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Subject[PATCH v4 1/3] irqchip: brcmstb-l2: Remove some processing from the handler
Date
Saving the generic chip pointer in the brcmstb_l2_intc_data prevents
the need to call irq_get_domain_generic_chip(). Also don't need to
save parent_irq and base there since local variables in the
brcmstb_l2_intc_of_init() function are just as good.

The handle_edge_irq flow or chained_irq_enter takes care of the
acknowledgment of the interrupt so it is redundant to clear it in
brcmstb_l2_intc_irq_handle().

irq_linear_revmap() is a fast path equivalent of irq_find_mapping()
that is appropriate to use for domain controllers of this type.

Defining irq_mask_ack is slightly more efficient than just
implementing irq_mask and irq_ack separately.

Signed-off-by: Doug Berger <opendmb@gmail.com>
---
drivers/irqchip/irq-brcmstb-l2.c | 72 ++++++++++++++++++++++++++--------------
1 file changed, 48 insertions(+), 24 deletions(-)

diff --git a/drivers/irqchip/irq-brcmstb-l2.c b/drivers/irqchip/irq-brcmstb-l2.c
index b009b916a292..48bd1a36c7d4 100644
--- a/drivers/irqchip/irq-brcmstb-l2.c
+++ b/drivers/irqchip/irq-brcmstb-l2.c
@@ -1,7 +1,7 @@
/*
* Generic Broadcom Set Top Box Level 2 Interrupt controller driver
*
- * Copyright (C) 2014 Broadcom Corporation
+ * Copyright (C) 2014-2017 Broadcom
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
@@ -41,25 +41,49 @@

/* L2 intc private data structure */
struct brcmstb_l2_intc_data {
- int parent_irq;
- void __iomem *base;
struct irq_domain *domain;
+ struct irq_chip_generic *gc;
bool can_wake;
u32 saved_mask; /* for suspend/resume */
};

+/**
+ * brcmstb_l2_mask_and_ack - Mask and ack pending interrupt
+ * @d: irq_data
+ *
+ * Chip has separate enable/disable registers instead of a single mask
+ * register and pending interrupt is acknowledged by setting a bit.
+ *
+ * Note: This function is generic and could easily be added to the
+ * generic irqchip implementation if there ever becomes a will to do so.
+ * Perhaps with a name like irq_gc_mask_disable_and_ack_set().
+ *
+ * e.g.: https://patchwork.kernel.org/patch/9831047/
+ */
+static void brcmstb_l2_mask_and_ack(struct irq_data *d)
+{
+ struct irq_chip_generic *gc = irq_data_get_irq_chip_data(d);
+ struct irq_chip_type *ct = irq_data_get_chip_type(d);
+ u32 mask = d->mask;
+
+ irq_gc_lock(gc);
+ irq_reg_writel(gc, mask, ct->regs.disable);
+ *ct->mask_cache &= ~mask;
+ irq_reg_writel(gc, mask, ct->regs.ack);
+ irq_gc_unlock(gc);
+}
+
static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)
{
struct brcmstb_l2_intc_data *b = irq_desc_get_handler_data(desc);
- struct irq_chip_generic *gc = irq_get_domain_generic_chip(b->domain, 0);
struct irq_chip *chip = irq_desc_get_chip(desc);
unsigned int irq;
u32 status;

chained_irq_enter(chip, desc);

- status = irq_reg_readl(gc, CPU_STATUS) &
- ~(irq_reg_readl(gc, CPU_MASK_STATUS));
+ status = irq_reg_readl(b->gc, CPU_STATUS) &
+ ~(irq_reg_readl(b->gc, CPU_MASK_STATUS));

if (status == 0) {
raw_spin_lock(&desc->lock);
@@ -70,10 +94,8 @@ static void brcmstb_l2_intc_irq_handle(struct irq_desc *desc)

do {
irq = ffs(status) - 1;
- /* ack at our level */
- irq_reg_writel(gc, 1 << irq, CPU_CLEAR);
status &= ~(1 << irq);
- generic_handle_irq(irq_find_mapping(b->domain, irq));
+ generic_handle_irq(irq_linear_revmap(b->domain, irq));
} while (status);
out:
chained_irq_exit(chip, desc);
@@ -116,32 +138,33 @@ static int __init brcmstb_l2_intc_of_init(struct device_node *np,
{
unsigned int clr = IRQ_NOREQUEST | IRQ_NOPROBE | IRQ_NOAUTOEN;
struct brcmstb_l2_intc_data *data;
- struct irq_chip_generic *gc;
struct irq_chip_type *ct;
int ret;
unsigned int flags;
+ int parent_irq;
+ void __iomem *base;

data = kzalloc(sizeof(*data), GFP_KERNEL);
if (!data)
return -ENOMEM;

- data->base = of_iomap(np, 0);
- if (!data->base) {
+ base = of_iomap(np, 0);
+ if (!base) {
pr_err("failed to remap intc L2 registers\n");
ret = -ENOMEM;
goto out_free;
}

/* Disable all interrupts by default */
- writel(0xffffffff, data->base + CPU_MASK_SET);
+ writel(0xffffffff, base + CPU_MASK_SET);

/* Wakeup interrupts may be retained from S5 (cold boot) */
data->can_wake = of_property_read_bool(np, "brcm,irq-can-wake");
if (!data->can_wake)
- writel(0xffffffff, data->base + CPU_CLEAR);
+ writel(0xffffffff, base + CPU_CLEAR);

- data->parent_irq = irq_of_parse_and_map(np, 0);
- if (!data->parent_irq) {
+ parent_irq = irq_of_parse_and_map(np, 0);
+ if (!parent_irq) {
pr_err("failed to find parent interrupt\n");
ret = -EINVAL;
goto out_unmap;
@@ -170,18 +193,19 @@ static int __init brcmstb_l2_intc_of_init(struct device_node *np,
}

/* Set the IRQ chaining logic */
- irq_set_chained_handler_and_data(data->parent_irq,
+ irq_set_chained_handler_and_data(parent_irq,
brcmstb_l2_intc_irq_handle, data);

- gc = irq_get_domain_generic_chip(data->domain, 0);
- gc->reg_base = data->base;
- gc->private = data;
- ct = gc->chip_types;
+ data->gc = irq_get_domain_generic_chip(data->domain, 0);
+ data->gc->reg_base = base;
+ data->gc->private = data;
+ ct = data->gc->chip_types;

ct->chip.irq_ack = irq_gc_ack_set_bit;
ct->regs.ack = CPU_CLEAR;

ct->chip.irq_mask = irq_gc_mask_disable_reg;
+ ct->chip.irq_mask_ack = brcmstb_l2_mask_and_ack;
ct->regs.disable = CPU_MASK_SET;

ct->chip.irq_unmask = irq_gc_unmask_enable_reg;
@@ -195,19 +219,19 @@ static int __init brcmstb_l2_intc_of_init(struct device_node *np,
/* This IRQ chip can wake the system, set all child interrupts
* in wake_enabled mask
*/
- gc->wake_enabled = 0xffffffff;
+ data->gc->wake_enabled = 0xffffffff;
ct->chip.irq_set_wake = irq_gc_set_wake;
}

pr_info("registered L2 intc (mem: 0x%p, parent irq: %d)\n",
- data->base, data->parent_irq);
+ base, parent_irq);

return 0;

out_free_domain:
irq_domain_remove(data->domain);
out_unmap:
- iounmap(data->base);
+ iounmap(base);
out_free:
kfree(data);
return ret;
--
2.14.1
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