From 5a47c0fbd276b7f57bd38f153e8b15784b2f6f22 Mon Sep 17 00:00:00 2001 From: Lee Jones Date: Mon, 21 Oct 2019 10:47:37 +0100 Subject: [PATCH] mfd: mfd-core: Remove usage counting for .{en,dis}able() call-backs 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 Reviewed-by: Daniel Thompson Reviewed-by: Mark Brown --- 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 e38e411..2535dd3 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->disable) { 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 63ac3cc..d01d129 100644 --- a/include/linux/mfd/core.h +++ b/include/linux/mfd/core.h @@ -59,8 +59,6 @@ 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); -- 2.7.4