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net: sfp: change st_mutex locking

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Change st_mutex's use within SFP such that it only protects the various
state members, as it was originally supposed to, and isn't held while
making various calls outside the driver.

Reviewed-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Russell King (Oracle)
2023-05-17 11:38:07 +01:00
committed by Jakub Kicinski
parent 97a492050a
commit 1974fd3bf0
1 changed files with 42 additions and 14 deletions
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56
drivers/net/phy/sfp.c
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@@ -242,10 +242,17 @@ struct sfp {
bool need_poll;
/* Access rules:
* state_hw_drive: st_mutex held
* state_hw_mask: st_mutex held
* state_soft_mask: st_mutex held
* state: st_mutex held unless reading input bits
*/
struct mutex st_mutex; /* Protects state */
unsigned int state_hw_mask;
unsigned int state_soft_mask;
unsigned int state;
struct delayed_work poll;
struct delayed_work timeout;
struct mutex sm_mutex; /* Protects state machine */
@@ -692,7 +699,6 @@ static void sfp_soft_start_poll(struct sfp *sfp)
const struct sfp_eeprom_id *id = &sfp->id;
unsigned int mask = 0;
sfp->state_soft_mask = 0;
if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_DISABLE)
mask |= SFP_F_TX_DISABLE;
if (id->ext.enhopts & SFP_ENHOPTS_SOFT_TX_FAULT)
@@ -700,19 +706,26 @@ static void sfp_soft_start_poll(struct sfp *sfp)
if (id->ext.enhopts & SFP_ENHOPTS_SOFT_RX_LOS)
mask |= SFP_F_LOS;
mutex_lock(&sfp->st_mutex);
// Poll the soft state for hardware pins we want to ignore
sfp->state_soft_mask = ~sfp->state_hw_mask & mask;
if (sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT) &&
!sfp->need_poll)
mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);
mutex_unlock(&sfp->st_mutex);
}
static void sfp_soft_stop_poll(struct sfp *sfp)
{
mutex_lock(&sfp->st_mutex);
sfp->state_soft_mask = 0;
mutex_unlock(&sfp->st_mutex);
}
/* sfp_get_state() - must be called with st_mutex held, or in the
* initialisation path.
*/
static unsigned int sfp_get_state(struct sfp *sfp)
{
unsigned int soft = sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT);
@@ -725,6 +738,9 @@ static unsigned int sfp_get_state(struct sfp *sfp)
return state;
}
/* sfp_set_state() - must be called with st_mutex held, or in the
* initialisation path.
*/
static void sfp_set_state(struct sfp *sfp, unsigned int state)
{
sfp->set_state(sfp, state);
@@ -736,8 +752,10 @@ static void sfp_set_state(struct sfp *sfp, unsigned int state)
static void sfp_mod_state(struct sfp *sfp, unsigned int mask, unsigned int set)
{
mutex_lock(&sfp->st_mutex);
sfp->state = (sfp->state & ~mask) | set;
sfp_set_state(sfp, sfp->state);
mutex_unlock(&sfp->st_mutex);
}
static unsigned int sfp_check(void *buf, size_t len)
@@ -1603,16 +1621,18 @@ static void sfp_debugfs_exit(struct sfp *sfp)
static void sfp_module_tx_fault_reset(struct sfp *sfp)
{
unsigned int state = sfp->state;
unsigned int state;
if (state & SFP_F_TX_DISABLE)
return;
mutex_lock(&sfp->st_mutex);
state = sfp->state;
if (!(state & SFP_F_TX_DISABLE)) {
sfp_set_state(sfp, state | SFP_F_TX_DISABLE);
sfp_set_state(sfp, state | SFP_F_TX_DISABLE);
udelay(T_RESET_US);
udelay(T_RESET_US);
sfp_set_state(sfp, state);
sfp_set_state(sfp, state);
}
mutex_unlock(&sfp->st_mutex);
}
/* SFP state machine */
@@ -1957,6 +1977,7 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
/* SFP module inserted - read I2C data */
struct sfp_eeprom_id id;
bool cotsworks_sfbg;
unsigned int mask;
bool cotsworks;
u8 check;
int ret;
@@ -2096,14 +2117,13 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
if (ret < 0)
return ret;
/* Initialise state bits to use from hardware */
sfp->state_hw_mask = SFP_F_PRESENT;
mask = SFP_F_PRESENT;
if (sfp->gpio[GPIO_TX_DISABLE])
sfp->state_hw_mask |= SFP_F_TX_DISABLE;
mask |= SFP_F_TX_DISABLE;
if (sfp->gpio[GPIO_TX_FAULT])
sfp->state_hw_mask |= SFP_F_TX_FAULT;
mask |= SFP_F_TX_FAULT;
if (sfp->gpio[GPIO_LOS])
sfp->state_hw_mask |= SFP_F_LOS;
mask |= SFP_F_LOS;
sfp->module_t_start_up = T_START_UP;
sfp->module_t_wait = T_WAIT;
@@ -2121,8 +2141,14 @@ static int sfp_sm_mod_probe(struct sfp *sfp, bool report)
sfp->mdio_protocol = MDIO_I2C_NONE;
sfp->quirk = sfp_lookup_quirk(&id);
mutex_lock(&sfp->st_mutex);
/* Initialise state bits to use from hardware */
sfp->state_hw_mask = mask;
if (sfp->quirk && sfp->quirk->fixup)
sfp->quirk->fixup(sfp);
mutex_unlock(&sfp->st_mutex);
return 0;
}
@@ -2619,6 +2645,7 @@ static void sfp_check_state(struct sfp *sfp)
state |= sfp->state & (SFP_F_TX_DISABLE | SFP_F_RATE_SELECT);
sfp->state = state;
mutex_unlock(&sfp->st_mutex);
mutex_lock(&sfp->sm_mutex);
if (changed & SFP_F_PRESENT)
@@ -2633,7 +2660,6 @@ static void sfp_check_state(struct sfp *sfp)
__sfp_sm_event(sfp, state & SFP_F_LOS ?
SFP_E_LOS_HIGH : SFP_E_LOS_LOW);
mutex_unlock(&sfp->sm_mutex);
mutex_unlock(&sfp->st_mutex);
rtnl_unlock();
}
@@ -2652,6 +2678,8 @@ static void sfp_poll(struct work_struct *work)
sfp_check_state(sfp);
// st_mutex doesn't need to be held here for state_soft_mask,
// it's unimportant if we race while reading this.
if (sfp->state_soft_mask & (SFP_F_LOS | SFP_F_TX_FAULT) ||
sfp->need_poll)
mod_delayed_work(system_wq, &sfp->poll, poll_jiffies);