From 6c846d026d490b2383d395bc8e7b06336219667b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:37 +0100 Subject: gpio: Don't fiddle with irqchips marked as immutable In order to move away from gpiolib messing with the internals of unsuspecting irqchips, add a flag by which irqchips advertise that they are not to be messed with, and do solemnly swear that they correctly call into the gpiolib helpers when required. Also nudge the users into converting their drivers to the new model. Reviewed-by: Andy Shevchenko Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-2-maz@kernel.org --- drivers/gpio/gpiolib.c | 7 ++++++- include/linux/irq.h | 2 ++ kernel/irq/debugfs.c | 1 + 3 files changed, 9 insertions(+), 1 deletion(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index e59884cc12a7..48191e62a3cc 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1475,6 +1475,11 @@ static void gpiochip_set_irq_hooks(struct gpio_chip *gc) { struct irq_chip *irqchip = gc->irq.chip; + if (irqchip->flags & IRQCHIP_IMMUTABLE) + return; + + chip_warn(gc, "not an immutable chip, please consider fixing it!\n"); + if (!irqchip->irq_request_resources && !irqchip->irq_release_resources) { irqchip->irq_request_resources = gpiochip_irq_reqres; @@ -1633,7 +1638,7 @@ static void gpiochip_irqchip_remove(struct gpio_chip *gc) irq_domain_remove(gc->irq.domain); } - if (irqchip) { + if (irqchip && !(irqchip->flags & IRQCHIP_IMMUTABLE)) { if (irqchip->irq_request_resources == gpiochip_irq_reqres) { irqchip->irq_request_resources = NULL; irqchip->irq_release_resources = NULL; diff --git a/include/linux/irq.h b/include/linux/irq.h index f92788ccdba2..505308253d23 100644 --- a/include/linux/irq.h +++ b/include/linux/irq.h @@ -569,6 +569,7 @@ struct irq_chip { * IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND: Invokes __enable_irq()/__disable_irq() for wake irqs * in the suspend path if they are in disabled state * IRQCHIP_AFFINITY_PRE_STARTUP: Default affinity update before startup + * IRQCHIP_IMMUTABLE: Don't ever change anything in this chip */ enum { IRQCHIP_SET_TYPE_MASKED = (1 << 0), @@ -582,6 +583,7 @@ enum { IRQCHIP_SUPPORTS_NMI = (1 << 8), IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND = (1 << 9), IRQCHIP_AFFINITY_PRE_STARTUP = (1 << 10), + IRQCHIP_IMMUTABLE = (1 << 11), }; #include diff --git a/kernel/irq/debugfs.c b/kernel/irq/debugfs.c index 2b43f5f5033d..bc8e40cf2b65 100644 --- a/kernel/irq/debugfs.c +++ b/kernel/irq/debugfs.c @@ -58,6 +58,7 @@ static const struct irq_bit_descr irqchip_flags[] = { BIT_MASK_DESCR(IRQCHIP_SUPPORTS_LEVEL_MSI), BIT_MASK_DESCR(IRQCHIP_SUPPORTS_NMI), BIT_MASK_DESCR(IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND), + BIT_MASK_DESCR(IRQCHIP_IMMUTABLE), }; static void -- cgit From 704f08753b6dcd0e08c1953af0b2c7f3fac87111 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:38 +0100 Subject: gpio: Expose the gpiochip_irq_re[ql]res helpers The GPIO subsystem has a couple of internal helpers to manage resources on behalf of the irqchip. Expose them so that GPIO drivers can use them directly. Reviewed-by: Andy Shevchenko Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-3-maz@kernel.org --- drivers/gpio/gpiolib.c | 6 ++++-- include/linux/gpio/driver.h | 4 ++++ 2 files changed, 8 insertions(+), 2 deletions(-) diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 48191e62a3cc..36e436a66e09 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -1423,19 +1423,21 @@ static int gpiochip_to_irq(struct gpio_chip *gc, unsigned int offset) return irq_create_mapping(domain, offset); } -static int gpiochip_irq_reqres(struct irq_data *d) +int gpiochip_irq_reqres(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); return gpiochip_reqres_irq(gc, d->hwirq); } +EXPORT_SYMBOL(gpiochip_irq_reqres); -static void gpiochip_irq_relres(struct irq_data *d) +void gpiochip_irq_relres(struct irq_data *d) { struct gpio_chip *gc = irq_data_get_irq_chip_data(d); gpiochip_relres_irq(gc, d->hwirq); } +EXPORT_SYMBOL(gpiochip_irq_relres); static