irqchip/loongson-eiointc: Add virt extension support (9899b820) · Commits · git / linux-net

Documentation/arch/loongarch/irq-chip-model.rst

+64 −0

Original line number	Diff line number	Diff line
		@@ -85,6 +85,70 @@ to CPUINTC directly::
		\| Devices \|
		+---------+

		Virtual Extended IRQ model
		==========================

		In this model, IPI (Inter-Processor Interrupt) and CPU Local Timer interrupt
		go to CPUINTC directly, CPU UARTS interrupts go to PCH-PIC, while all other
		devices interrupts go to PCH-PIC/PCH-MSI and gathered by V-EIOINTC (Virtual
		Extended I/O Interrupt Controller), and then go to CPUINTC directly::

		+-----+ +-------------------+ +-------+
		\| IPI \|--> \| CPUINTC(0-255vcpu)\| <-- \| Timer \|
		+-----+ +-------------------+ +-------+
		^
		\|
		+-----------+
		\| V-EIOINTC \|
		+-----------+
		^ ^
		\| \|
		+---------+ +---------+
		\| PCH-PIC \| \| PCH-MSI \|
		+---------+ +---------+
		^ ^ ^
		\| \| \|
		+--------+ +---------+ +---------+
		\| UARTs \| \| Devices \| \| Devices \|
		+--------+ +---------+ +---------+


		Description
		-----------
		V-EIOINTC (Virtual Extended I/O Interrupt Controller) is an extension of
		EIOINTC, it only works in VM mode which runs in KVM hypervisor. Interrupts can
		be routed to up to four vCPUs via standard EIOINTC, however with V-EIOINTC
		interrupts can be routed to up to 256 virtual cpus.

		With standard EIOINTC, interrupt routing setting includes two parts: eight
		bits for CPU selection and four bits for CPU IP (Interrupt Pin) selection.
		For CPU selection there is four bits for EIOINTC node selection, four bits
		for EIOINTC CPU selection. Bitmap method is used for CPU selection and
		CPU IP selection, so interrupt can only route to CPU0 - CPU3 and IP0-IP3 in
		one EIOINTC node.

		With V-EIOINTC it supports to route more CPUs and CPU IP (Interrupt Pin),
		there are two newly added registers with V-EIOINTC.

		EXTIOI_VIRT_FEATURES
		--------------------
		This register is read-only register, which indicates supported features with
		V-EIOINTC. Feature EXTIOI_HAS_INT_ENCODE and EXTIOI_HAS_CPU_ENCODE is added.

		Feature EXTIOI_HAS_INT_ENCODE is part of standard EIOINTC. If it is 1, it
		indicates that CPU Interrupt Pin selection can be normal method rather than
		bitmap method, so interrupt can be routed to IP0 - IP15.

		Feature EXTIOI_HAS_CPU_ENCODE is entension of V-EIOINTC. If it is 1, it
		indicates that CPU selection can be normal method rather than bitmap method,
		so interrupt can be routed to CPU0 - CPU255.

		EXTIOI_VIRT_CONFIG
		------------------
		This register is read-write register, for compatibility intterupt routed uses
		the default method which is the same with standard EIOINTC. If the bit is set
		with 1, it indicated HW to use normal method rather than bitmap method.

		Advanced Extended IRQ model
		===========================

Documentation/translations/zh_CN/arch/loongarch/irq-chip-model.rst

+55 −0

Original line number	Diff line number	Diff line
		@@ -87,6 +87,61 @@ PCH-LPC/PCH-MSI，然后被EIOINTC统一收集，再直接到达CPUINTC::
		\| Devices \|
		+---------+

		虚拟扩展IRQ模型
		===============

		在这种模型里面, IPI(Inter-Processor Interrupt) 和CPU本地时钟中断直接发送到CPUINTC,
		CPU串口 (UARTs) 中断发送到PCH-PIC, 而其他所有设备的中断则分别发送到所连接的PCH_PIC/
		PCH-MSI, 然后V-EIOINTC统一收集，再直接到达CPUINTC::

