| Message ID | 20220607145639.2362750-13-tzungbi@kernel.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
| Series | platform/chrome: Kunit tests and refactor for cros_ec_query_all() | expand |
On Tue, Jun 7, 2022 at 7:57 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote: > > Use krealloc() to re-allocate `din` and `dout`. Don't use devm variant > because the two buffers could be re-allocated multiple times during > runtime. Their life cycles aren't quite aligned to the device's. While this saves a few lines of code, it is runtime-expensive: krealloc() copies the old data, which is a waste of time/resources. Maybe it would be better to just use kfree() followed by kzalloc(). > > Free the memory in cros_ec_unregister() if any. > > No need to free memory if krealloc() fails. They will be freed > eventually in either of the following: > - Error handling path in cros_ec_register(). > - In cros_ec_unregister(). > - Next krealloc() in cros_ec_query_all(). > > Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> > --- > Changes from v1: > - Don't use devm. > - Free in cros_ec_unregister(). > > drivers/platform/chrome/cros_ec.c | 4 +++ > drivers/platform/chrome/cros_ec_proto.c | 29 +++++++------------- > drivers/platform/chrome/cros_ec_proto_test.c | 3 +- > 3 files changed, 15 insertions(+), 21 deletions(-) > > diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c > index 29d3b544dafb..fb8cb8a73295 100644 > --- a/drivers/platform/chrome/cros_ec.c > +++ b/drivers/platform/chrome/cros_ec.c > @@ -285,6 +285,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev) > exit: > platform_device_unregister(ec_dev->ec); > platform_device_unregister(ec_dev->pd); > + kfree(ec_dev->din); > + kfree(ec_dev->dout); > return err; > } > EXPORT_SYMBOL(cros_ec_register); > @@ -302,6 +304,8 @@ void cros_ec_unregister(struct cros_ec_device *ec_dev) > if (ec_dev->pd) > platform_device_unregister(ec_dev->pd); > platform_device_unregister(ec_dev->ec); > + kfree(ec_dev->din); > + kfree(ec_dev->dout); > } > EXPORT_SYMBOL(cros_ec_unregister); > > diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c > index 473654f50bca..de6bc457e496 100644 > --- a/drivers/platform/chrome/cros_ec_proto.c > +++ b/drivers/platform/chrome/cros_ec_proto.c > @@ -469,9 +469,9 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev, > */ > int cros_ec_query_all(struct cros_ec_device *ec_dev) > { > - struct device *dev = ec_dev->dev; > u32 ver_mask = 0; > int ret; > + u8 *din, *dout; > > /* First try sending with proto v3. */ > if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) { > @@ -492,21 +492,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev) > } > } > > - devm_kfree(dev, ec_dev->din); > - devm_kfree(dev, ec_dev->dout); > - > - ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); > - if (!ec_dev->din) { > - ret = -ENOMEM; > - goto exit; > - } > + din = krealloc(ec_dev->din, ec_dev->din_size, GFP_KERNEL); > + if (!din) > + return -ENOMEM; I would suggest assigning the values directly; the new variables don't really add value. Thanks, Guenter > + ec_dev->din = din; > > - ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); > - if (!ec_dev->dout) { > - devm_kfree(dev, ec_dev->din); > - ret = -ENOMEM; > - goto exit; > - } > + dout = krealloc(ec_dev->dout, ec_dev->dout_size, GFP_KERNEL); > + if (!dout) > + return -ENOMEM; > + ec_dev->dout = dout; > > /* Probe if MKBP event is supported */ > ret = cros_ec_get_host_command_version_mask(ec_dev, > @@ -555,10 +549,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev) > "failed to retrieve wake mask: %d\n", ret); > } > > - ret = 0; > - > -exit: > - return ret; > + return 0; > } > EXPORT_SYMBOL(cros_ec_query_all); > > diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c > index 730248be42a7..27b81a5a9880 100644 > --- a/drivers/platform/chrome/cros_ec_proto_test.c > +++ b/drivers/platform/chrome/cros_ec_proto_test.c > @@ -180,8 +180,7 @@ static void cros_ec_proto_test_query_all_pretest(struct kunit *test) > > /* > * cros_ec_query_all() will free din and dout and allocate them again to fit the usage by > - * calling devm_kfree() and devm_kzalloc(). Set them to NULL as they aren't managed by > - * ec_dev->dev. > + * calling krealloc(). Set them to NULL as they aren't allocated by kalloc(). > */ > ec_dev->din = NULL; > ec_dev->dout = NULL; > -- > 2.36.1.255.ge46751e96f-goog >
