Re:Re:[PATCH v11 12/14] irqchip/riscv-aplic: Add support for MSI-mode

[Ben <figure1802@126.com>]

At 2023-11-04 08:58:10, "Ben" <figure1802@126.com> wrote:
>At 2023-10-24 01:27:58, "Anup Patel" <apatel@ventanamicro.com> wrote:
>>The RISC-V advanced platform-level interrupt controller (APLIC) has
>>two modes of operation: 1) Direct mode and 2) MSI mode.
>>(For more details, refer https://github.com/riscv/riscv-aia)
>>
>>In APLIC MSI-mode, wired interrupts are forwared as message signaled
>>interrupts (MSIs) to CPUs via IMSIC.
>>
>>We extend the existing APLIC irqchip driver to support MSI-mode for
>>RISC-V platforms having both wired interrupts and MSIs.
>>
>>Signed-off-by: Anup Patel <apatel@ventanamicro.com>
>>---
>> drivers/irqchip/Kconfig                |   6 +
>> drivers/irqchip/Makefile               |   1 +
>> drivers/irqchip/irq-riscv-aplic-main.c |   2 +-
>> drivers/irqchip/irq-riscv-aplic-main.h |   8 +
>> drivers/irqchip/irq-riscv-aplic-msi.c  | 285 +++++++++++++++++++++++++
>> 5 files changed, 301 insertions(+), 1 deletion(-)
>> create mode 100644 drivers/irqchip/irq-riscv-aplic-msi.c
>>
>>diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
>>index 1996cc6f666a..7adc4dbe07ff 100644
>>--- a/drivers/irqchip/Kconfig
>>+++ b/drivers/irqchip/Kconfig
>>@@ -551,6 +551,12 @@ config RISCV_APLIC
>> 	depends on RISCV
>> 	select IRQ_DOMAIN_HIERARCHY
>> 
>>+config RISCV_APLIC_MSI
>>+	bool
>>+	depends on RISCV_APLIC
>>+	select GENERIC_MSI_IRQ
>>+	default RISCV_APLIC
>>+
>> config RISCV_IMSIC
>> 	bool
>> 	depends on RISCV
>>diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
>>index 7f8289790ed8..47995fdb2c60 100644
>>--- a/drivers/irqchip/Makefile
>>+++ b/drivers/irqchip/Makefile
>>@@ -96,6 +96,7 @@ obj-$(CONFIG_CSKY_MPINTC)		+= irq-csky-mpintc.o
>> obj-$(CONFIG_CSKY_APB_INTC)		+= irq-csky-apb-intc.o
>> obj-$(CONFIG_RISCV_INTC)		+= irq-riscv-intc.o
>> obj-$(CONFIG_RISCV_APLIC)		+= irq-riscv-aplic-main.o irq-riscv-aplic-direct.o
>>+obj-$(CONFIG_RISCV_APLIC_MSI)		+= irq-riscv-aplic-msi.o
>> obj-$(CONFIG_RISCV_IMSIC)		+= irq-riscv-imsic-state.o irq-riscv-imsic-early.o irq-riscv-imsic-platform.o
>> obj-$(CONFIG_SIFIVE_PLIC)		+= irq-sifive-plic.o
>> obj-$(CONFIG_IMX_IRQSTEER)		+= irq-imx-irqsteer.o
>>diff --git a/drivers/irqchip/irq-riscv-aplic-main.c b/drivers/irqchip/irq-riscv-aplic-main.c
>>index 87450708a733..d1b342b66551 100644
>>--- a/drivers/irqchip/irq-riscv-aplic-main.c
>>+++ b/drivers/irqchip/irq-riscv-aplic-main.c
>>@@ -205,7 +205,7 @@ static int aplic_probe(struct platform_device *pdev)
>> 		msi_mode = of_property_present(to_of_node(dev->fwnode),
>> 						"msi-parent");
>> 	if (msi_mode)
>>-		rc = -ENODEV;
>>+		rc = aplic_msi_setup(dev, regs);
>> 	else
>> 		rc = aplic_direct_setup(dev, regs);
>> 	if (rc) {
>>diff --git a/drivers/irqchip/irq-riscv-aplic-main.h b/drivers/irqchip/irq-riscv-aplic-main.h
>>index 474a04229334..78267ec58098 100644
>>--- a/drivers/irqchip/irq-riscv-aplic-main.h
>>+++ b/drivers/irqchip/irq-riscv-aplic-main.h
>>@@ -41,5 +41,13 @@ void aplic_init_hw_global(struct aplic_priv *priv, bool msi_mode);
>> int aplic_setup_priv(struct aplic_priv *priv, struct device *dev,
>> 		     void __iomem *regs);
>> int aplic_direct_setup(struct device *dev, void __iomem *regs);
>>+#ifdef CONFIG_RISCV_APLIC_MSI
>>+int aplic_msi_setup(struct device *dev, void __iomem *regs);
>>+#else
>>+static inline int aplic_msi_setup(struct device *dev, void __iomem *regs)
>>+{
>>+	return -ENODEV;
>>+}
>>+#endif
>> 
>> #endif
>>diff --git a/drivers/irqchip/irq-riscv-aplic-msi.c b/drivers/irqchip/irq-riscv-aplic-msi.c
>>new file mode 100644
>>index 000000000000..086d00e0429e
>>--- /dev/null