		+-----+ +-------------------+ +-------+
		\| IPI \|--> \| CPUINTC(0-255vcpu)\| <-- \| Timer \|
		+-----+ +-------------------+ +-------+
		^
		\|
		+-----------+
		\| V-EIOINTC \|
		+-----------+
		^ ^
		\| \|
		+---------+ +---------+
		\| PCH-PIC \| \| PCH-MSI \|
		+---------+ +---------+
		^ ^ ^
		\| \| \|
		+--------+ +---------+ +---------+
		\| UARTs \| \| Devices \| \| Devices \|
		+--------+ +---------+ +---------+

		V-EIOINTC 是EIOINTC的扩展, 仅工作在虚拟机模式下, 中断经EIOINTC最多可个路由到
		４个虚拟CPU. 但中断经V-EIOINTC最多可个路由到256个虚拟CPU.

		传统的EIOINTC中断控制器，中断路由分为两个部分：8比特用于控制路由到哪个CPU，
		4比特用于控制路由到特定CPU的哪个中断管脚。控制CPU路由的8比特前4比特用于控制
		路由到哪个EIOINTC节点，后4比特用于控制此节点哪个CPU。中断路由在选择CPU路由
		和CPU中断管脚路由时，使用bitmap编码方式而不是正常编码方式，所以对于一个
		EIOINTC中断控制器节点，中断只能路由到CPU0 - CPU3，中断管脚IP0-IP3。

		V-EIOINTC新增了两个寄存器，支持中断路由到更多CPU个和中断管脚。

		V-EIOINTC功能寄存器
		-------------------
		功能寄存器是只读寄存器，用于显示V-EIOINTC支持的特性，目前两个支持两个特性
		EXTIOI_HAS_INT_ENCODE 和 EXTIOI_HAS_CPU_ENCODE。

		特性EXTIOI_HAS_INT_ENCODE是传统EIOINTC中断控制器的一个特性，如果此比特为1，
		显示CPU中断管脚路由方式支持正常编码，而不是bitmap编码，所以中断可以路由到
		管脚IP0 - IP15。

		特性EXTIOI_HAS_CPU_ENCODE是V-EIOINTC新增特性，如果此比特为1，表示CPU路由
		方式支持正常编码，而不是bitmap编码，所以中断可以路由到CPU0 - CPU255。

		V-EIOINTC配置寄存器
		-------------------
		配置寄存器是可读写寄存器，为了兼容性考虑，如果不写此寄存器，中断路由采用
		和传统EIOINTC相同的路由设置。如果对应比特设置为1，表示采用正常路由方式而
		不是bitmap编码的路由方式。

		高级扩展IRQ模型
		===============

arch/loongarch/include/asm/irq.h

+1 −0

Original line number	Diff line number	Diff line
		@@ -65,6 +65,7 @@ extern struct acpi_vector_group pch_group[MAX_IO_PICS];
		extern struct acpi_vector_group msi_group[MAX_IO_PICS];

		#define CORES_PER_EIO_NODE 4
		#define CORES_PER_VEIO_NODE 256

		#define LOONGSON_CPU_UART0_VEC 10 /* CPU UART0 */
		#define LOONGSON_CPU_THSENS_VEC 14 /* CPU Thsens */

drivers/irqchip/irq-loongson-eiointc.c

+87 −21

Original line number	Diff line number	Diff line
		@@ -14,6 +14,7 @@
		#include <linux/irqdomain.h>
		#include <linux/irqchip/chained_irq.h>
		#include <linux/kernel.h>
		#include <linux/kvm_para.h>
		#include <linux/syscore_ops.h>
		#include <asm/numa.h>

		@@ -26,15 +27,37 @@
		#define EIOINTC_REG_ISR 0x1800
		#define EIOINTC_REG_ROUTE 0x1c00