On Tue, Jun 07, 2022 at 12:06:23PM -0700, Guenter Roeck wrote: > On Tue, Jun 7, 2022 at 7:57 AM Tzung-Bi Shih <tzungbi@kernel.org> wrote: > > > > Use krealloc() to re-allocate `din` and `dout`. Don't use devm variant > > because the two buffers could be re-allocated multiple times during > > runtime. Their life cycles aren't quite aligned to the device's. > > While this saves a few lines of code, it is runtime-expensive: > krealloc() copies the old data, which is a waste of time/resources. > Maybe it would be better to just use kfree() followed by kzalloc(). Ack. I wasn't aware of the memcpy(). Let's don't use it. > > @@ -469,9 +469,9 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev, > > */ > > int cros_ec_query_all(struct cros_ec_device *ec_dev) > > { > > - struct device *dev = ec_dev->dev; > > u32 ver_mask = 0; > > int ret; > > + u8 *din, *dout; > > > > /* First try sending with proto v3. */ > > if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) { > > @@ -492,21 +492,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev) > > } > > } > > > > - devm_kfree(dev, ec_dev->din); > > - devm_kfree(dev, ec_dev->dout); > > - > > - ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); > > - if (!ec_dev->din) { > > - ret = -ENOMEM; > > - goto exit; > > - } > > + din = krealloc(ec_dev->din, ec_dev->din_size, GFP_KERNEL); > > + if (!din) > > + return -ENOMEM; > > I would suggest assigning the values directly; the new variables don't > really add value. checkpatch.pl generated a warning for it. See [1]. Will remove the krealloc()s anyway. [1]: https://github.com/torvalds/linux/commit/972fdea2e6ece7578915d386a5447bc78d3fb8b8
diff --git a/drivers/platform/chrome/cros_ec.c b/drivers/platform/chrome/cros_ec.c index 29d3b544dafb..fb8cb8a73295 100644 --- a/drivers/platform/chrome/cros_ec.c +++ b/drivers/platform/chrome/cros_ec.c @@ -285,6 +285,8 @@ int cros_ec_register(struct cros_ec_device *ec_dev) exit: platform_device_unregister(ec_dev->ec); platform_device_unregister(ec_dev->pd); + kfree(ec_dev->din); + kfree(ec_dev->dout); return err; } EXPORT_SYMBOL(cros_ec_register); @@ -302,6 +304,8 @@ void cros_ec_unregister(struct cros_ec_device *ec_dev) if (ec_dev->pd) platform_device_unregister(ec_dev->pd); platform_device_unregister(ec_dev->ec); + kfree(ec_dev->din); + kfree(ec_dev->dout); } EXPORT_SYMBOL(cros_ec_unregister); diff --git a/drivers/platform/chrome/cros_ec_proto.c b/drivers/platform/chrome/cros_ec_proto.c index 473654f50bca..de6bc457e496 100644 --- a/drivers/platform/chrome/cros_ec_proto.c +++ b/drivers/platform/chrome/cros_ec_proto.c @@ -469,9 +469,9 @@ static int cros_ec_get_host_command_version_mask(struct cros_ec_device *ec_dev, */ int cros_ec_query_all(struct cros_ec_device *ec_dev) { - struct device *dev = ec_dev->dev; u32 ver_mask = 0; int ret; + u8 *din, *dout; /* First try sending with proto v3. */ if (!cros_ec_get_proto_info(ec_dev, CROS_EC_DEV_EC_INDEX)) { @@ -492,21 +492,15 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev) } } - devm_kfree(dev, ec_dev->din); - devm_kfree(dev, ec_dev->dout); - - ec_dev->din = devm_kzalloc(dev, ec_dev->din_size, GFP_KERNEL); - if (!ec_dev->din) { - ret = -ENOMEM; - goto exit; - } + din = krealloc(ec_dev->din, ec_dev->din_size, GFP_KERNEL); + if (!din) + return -ENOMEM; + ec_dev->din = din; - ec_dev->dout = devm_kzalloc(dev, ec_dev->dout_size, GFP_KERNEL); - if (!ec_dev->dout) { - devm_kfree(dev, ec_dev->din); - ret = -ENOMEM; - goto exit; - } + dout = krealloc(ec_dev->dout, ec_dev->dout_size, GFP_KERNEL); + if (!dout) + return -ENOMEM; + ec_dev->dout = dout; /* Probe if MKBP event is supported */ ret = cros_ec_get_host_command_version_mask(ec_dev, @@ -555,10 +549,7 @@ int cros_ec_query_all(struct cros_ec_device *ec_dev) "failed to retrieve wake mask: %d\n", ret); } - ret = 0; - -exit: - return ret; + return 0; } EXPORT_SYMBOL(cros_ec_query_all); diff --git a/drivers/platform/chrome/cros_ec_proto_test.c b/drivers/platform/chrome/cros_ec_proto_test.c index 730248be42a7..27b81a5a9880 100644 --- a/drivers/platform/chrome/cros_ec_proto_test.c +++ b/drivers/platform/chrome/cros_ec_proto_test.c @@ -180,8 +180,7 @@ static void cros_ec_proto_test_query_all_pretest(struct kunit *test) /* * cros_ec_query_all() will free din and dout and allocate them again to fit the usage by - * calling devm_kfree() and devm_kzalloc(). Set them to NULL as they aren't managed by - * ec_dev->dev. + * calling krealloc(). Set them to NULL as they aren't allocated by kalloc(). */ ec_dev->din = NULL; ec_dev->dout = NULL;
Use krealloc() to re-allocate `din` and `dout`. Don't use devm variant because the two buffers could be re-allocated multiple times during runtime. Their life cycles aren't quite aligned to the device's. Free the memory in cros_ec_unregister() if any. No need to free memory if krealloc() fails. They will be freed eventually in either of the following: - Error handling path in cros_ec_register(). - In cros_ec_unregister(). - Next krealloc() in cros_ec_query_all(). Signed-off-by: Tzung-Bi Shih <tzungbi@kernel.org> --- Changes from v1: - Don't use devm. - Free in cros_ec_unregister(). drivers/platform/chrome/cros_ec.c | 4 +++ drivers/platform/chrome/cros_ec_proto.c | 29 +++++++------------- drivers/platform/chrome/cros_ec_proto_test.c | 3 +- 3 files changed, 15 insertions(+), 21 deletions(-)