From ace9429bb58fd418f0c81d4c2835699bddf6bde6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Thu, 11 Apr 2024 10:27:49 +0200 Subject: Adding upstream version 6.6.15. Signed-off-by: Daniel Baumann --- Documentation/arch/loongarch/irq-chip-model.rst | 160 ++++++++++++++++++++++++ 1 file changed, 160 insertions(+) create mode 100644 Documentation/arch/loongarch/irq-chip-model.rst (limited to 'Documentation/arch/loongarch/irq-chip-model.rst') diff --git a/Documentation/arch/loongarch/irq-chip-model.rst b/Documentation/arch/loongarch/irq-chip-model.rst new file mode 100644 index 0000000000..7988f41923 --- /dev/null +++ b/Documentation/arch/loongarch/irq-chip-model.rst @@ -0,0 +1,160 @@ +.. SPDX-License-Identifier: GPL-2.0 + +======================================= +IRQ chip model (hierarchy) of LoongArch +======================================= + +Currently, LoongArch based processors (e.g. Loongson-3A5000) can only work together +with LS7A chipsets. The irq chips in LoongArch computers include CPUINTC (CPU Core +Interrupt Controller), LIOINTC (Legacy I/O Interrupt Controller), EIOINTC (Extended +I/O Interrupt Controller), HTVECINTC (Hyper-Transport Vector Interrupt Controller), +PCH-PIC (Main Interrupt Controller in LS7A chipset), PCH-LPC (LPC Interrupt Controller +in LS7A chipset) and PCH-MSI (MSI Interrupt Controller). + +CPUINTC is a per-core controller (in CPU), LIOINTC/EIOINTC/HTVECINTC are per-package +controllers (in CPU), while PCH-PIC/PCH-LPC/PCH-MSI are controllers out of CPU (i.e., +in chipsets). These controllers (in other words, irqchips) are linked in a hierarchy, +and there are two models of hierarchy (legacy model and extended model). + +Legacy IRQ model +================ + +In this model, IPI (Inter-Processor Interrupt) and CPU Local Timer interrupt go +to CPUINTC directly, CPU UARTS interrupts go to LIOINTC, while all other devices +interrupts go to PCH-PIC/PCH-LPC/PCH-MSI and gathered by HTVECINTC, and then go +to LIOINTC, and then CPUINTC:: + + +-----+ +---------+ +-------+ + | IPI | --> | CPUINTC | <-- | Timer | + +-----+ +---------+ +-------+ + ^ + | + +---------+ +-------+ + | LIOINTC | <-- | UARTs | + +---------+ +-------+ + ^ + | + +-----------+ + | HTVECINTC | + +-----------+ + ^ ^ + | | + +---------+ +---------+ + | PCH-PIC | | PCH-MSI | + +---------+ +---------+ + ^ ^ ^ + | | | + +---------+ +---------+ +---------+ + | PCH-LPC | | Devices | | Devices | + +---------+ +---------+ +---------+ + ^ + | + +---------+ + | Devices | + +---------+ + +Extended IRQ model +================== + +In this model, IPI (Inter-Processor Interrupt) and CPU Local Timer interrupt go +to CPUINTC directly, CPU UARTS interrupts go to LIOINTC, while all other devices +interrupts go to PCH-PIC/PCH-LPC/PCH-MSI and gathered by EIOINTC, and then go to +to CPUINTC directly:: + + +-----+ +---------+ +-------+ + | IPI | --> | CPUINTC | <-- | Timer | + +-----+ +---------+ +-------+ + ^ ^ + | | + +---------+ +---------+ +-------+ + | EIOINTC | | LIOINTC | <-- | UARTs | + +---------+ +---------+ +-------+ + ^ ^ + | | + +---------+ +---------+ + | PCH-PIC | | PCH-MSI | + +---------+ +---------+ + ^ ^ ^ + | | | + +---------+ +---------+ +---------+ + | PCH-LPC | | Devices | | Devices | + +---------+ +---------+ +---------+ + ^ + | + +---------+ + | Devices | + +---------+ + +ACPI-related definitions +======================== + +CPUINTC:: + + ACPI_MADT_TYPE_CORE_PIC; + struct acpi_madt_core_pic; + enum acpi_madt_core_pic_version; + +LIOINTC:: + + ACPI_MADT_TYPE_LIO_PIC; + struct acpi_madt_lio_pic; + enum acpi_madt_lio_pic_version; + +EIOINTC:: + + ACPI_MADT_TYPE_EIO_PIC; + struct acpi_madt_eio_pic; + enum acpi_madt_eio_pic_version; + +HTVECINTC:: + + ACPI_MADT_TYPE_HT_PIC; + struct acpi_madt_ht_pic; + enum acpi_madt_ht_pic_version; + +PCH-PIC:: + + ACPI_MADT_TYPE_BIO_PIC; + struct acpi_madt_bio_pic; + enum acpi_madt_bio_pic_version; + +PCH-MSI:: + + ACPI_MADT_TYPE_MSI_PIC; + struct acpi_madt_msi_pic; + enum acpi_madt_msi_pic_version; + +PCH-LPC:: + + ACPI_MADT_TYPE_LPC_PIC; + struct acpi_madt_lpc_pic; + enum acpi_madt_lpc_pic_version; + +References +========== + +Documentation of Loongson-3A5000: + + https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-3A5000-usermanual-1.02-CN.pdf (in Chinese) + + https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-3A5000-usermanual-1.02-EN.pdf (in English) + +Documentation of Loongson's LS7A chipset: + + https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-7A1000-usermanual-2.00-CN.pdf (in Chinese) + + https://github.com/loongson/LoongArch-Documentation/releases/latest/download/Loongson-7A1000-usermanual-2.00-EN.pdf (in English) + +.. Note:: + - CPUINTC is CSR.ECFG/CSR.ESTAT and its interrupt controller described + in Section 7.4 of "LoongArch Reference Manual, Vol 1"; + - LIOINTC is "Legacy I/OInterrupts" described in Section 11.1 of + "Loongson 3A5000 Processor Reference Manual"; + - EIOINTC is "Extended I/O Interrupts" described in Section 11.2 of + "Loongson 3A5000 Processor Reference Manual"; + - HTVECINTC is "HyperTransport Interrupts" described in Section 14.3 of + "Loongson 3A5000 Processor Reference Manual"; + - PCH-PIC/PCH-MSI is "Interrupt Controller" described in Section 5 of + "Loongson 7A1000 Bridge User Manual"; + - PCH-LPC is "LPC Interrupts" described in Section 24.3 of + "Loongson 7A1000 Bridge User Manual". -- cgit v1.2.3