		#define EXTIOI_VIRT_FEATURES 0x40000000
		#define EXTIOI_HAS_VIRT_EXTENSION BIT(0)
		#define EXTIOI_HAS_ENABLE_OPTION BIT(1)
		#define EXTIOI_HAS_INT_ENCODE BIT(2)
		#define EXTIOI_HAS_CPU_ENCODE BIT(3)
		#define EXTIOI_VIRT_CONFIG 0x40000004
		#define EXTIOI_ENABLE BIT(1)
		#define EXTIOI_ENABLE_INT_ENCODE BIT(2)
		#define EXTIOI_ENABLE_CPU_ENCODE BIT(3)

		#define VEC_REG_COUNT 4
		#define VEC_COUNT_PER_REG 64
		#define VEC_COUNT (VEC_REG_COUNT * VEC_COUNT_PER_REG)
		#define VEC_REG_IDX(irq_id) ((irq_id) / VEC_COUNT_PER_REG)
		#define VEC_REG_BIT(irq_id) ((irq_id) % VEC_COUNT_PER_REG)
		#define EIOINTC_ALL_ENABLE 0xffffffff
		#define EIOINTC_ALL_ENABLE_VEC_MASK(vector) (EIOINTC_ALL_ENABLE & ~BIT(vector & 0x1f))
		#define EIOINTC_REG_ENABLE_VEC(vector) (EIOINTC_REG_ENABLE + ((vector >> 5) << 2))
		#define EIOINTC_USE_CPU_ENCODE BIT(0)

		#define MAX_EIO_NODES (NR_CPUS / CORES_PER_EIO_NODE)

		/*
		* Routing registers are 32bit, and there is 8-bit route setting for every
		* interrupt vector. So one Route register contains four vectors routing
		* information.
		*/
		#define EIOINTC_REG_ROUTE_VEC(vector) (EIOINTC_REG_ROUTE + (vector & ~0x03))
		#define EIOINTC_REG_ROUTE_VEC_SHIFT(vector) ((vector & 0x03) << 3)
		#define EIOINTC_REG_ROUTE_VEC_MASK(vector) (0xff << EIOINTC_REG_ROUTE_VEC_SHIFT(vector))

		static int nr_pics;

		struct eiointc_priv {
		@@ -44,6 +67,7 @@ struct eiointc_priv {
		cpumask_t cpuspan_map;
		struct fwnode_handle *domain_handle;
		struct irq_domain *eiointc_domain;
		int flags;
		};

		static struct eiointc_priv *eiointc_priv[MAX_IO_PICS];
		@@ -59,7 +83,10 @@ static void eiointc_enable(void)

		static int cpu_to_eio_node(int cpu)
		{
		if (!kvm_para_has_feature(KVM_FEATURE_VIRT_EXTIOI))
		return cpu_logical_map(cpu) / CORES_PER_EIO_NODE;
		else
		return cpu_logical_map(cpu) / CORES_PER_VEIO_NODE;
		}

		#ifdef CONFIG_SMP
		@@ -89,6 +116,17 @@ static void eiointc_set_irq_route(int pos, unsigned int cpu, unsigned int mnode,
		}
		}

		static void veiointc_set_irq_route(unsigned int vector, unsigned int cpu)
		{
		unsigned long reg = EIOINTC_REG_ROUTE_VEC(vector);
		unsigned int data;

		data = iocsr_read32(reg);
		data &= ~EIOINTC_REG_ROUTE_VEC_MASK(vector);
		data \|= cpu_logical_map(cpu) << EIOINTC_REG_ROUTE_VEC_SHIFT(vector);
		iocsr_write32(data, reg);
		}

		static DEFINE_RAW_SPINLOCK(affinity_lock);

		static int eiointc_set_irq_affinity(struct irq_data d, const struct cpumask affinity, bool force)
		@@ -107,10 +145,15 @@ static int eiointc_set_irq_affinity(struct irq_data d, const struct cpumask af
		}

		vector = d->hwirq;
		regaddr = EIOINTC_REG_ENABLE + ((vector >> 5) << 2);
		regaddr = EIOINTC_REG_ENABLE_VEC(vector);