void gpiochip_irq_mask(struct irq_data *d) { diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 98c93510640e..066bcfdf878d 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -579,6 +579,10 @@ void gpiochip_relres_irq(struct gpio_chip *gc, unsigned int offset); void gpiochip_disable_irq(struct gpio_chip *gc, unsigned int offset); void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset); +/* irq_data versions of the above */ +int gpiochip_irq_reqres(struct irq_data *data); +void gpiochip_irq_relres(struct irq_data *data); + /* Line status inquiry for drivers */ bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset); bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset); -- cgit From 36b78aae4bfee749bbde73be570796bfd0f56bec Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:39 +0100 Subject: gpio: Add helpers to ease the transition towards immutable irq_chip Add a couple of new helpers to make it slightly simpler to convert drivers to immutable irq_chip structures: - GPIOCHIP_IRQ_RESOURCE_HELPERS populates the irq_chip structure with the resource management callbacks - gpio_irq_chip_set_chip() populates the gpio_irq_chip.chip structure, avoiding the proliferation of ugly casts Reviewed-by: Andy Shevchenko Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-4-maz@kernel.org --- include/linux/gpio/driver.h | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h index 066bcfdf878d..832990099097 100644 --- a/include/linux/gpio/driver.h +++ b/include/linux/gpio/driver.h @@ -583,6 +583,18 @@ void gpiochip_enable_irq(struct gpio_chip *gc, unsigned int offset); int gpiochip_irq_reqres(struct irq_data *data); void gpiochip_irq_relres(struct irq_data *data); +/* Paste this in your irq_chip structure */ +#define GPIOCHIP_IRQ_RESOURCE_HELPERS \ + .irq_request_resources = gpiochip_irq_reqres, \ + .irq_release_resources = gpiochip_irq_relres + +static inline void gpio_irq_chip_set_chip(struct gpio_irq_chip *girq, + const struct irq_chip *chip) +{ + /* Yes, dropping const is ugly, but it isn't like we have a choice */ + girq->chip = (struct irq_chip *)chip; +} + /* Line status inquiry for drivers */ bool gpiochip_line_is_open_drain(struct gpio_chip *gc, unsigned int offset); bool gpiochip_line_is_open_source(struct gpio_chip *gc, unsigned int offset); -- cgit From bba00555ede79ad8a743da908f708466f6bac0f8 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:40 +0100 Subject: gpio: tegra186: Make the irqchip immutable Prevent gpiolib from messing with the irqchip by advertising the irq_chip structure as immutable, making it const, and adding the various calls that gpiolib relies upon. Acked-by: Thierry Reding Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-5-maz@kernel.org --- drivers/gpio/gpio-tegra186.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) diff --git a/drivers/gpio/gpio-tegra186.c b/drivers/gpio/gpio-tegra186.c index 031fe105b58e..84c4f1e9fb0c 100644 --- a/drivers/gpio/gpio-tegra186.c +++ b/drivers/gpio/gpio-tegra186.c @@ -80,7 +80,6 @@ struct tegra_gpio_soc { struct tegra_gpio { struct gpio_chip gpio; - struct irq_chip intc; unsigned int num_irq; unsigned int *irq; @@ -372,6 +371,8 @@ static void tegra186_irq_mask(struct irq_data *data) value = readl(base + TEGRA186_GPIO_ENABLE_CONFIG); value &= ~TEGRA186_GPIO_ENABLE_CONFIG_INTERRUPT; writel(value, base + TEGRA186_GPIO_ENABLE_CONFIG); + + gpiochip_disable_irq(&gpio->gpio, data->hwirq); } static void tegra186_irq_unmask(struct irq_data *data) @@ -385,6 +386,8 @@ static void tegra186_irq_unmask(struct irq_data *data) if (WARN_ON(base == NULL)) return; + gpiochip_enable_irq(&gpio->gpio, data->hwirq); + value = readl(base + TEGRA186_GPIO_ENABLE_CONFIG); value |= TEGRA186_GPIO_ENABLE_CONFIG_INTERRUPT; writel(value, base + TEGRA186_GPIO_ENABLE_CONFIG); @@ -456,6 +459,24 @@ static int tegra186_irq_set_wake(struct irq_data *data, unsigned int on) return 0; } +static void tegra186_irq_print_chip(struct