(lp->dev, "temac_mdio_read(phy_id=%i, reg=%x) == %x\n",
phy_id, reg, rc);
@@ -43,6 +44,7 @@ static int temac_mdio_read(struct mii_bus *bus, int phy_id, int reg)
static int temac_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
{
struct temac_local *lp = bus->priv;
+ unsigned long flags;
dev_dbg(lp->dev, "temac_mdio_write(phy_id=%i, reg=%x, val=%x)\n",
phy_id, reg, val);
@@ -50,10 +52,10 @@ static int temac_mdio_write(struct mii_bus *bus, int phy_id, int reg, u16 val)
/* First write the desired value into the write data register
* and then write the address into the access initiator register
*/
- mutex_lock(lp->indirect_mutex);
- temac_indirect_out32(lp, XTE_MGTDR_OFFSET, val);
- temac_indirect_out32(lp, XTE_MIIMAI_OFFSET, (phy_id << 5) | reg);
- mutex_unlock(lp->indirect_mutex);
+ spin_lock_irqsave(lp->indirect_lock, flags);
+ temac_indirect_out32_locked(lp, XTE_MGTDR_OFFSET, val);
+ temac_indirect_out32_locked(lp, XTE_MIIMAI_OFFSET, (phy_id << 5) | reg);
+ spin_unlock_irqrestore(lp->indirect_lock, flags);
return 0;
}
@@ -87,9 +89,7 @@ int temac_mdio_setup(struct temac_local *lp, struct platform_device *pdev)
/* Enable the MDIO bus by asserting the enable bit and writing
* in the clock config */
- mutex_lock(lp->indirect_mutex);
temac_indirect_out32(lp, XTE_MC_OFFSET, 1 << 6 | clk_div);
- mutex_unlock(lp->indirect_mutex);
bus = devm_mdiobus_alloc(&pdev->dev);
if (!bus)
@@ -116,10 +116,8 @@ int temac_mdio_setup(struct temac_local *lp, struct platform_device *pdev)
if (rc)
return rc;
- mutex_lock(lp->indirect_mutex);
dev_dbg(lp->dev, "MDIO bus registered; MC:%x\n",
temac_indirect_in32(lp, XTE_MC_OFFSET));
- mutex_unlock(lp->indirect_mutex);
return 0;
}
diff --git a/include/linux/platform_data/xilinx-ll-temac.h b/include/linux/platform_data/xilinx-ll-temac.h
index 368530f..f4a6813 100644
--- a/include/linux/platform_data/xilinx-ll-temac.h
+++ b/include/linux/platform_data/xilinx-ll-temac.h
@@ -4,6 +4,7 @@
#include <linux/if_ether.h>
#include <linux/phy.h>
+#include <linux/spinlock.h>
struct ll_temac_platform_data {
bool txcsum; /* Enable/disable TX checksum */
@@ -21,7 +22,7 @@ struct ll_temac_platform_data {
* TEMAC IP block, the same mutex should be passed here, as
* they share the same DCR bus bridge.
*/
- struct mutex *indirect_mutex;
+ spinlock_t *indirect_lock;
/* DMA channel control setup */
u8 tx_irq_timeout; /* TX Interrupt Delay Time-out */
u8 tx_irq_count; /* TX Interrupt Coalescing Threshold Count */
--
2.4.11
^ permalink raw reply related [flat|nested] 6+ messages in thread