Introduce the redirect interrupt controllers.When the redirect interrupt
controller is enabled, the routing target of MSI interrupts is no longer
a specific CPU and vector number, but a specific redirect entry. The
actual CPU and vector number used are described by the redirect entry.

Signed-off-by: Tianyang Zhang <zhangtianyang@loongson.cn>
---
 .../arch/loongarch/irq-chip-model.rst         | 38 +++++++++++++++++++
 .../zh_CN/arch/loongarch/irq-chip-model.rst   | 37 ++++++++++++++++++
 2 files changed, 75 insertions(+)

diff --git a/Documentation/arch/loongarch/irq-chip-model.rst b/Documentation/arch/loongarch/irq-chip-model.rst
index a7ecce11e445..d9a2e8d7f70e 100644
--- a/Documentation/arch/loongarch/irq-chip-model.rst
+++ b/Documentation/arch/loongarch/irq-chip-model.rst
@@ -181,6 +181,44 @@ go to PCH-PIC/PCH-LPC and gathered by EIOINTC, and then go to CPUINTC directly::
              | Devices |
              +---------+
 
+Advanced Extended IRQ model (with redirection)
+==============================================
+
+In this model, IPI (Inter-Processor Interrupt) and CPU Local Timer interrupt go
+to CPUINTC directly, CPU UARTS interrupts go to LIOINTC, PCH-MSI interrupts go
+to REDIRECT for remapping it to AVEC, and then go to CPUINTC directly, while all
+other devices interrupts go to PCH-PIC/PCH-LPC and gathered by EIOINTC, and then
+go to CPUINTC directly::
+
+ +-----+     +-----------------------+     +-------+
+ | IPI | --> |        CPUINTC        | <-- | Timer |
+ +-----+     +-----------------------+     +-------+
+              ^          ^          ^
+              |          |          |
+       +---------+ +----------+ +---------+     +-------+
+       | EIOINTC | | AVECINTC | | LIOINTC | <-- | UARTs |
+       +---------+ +----------+ +---------+     +-------+
+            ^            ^
+            |            |
+            |      +----------+
+            |      | REDIRECT |
+            |      +----------+
+            |            ^
+            |            |
+       +---------+  +---------+
+       | PCH-PIC |  | PCH-MSI |
+       +---------+  +---------+
+         ^     ^           ^
+         |     |           |
+ +---------+ +---------+ +---------+
+ | Devices | | PCH-LPC | | Devices |
+ +---------+ +---------+ +---------+
+                  ^
+                  |
+             +---------+
+             | Devices |
+             +---------+
+
 ACPI-related definitions
 ========================
 
diff --git a/Documentation/translations/zh_CN/arch/loongarch/irq-chip-model.rst b/Documentation/translations/zh_CN/arch/loongarch/irq-chip-model.rst
index d4ff80de47b6..7e4e3e55c7ad 100644
--- a/Documentation/translations/zh_CN/arch/loongarch/irq-chip-model.rst
+++ b/Documentation/translations/zh_CN/arch/loongarch/irq-chip-model.rst
@@ -174,6 +174,43 @@ CPU串口（UARTs）中断发送到LIOINTC，PCH-MSI中断发送到AVECINTC，
              | Devices |
              +---------+
 
+高级扩展IRQ模型 (带重定向)
+==========================
+
+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LIOINTC，PCH-MSI中断首先发送到REDIRECT模块,完成重定向后发
+送到AVECINTC，而后通过AVECINTC直接送达CPUINTC，而其他所有设备的中断则分别发送到所连
+接的PCH-PIC/PCH-LPC，然后由EIOINTC统一收集，再直接到达CPUINTC::
+
+ +-----+     +-----------------------+     +-------+
+ | IPI | --> |        CPUINTC        | <-- | Timer |
+ +-----+     +-----------------------+     +-------+
+              ^          ^          ^
+              |          |          |
+       +---------+ +----------+ +---------+     +-------+
+       | EIOINTC | | AVECINTC | | LIOINTC | <-- | UARTs |
+       +---------+ +----------+ +---------+     +-------+
+            ^            ^
+            |            |
+            |      +----------+
+            |      | REDIRECT |
+            |      +----------+
+            |            ^
+            |            |
+       +---------+  +---------+
+       | PCH-PIC |  | PCH-MSI |
+       +---------+  +---------+
+         ^     ^           ^
+         |     |           |
+ +---------+ +---------+ +---------+
+ | Devices | | PCH-LPC | | Devices |
+ +---------+ +---------+ +---------+
+                  ^
+                  |
+             +---------+
+             | Devices |
+             +---------+
+
 ACPI相关的定义
 ==============
 
-- 
2.41.0