irq_data *data, struct seq_file *p) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + + seq_printf(p, dev_name(gc->parent)); +} + +static const struct irq_chip tegra186_gpio_irq_chip = { + .irq_ack = tegra186_irq_ack, + .irq_mask = tegra186_irq_mask, + .irq_unmask = tegra186_irq_unmask, + .irq_set_type = tegra186_irq_set_type, + .irq_set_wake = tegra186_irq_set_wake, + .irq_print_chip = tegra186_irq_print_chip, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + static void tegra186_gpio_irq(struct irq_desc *desc) { struct tegra_gpio *gpio = irq_desc_get_handler_data(desc); @@ -760,15 +781,8 @@ static int tegra186_gpio_probe(struct platform_device *pdev) gpio->gpio.of_xlate = tegra186_gpio_of_xlate; #endif /* CONFIG_OF_GPIO */ - gpio->intc.name = dev_name(&pdev->dev); - gpio->intc.irq_ack = tegra186_irq_ack; - gpio->intc.irq_mask = tegra186_irq_mask; - gpio->intc.irq_unmask = tegra186_irq_unmask; - gpio->intc.irq_set_type = tegra186_irq_set_type; - gpio->intc.irq_set_wake = tegra186_irq_set_wake; - irq = &gpio->gpio.irq; - irq->chip = &gpio->intc; + gpio_irq_chip_set_chip(irq, &tegra186_gpio_irq_chip); irq->fwnode = of_node_to_fwnode(pdev->dev.of_node); irq->child_to_parent_hwirq = tegra186_gpio_child_to_parent_hwirq; irq->populate_parent_alloc_arg = tegra186_gpio_populate_parent_fwspec; -- cgit From 15d8c14ac849f41f2d41dbddb69f402aaf73ff8b Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:41 +0100 Subject: gpio: pl061: Make the irqchip immutable Prevent gpiolib from messing with the irqchip by advertising the irq_chip structure as immutable, making it const, and adding the various calls that gpiolib relies upon. Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-6-maz@kernel.org --- drivers/gpio/gpio-pl061.c | 32 +++++++++++++++++++++++--------- 1 file changed, 23 insertions(+), 9 deletions(-) diff --git a/drivers/gpio/gpio-pl061.c b/drivers/gpio/gpio-pl061.c index 4ecab700f23f..6464056cb6ae 100644 --- a/drivers/gpio/gpio-pl061.c +++ b/drivers/gpio/gpio-pl061.c @@ -52,7 +52,6 @@ struct pl061 { void __iomem *base; struct gpio_chip gc; - struct irq_chip irq_chip; int parent_irq; #ifdef CONFIG_PM @@ -241,6 +240,8 @@ static void pl061_irq_mask(struct irq_data *d) gpioie = readb(pl061->base + GPIOIE) & ~mask; writeb(gpioie, pl061->base + GPIOIE); raw_spin_unlock(&pl061->lock); + + gpiochip_disable_irq(gc, d->hwirq); } static void pl061_irq_unmask(struct irq_data *d) @@ -250,6 +251,8 @@ static void pl061_irq_unmask(struct irq_data *d) u8 mask = BIT(irqd_to_hwirq(d) % PL061_GPIO_NR); u8 gpioie; + gpiochip_enable_irq(gc, d->hwirq); + raw_spin_lock(&pl061->lock); gpioie = readb(pl061->base + GPIOIE) | mask; writeb(gpioie, pl061->base + GPIOIE); @@ -283,6 +286,24 @@ static int pl061_irq_set_wake(struct irq_data *d, unsigned int state) return irq_set_irq_wake(pl061->parent_irq, state); } +static void pl061_irq_print_chip(struct irq_data *data, struct seq_file *p) +{ + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + + seq_printf(p, dev_name(gc->parent)); +} + +static const struct irq_chip pl061_irq_chip = { + .irq_ack = pl061_irq_ack, + .irq_mask = pl061_irq_mask, + .irq_unmask = pl061_irq_unmask, + .irq_set_type = pl061_irq_type, + .irq_set_wake = pl061_irq_set_wake, + .irq_print_chip = pl061_irq_print_chip, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, +}; + static int pl061_probe(struct amba_device *adev, const struct amba_id *id) { struct device *dev = &adev->dev; @@ -315,13 +336,6 @@ static int pl061_probe(struct amba_device *adev, const struct amba_id *id) /* * irq_chip support */ - pl061->irq_chip.name = dev_name(dev); - pl061->irq_chip.irq_ack = pl061_irq_ack; - pl061->irq_chip.irq_mask = pl061_irq_mask; - pl061->irq_chip.irq_unmask = pl061_irq_unmask; - pl061->irq_chip.irq_set_type = pl061_irq_type; - pl061->irq_chip.irq_set_wake = pl061_irq_set_wake; - writeb(0, pl061->base + GPIOIE); /* disable irqs */ irq = adev->irq[0]; if (!irq) @@ -329,7 +343,7 @@ static int