[PATCH 1/3] drm/komeda: Consolidate struct komeda_drv allocations

From: Mihail Atanassov
Date: Fri Oct 04 2019 - 10:35:08 EST


struct komeda_drv has two pointer members only, and both
it and its members get allocated separately. Since both
members' types are in scope, there's not a lot to gain by
keeping the indirection around.

To avoid double-free issues, provide a barebones ->release()
hook for the driver.

Signed-off-by: Mihail Atanassov <mihail.atanassov@xxxxxxx>
---
.../gpu/drm/arm/display/komeda/komeda_dev.c | 21 ++++-------
.../gpu/drm/arm/display/komeda/komeda_dev.h | 4 +--
.../gpu/drm/arm/display/komeda/komeda_drv.c | 36 +++++++++----------
.../gpu/drm/arm/display/komeda/komeda_kms.c | 26 ++++++++------
.../gpu/drm/arm/display/komeda/komeda_kms.h | 4 +--
5 files changed, 42 insertions(+), 49 deletions(-)

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
index 937a6d4c4865..c84f978cacc3 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.c
@@ -179,28 +179,23 @@ static int komeda_parse_dt(struct device *dev, struct komeda_dev *mdev)
return ret;
}

-struct komeda_dev *komeda_dev_create(struct device *dev)
+int komeda_dev_init(struct komeda_dev *mdev, struct device *dev)
{
struct platform_device *pdev = to_platform_device(dev);
const struct komeda_product_data *product;
- struct komeda_dev *mdev;
struct resource *io_res;
int err = 0;

product = of_device_get_match_data(dev);
if (!product)
- return ERR_PTR(-ENODEV);
+ return -ENODEV;

io_res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
if (!io_res) {
DRM_ERROR("No registers defined.\n");
- return ERR_PTR(-ENODEV);
+ return -ENODEV;
}

- mdev = devm_kzalloc(dev, sizeof(*mdev), GFP_KERNEL);
- if (!mdev)
- return ERR_PTR(-ENOMEM);
-
mutex_init(&mdev->lock);

mdev->dev = dev;
@@ -284,16 +279,16 @@ struct komeda_dev *komeda_dev_create(struct device *dev)
komeda_debugfs_init(mdev);
#endif

- return mdev;
+ return 0;

disable_clk:
clk_disable_unprepare(mdev->aclk);
err_cleanup:
- komeda_dev_destroy(mdev);
- return ERR_PTR(err);
+ komeda_dev_fini(mdev);
+ return err;
}

-void komeda_dev_destroy(struct komeda_dev *mdev)
+void komeda_dev_fini(struct komeda_dev *mdev)
{
struct device *dev = mdev->dev;
const struct komeda_dev_funcs *funcs = mdev->funcs;
@@ -335,8 +330,6 @@ void komeda_dev_destroy(struct komeda_dev *mdev)
devm_clk_put(dev, mdev->aclk);
mdev->aclk = NULL;
}
-
- devm_kfree(dev, mdev);
}

int komeda_dev_resume(struct komeda_dev *mdev)
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
index 414200233b64..e392b8ffc372 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_dev.h
@@ -213,8 +213,8 @@ komeda_product_match(struct komeda_dev *mdev, u32 target)
const struct komeda_dev_funcs *
d71_identify(u32 __iomem *reg, struct komeda_chip_info *chip);

-struct komeda_dev *komeda_dev_create(struct device *dev);
-void komeda_dev_destroy(struct komeda_dev *mdev);
+int komeda_dev_init(struct komeda_dev *mdev, struct device *dev);
+void komeda_dev_fini(struct komeda_dev *mdev);

struct komeda_dev *dev_to_mdev(struct device *dev);

diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
index d6c2222c5d33..660181bdc008 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_drv.c
@@ -14,15 +14,15 @@
#include "komeda_kms.h"

struct komeda_drv {
- struct komeda_dev *mdev;
- struct komeda_kms_dev *kms;
+ struct komeda_dev mdev;
+ struct komeda_kms_dev kms;
};

struct komeda_dev *dev_to_mdev(struct device *dev)
{
struct komeda_drv *mdrv = dev_get_drvdata(dev);

- return mdrv ? mdrv->mdev : NULL;
+ return mdrv ? &mdrv->mdev : NULL;
}

static void komeda_unbind(struct device *dev)
@@ -32,8 +32,8 @@ static void komeda_unbind(struct device *dev)
if (!mdrv)
return;

- komeda_kms_detach(mdrv->kms);
- komeda_dev_destroy(mdrv->mdev);
+ komeda_kms_fini(mdrv->kms);
+ komeda_dev_fini(mdrv->mdev);

dev_set_drvdata(dev, NULL);
devm_kfree(dev, mdrv);
@@ -48,24 +48,20 @@ static int komeda_bind(struct device *dev)
if (!mdrv)
return -ENOMEM;

- mdrv->mdev = komeda_dev_create(dev);
- if (IS_ERR(mdrv->mdev)) {
- err = PTR_ERR(mdrv->mdev);
+ err = komeda_dev_init(&mdrv->mdev, dev);
+ if (err)
goto free_mdrv;
- }