		if (priv->flags & EIOINTC_USE_CPU_ENCODE) {
		iocsr_write32(EIOINTC_ALL_ENABLE_VEC_MASK(vector), regaddr);
		veiointc_set_irq_route(vector, cpu);
		iocsr_write32(EIOINTC_ALL_ENABLE, regaddr);
		} else {
		/* Mask target vector */
		csr_any_send(regaddr, EIOINTC_ALL_ENABLE & (~BIT(vector & 0x1F)),
		csr_any_send(regaddr, EIOINTC_ALL_ENABLE_VEC_MASK(vector),
		0x0, priv->node * CORES_PER_EIO_NODE);

		/* Set route for target vector */
		@@ -119,6 +162,7 @@ static int eiointc_set_irq_affinity(struct irq_data d, const struct cpumask af
		/* Unmask target vector */
		csr_any_send(regaddr, EIOINTC_ALL_ENABLE,
		0x0, priv->node * CORES_PER_EIO_NODE);
		}

		irq_data_update_effective_affinity(d, cpumask_of(cpu));

		@@ -142,17 +186,23 @@ static int eiointc_index(int node)

		static int eiointc_router_init(unsigned int cpu)
		{
		int i, bit;
		uint32_t data;
		uint32_t node = cpu_to_eio_node(cpu);
		int index = eiointc_index(node);
		int i, bit, cores, index, node;
		unsigned int data;

		node = cpu_to_eio_node(cpu);
		index = eiointc_index(node);

		if (index < 0) {
		pr_err("Error: invalid nodemap!\n");
		return -1;
		return -EINVAL;
		}

		if ((cpu_logical_map(cpu) % CORES_PER_EIO_NODE) == 0) {
		if (!(eiointc_priv[index]->flags & EIOINTC_USE_CPU_ENCODE))
		cores = CORES_PER_EIO_NODE;
		else
		cores = CORES_PER_VEIO_NODE;

		if ((cpu_logical_map(cpu) % cores) == 0) {
		eiointc_enable();

		for (i = 0; i < eiointc_priv[0]->vec_count / 32; i++) {
		@@ -168,7 +218,9 @@ static int eiointc_router_init(unsigned int cpu)

		for (i = 0; i < eiointc_priv[0]->vec_count / 4; i++) {
		/* Route to Node-0 Core-0 */
		if (index == 0)
		if (eiointc_priv[index]->flags & EIOINTC_USE_CPU_ENCODE)
		bit = cpu_logical_map(0);
		else if (index == 0)
		bit = BIT(cpu_logical_map(0));
		else
		bit = (eiointc_priv[index]->node << 4) \| 1;
		@@ -375,7 +427,7 @@ static int __init acpi_cascade_irqdomain_init(void)
		static int __init eiointc_init(struct eiointc_priv *priv, int parent_irq,
		u64 node_map)
		{
		int i;
		int i, val;

		node_map = node_map ? node_map : -1ULL;
		for_each_possible_cpu(i) {
		@@ -395,6 +447,20 @@ static int __init eiointc_init(struct eiointc_priv *priv, int parent_irq,
		return -ENOMEM;
		}

		if (kvm_para_has_feature(KVM_FEATURE_VIRT_EXTIOI)) {
		val = iocsr_read32(EXTIOI_VIRT_FEATURES);
		/*
		* With EXTIOI_ENABLE_CPU_ENCODE set
		* interrupts can route to 256 vCPUs.
		*/
		if (val & EXTIOI_HAS_CPU_ENCODE) {
		val = iocsr_read32(EXTIOI_VIRT_CONFIG);
		val \|= EXTIOI_ENABLE_CPU_ENCODE;
		iocsr_write32(val, EXTIOI_VIRT_CONFIG);
		priv->flags = EIOINTC_USE_CPU_ENCODE;
		}
		}

		eiointc_priv[nr_pics++] = priv;
		eiointc_router_init(0);
		irq_set_chained_handler_and_data(parent_irq, eiointc_irq_dispatch, priv);