pl061_probe(struct amba_device *adev, const struct amba_id *id) pl061->parent_irq = irq; girq = &pl061->gc.irq; - girq->chip = &pl061->irq_chip; + gpio_irq_chip_set_chip(girq, &pl061_irq_chip); girq->parent_handler = pl061_irq_handler; girq->num_parents = 1; girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents), -- cgit From 374b87a0fcf9fa5dd1379271337ae19f95682956 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:42 +0100 Subject: pinctrl: apple-gpio: Make the irqchip immutable Prevent gpiolib from messing with the irqchip by advertising the irq_chip structure as immutable, making it const, and adding the various calls that gpiolib relies upon. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-7-maz@kernel.org --- drivers/pinctrl/pinctrl-apple-gpio.c | 29 ++++++++++++++++------------- 1 file changed, 16 insertions(+), 13 deletions(-) diff --git a/drivers/pinctrl/pinctrl-apple-gpio.c b/drivers/pinctrl/pinctrl-apple-gpio.c index 72f4dd2466e1..5e610849dfc3 100644 --- a/drivers/pinctrl/pinctrl-apple-gpio.c +++ b/drivers/pinctrl/pinctrl-apple-gpio.c @@ -36,7 +36,6 @@ struct apple_gpio_pinctrl { struct pinctrl_desc pinctrl_desc; struct gpio_chip gpio_chip; - struct irq_chip irq_chip; u8 irqgrps[]; }; @@ -275,17 +274,21 @@ static unsigned int apple_gpio_irq_type(unsigned int type) static void apple_gpio_irq_mask(struct irq_data *data) { - struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data)); + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(gc); apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE, FIELD_PREP(REG_GPIOx_MODE, REG_GPIOx_IN_IRQ_OFF)); + gpiochip_disable_irq(gc, data->hwirq); } static void apple_gpio_irq_unmask(struct irq_data *data) { - struct apple_gpio_pinctrl *pctl = gpiochip_get_data(irq_data_get_irq_chip_data(data)); + struct gpio_chip *gc = irq_data_get_irq_chip_data(data); + struct apple_gpio_pinctrl *pctl = gpiochip_get_data(gc); unsigned int irqtype = apple_gpio_irq_type(irqd_get_trigger_type(data)); + gpiochip_enable_irq(gc, data->hwirq); apple_gpio_set_reg(pctl, data->hwirq, REG_GPIOx_MODE, FIELD_PREP(REG_GPIOx_MODE, irqtype)); } @@ -343,13 +346,15 @@ static void apple_gpio_irq_handler(struct irq_desc *desc) chained_irq_exit(chip, desc); } -static struct irq_chip apple_gpio_irqchip = { - .name = "Apple-GPIO", - .irq_startup = apple_gpio_irq_startup, - .irq_ack = apple_gpio_irq_ack, - .irq_mask = apple_gpio_irq_mask, - .irq_unmask = apple_gpio_irq_unmask, - .irq_set_type = apple_gpio_irq_set_type, +static const struct irq_chip apple_gpio_irqchip = { + .name = "Apple-GPIO", + .irq_startup = apple_gpio_irq_startup, + .irq_ack = apple_gpio_irq_ack, + .irq_mask = apple_gpio_irq_mask, + .irq_unmask = apple_gpio_irq_unmask, + .irq_set_type = apple_gpio_irq_set_type, + .flags = IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, }; /* Probe & register */ @@ -360,8 +365,6 @@ static int apple_gpio_register(struct apple_gpio_pinctrl *pctl) void **irq_data = NULL; int ret; - pctl->irq_chip = apple_gpio_irqchip; - pctl->gpio_chip.label = dev_name(pctl->dev); pctl->gpio_chip.request = gpiochip_generic_request; pctl->gpio_chip.free = gpiochip_generic_free; @@ -377,7 +380,7 @@ static int apple_gpio_register(struct apple_gpio_pinctrl *pctl) if (girq->num_parents) { int i; - girq->chip = &pctl->irq_chip; + gpio_irq_chip_set_chip(girq, &apple_gpio_irqchip); girq->parent_handler = apple_gpio_irq_handler; girq->parents = kmalloc_array(girq->num_parents, -- cgit From 14dbe186b9d42cbf662eae5a4da14687edbf0edb Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:43 +0100 Subject: pinctrl: msmgpio: Make the irqchip immutable Prevent gpiolib from messing with the irqchip by advertising the irq_chip structure as immutable, making it const, and adding the various calls that gpiolib relies upon. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-8-maz@kernel.org --- drivers/pinctrl/qcom/pinctrl-msm.c | 53 ++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 20 deletions(-) diff --git a/drivers/pinctrl/qcom/pinctrl-msm.c b/drivers/pinctrl/qcom/pinctrl-msm.c index 966ea6622ff3..a2abfe987ab1 100644 --- a/drivers/pinctrl/qcom/pinctrl-msm.c +++ b/drivers/pinctrl/qcom/pinctrl-msm.c @@ -42,7 +42,6 @@ * @chip: gpiochip handle. * @desc: pin controller descriptor * @restart_nb: restart notifier block. - * @irq_chip: irq chip information * @irq: parent irq for the TLMM irq_chip. * @intr_target_use_scm: route irq to application cpu using scm calls * @lock: Spinlock to protect register resources as well @@ -63,7 +62,6 @@ struct msm_pinctrl { struct pinctrl_desc desc; struct notifier_block restart_nb; - struct irq_chip irq_chip; int irq; bool intr_target_use_scm; @@ -868,6 +866,8 @@ static void msm_gpio_irq_enable(struct irq_data *d) struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct msm_pinctrl *pctrl = gpiochip_get_data(gc); + gpiochip_enable_irq(gc, d->hwirq); + if (d->parent_data) irq_chip_enable_parent(d); @@ -885,6 +885,8 @@ static void msm_gpio_irq_disable(struct irq_data *d) if (!test_bit(d->hwirq, pctrl->skip_wake_irqs)) msm_gpio_irq_mask(d); + + gpiochip_disable_irq(gc, d->hwirq); } /** @@ -958,6 +960,14 @@ static void msm_gpio_irq_ack(struct irq_data *d) raw_spin_unlock_irqrestore(&pctrl->lock, flags); } +static void msm_gpio_irq_eoi(struct irq_data *d) +{ + d = d->parent_data; + + if (d) + d->chip->irq_eoi(d); +} + static bool msm_gpio_needs_dual_edge_parent_workaround(struct irq_data *d, unsigned int type) { @@ -1255,6 +1265,26 @@ static bool msm_gpio_needs_valid_mask(struct msm_pinctrl *pctrl) return device_property_count_u16(pctrl->dev, "gpios") > 0; } +static const struct irq_chip msm_gpio_irq_chip = { + .name = "msmgpio", + .irq_enable = msm_gpio_irq_enable, + .irq_disable = msm_gpio_irq_disable, + .irq_mask = msm_gpio_irq_mask, + .irq_unmask = msm_gpio_irq_unmask, + .irq_ack = msm_gpio_irq_ack, + .irq_eoi = msm_gpio_irq_eoi, + .irq_set_type = msm_gpio_irq_set_type, + .irq_set_wake = msm_gpio_irq_set_wake, + .irq_request_resources = msm_gpio_irq_reqres, + .irq_release_resources = msm_gpio_irq_relres, + .irq_set_affinity = msm_gpio_irq_set_affinity, + .irq_set_vcpu_affinity = msm_gpio_irq_set_vcpu_affinity, + .flags = (IRQCHIP_MASK_ON_SUSPEND | + IRQCHIP_SET_TYPE_MASKED | + IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND | + IRQCHIP_IMMUTABLE), +}; + static int msm_gpio_init(struct msm_pinctrl *pctrl) { struct gpio_chip *chip; @@ -1276,22 +1306,6 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl) if (msm_gpio_needs_valid_mask(pctrl)) chip->init_valid_mask = msm_gpio_init_valid_mask; - pctrl->irq_chip.name = "msmgpio"; - pctrl->irq_chip.irq_enable = msm_gpio_irq_enable; - pctrl->irq_chip.irq_disable = msm_gpio_irq_disable; - pctrl->irq_chip.irq_mask = msm_gpio_irq_mask; - pctrl->irq_chip.irq_unmask = msm_gpio_irq_unmask; - pctrl->irq_chip.irq_ack = msm_gpio_irq_ack; - pctrl->irq_chip.irq_set_type = msm_gpio_irq_set_type; - pctrl->irq_chip.irq_set_wake = msm_gpio_irq_set_wake; - pctrl->irq_chip.irq_request_resources = msm_gpio_irq_reqres; - pctrl->irq_chip.irq_release_resources = msm_gpio_irq_relres; - pctrl->irq_chip.irq_set_affinity = msm_gpio_irq_set_affinity; - pctrl->irq_chip.irq_set_vcpu_affinity = msm_gpio_irq_set_vcpu_affinity; - pctrl->irq_chip.flags = IRQCHIP_MASK_ON_SUSPEND | - IRQCHIP_SET_TYPE_MASKED | - IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND; - np = of_parse_phandle(pctrl->dev->of_node, "wakeup-parent", 0); if (np) { chip->irq.parent_domain = irq_find_matching_host(np, @@ -1300,7 +1314,6 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl) if (!chip->irq.parent_domain) return -EPROBE_DEFER; chip->irq.child_to_parent_hwirq = msm_gpio_wakeirq; - pctrl->irq_chip.irq_eoi = irq_chip_eoi_parent; /* * Let's skip handling the GPIOs, if the parent irqchip * is handling the direct connect IRQ of the GPIO. @@ -1313,7 +1326,7 @@ static int msm_gpio_init(struct msm_pinctrl *pctrl) } girq = &chip->irq; - girq->chip = &pctrl->irq_chip; + gpio_irq_chip_set_chip(girq, &msm_gpio_irq_chip); girq->parent_handler = msm_gpio_irq_handler; girq->fwnode = pctrl->dev->fwnode; girq->num_parents = 1; -- cgit From 6173e56f76c712aac9d45208ccec7a065382911f Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:44 +0100 Subject: pinctrl: amd: Make the irqchip immutable Prevent gpiolib from messing with the irqchip by advertising the irq_chip structure as immutable, making it const, and adding the various calls that gpiolib relies upon. Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-9-maz@kernel.org --- drivers/pinctrl/pinctrl-amd.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/pinctrl/pinctrl-amd.c b/drivers/pinctrl/pinctrl-amd.c index 1a7d686494ff..0645c2c24f50 100644 --- a/drivers/pinctrl/pinctrl-amd.c +++ b/drivers/pinctrl/pinctrl-amd.c @@ -387,6 +387,8 @@ static void amd_gpio_irq_enable(struct irq_data *d) struct gpio_chip *gc = irq_data_get_irq_chip_data(d); struct amd_gpio *gpio_dev = gpiochip_get_data(gc); + gpiochip_enable_irq(gc, d->hwirq); + raw_spin_lock_irqsave(&gpio_dev->lock, flags); pin_reg = readl(gpio_dev->base + (d->hwirq)*4); pin_reg |= BIT(INTERRUPT_ENABLE_OFF); @@ -408,6 +410,8 @@ static void amd_gpio_irq_disable(struct irq_data *d) pin_reg &= ~BIT(INTERRUPT_MASK_OFF); writel(pin_reg, gpio_dev->base + (d->hwirq)*4); raw_spin_unlock_irqrestore(&gpio_dev->lock, flags); + + gpiochip_disable_irq(gc, d->hwirq); } static void amd_gpio_irq_mask(struct irq_data *d) @@ -577,7 +581,7 @@ static void amd_irq_ack(struct irq_data *d) */ } -static struct irq_chip amd_gpio_irqchip = { +static const struct irq_chip amd_gpio_irqchip = { .name = "amd_gpio", .irq_ack = amd_irq_ack, .irq_enable = amd_gpio_irq_enable, @@ -593,7 +597,8 @@ static struct irq_chip amd_gpio_irqchip = { * the wake event. Otherwise the wake event will never clear and * prevent the system from suspending. */ - .flags = IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND, + .flags = IRQCHIP_ENABLE_WAKEUP_ON_SUSPEND | IRQCHIP_IMMUTABLE, + GPIOCHIP_IRQ_RESOURCE_HELPERS, }; #define PIN_IRQ_PENDING (BIT(INTERRUPT_STS_OFF) | BIT(WAKE_STS_OFF)) @@ -1026,7 +1031,7 @@ static int amd_gpio_probe(struct platform_device *pdev) amd_gpio_irq_init(gpio_dev); girq = &gpio_dev->gc.irq; - girq->chip = &amd_gpio_irqchip; + gpio_irq_chip_set_chip(girq, &amd_gpio_irqchip); /* This will let us handle the parent IRQ in the driver */ girq->parent_handler = NULL; girq->num_parents = 0; -- cgit From afefc3266272d40cdcd0fd713c7b42008fea19d5 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:45 +0100 Subject: gpio: Update TODO to mention immutable irq_chip structures 5 drivers are converted, a few hundred to go. Definitely worth of a TODO entry, in the hope that someone will notice it and do a bulk update. Reviewed-by: Andy Shevchenko Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-10-maz@kernel.org --- drivers/gpio/TODO | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/drivers/gpio/TODO b/drivers/gpio/TODO index b8b1473a5b1e..f87ff3fa8a53 100644 --- a/drivers/gpio/TODO +++ b/drivers/gpio/TODO @@ -178,3 +178,22 @@ discussed but the idea is to provide a low-level access point for debugging and hacking and to expose all lines without the need of any exporting. Also provide ample ammunition to shoot oneself in the foot, because this is debugfs after all. + + +Moving over to immutable irq_chip structures + +Most of the gpio chips implementing interrupt support rely on gpiolib +intercepting some of the irq_chip callbacks, preventing the structures +from being made read-only and forcing duplication of structures that +should otherwise be unique. + +The solution is to call into the gpiolib code when needed (resource +management, enable/disable or unmask/mask callbacks), and to let the +core code know about that by exposing a flag (IRQCHIP_IMMUTABLE) in +the irq_chip structure. The irq_chip structure can then be made unique +and const. + +A small number of drivers have been converted (pl061, tegra186, msm, +amd, apple), and can be used as examples of how to proceed with this +conversion. Note that drivers using the generic irqchip framework +cannot be converted yet, but watch this space! -- cgit From 5644b66a9c63c3cadc6ba85faf5a15604e6cf29a Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Tue, 19 Apr 2022 15:18:46 +0100 Subject: Documentation: Update the recommended pattern for GPIO irqchips Update the documentation to get rid of the per-gpio_irq_chip irq_chip structure, and give examples of the new pattern. Reviewed-by: Andy Shevchenko Reviewed-by: Bartosz Golaszewski Signed-off-by: Marc Zyngier Link: https://lore.kernel.org/r/20220419141846.598305-11-maz@kernel.org --- Documentation/driver-api/gpio/driver.rst | 175 +++++++++++++++++++++++++------ 1 file changed, 142 insertions(+), 33 deletions(-) diff --git a/Documentation/driver-api/gpio/driver.rst b/Documentation/driver-api/gpio/driver.rst index bbc53920d4dd..a1ddefa1f55f 100644 --- a/Documentation/driver-api/gpio/driver.rst +++ b/Documentation/driver-api/gpio/driver.rst @@ -417,30 +417,66 @@ struct gpio_irq_chip inside struct gpio_chip before adding the gpio_chip. If you do this, the additional irq_chip will be set up by gpiolib at the same time as setting up the rest of the GPIO functionality. The following is a typical example of a chained cascaded interrupt handler using -the gpio_irq_chip: +the gpio_irq_chip. Note how the mask/unmask (or disable/enable) functions +call into the core gpiolib code: .. code-block:: c - /* Typical state container with dynamic irqchip */ + /* Typical state container */ struct my_gpio { struct gpio_chip gc; - struct irq_chip irq; + }; + + static void my_gpio_mask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_desc_get_handler_data(d); + + /* + * Perform any necessary action to mask the interrupt, + * and then call into the core code to synchronise the + * state. + */ + + gpiochip_disable_irq(gc, d->hwirq); + } + + static void my_gpio_unmask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_desc_get_handler_data(d); + + gpiochip_enable_irq(gc, d->hwirq); + + /* + * Perform any necessary action to unmask the interrupt, + * after having called into the core code to synchronise + * the state. + */ + } + + /* + * Statically populate the irqchip. Note that it is made const + * (further indicated by the IRQCHIP_IMMUTABLE flag), and that + * the GPIOCHIP_IRQ_RESOURCE_HELPER macro adds some extra + * callbacks to the structure. + */ + static const struct irq_chip my_gpio_irq_chip = { + .name = "my_gpio_irq", + .irq_ack = my_gpio_ack_irq, + .irq_mask = my_gpio_mask_irq, + .irq_unmask = my_gpio_unmask_irq, + .irq_set_type = my_gpio_set_irq_type, + .flags = IRQCHIP_IMMUTABLE, + /* Provide the gpio resource callbacks */ + GPIOCHIP_IRQ_RESOURCE_HELPERS, }; int irq; /* from platform etc */ struct my_gpio *g; struct gpio_irq_chip *girq; - /* Set up the irqchip dynamically */ - g->irq.name = "my_gpio_irq"; - g->irq.irq_ack = my_gpio_ack_irq; - g->irq.irq_mask = my_gpio_mask_irq; - g->irq.irq_unmask = my_gpio_unmask_irq; - g->irq.irq_set_type = my_gpio_set_irq_type; - /* Get a pointer to the gpio_irq_chip */ girq = &g->gc.irq; - girq->chip = &g->irq; + gpio_irq_chip_set_chip(girq, &my_gpio_irq_chip); girq->parent_handler = ftgpio_gpio_irq_handler; girq->num_parents = 1; girq->parents = devm_kcalloc(dev, 1, sizeof(*girq->parents), @@ -458,23 +494,58 @@ the interrupt separately and go with it: .. code-block:: c - /* Typical state container with dynamic irqchip */ + /* Typical state container */ struct my_gpio { struct gpio_chip gc; - struct irq_chip irq; + }; + + static void my_gpio_mask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_desc_get_handler_data(d); + + /* + * Perform any necessary action to mask the interrupt, + * and then call into the core code to synchronise the + * state. + */ + + gpiochip_disable_irq(gc, d->hwirq); + } + + static void