- mdrv->kms = komeda_kms_attach(mdrv->mdev);
- if (IS_ERR(mdrv->kms)) {
- err = PTR_ERR(mdrv->kms);
- goto destroy_mdev;
- }
+ err = komeda_kms_init(&mdrv->kms, &mdrv->mdev);
+ if (err)
+ goto fini_mdev;

dev_set_drvdata(dev, mdrv);

return 0;

-destroy_mdev:
- komeda_dev_destroy(mdrv->mdev);
+fini_mdev:
+ komeda_dev_fini(&mdrv->mdev);

free_mdrv:
devm_kfree(dev, mdrv);
@@ -140,12 +136,12 @@ MODULE_DEVICE_TABLE(of, komeda_of_match);
static int __maybe_unused komeda_pm_suspend(struct device *dev)
{
struct komeda_drv *mdrv = dev_get_drvdata(dev);
- struct drm_device *drm = &mdrv->kms->base;
+ struct drm_device *drm = &mdrv->kms.base;
int res;

res = drm_mode_config_helper_suspend(drm);

- komeda_dev_suspend(mdrv->mdev);
+ komeda_dev_suspend(&mdrv->mdev);

return res;
}
@@ -153,9 +149,9 @@ static int __maybe_unused komeda_pm_suspend(struct device *dev)
static int __maybe_unused komeda_pm_resume(struct device *dev)
{
struct komeda_drv *mdrv = dev_get_drvdata(dev);
- struct drm_device *drm = &mdrv->kms->base;
+ struct drm_device *drm = &mdrv->kms.base;

- komeda_dev_resume(mdrv->mdev);
+ komeda_dev_resume(&mdrv->mdev);

return drm_mode_config_helper_resume(drm);
}
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
index d49772de93e0..03dcf1d7688f 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.c
@@ -23,6 +23,15 @@

DEFINE_DRM_GEM_CMA_FOPS(komeda_cma_fops);

+static void komeda_kms_release(struct drm_device *dev)
+{
+ drm_dev_fini(dev);
+ /*
+ * No need to kfree(dev) since we're stored in an aggregate struct
+ * that's managed separately.
+ */
+}
+
static int komeda_gem_cma_dumb_create(struct drm_file *file,
struct drm_device *dev,
struct drm_mode_create_dumb *args)
@@ -60,6 +69,7 @@ static irqreturn_t komeda_kms_irq_handler(int irq, void *data)
static struct drm_driver komeda_kms_driver = {
.driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC,
.lastclose = drm_fb_helper_lastclose,
+ .release = komeda_kms_release,
.gem_free_object_unlocked = drm_gem_cma_free_object,
.gem_vm_ops = &drm_gem_cma_vm_ops,
.dumb_create = komeda_gem_cma_dumb_create,
@@ -257,19 +267,15 @@ static void komeda_kms_mode_config_init(struct komeda_kms_dev *kms,
config->helper_private = &komeda_mode_config_helpers;
}

-struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev)
+int komeda_kms_init(struct komeda_kms_dev *kms, struct komeda_dev *mdev)
{
- struct komeda_kms_dev *kms = kzalloc(sizeof(*kms), GFP_KERNEL);
struct drm_device *drm;
int err;

- if (!kms)
- return ERR_PTR(-ENOMEM);
-
drm = &kms->base;
err = drm_dev_init(drm, &komeda_kms_driver, mdev->dev);
if (err)
- goto free_kms;
+ return err;

drm->dev_private = mdev;

@@ -319,7 +325,7 @@ struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev)
if (err)
goto free_interrupts;

- return kms;
+ return 0;

free_interrupts:
drm_kms_helper_poll_fini(drm);
@@ -332,12 +338,10 @@ struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev)
komeda_kms_cleanup_private_objs(kms);
drm->dev_private = NULL;
drm_dev_put(drm);
-free_kms:
- kfree(kms);
- return ERR_PTR(err);
+ return err;
}

-void komeda_kms_detach(struct komeda_kms_dev *kms)
+void komeda_kms_fini(struct komeda_kms_dev *kms)
{
struct drm_device *drm = &kms->base;
struct komeda_dev *mdev = drm->dev_private;
diff --git a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
index 45c498e15e7a..e81ceb298034 100644
--- a/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
+++ b/drivers/gpu/drm/arm/display/komeda/komeda_kms.h
@@ -181,7 +181,7 @@ void komeda_kms_cleanup_private_objs(struct komeda_kms_dev *kms);
void komeda_crtc_handle_event(struct komeda_crtc *kcrtc,
struct komeda_events *evts);

-struct komeda_kms_dev *komeda_kms_attach(struct komeda_dev *mdev);
-void komeda_kms_detach(struct komeda_kms_dev *kms);
+int komeda_kms_init(struct komeda_kms_dev *kms, struct komeda_dev *mdev);
+void komeda_kms_fini(struct komeda_kms_dev *kms);

#endif /*_KOMEDA_KMS_H_*/
--
2.23.0