Re: [PATCH 2/3] irqchip: mstar: msc313-intc interrupt controller driver
From: Marc Zyngier
Date: Wed Aug 05 2020 - 16:02:35 EST
[+ Mark-PK Tsai]
Hi Daniel,
On 2020-08-05 12:00, Daniel Palmer wrote:
Add a driver for the two peripheral interrupt controllers
in MStar MSC313 and other MStar/Sigmastar Armv7 SoCs.
Supports both the "IRQ" and "FIQ" controllers that
forward interrupts from the various IP blocks inside the
SoC to the ARM GIC.
They are basically the same thing except for one difference:
The FIQ controller needs to clear the interrupt and the IRQ
controller doesn't.
Signed-off-by: Daniel Palmer <daniel@xxxxxxxx>
Tested-by: Willy Tarreau <w@xxxxxx>
---
MAINTAINERS | 1 +
drivers/irqchip/Makefile | 1 +
drivers/irqchip/irq-msc313-intc.c | 210 ++++++++++++++++++++++++++++++
3 files changed, 212 insertions(+)
create mode 100644 drivers/irqchip/irq-msc313-intc.c
diff --git a/MAINTAINERS b/MAINTAINERS
index 6e64d17aad7b..4d07403a7726 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -2157,6 +2157,7 @@ F: arch/arm/boot/dts/infinity*.dtsi
F: arch/arm/boot/dts/mercury*.dtsi
F: arch/arm/boot/dts/mstar-v7.dtsi
F: arch/arm/mach-mstar/
+F: drivers/irqchip/irq-msc313-intc.c
ARM/NEC MOBILEPRO 900/c MACHINE SUPPORT
M: Michael Petchkovsky <mkpetch@xxxxxxxxxxxxxxxx>
diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index 133f9c45744a..67f3ae3507b8 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -111,3 +111,4 @@ obj-$(CONFIG_LOONGSON_HTPIC) +=
irq-loongson-htpic.o
obj-$(CONFIG_LOONGSON_HTVEC) += irq-loongson-htvec.o
obj-$(CONFIG_LOONGSON_PCH_PIC) += irq-loongson-pch-pic.o
obj-$(CONFIG_LOONGSON_PCH_MSI) += irq-loongson-pch-msi.o
+obj-$(CONFIG_ARCH_MSTARV7) += irq-msc313-intc.o
diff --git a/drivers/irqchip/irq-msc313-intc.c
b/drivers/irqchip/irq-msc313-intc.c
new file mode 100644
index 000000000000..b50f5c858d38
--- /dev/null
+++ b/drivers/irqchip/irq-msc313-intc.c
@@ -0,0 +1,210 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 Daniel Palmer
+ */
+
+#include <linux/irq.h>
+#include <linux/irqchip.h>
+#include <linux/irqdomain.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+#define REGOFF_MASK 0x0
+#define REGOFF_POLARITY 0x10
+#define REGOFF_STATUSCLEAR 0x20
+#define IRQSPERREG 16
+#define IRQBIT(hwirq) BIT((hwirq % IRQSPERREG))
+#define REGOFF(hwirq) ((hwirq >> 4) * 4)
+
+struct msc313_intc {
+ struct irq_domain *domain;
+ void __iomem *base;
+ struct irq_chip irqchip;
Why do you need to embed the irq_chip on a per-controller basis?
+ u8 gicoff;
Given that basic SPIs can be in the 32-1019 range, this is at
best risky. u32s are free, please use them.
+};
+
+static void msc313_intc_maskunmask(struct msc313_intc *intc, int
hwirq, bool mask)
+{
+ int regoff = REGOFF(hwirq);
+ void __iomem *addr = intc->base + REGOFF_MASK + regoff;
+ u16 bit = IRQBIT(hwirq);
+ u16 reg = readw_relaxed(addr);
+
+ if (mask)
+ reg |= bit;
+ else
+ reg &= ~bit;
+
+ writew_relaxed(reg, addr);
RMW on a shared MMIO register. Not going to end well. This is valid
for all the callbacks, I believe.
Also, please inline the maskunmask code in their respective callers.
It will be much more readable.
+}
+
+static void msc313_intc_mask_irq(struct irq_data *data)
+{
+ struct msc313_intc *intc = data->chip_data;
+
+ msc313_intc_maskunmask(intc, data->hwirq, true);
+ irq_chip_mask_parent(data);
+}
+
+static void msc313_intc_unmask_irq(struct irq_data *data)
+{
+ struct msc313_intc *intc = data->chip_data;
+
+ msc313_intc_maskunmask(intc, data->hwirq, false);
+ irq_chip_unmask_parent(data);
+}
+
+static int msc313_intc_set_type_irq(struct irq_data *data, unsigned
int flow_type)
+{
+ struct msc313_intc *intc = data->chip_data;
+ int irq = data->hwirq;
+ int regoff = REGOFF(irq);
+ void __iomem *addr = intc->base + REGOFF_POLARITY + regoff;
+ u16 bit = IRQBIT(irq);
+ u16 reg = readw_relaxed(addr);
Please try to write this in a more readable way. For example:
struct msc313_intc *intc = data->chip_data;
void __iomem *addr;
u16 reg, bit;
addr = intc->base + REGOFF_POLARITY + REGOFF(d->hwirq);
reg = readw_relaxed(addr);
bit = IRQBIT(d->hwirq);
White space is free, and some of the variables are really useless.
+
+ if (flow_type & (IRQ_TYPE_EDGE_FALLING | IRQ_TYPE_LEVEL_HIGH))
+ reg &= ~bit;
+ else
+ reg |= bit;
I don't follow grasp the logic here. What happens on EDGE_BOTH, for
example?