my_gpio_unmask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_desc_get_handler_data(d); + + gpiochip_enable_irq(gc, d->hwirq); + + /* + * Perform any necessary action to unmask the interrupt, + * after having called into the core code to synchronise + * the state. + */ + } + + /* + * Statically populate the irqchip. Note that it is made const + * (further indicated by the IRQCHIP_IMMUTABLE flag), and that + * the GPIOCHIP_IRQ_RESOURCE_HELPER macro adds some extra + * callbacks to the structure. + */ + static const struct irq_chip my_gpio_irq_chip = { + .name = "my_gpio_irq", + .irq_ack = my_gpio_ack_irq, + .irq_mask = my_gpio_mask_irq, + .irq_unmask = my_gpio_unmask_irq, + .irq_set_type = my_gpio_set_irq_type, + .flags = IRQCHIP_IMMUTABLE, + /* Provide the gpio resource callbacks */ + GPIOCHIP_IRQ_RESOURCE_HELPERS, }; int irq; /* from platform etc */ struct my_gpio *g; struct gpio_irq_chip *girq; - /* Set up the irqchip dynamically */ - g->irq.name = "my_gpio_irq"; - g->irq.irq_ack = my_gpio_ack_irq; - g->irq.irq_mask = my_gpio_mask_irq; - g->irq.irq_unmask = my_gpio_unmask_irq; - g->irq.irq_set_type = my_gpio_set_irq_type; - ret = devm_request_threaded_irq(dev, irq, NULL, irq_thread_fn, IRQF_ONESHOT, "my-chip", g); if (ret < 0) @@ -482,7 +553,7 @@ the interrupt separately and go with it: /* Get a pointer to the gpio_irq_chip */ girq = &g->gc.irq; - girq->chip = &g->irq; + gpio_irq_chip_set_chip(girq, &my_gpio_irq_chip); /* This will let us handle the parent IRQ in the driver */ girq->parent_handler = NULL; girq->num_parents = 0; @@ -500,24 +571,61 @@ In this case the typical set-up will look like this: /* Typical state container with dynamic irqchip */ struct my_gpio { struct gpio_chip gc; - struct irq_chip irq; struct fwnode_handle *fwnode; }; - int irq; /* from platform etc */ + static void my_gpio_mask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_desc_get_handler_data(d); + + /* + * Perform any necessary action to mask the interrupt, + * and then call into the core code to synchronise the + * state. + */ + + gpiochip_disable_irq(gc, d->hwirq); + irq_mask_mask_parent(d); + } + + static void my_gpio_unmask_irq(struct irq_data *d) + { + struct gpio_chip *gc = irq_desc_get_handler_data(d); + + gpiochip_enable_irq(gc, d->hwirq); + + /* + * Perform any necessary action to unmask the interrupt, + * after having called into the core code to synchronise + * the state. + */ + + irq_mask_unmask_parent(d); + } + + /* + * Statically populate the irqchip. Note that it is made const + * (further indicated by the IRQCHIP_IMMUTABLE flag), and that + * the GPIOCHIP_IRQ_RESOURCE_HELPER macro adds some extra + * callbacks to the structure. + */ + static const struct irq_chip my_gpio_irq_chip = { + .name = "my_gpio_irq", + .irq_ack = my_gpio_ack_irq, + .irq_mask = my_gpio_mask_irq, + .irq_unmask = my_gpio_unmask_irq, + .irq_set_type = my_gpio_set_irq_type, + .flags = IRQCHIP_IMMUTABLE, + /* Provide the gpio resource callbacks */ + GPIOCHIP_IRQ_RESOURCE_HELPERS, + }; + struct my_gpio *g; struct gpio_irq_chip *girq; - /* Set up the irqchip dynamically */ - g->irq.name = "my_gpio_irq"; - g->irq.irq_ack = my_gpio_ack_irq; - g->irq.irq_mask = my_gpio_mask_irq; - g->irq.irq_unmask = my_gpio_unmask_irq; - g->irq.irq_set_type = my_gpio_set_irq_type; - /* Get a pointer to the gpio_irq_chip */ girq = &g->gc.irq; - girq->chip = &g->irq; + gpio_irq_chip_set_chip(girq, &my_gpio_irq_chip); girq->default_type = IRQ_TYPE_NONE; girq->handler = handle_bad_irq; girq->fwnode = g->fwnode; @@ -605,8 +713,9 @@ When implementing an irqchip inside a GPIO driver, these two functions should typically be called in the .irq_disable() and .irq_enable() callbacks from the irqchip. -When using the gpiolib irqchip helpers, these callbacks are automatically -assigned. +When IRQCHIP_IMMUTABLE is not advertised by the irqchip, these callbacks +are automatically assigned. This behaviour is deprecated and on its way +to be removed from the kernel. Real-Time compliance for GPIO IRQ chips -- cgit