| Message ID | 20191021105822.20271-9-lee.jones@linaro.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Simplify MFD Core | expand |
On Mon, Oct 21, 2019 at 11:58:21AM +0100, Lee Jones wrote: > The MFD implementation for reference counting was complex and unnecessary. > There was only one bona fide user which has now been converted to handle > the process in a different way. Any future resource protection, shared > enablement functions should be handed by the parent device, rather than > through the MFD subsystem API. > > Signed-off-by: Lee Jones <lee.jones@linaro.org> Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org> > --- > drivers/mfd/mfd-core.c | 57 +++++++--------------------------------- > include/linux/mfd/core.h | 2 -- > 2 files changed, 9 insertions(+), 50 deletions(-) > > diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c > index 90b43b44a15a..5d56015baeeb 100644 > --- a/drivers/mfd/mfd-core.c > +++ b/drivers/mfd/mfd-core.c > @@ -26,53 +26,31 @@ static struct device_type mfd_dev_type = { > int mfd_cell_enable(struct platform_device *pdev) > { > const struct mfd_cell *cell = mfd_get_cell(pdev); > - int err = 0; > > if (!cell->enable) { > dev_dbg(&pdev->dev, "No .enable() call-back registered\n"); > return 0; > } > > - /* only call enable hook if the cell wasn't previously enabled */ > - if (atomic_inc_return(cell->usage_count) == 1) > - err = cell->enable(pdev); > - > - /* if the enable hook failed, decrement counter to allow retries */ > - if (err) > - atomic_dec(cell->usage_count); > - > - return err; > + return cell->enable(pdev); > } > EXPORT_SYMBOL(mfd_cell_enable); > > int mfd_cell_disable(struct platform_device *pdev) > { > const struct mfd_cell *cell = mfd_get_cell(pdev); > - int err = 0; > > if (!cell->enable) { > dev_dbg(&pdev->dev, "No .disable() call-back registered\n"); > return 0; > } > > - /* only disable if no other clients are using it */ > - if (atomic_dec_return(cell->usage_count) == 0) > - err = cell->disable(pdev); > - > - /* if the disable hook failed, increment to allow retries */ > - if (err) > - atomic_inc(cell->usage_count); > - > - /* sanity check; did someone call disable too many times? */ > - WARN_ON(atomic_read(cell->usage_count) < 0); > - > - return err; > + return cell->disable(pdev); > } > EXPORT_SYMBOL(mfd_cell_disable); > > static int mfd_platform_add_cell(struct platform_device *pdev, > - const struct mfd_cell *cell, > - atomic_t *usage_count) > + const struct mfd_cell *cell) > { > if (!cell) > return 0; > @@ -81,7 +59,6 @@ static int mfd_platform_add_cell(struct platform_device *pdev, > if (!pdev->mfd_cell) > return -ENOMEM; > > - pdev->mfd_cell->usage_count = usage_count; > return 0; > } > > @@ -144,7 +121,7 @@ static inline void mfd_acpi_add_device(const struct mfd_cell *cell, > #endif > > static int mfd_add_device(struct device *parent, int id, > - const struct mfd_cell *cell, atomic_t *usage_count, > + const struct mfd_cell *cell, > struct resource *mem_base, > int irq_base, struct irq_domain *domain) > { > @@ -206,7 +183,7 @@ static int mfd_add_device(struct device *parent, int id, > goto fail_alias; > } > > - ret = mfd_platform_add_cell(pdev, cell, usage_count); > + ret = mfd_platform_add_cell(pdev, cell); > if (ret) > goto fail_alias; > > @@ -296,16 +273,9 @@ int mfd_add_devices(struct device *parent, int id, > { > int i; > int ret; > - atomic_t *cnts; > - > - /* initialize reference counting for all cells */ > - cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL); > - if (!cnts) > - return -ENOMEM; > > for (i = 0; i < n_devs; i++) { > - atomic_set(&cnts[i], 0); > - ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base, > + ret = mfd_add_device(parent, id, cells + i, mem_base, > irq_base, domain); > if (ret) > goto fail; > @@ -316,17 +286,15 @@ int mfd_add_devices(struct device *parent, int id, > fail: > if (i) > mfd_remove_devices(parent); > - else > - kfree(cnts); > + > return ret; > } > EXPORT_SYMBOL(mfd_add_devices); > > -static int mfd_remove_devices_fn(struct device *dev, void *c) > +static int mfd_remove_devices_fn(struct device *dev, void *data) > { > struct platform_device *pdev; > const struct mfd_cell *cell; > - atomic_t **usage_count = c; > > if (dev->type != &mfd_dev_type) > return 0; > @@ -337,20 +305,13 @@ static int mfd_remove_devices_fn(struct device *dev, void *c) > regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies, > cell->num_parent_supplies); > > - /* find the base address of usage_count pointers (for freeing) */ > - if (!*usage_count || (cell->usage_count < *usage_count)) > - *usage_count = cell->usage_count; > - > platform_device_unregister(pdev); > return 0; > } > > void mfd_remove_devices(struct device *parent) > { > - atomic_t *cnts = NULL; > - > - device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn); > - kfree(cnts); > + device_for_each_child_reverse(parent, NULL, mfd_remove_devices_fn); > } > EXPORT_SYMBOL(mfd_remove_devices); > > diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h > index bd8c0e089164..919f09fb07b7 100644 > --- a/include/linux/mfd/core.h > +++ b/include/linux/mfd/core.h > @@ -30,8 +30,6 @@ struct mfd_cell { > const char *name; > int id; > > - /* refcounting for multiple drivers to use a single cell */ > - atomic_t *usage_count; > int (*enable)(struct platform_device *dev); > int (*disable)(struct platform_device *dev); > > -- > 2.17.1 >
