net: dsa: mv88e6xxx: assert SMI lock

vivien · davem330 · commit 3996a4ffb01f · 2015-11-02T15:54:13.000-05:00
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 &lt;vivien.didelot@savoirfairelinux.com&gt;
Acked-by: Andrew Lunn &lt;andrew@lunn.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git a/drivers/net/dsa/mv88e6xxx.c b/drivers/net/dsa/mv88e6xxx.c
@@ -24,6 +24,16 @@
 #include <net/switchdev.h>
 #include "mv88e6xxx.h"
 
+static 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 +90,13 @@ 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);
 	int ret;
 
+	assert_smi_lock(ds);
+
 	if (bus == NULL)
 		return -EINVAL;
 
@@ -143,12 +154,13 @@ 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);
 
+	assert_smi_lock(ds);
+
 	if (bus == NULL)
 		return -EINVAL;
 
@@ -204,15 +216,13 @@ 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)
 		return _mv88e6xxx_reg_read(ds, addr, 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 +548,6 @@ void mv88e6xxx_adjust_link(struct dsa_switch *ds, int port,
 	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 +562,6 @@ 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 +584,6 @@ 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 +796,6 @@ 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 +845,12 @@ 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 +869,6 @@ 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)
 {

Original file line number	Diff line number	Diff line change
`@@ -24,6 +24,16 @@`
`24`	`24`	`#include <net/switchdev.h>`
`25`	`25`	`#include "mv88e6xxx.h"`
`26`	`26`
	`27`	`+static void assert_smi_lock(struct dsa_switch *ds)`
	`28`	`+{`
	`29`	`+ struct mv88e6xxx_priv_state *ps = ds_to_priv(ds);`
	`30`	`+`
	`31`	`+ if (unlikely(!mutex_is_locked(&ps->smi_mutex))) {`
	`32`	`+ dev_err(ds->master_dev, "SMI lock not held!\n");`
	`33`	`+ dump_stack();`
	`34`	`+ }`
	`35`	`+}`
	`36`	`+`
`27`	`37`	`/* If the switch's ADDR[4:0] strap pins are strapped to zero, it will`
`28`	`38`	`* use all 32 SMI bus addresses on its SMI bus, and all switch registers`
`29`	`39`	`* will be directly accessible on some {device address,register address}`
`@@ -80,12 +90,13 @@ int __mv88e6xxx_reg_read(struct mii_bus *bus, int sw_addr, int addr, int reg)`
`80`	`90`	`return ret & 0xffff;`
`81`	`91`	`}`
`82`	`92`
`83`		`-/* Must be called with SMI mutex held */`
`84`	`93`	`static int _mv88e6xxx_reg_read(struct dsa_switch *ds, int addr, int reg)`
`85`	`94`	`{`
`86`	`95`	`struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);`
`87`	`96`	`int ret;`
`88`	`97`
	`98`	`+ assert_smi_lock(ds);`
	`99`	`+`
`89`	`100`	`if (bus == NULL)`
`90`	`101`	`return -EINVAL;`
`91`	`102`
`@@ -143,12 +154,13 @@ int __mv88e6xxx_reg_write(struct mii_bus *bus, int sw_addr, int addr,`
`143`	`154`	`return 0;`
`144`	`155`	`}`
`145`	`156`
`146`		`-/* Must be called with SMI mutex held */`
`147`	`157`	`static int _mv88e6xxx_reg_write(struct dsa_switch *ds, int addr, int reg,`
`148`	`158`	`u16 val)`
`149`	`159`	`{`
