irqchip: Add driver for the RPMI system MSI service group

The RPMI specification defines a system MSI service group which
allows application processors to receive MSIs upon system events
such as graceful shutdown/reboot request, CPU hotplug event, memory
hotplug event, etc.

Add an irqchip driver for the RISC-V RPMI system MSI service group
to directly receive system MSIs in Linux kernel.

Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Anup Patel <apatel@ventanamicro.com>
Link: https://lore.kernel.org/r/20250818040920.272664-14-apatel@ventanamicro.com
Signed-off-by: Paul Walmsley <pjw@kernel.org>
This commit is contained in:
Anup Patel
2025-08-18 09:39:09 +05:30
committed by Paul Walmsley
parent 3e6cf38486
commit aa43953e86
4 changed files with 308 additions and 0 deletions
+7
View File
@@ -634,6 +634,13 @@ config RISCV_IMSIC
select GENERIC_MSI_IRQ
select IRQ_MSI_LIB
config RISCV_RPMI_SYSMSI
bool
depends on MAILBOX
select IRQ_DOMAIN_HIERARCHY
select GENERIC_MSI_IRQ
default RISCV
config SIFIVE_PLIC
bool
depends on RISCV
+1
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@@ -106,6 +106,7 @@ 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-$(CONFIG_RISCV_RPMI_SYSMSI) += irq-riscv-rpmi-sysmsi.o
obj-$(CONFIG_SIFIVE_PLIC) += irq-sifive-plic.o
obj-$(CONFIG_STARFIVE_JH8100_INTC) += irq-starfive-jh8100-intc.o
obj-$(CONFIG_ACLINT_SSWI) += irq-aclint-sswi.o
+287
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@@ -0,0 +1,287 @@
// SPDX-License-Identifier: GPL-2.0
/* Copyright (C) 2025 Ventana Micro Systems Inc. */
#include <linux/bits.h>
#include <linux/bug.h>
#include <linux/device.h>
#include <linux/device/devres.h>
#include <linux/dev_printk.h>
#include <linux/errno.h>
#include <linux/irq.h>
#include <linux/irqdomain.h>
#include <linux/mailbox_client.h>
#include <linux/mailbox/riscv-rpmi-message.h>
#include <linux/module.h>
#include <linux/msi.h>
#include <linux/of_irq.h>
#include <linux/platform_device.h>
#include <linux/types.h>
struct rpmi_sysmsi_get_attrs_rx {
__le32 status;
__le32 sys_num_msi;
__le32 flag0;
__le32 flag1;
};
#define RPMI_SYSMSI_MSI_ATTRIBUTES_FLAG0_PREF_PRIV BIT(0)
struct rpmi_sysmsi_set_msi_state_tx {
__le32 sys_msi_index;
__le32 sys_msi_state;
};
struct rpmi_sysmsi_set_msi_state_rx {
__le32 status;
};
#define RPMI_SYSMSI_MSI_STATE_ENABLE BIT(0)
#define RPMI_SYSMSI_MSI_STATE_PENDING BIT(1)
struct rpmi_sysmsi_set_msi_target_tx {
__le32 sys_msi_index;
__le32 sys_msi_address_low;
__le32 sys_msi_address_high;
__le32 sys_msi_data;
};
struct rpmi_sysmsi_set_msi_target_rx {
__le32 status;
};
struct rpmi_sysmsi_priv {
struct device *dev;
struct mbox_client client;
struct mbox_chan *chan;
u32 nr_irqs;
u32 gsi_base;
};
static int rpmi_sysmsi_get_num_msi(struct rpmi_sysmsi_priv *priv)
{
struct rpmi_sysmsi_get_attrs_rx rx;
struct rpmi_mbox_message msg;
int ret;
rpmi_mbox_init_send_with_response(&msg, RPMI_SYSMSI_SRV_GET_ATTRIBUTES,
NULL, 0, &rx, sizeof(rx));
ret = rpmi_mbox_send_message(priv->chan, &msg);
if (ret)
return ret;
if (rx.status)
return rpmi_to_linux_error(le32_to_cpu(rx.status));
return le32_to_cpu(rx.sys_num_msi);
}
static int rpmi_sysmsi_set_msi_state(struct rpmi_sysmsi_priv *priv,
