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crypto: ccree - fix PM race condition

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The PM code was racy, possibly causing the driver to submit
requests to a powered down device. Fix the race and while
at it simplify the PM code.

Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Fixes: 1358c13a48 ("crypto: ccree - fix resume race condition on init")
Cc: stable@kernel.org # v4.20
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Gilad Ben-Yossef 2020-01-16 12:14:43 +02:00 committed by Herbert Xu
parent 5c83e8ec4d
commit 15fd2566bf
4 changed files with 7 additions and 80 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
drivers/crypto/ccree/cc_driver.h
View File

@ -160,6 +160,7 @@ struct cc_drvdata {
int std_bodies;
bool sec_disabled;
u32 comp_mask;
bool pm_on;
};
struct cc_crypto_alg {

28
drivers/crypto/ccree/cc_pm.c
View File

@ -22,14 +22,8 @@ const struct dev_pm_ops ccree_pm = {
int cc_pm_suspend(struct device *dev)
{
struct cc_drvdata *drvdata = dev_get_drvdata(dev);
int rc;
dev_dbg(dev, "set HOST_POWER_DOWN_EN\n");
rc = cc_suspend_req_queue(drvdata);
if (rc) {
dev_err(dev, "cc_suspend_req_queue (%x)\n", rc);
return rc;
}
fini_cc_regs(drvdata);
cc_iowrite(drvdata, CC_REG(HOST_POWER_DOWN_EN), POWER_DOWN_ENABLE);
cc_clk_off(drvdata);
@ -63,13 +57,6 @@ int cc_pm_resume(struct device *dev)
/* check if tee fips error occurred during power down */
cc_tee_handle_fips_error(drvdata);
rc = cc_resume_req_queue(drvdata);
if (rc) {
dev_err(dev, "cc_resume_req_queue (%x)\n", rc);
return rc;
}
/* must be after the queue resuming as it uses the HW queue*/
cc_init_hash_sram(drvdata);
return 0;
@ -80,10 +67,8 @@ int cc_pm_get(struct device *dev)
int rc = 0;
struct cc_drvdata *drvdata = dev_get_drvdata(dev);
if (cc_req_queue_suspended(drvdata))
if (drvdata->pm_on)
rc = pm_runtime_get_sync(dev);
else
pm_runtime_get_noresume(dev);
return (rc == 1 ? 0 : rc);
}
@ -93,14 +78,11 @@ int cc_pm_put_suspend(struct device *dev)
int rc = 0;
struct cc_drvdata *drvdata = dev_get_drvdata(dev);
if (!cc_req_queue_suspended(drvdata)) {
if (drvdata->pm_on) {
pm_runtime_mark_last_busy(dev);
rc = pm_runtime_put_autosuspend(dev);
} else {
/* Something wrong happens*/
dev_err(dev, "request to suspend already suspended queue");
rc = -EBUSY;
}
return rc;
}
@ -117,7 +99,7 @@ int cc_pm_init(struct cc_drvdata *drvdata)
/* must be before the enabling to avoid redundant suspending */
pm_runtime_set_autosuspend_delay(dev, CC_SUSPEND_TIMEOUT);
pm_runtime_use_autosuspend(dev);
/* activate the PM module */
/* set us as active - note we won't do PM ops until cc_pm_go()! */
return pm_runtime_set_active(dev);
}
@ -125,9 +107,11 @@ int cc_pm_init(struct cc_drvdata *drvdata)
void cc_pm_go(struct cc_drvdata *drvdata)
{
pm_runtime_enable(drvdata_to_dev(drvdata));
drvdata->pm_on = true;
}
void cc_pm_fini(struct cc_drvdata *drvdata)
{
pm_runtime_disable(drvdata_to_dev(drvdata));
drvdata->pm_on = false;
}

50
drivers/crypto/ccree/cc_request_mgr.c
View File

@ -41,7 +41,6 @@ struct cc_req_mgr_handle {
#else
struct tasklet_struct comptask;
#endif
bool is_runtime_suspended;
};
struct cc_bl_item {
@ -664,52 +663,3 @@ static void comp_handler(unsigned long devarg)
cc_proc_backlog(drvdata);
dev_dbg(dev, "Comp. handler done.\n");
}
/*
* resume the queue configuration - no need to take the lock as this happens
* inside the spin lock protection
*/
#if defined(CONFIG_PM)
int cc_resume_req_queue(struct cc_drvdata *drvdata)
{
struct cc_req_mgr_handle *request_mgr_handle =
drvdata->request_mgr_handle;
spin_lock_bh(&request_mgr_handle->hw_lock);
request_mgr_handle->is_runtime_suspended = false;
spin_unlock_bh(&request_mgr_handle->hw_lock);
return 0;
}
/*
* suspend the queue configuration. Since it is used for the runtime suspend
* only verify that the queue can be suspended.
*/
int cc_suspend_req_queue(struct cc_drvdata *drvdata)
{
struct cc_req_mgr_handle *request_mgr_handle =
drvdata->request_mgr_handle;
/* lock the send_request */
spin_lock_bh(&request_mgr_handle->hw_lock);
if (request_mgr_handle->req_queue_head !=
request_mgr_handle->req_queue_tail) {
spin_unlock_bh(&request_mgr_handle->hw_lock);
return -EBUSY;
}
request_mgr_handle->is_runtime_suspended = true;
spin_unlock_bh(&request_mgr_handle->hw_lock);
return 0;
}
bool cc_req_queue_suspended(struct cc_drvdata *drvdata)
{
struct cc_req_mgr_handle *request_mgr_handle =
drvdata->request_mgr_handle;
return request_mgr_handle->is_runtime_suspended;
}
#endif

8
drivers/crypto/ccree/cc_request_mgr.h
View File

@ -40,12 +40,4 @@ void complete_request(struct cc_drvdata *drvdata);
void cc_req_mgr_fini(struct cc_drvdata *drvdata);
#if defined(CONFIG_PM)
int cc_resume_req_queue(struct cc_drvdata *drvdata);
int cc_suspend_req_queue(struct cc_drvdata *drvdata);
bool cc_req_queue_suspended(struct cc_drvdata *drvdata);
#endif
#endif /*__REQUEST_MGR_H__*/