+
+ writew_relaxed(reg, addr);
Surely you need to communicate the change of signalling mode
to the parent irqchip, don't you?
+ return 0;
+}
+
+static void msc313_intc_irq_eoi(struct irq_data *data)
+{
+ struct msc313_intc *intc = data->chip_data;
+ int irq = data->hwirq;
+ int regoff = REGOFF(irq);
+ void __iomem *addr = intc->base + REGOFF_STATUSCLEAR + regoff;
+ u16 bit = IRQBIT(irq);
+ u16 reg = readw_relaxed(addr);
+
+ reg |= bit;
+ writew_relaxed(reg, addr);
+ irq_chip_eoi_parent(data);
+}
+
+static int msc313_intc_domain_translate(struct irq_domain *d,
+ struct irq_fwspec *fwspec,
+ unsigned long *hwirq,
+ unsigned int *type)
+{
+ if (!is_of_node(fwspec->fwnode) || fwspec->param_count != 2)
+ return -EINVAL;
+
+ *hwirq = fwspec->param[0];
Don't you want to check that the input you get is actually in range?
Not a big deal, given that you then use it as an input parameter
to the GIC driver, it'd better be correct.
+ *type = fwspec->param[1];
+
+ return 0;
+}
+
+static int msc313_intc_domain_alloc(struct irq_domain *domain,
unsigned int virq,
+ unsigned int nr_irqs, void *data)
+{
+ struct irq_fwspec *fwspec = data;
+ struct irq_fwspec parent_fwspec;
+ struct msc313_intc *intc = domain->host_data;
+
+ if (fwspec->param_count != 2)
+ return -EINVAL;
+
+ irq_domain_set_hwirq_and_chip(domain, virq, fwspec->param[0],
&intc->irqchip, intc);
+
+ parent_fwspec.fwnode = domain->parent->fwnode;
+ parent_fwspec.param[0] = GIC_SPI;
+ parent_fwspec.param[1] = fwspec->param[0] + intc->gicoff;
+ parent_fwspec.param[2] = fwspec->param[1];
+ parent_fwspec.param_count = 3;
+
+ return irq_domain_alloc_irqs_parent(domain, virq, nr_irqs,
+ &parent_fwspec);
+}
+
+static const struct irq_domain_ops msc313_intc_domain_ops = {
+ .translate = msc313_intc_domain_translate,
+ .alloc = msc313_intc_domain_alloc,
+ .free = irq_domain_free_irqs_common,
+};
+
+static int msc313_intc_of_init(struct device_node *node,
+ struct device_node *parent,
+ void (*eoi)(struct irq_data *data))
+{
+ struct irq_domain *domain_parent;
+ struct msc313_intc *intc;
+ int ret = 0;
+ u32 gicoffset, numirqs;
+
+ if (of_property_read_u32(node, "mstar,gic-offset", &gicoffset)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ if (of_property_read_u32(node, "mstar,nr-interrupts", &numirqs)) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ domain_parent = irq_find_host(parent);
+ if (!domain_parent) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ intc = kzalloc(sizeof(*intc), GFP_KERNEL);
+ if (!intc) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ intc->base = of_iomap(node, 0);
+ if (IS_ERR(intc->base)) {
+ ret = PTR_ERR(intc->base);
+ goto free_intc;
+ }
+
+ intc->irqchip.name = node->name;
No, please. /proc/interrupt isn't a dumping ground for DT related
information. We have debugfs for that.
+ intc->irqchip.irq_mask = msc313_intc_mask_irq;
+ intc->irqchip.irq_unmask = msc313_intc_unmask_irq;
+ intc->irqchip.irq_eoi = eoi;
+ intc->irqchip.irq_set_type = msc313_intc_set_type_irq;
+ intc->irqchip.flags = IRQCHIP_MASK_ON_SUSPEND;
This needs to be a static irq_chip structure. Use two for the EOI
weirdness, or test a flag in your eoi callback.
+
+ intc->gicoff = gicoffset;
+
+ intc->domain = irq_domain_add_hierarchy(domain_parent, 0, numirqs,
node,
+ &msc313_intc_domain_ops, intc);
+ if (!intc->domain) {
+ ret = -ENOMEM;
+ goto unmap;
+ }
+
+ return 0;
+
+unmap:
+ iounmap(intc->base);
+free_intc:
+ kfree(intc);
+out:
+ return ret;
+}
+
+static int __init msc313_intc_irq_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ return msc313_intc_of_init(node, parent, irq_chip_eoi_parent);
+};
+
+static int __init msc313_intc_fiq_of_init(struct device_node *node,
+ struct device_node *parent)
+{
+ return msc313_intc_of_init(node, parent, msc313_intc_irq_eoi);
+};
+
+IRQCHIP_DECLARE(msc313_intc_irq, "mstar,msc313-intc-irq",
+ msc313_intc_irq_of_init);
+IRQCHIP_DECLARE(mstar_intc_fiq, "mstar,msc313-intc-fiq",
+ msc313_intc_fiq_of_init);
This driver has a massive feeling of déja-vu. It is almost
a copy of the one posted at [1], which I reviewed early
this week. The issues are the exact same, and I'm 98%
sure this is the same IP block used by two SoC vendors.
Please talk to each other and come up with a single driver.
Thanks,
M.
[1]
https://lore.kernel.org/r/20200803062214.24076-1-mark-pk.tsai@xxxxxxxxxxxx
--
Jazz is not dead. It just smells funny...