u32 sys_msi_index, u32 sys_msi_state)
{
struct rpmi_sysmsi_set_msi_state_tx tx;
struct rpmi_sysmsi_set_msi_state_rx rx;
struct rpmi_mbox_message msg;
int ret;
tx.sys_msi_index = cpu_to_le32(sys_msi_index);
tx.sys_msi_state = cpu_to_le32(sys_msi_state);
rpmi_mbox_init_send_with_response(&msg, RPMI_SYSMSI_SRV_SET_MSI_STATE,
&tx, sizeof(tx), &rx, sizeof(rx));
ret = rpmi_mbox_send_message(priv->chan, &msg);
if (ret)
return ret;
if (rx.status)
return rpmi_to_linux_error(le32_to_cpu(rx.status));
return 0;
}
static int rpmi_sysmsi_set_msi_target(struct rpmi_sysmsi_priv *priv,
u32 sys_msi_index, struct msi_msg *m)
{
struct rpmi_sysmsi_set_msi_target_tx tx;
struct rpmi_sysmsi_set_msi_target_rx rx;
struct rpmi_mbox_message msg;
int ret;
tx.sys_msi_index = cpu_to_le32(sys_msi_index);
tx.sys_msi_address_low = cpu_to_le32(m->address_lo);
tx.sys_msi_address_high = cpu_to_le32(m->address_hi);
tx.sys_msi_data = cpu_to_le32(m->data);
rpmi_mbox_init_send_with_response(&msg, RPMI_SYSMSI_SRV_SET_MSI_TARGET,
&tx, sizeof(tx), &rx, sizeof(rx));
ret = rpmi_mbox_send_message(priv->chan, &msg);
if (ret)
return ret;
if (rx.status)
return rpmi_to_linux_error(le32_to_cpu(rx.status));
return 0;
}
static void rpmi_sysmsi_irq_mask(struct irq_data *d)
{
struct rpmi_sysmsi_priv *priv = irq_data_get_irq_chip_data(d);
irq_hw_number_t hwirq = irqd_to_hwirq(d);
int ret;
ret = rpmi_sysmsi_set_msi_state(priv, hwirq, 0);
if (ret)
dev_warn(priv->dev, "Failed to mask hwirq %lu (error %d)\n", hwirq, ret);
irq_chip_mask_parent(d);
}
static void rpmi_sysmsi_irq_unmask(struct irq_data *d)
{
struct rpmi_sysmsi_priv *priv = irq_data_get_irq_chip_data(d);
irq_hw_number_t hwirq = irqd_to_hwirq(d);
int ret;
irq_chip_unmask_parent(d);
ret = rpmi_sysmsi_set_msi_state(priv, hwirq, RPMI_SYSMSI_MSI_STATE_ENABLE);
if (ret)
dev_warn(priv->dev, "Failed to unmask hwirq %lu (error %d)\n", hwirq, ret);
}
static void rpmi_sysmsi_write_msg(struct irq_data *d, struct msi_msg *msg)
{
struct rpmi_sysmsi_priv *priv = irq_data_get_irq_chip_data(d);
irq_hw_number_t hwirq = irqd_to_hwirq(d);
int ret;
/* For zeroed MSI, do nothing as of now */
if (!msg->address_hi && !msg->address_lo && !msg->data)
return;
ret = rpmi_sysmsi_set_msi_target(priv, hwirq, msg);
if (ret)
dev_warn(priv->dev, "Failed to set target for hwirq %lu (error %d)\n", hwirq, ret);
}
static void rpmi_sysmsi_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
{
arg->desc = desc;
arg->hwirq = desc->data.icookie.value;
}
static int rpmi_sysmsi_translate(struct irq_domain *d, struct irq_fwspec *fwspec,
unsigned long *hwirq, unsigned int *type)
{
struct msi_domain_info *info = d->host_data;
struct rpmi_sysmsi_priv *priv = info->data;
if (WARN_ON(fwspec->param_count < 1))
return -EINVAL;
/* For DT, gsi_base is always zero. */
*hwirq = fwspec->param[0] - priv->gsi_base;
*type = IRQ_TYPE_NONE;
return 0;
}
static const struct msi_domain_template rpmi_sysmsi_template = {
.chip = {
.name = "RPMI-SYSMSI",
.irq_mask = rpmi_sysmsi_irq_mask,
.irq_unmask = rpmi_sysmsi_irq_unmask,
#ifdef CONFIG_SMP
.irq_set_affinity = irq_chip_set_affinity_parent,
#endif