`150`	`160`	`struct mii_bus *bus = dsa_host_dev_to_mii_bus(ds->master_dev);`
`151`	`161`
	`162`	`+ assert_smi_lock(ds);`
	`163`	`+`
`152`	`164`	`if (bus == NULL)`
`153`	`165`	`return -EINVAL;`
`154`	`166`
`@@ -204,15 +216,13 @@ int mv88e6xxx_set_addr_indirect(struct dsa_switch ds, u8 addr)`
`204`	`216`	`return 0;`
`205`	`217`	`}`
`206`	`218`
`207`		`-/* Must be called with SMI mutex held */`
`208`	`219`	`static int _mv88e6xxx_phy_read(struct dsa_switch *ds, int addr, int regnum)`
`209`	`220`	`{`
`210`	`221`	`if (addr >= 0)`
`211`	`222`	`return _mv88e6xxx_reg_read(ds, addr, regnum);`
`212`	`223`	`return 0xffff;`
`213`	`224`	`}`
`214`	`225`
`215`		`-/* Must be called with SMI mutex held */`
`216`	`226`	`static int _mv88e6xxx_phy_write(struct dsa_switch *ds, int addr, int regnum,`
`217`	`227`	`u16 val)`
`218`	`228`	`{`
`@@ -538,7 +548,6 @@ void mv88e6xxx_adjust_link(struct dsa_switch *ds, int port,`
`538`	`548`	`mutex_unlock(&ps->smi_mutex);`
`539`	`549`	`}`
`540`	`550`
`541`		`-/* Must be called with SMI mutex held */`
`542`	`551`	`static int _mv88e6xxx_stats_wait(struct dsa_switch *ds)`
`543`	`552`	`{`
`544`	`553`	`int ret;`
`@@ -553,7 +562,6 @@ static int _mv88e6xxx_stats_wait(struct dsa_switch *ds)`
`553`	`562`	`return -ETIMEDOUT;`
`554`	`563`	`}`
`555`	`564`
`556`		`-/* Must be called with SMI mutex held */`
`557`	`565`	`static int _mv88e6xxx_stats_snapshot(struct dsa_switch *ds, int port)`
`558`	`566`	`{`
`559`	`567`	`int ret;`
`@@ -576,7 +584,6 @@ static int _mv88e6xxx_stats_snapshot(struct dsa_switch *ds, int port)`
`576`	`584`	`return 0;`
`577`	`585`	`}`
`578`	`586`
`579`		`-/* Must be called with SMI mutex held */`
`580`	`587`	`static void _mv88e6xxx_stats_read(struct dsa_switch ds, int stat, u32 val)`
`581`	`588`	`{`
`582`	`589`	`u32 _val;`
`@@ -789,7 +796,6 @@ void mv88e6xxx_get_regs(struct dsa_switch *ds, int port,`
`789`	`796`	`}`
`790`	`797`	`}`
`791`	`798`
`792`		`-/* Must be called with SMI lock held */`
`793`	`799`	`static int _mv88e6xxx_wait(struct dsa_switch *ds, int reg, int offset,`
`794`	`800`	`u16 mask)`
`795`	`801`	`{`
`@@ -839,14 +845,12 @@ int mv88e6xxx_eeprom_busy_wait(struct dsa_switch *ds)`
`839`	`845`	`GLOBAL2_EEPROM_OP_BUSY);`
`840`	`846`	`}`
`841`	`847`
`842`		`-/* Must be called with SMI lock held */`
`843`	`848`	`static int _mv88e6xxx_atu_wait(struct dsa_switch *ds)`
`844`	`849`	`{`
`845`	`850`	`return _mv88e6xxx_wait(ds, REG_GLOBAL, GLOBAL_ATU_OP,`
`846`	`851`	`GLOBAL_ATU_OP_BUSY);`
`847`	`852`	`}`
`848`	`853`
`849`		`-/* Must be called with SMI mutex held */`
`850`	`854`	`static int _mv88e6xxx_phy_read_indirect(struct dsa_switch *ds, int addr,`
`851`	`855`	`int regnum)`
`852`	`856`	`{`
`@@ -865,7 +869,6 @@ static int _mv88e6xxx_phy_read_indirect(struct dsa_switch *ds, int addr,`
`865`	`869`	`return _mv88e6xxx_reg_read(ds, REG_GLOBAL2, GLOBAL2_SMI_DATA);`
`866`	`870`	`}`
`867`	`871`
`868`		`-/* Must be called with SMI mutex held */`
`869`	`872`	`static int _mv88e6xxx_phy_write_indirect(struct dsa_switch *ds, int addr,`
`870`	`873`	`int regnum, u16 val)`
`871`	`874`	`{`