>>+++ b/drivers/irqchip/irq-riscv-aplic-msi.c
>>@@ -0,0 +1,285 @@
>>+// SPDX-License-Identifier: GPL-2.0
>>+/*
>>+ * Copyright (C) 2021 Western Digital Corporation or its affiliates.
>>+ * Copyright (C) 2022 Ventana Micro Systems Inc.
>>+ */
>>+
>>+#include <linux/bitops.h>
>>+#include <linux/cpu.h>
>>+#include <linux/interrupt.h>
>>+#include <linux/irqchip.h>
>>+#include <linux/irqchip/riscv-aplic.h>
>>+#include <linux/irqchip/riscv-imsic.h>
>>+#include <linux/module.h>
>>+#include <linux/msi.h>
>>+#include <linux/of_irq.h>
>>+#include <linux/platform_device.h>
>>+#include <linux/printk.h>
>>+#include <linux/smp.h>
>>+
>>+#include "irq-riscv-aplic-main.h"
>>+
>>+static void aplic_msi_irq_unmask(struct irq_data *d)
>>+{
>>+	aplic_irq_unmask(d);
>>+	irq_chip_unmask_parent(d);
>>+}
>>+
>>+static void aplic_msi_irq_mask(struct irq_data *d)
>>+{
>>+	aplic_irq_mask(d);
>>+	irq_chip_mask_parent(d);
>>+}
>>+
>>+static void aplic_msi_irq_eoi(struct irq_data *d)
>>+{
>>+	struct aplic_priv *priv = irq_data_get_irq_chip_data(d);
>>+	u32 reg_off, reg_mask;
>>+
>>+	/*
>>+	 * EOI handling only required only for level-triggered
>>+	 * interrupts in APLIC MSI mode.
>>+	 */
>>+
>>+	reg_off = APLIC_CLRIP_BASE + ((d->hwirq / APLIC_IRQBITS_PER_REG) * 4);
>>+	reg_mask = BIT(d->hwirq % APLIC_IRQBITS_PER_REG);
>>+	switch (irqd_get_trigger_type(d)) {
>>+	case IRQ_TYPE_LEVEL_LOW:
>>+		if (!(readl(priv->regs + reg_off) & reg_mask))
>>+			writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE);
>>+		break;
>>+	case IRQ_TYPE_LEVEL_HIGH:
>>+		if (readl(priv->regs + reg_off) & reg_mask)
>>+			writel(d->hwirq, priv->regs + APLIC_SETIPNUM_LE);
>>+		break;
>>+	}
>>+}
>>+
>>+static struct irq_chip aplic_msi_chip = {
>>+	.name		= "APLIC-MSI",
>>+	.irq_mask	= aplic_msi_irq_mask,
>>+	.irq_unmask	= aplic_msi_irq_unmask,
>>+	.irq_set_type	= aplic_irq_set_type,
>>+	.irq_eoi	= aplic_msi_irq_eoi,
>>+#ifdef CONFIG_SMP
>>+	.irq_set_affinity = irq_chip_set_affinity_parent,
>>+#endif
>>+	.flags		= IRQCHIP_SET_TYPE_MASKED |
>>+			  IRQCHIP_SKIP_SET_WAKE |
>>+			  IRQCHIP_MASK_ON_SUSPEND,
>>+};
>>+
>>+static int aplic_msi_irqdomain_translate(struct irq_domain *d,
>>+					 struct irq_fwspec *fwspec,
>>+					 unsigned long *hwirq,
>>+					 unsigned int *type)
>>+{
>>+	struct aplic_priv *priv = platform_msi_get_host_data(d);
>>+
>>+	return aplic_irqdomain_translate(fwspec, priv->gsi_base, hwirq, type);
>>+}
>>+
>>+static int aplic_msi_irqdomain_alloc(struct irq_domain *domain,
>>+				     unsigned int virq, unsigned int nr_irqs,
>>+				     void *arg)
>>+{
>>+	int i, ret;
>>+	unsigned int type;
>>+	irq_hw_number_t hwirq;
>>+	struct irq_fwspec *fwspec = arg;
>>+	struct aplic_priv *priv = platform_msi_get_host_data(domain);
>>+
>>+	ret = aplic_irqdomain_translate(fwspec, priv->gsi_base, &hwirq, &type);
>>+	if (ret)
>>+		return ret;
>
>In your patchset, the wired IRQ and IRQ of platform device will go into APLIC-MSI domain firstly.
>Let me assume here is a MSI IRQ not wired IRQ on a device, and it is a platform device in system.
>so in aplic_irqdomain_translate() function, it will parse the APLIC physical IRQ number by fwspec->param[0],
>but this is not a wried IRQ, it is a MSI IRQ, it should not has a APLIC physical IRQ number, the hwirq number should be allocated by MSI bitmap,
>what value will be parse by DTS? zero or negative? 
>
>if this is a nonexistent physical IRQ number for APLIC, in aplic_msi_irq_unmask()->aplic_irq_unmask(), how it works?
>
>writel(d->hwirq, priv->regs + APLIC_SETIENUM);

hi Anup,
Any comments about this question for an MSI interrupt (not wired interrupt) of non-PCI device?

Thanks,
Ben


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