.irq_write_msi_msg = rpmi_sysmsi_write_msg,
.flags = IRQCHIP_SET_TYPE_MASKED |
IRQCHIP_SKIP_SET_WAKE |
IRQCHIP_MASK_ON_SUSPEND,
},
.ops = {
.set_desc = rpmi_sysmsi_set_desc,
.msi_translate = rpmi_sysmsi_translate,
},
.info = {
.bus_token = DOMAIN_BUS_WIRED_TO_MSI,
.flags = MSI_FLAG_USE_DEV_FWNODE,
.handler = handle_simple_irq,
.handler_name = "simple",
},
};
static int rpmi_sysmsi_probe(struct platform_device *pdev)
{
struct device *dev = &pdev->dev;
struct rpmi_sysmsi_priv *priv;
int rc;
priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
if (!priv)
return -ENOMEM;
priv->dev = dev;
/* Setup mailbox client */
priv->client.dev = priv->dev;
priv->client.rx_callback = NULL;
priv->client.tx_block = false;
priv->client.knows_txdone = true;
priv->client.tx_tout = 0;
/* Request mailbox channel */
priv->chan = mbox_request_channel(&priv->client, 0);
if (IS_ERR(priv->chan))
return PTR_ERR(priv->chan);
/* Get number of system MSIs */
rc = rpmi_sysmsi_get_num_msi(priv);
if (rc < 1) {
mbox_free_channel(priv->chan);
if (rc)
return dev_err_probe(dev, rc, "Failed to get number of system MSIs\n");
else
return dev_err_probe(dev, -ENODEV, "No system MSIs found\n");
}
priv->nr_irqs = rc;
/*
* The device MSI domain for platform devices on RISC-V architecture
* is only available after the MSI controller driver is probed so,
* explicitly configure here.
*/
if (!dev_get_msi_domain(dev)) {
/*
* The device MSI domain for OF devices is only set at the
* time of populating/creating OF device. If the device MSI
* domain is discovered later after the OF device is created
* then we need to set it explicitly before using any platform
* MSI functions.
*/
if (dev_of_node(dev))
of_msi_configure(dev, dev_of_node(dev));
if (!dev_get_msi_domain(dev)) {
mbox_free_channel(priv->chan);
return -EPROBE_DEFER;
}
}
if (!msi_create_device_irq_domain(dev, MSI_DEFAULT_DOMAIN,
&rpmi_sysmsi_template,
priv->nr_irqs, priv, priv)) {
mbox_free_channel(priv->chan);
return dev_err_probe(dev, -ENOMEM, "failed to create MSI irq domain\n");
}
dev_info(dev, "%u system MSIs registered\n", priv->nr_irqs);
return 0;
}
static const struct of_device_id rpmi_sysmsi_match[] = {
{ .compatible = "riscv,rpmi-system-msi" },
{}
};
static struct platform_driver rpmi_sysmsi_driver = {
.driver = {
.name = "rpmi-sysmsi",
.of_match_table = rpmi_sysmsi_match,
},
.probe = rpmi_sysmsi_probe,
};
builtin_platform_driver(rpmi_sysmsi_driver);
@@ -91,6 +91,7 @@ static inline int rpmi_to_linux_error(int rpmi_error)
}
/* RPMI service group IDs */
#define RPMI_SRVGRP_SYSTEM_MSI 0x00002
#define RPMI_SRVGRP_CLOCK 0x00008
/* RPMI clock service IDs */
@@ -106,6 +107,18 @@ enum rpmi_clock_service_id {
RPMI_CLK_SRV_ID_MAX_COUNT
};
/* RPMI system MSI service IDs */
enum rpmi_sysmsi_service_id {
RPMI_SYSMSI_SRV_ENABLE_NOTIFICATION = 0x01,
RPMI_SYSMSI_SRV_GET_ATTRIBUTES = 0x02,
RPMI_SYSMSI_SRV_GET_MSI_ATTRIBUTES = 0x03,
RPMI_SYSMSI_SRV_SET_MSI_STATE = 0x04,
RPMI_SYSMSI_SRV_GET_MSI_STATE = 0x05,
RPMI_SYSMSI_SRV_SET_MSI_TARGET = 0x06,
RPMI_SYSMSI_SRV_GET_MSI_TARGET = 0x07,
RPMI_SYSMSI_SRV_ID_MAX_COUNT
};
/* RPMI Linux mailbox attribute IDs */
enum rpmi_mbox_attribute_id {
RPMI_MBOX_ATTR_SPEC_VERSION,