[PATCH v11 12/14] irqchip/riscv-aplic: Add support for MSI-mode
Anup Patel
apatel at ventanamicro.com
Wed Nov 8 06:56:59 PST 2023
On Wed, Nov 8, 2023 at 8:23 PM Ben <figure1802 at 126.com> wrote:
>
> At 2023-11-08 22:43:25, "Anup Patel" <apatel at ventanamicro.com> wrote:
> >On Sat, Nov 4, 2023 at 6:30 AM Ben <figure1802 at 126.com> wrote:
> >>
> >> At 2023-10-24 01:27:58, "Anup Patel" <apatel at 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 at 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.
> >
> >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?
The APLIC in MSI-mode acts like a platform device with MSIs so yes this
is tested on QEMU.
Regards,
Anup
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