From 004c8a8bc569c8b18fca6fc90ffe3223daaf17b7 Mon Sep 17 00:00:00 2001 From: Andrey Makarov Date: Sat, 16 Jul 2022 14:32:10 +0300 Subject: [PATCH] Align Raspberry Pi DMA interrupts with Linux DTS There is nothing in the specs on DMA engine interrupt lines: it should have been in the "BCM2835 ARM Peripherals" datasheet but the appropriate "ARM peripherals interrupt table" (p.113) is nearly empty. All Raspberry Pi models 1-3 (based on bcm2835) have Linux device tree (arch/arm/boot/dts/bcm2835-common.dtsi +25): /* dma channel 11-14 share one irq */ This information is repeated in the driver code (drivers/dma/bcm2835-dma.c +1344): /* * in case of channel >= 11 * use the 11th interrupt and that is shared */ In this patch channels 0--10 and 11--14 are handled separately. Signed-off-by: Andrey Makarov Message-id: 20220716113210.349153-1-andrey.makarov@auriga.com [PMM: fixed checkpatch nits] Reviewed-by: Peter Maydell Signed-off-by: Peter Maydell --- hw/arm/bcm2835_peripherals.c | 26 +++++- include/hw/arm/bcm2835_peripherals.h | 2 + tests/qtest/bcm2835-dma-test.c | 118 +++++++++++++++++++++++++++ tests/qtest/meson.build | 3 +- 4 files changed, 147 insertions(+), 2 deletions(-) create mode 100644 tests/qtest/bcm2835-dma-test.c diff --git a/hw/arm/bcm2835_peripherals.c b/hw/arm/bcm2835_peripherals.c index 48538c9360..3c2a4160cd 100644 --- a/hw/arm/bcm2835_peripherals.c +++ b/hw/arm/bcm2835_peripherals.c @@ -23,6 +23,13 @@ /* Capabilities for SD controller: no DMA, high-speed, default clocks etc. */ #define BCM2835_SDHC_CAPAREG 0x52134b4 +/* + * According to Linux driver & DTS, dma channels 0--10 have separate IRQ, + * while channels 11--14 share one IRQ: + */ +#define SEPARATE_DMA_IRQ_MAX 10 +#define ORGATED_DMA_IRQ_COUNT 4 + static void create_unimp(BCM2835PeripheralState *ps, UnimplementedDeviceState *uds, const char *name, hwaddr ofs, hwaddr size) @@ -101,6 +108,11 @@ static void bcm2835_peripherals_init(Object *obj) /* DMA Channels */ object_initialize_child(obj, "dma", &s->dma, TYPE_BCM2835_DMA); + object_initialize_child(obj, "orgated-dma-irq", + &s->orgated_dma_irq, TYPE_OR_IRQ); + object_property_set_int(OBJECT(&s->orgated_dma_irq), "num-lines", + ORGATED_DMA_IRQ_COUNT, &error_abort); + object_property_add_const_link(OBJECT(&s->dma), "dma-mr", OBJECT(&s->gpu_bus_mr)); @@ -322,12 +334,24 @@ static void bcm2835_peripherals_realize(DeviceState *dev, Error **errp) memory_region_add_subregion(&s->peri_mr, DMA15_OFFSET, sysbus_mmio_get_region(SYS_BUS_DEVICE(&s->dma), 1)); - for (n = 0; n <= 12; n++) { + for (n = 0; n <= SEPARATE_DMA_IRQ_MAX; n++) { sysbus_connect_irq(SYS_BUS_DEVICE(&s->dma), n, qdev_get_gpio_in_named(DEVICE(&s->ic), BCM2835_IC_GPU_IRQ, INTERRUPT_DMA0 + n)); } + if (!qdev_realize(DEVICE(&s->orgated_dma_irq), NULL, errp)) { + return; + } + for (n = 0; n < ORGATED_DMA_IRQ_COUNT; n++) { + sysbus_connect_irq(SYS_BUS_DEVICE(&s->dma), + SEPARATE_DMA_IRQ_MAX + 1 + n, + qdev_get_gpio_in(DEVICE(&s->orgated_dma_irq), n)); + } + qdev_connect_gpio_out(DEVICE(&s->orgated_dma_irq), 0, + qdev_get_gpio_in_named(DEVICE(&s->ic), + BCM2835_IC_GPU_IRQ, + INTERRUPT_DMA0 + SEPARATE_DMA_IRQ_MAX + 1)); /* THERMAL */ if (!sysbus_realize(SYS_BUS_DEVICE(&s->thermal), errp)) { diff --git a/include/hw/arm/bcm2835_peripherals.h b/include/hw/arm/bcm2835_peripherals.h index d864879421..c9d25d493e 100644 --- a/include/hw/arm/bcm2835_peripherals.h +++ b/include/hw/arm/bcm2835_peripherals.h @@ -17,6 +17,7 @@ #include "hw/char/bcm2835_aux.h" #include "hw/display/bcm2835_fb.h" #include "hw/dma/bcm2835_dma.h" +#include "hw/or-irq.h" #include "hw/intc/bcm2835_ic.h" #include "hw/misc/bcm2835_property.h" #include "hw/misc/bcm2835_rng.h" @@ -55,6 +56,7 @@ struct BCM2835PeripheralState { BCM2835AuxState aux; BCM2835FBState fb; BCM2835DMAState dma; + qemu_or_irq orgated_dma_irq; BCM2835ICState ic; BCM2835PropertyState property; BCM2835RngState rng; diff --git a/tests/qtest/bcm2835-dma-test.c b/tests/qtest/bcm2835-dma-test.c new file mode 100644 index 0000000000..8293d822b9 --- /dev/null +++ b/tests/qtest/bcm2835-dma-test.c @@ -0,0 +1,118 @@ +/* + * QTest testcase for BCM283x DMA engine (on Raspberry Pi 3) + * and its interrupts coming to Interrupt Controller. + * + * Copyright (c) 2022 Auriga LLC + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "libqtest-single.h" + +/* Offsets in raspi3b platform: */ +#define RASPI3_DMA_BASE 0x3f007000 +#define RASPI3_IC_BASE 0x3f00b200 + +/* Used register/fields definitions */ + +/* DMA engine registers: */ +#define BCM2708_DMA_CS 0 +#define BCM2708_DMA_ACTIVE (1 << 0) +#define BCM2708_DMA_INT (1 << 2) + +#define BCM2708_DMA_ADDR 0x04 + +#define BCM2708_DMA_INT_STATUS 0xfe0 + +/* DMA Trasfer Info fields: */ +#define BCM2708_DMA_INT_EN (1 << 0) +#define BCM2708_DMA_D_INC (1 << 4) +#define BCM2708_DMA_S_INC (1 << 8) + +/* Interrupt controller registers: */ +#define IRQ_PENDING_BASIC 0x00 +#define IRQ_GPU_PENDING1_AGGR (1 << 8) +#define IRQ_PENDING_1 0x04 +#define IRQ_ENABLE_1 0x10 + +/* Data for the test: */ +#define SCB_ADDR 256 +#define S_ADDR 32 +#define D_ADDR 64 +#define TXFR_LEN 32 +const uint32_t check_data = 0x12345678; + +static void bcm2835_dma_test_interrupt(int dma_c, int irq_line) +{ + uint64_t dma_base = RASPI3_DMA_BASE + dma_c * 0x100; + int gpu_irq_line = 16 + irq_line; + + /* Check that interrupts are silent by default: */ + writel(RASPI3_IC_BASE + IRQ_ENABLE_1, 1 << gpu_irq_line); + int isr = readl(dma_base + BCM2708_DMA_INT_STATUS); + g_assert_cmpint(isr, ==, 0); + uint32_t reg0 = readl(dma_base + BCM2708_DMA_CS); + g_assert_cmpint(reg0, ==, 0); + uint32_t ic_pending = readl(RASPI3_IC_BASE + IRQ_PENDING_BASIC); + g_assert_cmpint(ic_pending, ==, 0); + uint32_t gpu_pending1 = readl(RASPI3_IC_BASE + IRQ_PENDING_1); + g_assert_cmpint(gpu_pending1, ==, 0); + + /* Prepare Control Block: */ + writel(SCB_ADDR + 0, BCM2708_DMA_S_INC | BCM2708_DMA_D_INC | + BCM2708_DMA_INT_EN); /* transfer info */ + writel(SCB_ADDR + 4, S_ADDR); /* source address */ + writel(SCB_ADDR + 8, D_ADDR); /* destination address */ + writel(SCB_ADDR + 12, TXFR_LEN); /* transfer length */ + writel(dma_base + BCM2708_DMA_ADDR, SCB_ADDR); + + writel(S_ADDR, check_data); + for (int word = S_ADDR + 4; word < S_ADDR + TXFR_LEN; word += 4) { + writel(word, ~check_data); + } + /* Perform the transfer: */ + writel(dma_base + BCM2708_DMA_CS, BCM2708_DMA_ACTIVE); + + /* Check that destination == source: */ + uint32_t data = readl(D_ADDR); + g_assert_cmpint(data, ==, check_data); + for (int word = D_ADDR + 4; word < D_ADDR + TXFR_LEN; word += 4) { + data = readl(word); + g_assert_cmpint(data, ==, ~check_data); + } + + /* Check that interrupt status is set both in DMA and IC controllers: */ + isr = readl(RASPI3_DMA_BASE + BCM2708_DMA_INT_STATUS); + g_assert_cmpint(isr, ==, 1 << dma_c); + + ic_pending = readl(RASPI3_IC_BASE + IRQ_PENDING_BASIC); + g_assert_cmpint(ic_pending, ==, IRQ_GPU_PENDING1_AGGR); + + gpu_pending1 = readl(RASPI3_IC_BASE + IRQ_PENDING_1); + g_assert_cmpint(gpu_pending1, ==, 1 << gpu_irq_line); + + /* Clean up, clear interrupt: */ + writel(dma_base + BCM2708_DMA_CS, BCM2708_DMA_INT); +} + +static void bcm2835_dma_test_interrupts(void) +{ + /* DMA engines 0--10 have separate IRQ lines, 11--14 - only one: */ + bcm2835_dma_test_interrupt(0, 0); + bcm2835_dma_test_interrupt(10, 10); + bcm2835_dma_test_interrupt(11, 11); + bcm2835_dma_test_interrupt(14, 11); +} + +int main(int argc, char **argv) +{ + int ret; + g_test_init(&argc, &argv, NULL); + qtest_add_func("/bcm2835/dma/test_interrupts", + bcm2835_dma_test_interrupts); + qtest_start("-machine raspi3b"); + ret = g_test_run(); + qtest_end(); + return ret; +} diff --git a/tests/qtest/meson.build b/tests/qtest/meson.build index 31287a9173..3a474010e4 100644 --- a/tests/qtest/meson.build +++ b/tests/qtest/meson.build @@ -218,7 +218,8 @@ qtests_aarch64 = \ ['arm-cpu-features', 'numa-test', 'boot-serial-test', - 'migration-test'] + 'migration-test', + 'bcm2835-dma-test'] qtests_s390x = \ (slirp.found() ? ['pxe-test', 'test-netfilter'] : []) + \