[PATCH net-next] net: dsa: mv88e6xxx: assert SMI lock

From: Vivien Didelot
Date: Fri Oct 30 2015 - 16:42:30 EST


It's easy to forget to lock the smi_mutex before calling the low-level
_mv88e6xxx_reg_{read,write}, so add a assert_smi_lock function in them.

Signed-off-by: Vivien Didelot <vivien.didelot@xxxxxxxxxxxxxxxxxxxx>
---
drivers/net/dsa/mv88e6xxx.c | 31 ++++++++++++++++++-------------
1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
index b1b14f5..70a0106 100644
--- a/drivers/net/dsa/mv88e6xxx.c
+++ b/drivers/net/dsa/mv88e6xxx.c
@@ -24,6 +24,16 @@
#include <net/switchdev.h>
#include "mv88e6xxx.h"

+static inline void assert_smi_lock(struct dsa_switch *ds)
+{
+ struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);
+
+ if (unlikely(!mutex_is_locked(&ps->smi_mutex))) {
+ dev_err(ds->master_dev, "SMI lock not held!\n");
+ dump_stack();
+ }
+}
+
/* If the switch's ADDR[4:0] strap pins are strapped to zero, it will
* use all 32 SMI bus addresses on its SMI bus, and all switch registers
* will be directly accessible on some {device address,register address}
@@ -80,12 +90,14 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg)
return ret & 0xffff;
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)
{
- struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
+ struct mii_bus *bus;
int ret;

+ assert_smi_lock(ds);
+
+ bus = dsa_host_dev_to_mii_bus(ds->master_dev);
if (bus == NULL)
return -EINVAL;

@@ -143,12 +155,14 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr,
return 0;
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg,
u16 val)
{
- struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);
+ struct mii_bus *bus;
+
+ assert_smi_lock(ds);

+ bus = dsa_host_dev_to_mii_bus(ds->master_dev);
if (bus == NULL)
return -EINVAL;

@@ -204,7 +218,6 @@ int mv88e6xxx_set_addr_indirect(struct dsa_switch *ds, u8 *addr)
return 0;
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_phy_read(struct dsa_switch *ds, int addr, int regnum)
{
if (addr >= 0)
@@ -212,7 +225,6 @@ static int _mv88e6xxx_phy_read(struct dsa_switch *ds, int addr, int regnum)
return 0xffff;
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_phy_write(struct dsa_switch *ds, int addr, int regnum,
u16 val)
{
@@ -538,7 +550,6 @@ out:
mutex_unlock(&ps->smi_mutex);
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_stats_wait(struct dsa_switch *ds)
{
int ret;
@@ -553,7 +564,6 @@ static int _mv88e6xxx_stats_wait(struct dsa_switch *ds)
return -ETIMEDOUT;
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_stats_snapshot(struct dsa_switch *ds, int port)
{
int ret;
@@ -576,7 +586,6 @@ static int _mv88e6xxx_stats_snapshot(struct dsa_switch *ds, int port)
return 0;
}

-/* Must be called with SMI mutex held */
static void _mv88e6xxx_stats_read(struct dsa_switch *ds, int stat, u32 *val)
{
u32 _val;
@@ -789,7 +798,6 @@ void mv88e6xxx_get_regs(struct dsa_switch *ds, int port,
}
}

-/* Must be called with SMI lock held */
static int _mv88e6xxx_wait(struct dsa_switch *ds, int reg, int offset,
u16 mask)
{
@@ -839,14 +847,12 @@ int mv88e6xxx_eeprom_busy_wait(struct dsa_switch *ds)
GLOBAL2_EEPROM_OP_BUSY);
}

-/* Must be called with SMI lock held */
static int _mv88e6xxx_atu_wait(struct dsa_switch *ds)
{
return _mv88e6xxx_wait(ds, REG_GLOBAL, GLOBAL_ATU_OP,
GLOBAL_ATU_OP_BUSY);
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_phy_read_indirect(struct dsa_switch *ds, int addr,
int regnum)
{
@@ -865,7 +871,6 @@ static int _mv88e6xxx_phy_read_indirect(struct dsa_switch *ds, int addr,
return _mv88e6xxx_reg_read(ds, REG_GLOBAL2, GLOBAL2_SMI_DATA);
}

-/* Must be called with SMI mutex held */
static int _mv88e6xxx_phy_write_indirect(struct dsa_switch *ds, int addr,
int regnum, u16 val)
{
--
2.6.2

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