diff --git a/drivers/mfd/mfd-core.c b/drivers/mfd/mfd-core.c index 90b43b44a15a..5d56015baeeb 100644 --- a/drivers/mfd/mfd-core.c +++ b/drivers/mfd/mfd-core.c @@ -26,53 +26,31 @@ static struct device_type mfd_dev_type = { int mfd_cell_enable(struct platform_device *pdev) { const struct mfd_cell *cell = mfd_get_cell(pdev); - int err = 0; if (!cell->enable) { dev_dbg(&pdev->dev, "No .enable() call-back registered\n"); return 0; } - /* only call enable hook if the cell wasn't previously enabled */ - if (atomic_inc_return(cell->usage_count) == 1) - err = cell->enable(pdev); - - /* if the enable hook failed, decrement counter to allow retries */ - if (err) - atomic_dec(cell->usage_count); - - return err; + return cell->enable(pdev); } EXPORT_SYMBOL(mfd_cell_enable); int mfd_cell_disable(struct platform_device *pdev) { const struct mfd_cell *cell = mfd_get_cell(pdev); - int err = 0; if (!cell->enable) { dev_dbg(&pdev->dev, "No .disable() call-back registered\n"); return 0; } - /* only disable if no other clients are using it */ - if (atomic_dec_return(cell->usage_count) == 0) - err = cell->disable(pdev); - - /* if the disable hook failed, increment to allow retries */ - if (err) - atomic_inc(cell->usage_count); - - /* sanity check; did someone call disable too many times? */ - WARN_ON(atomic_read(cell->usage_count) < 0); - - return err; + return cell->disable(pdev); } EXPORT_SYMBOL(mfd_cell_disable); static int mfd_platform_add_cell(struct platform_device *pdev, - const struct mfd_cell *cell, - atomic_t *usage_count) + const struct mfd_cell *cell) { if (!cell) return 0; @@ -81,7 +59,6 @@ static int mfd_platform_add_cell(struct platform_device *pdev, if (!pdev->mfd_cell) return -ENOMEM; - pdev->mfd_cell->usage_count = usage_count; return 0; } @@ -144,7 +121,7 @@ static inline void mfd_acpi_add_device(const struct mfd_cell *cell, #endif static int mfd_add_device(struct device *parent, int id, - const struct mfd_cell *cell, atomic_t *usage_count, + const struct mfd_cell *cell, struct resource *mem_base, int irq_base, struct irq_domain *domain) { @@ -206,7 +183,7 @@ static int mfd_add_device(struct device *parent, int id, goto fail_alias; } - ret = mfd_platform_add_cell(pdev, cell, usage_count); + ret = mfd_platform_add_cell(pdev, cell); if (ret) goto fail_alias; @@ -296,16 +273,9 @@ int mfd_add_devices(struct device *parent, int id, { int i; int ret; - atomic_t *cnts; - - /* initialize reference counting for all cells */ - cnts = kcalloc(n_devs, sizeof(*cnts), GFP_KERNEL); - if (!cnts) - return -ENOMEM; for (i = 0; i < n_devs; i++) { - atomic_set(&cnts[i], 0); - ret = mfd_add_device(parent, id, cells + i, cnts + i, mem_base, + ret = mfd_add_device(parent, id, cells + i, mem_base, irq_base, domain); if (ret) goto fail; @@ -316,17 +286,15 @@ int mfd_add_devices(struct device *parent, int id, fail: if (i) mfd_remove_devices(parent); - else - kfree(cnts); + return ret; } EXPORT_SYMBOL(mfd_add_devices); -static int mfd_remove_devices_fn(struct device *dev, void *c) +static int mfd_remove_devices_fn(struct device *dev, void *data) { struct platform_device *pdev; const struct mfd_cell *cell; - atomic_t **usage_count = c; if (dev->type != &mfd_dev_type) return 0; @@ -337,20 +305,13 @@ static int mfd_remove_devices_fn(struct device *dev, void *c) regulator_bulk_unregister_supply_alias(dev, cell->parent_supplies, cell->num_parent_supplies); - /* find the base address of usage_count pointers (for freeing) */ - if (!*usage_count || (cell->usage_count < *usage_count)) - *usage_count = cell->usage_count; - platform_device_unregister(pdev); return 0; } void mfd_remove_devices(struct device *parent) { - atomic_t *cnts = NULL; - - device_for_each_child_reverse(parent, &cnts, mfd_remove_devices_fn); - kfree(cnts); + device_for_each_child_reverse(parent, NULL, mfd_remove_devices_fn); } EXPORT_SYMBOL(mfd_remove_devices); diff --git a/include/linux/mfd/core.h b/include/linux/mfd/core.h index bd8c0e089164..919f09fb07b7 100644 --- a/include/linux/mfd/core.h +++ b/include/linux/mfd/core.h @@ -30,8 +30,6 @@ struct mfd_cell { const char *name; int id; - /* refcounting for multiple drivers to use a single cell */ - atomic_t *usage_count; int (*enable)(struct platform_device *dev); int (*disable)(struct platform_device *dev);
The MFD implementation for reference counting was complex and unnecessary. There was only one bona fide user which has now been converted to handle the process in a different way. Any future resource protection, shared enablement functions should be handed by the parent device, rather than through the MFD subsystem API. Signed-off-by: Lee Jones <lee.jones@linaro.org> --- drivers/mfd/mfd-core.c | 57 +++++++--------------------------------- include/linux/mfd/core.h | 2 -- 2 files changed, 9 insertions(+), 50 deletions(-)