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

From: Ben
Date: Wed Nov 08 2023 - 09:53:20 EST

At 2023-11-08 22:43:25, "Anup Patel" <apatel@xxxxxxxxxxxxxxxx> wrote:
>On Sat, Nov 4, 2023 at 6:30 AM Ben <figure1802@xxxxxxx> wrote:
>>
>> At 2023-10-24 01:27:58, "Anup Patel" <apatel@xxxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxxx>
>> >---
>> > 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.
>
>Yes, that is correct. In general, this applies to AIA specification
>and nothing to do with this patchset.
>
>> 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?
>
>For platform devices with MSI support, the MSIs will directly target
>the per-HART
>IMSICs and the DT node of such devices will never point to APLIC as the parent
>MSI controller.
>

>The IMSIC driver implements the IMSIC-PLAT domain for platform MSIs.

Have you test this case on QEMU? would you like share the test steps?