Re: [PATCH 1/2] dmaengine: Add HiSilicon Ascend SDMA engine support

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在 2023/8/14 16:54, Krzysztof Kozlowski 写道:
On 11/08/2023 05:48, Guo Mengqi wrote:
This patch adds a driver for HiSilicon Ascend SDMA engine.

The DMA controller can do transfers between device and memory
or memory to memory. Currently, the controller only support
single copy. Drives can pass a substreamid to the DMA engine,
which will enable transfers in user-space addresses.
...

+
+static int sdma_device_probe(struct platform_device *pdev)
+{
+	int ret;
+	struct device *dev;
+	struct sdma_dev *sdev;
+	struct sdma_hardware_info info;
+
+	dev = &pdev->dev;
+
+	if (!pdev->dev.bus) {
+		pr_debug("the sdma dev bus is NULL\n");
How is this possible?
   This shall not be possible. Removed.

+		return -EPROBE_DEFER;
+	}
+
+	if (!pdev->dev.bus->iommu_ops) {
+		pr_debug("defer probe sdma device\n");
Anyway, no pr_xxx, but dev_xxx. Is it really, really possible?

If iommu driver is loaded later than this driver, then here iommu_ops may be uninitialized.
+		return -EPROBE_DEFER;> +	}
+
+	sdev = devm_kzalloc(dev, sizeof(*sdev), GFP_KERNEL);
+	if (!sdev) {
+		pr_err("alloc sdma_device failed\n");
+		return -ENOMEM;
+	}
+
+	sdev->pdev = pdev;
+	dev_set_drvdata(&pdev->dev, sdev);
Come on, you just stored pdev->dev under dev!
+
+	ret = of_sdma_collect_info(pdev, &info);
+	if (ret < 0) {
+		pr_err("collect device info failed, %d\n", ret);
dev_err

Please work on this driver to start looking like other kernel drivers.


+		return ret;
+	}
+
+	sdev->io_base = ioremap(info.base_addr, SDMA_IOMEM_SIZE);
+	if (!sdev->io_base) {
+		pr_err("ioremap failed\n");
+		ret = -ENOMEM;
+		return ret;
+	}
+
+	/* Fill in dmaengine */
+	sdma_init_dma_device(&sdev->dma_dev, dev);
+
+	ret = sdma_init_channels(sdev, &info);
+	if (ret < 0)
+		goto unmap_iobase;
+
+	ret = iommu_dev_enable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
+	if (ret) {
+		pr_err("iommu failed to init iopf, %d\n", ret);
+		goto destroy_channels;
+	}
+
+	ret = iommu_dev_enable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+	if (ret) {
+		pr_err("iommu failed to init sva, %d\n", ret);
+		goto disable_iopf;
+	}
+
+	sdev->streamid = pdev->dev.iommu->fwspec->ids[0];
+
+	snprintf(sdev->name, SDMA_DEVICE_NAME_LENGTH_MAX, "sdma%d", sdev->idx);
+	pr_info("%s device probe success\n", sdev->name);
No, drop.

+
+	ret = dma_async_device_register(&sdev->dma_dev);
+	if (ret) {
+		dev_err(dev, "failed to register slave DMA engine: %d\n", ret);
+		goto disable_sva;
+	}
+
+	return 0;
+
+disable_sva:
+	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+disable_iopf:
+	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
+destroy_channels:
+	sdma_destroy_channels(sdev);
+unmap_iobase:
+	iounmap(sdev->io_base);
+	return ret;
+}
+
+static int sdma_device_remove(struct platform_device *pdev)
+{
+	struct sdma_dev *psdma_dev = dev_get_drvdata(&pdev->dev);
+
+	dma_async_device_unregister(&psdma_dev->dma_dev);
+
+	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_SVA);
+	iommu_dev_disable_feature(&pdev->dev, IOMMU_DEV_FEAT_IOPF);
+
+	sdma_destroy_channels(psdma_dev);
+
+	iounmap(psdma_dev->io_base);
+
+	return 0;
+}
+
+static const struct of_device_id sdma_of_match[] = {
+	{ .compatible = "hisilicon,sdma" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, sdma_of_match);
+
+static struct platform_driver sdma_driver = {
+	.probe    = sdma_device_probe,
+	.remove   = sdma_device_remove,
+	.driver   = {
+		.name           = SDMA_DEVICE_NAME,
+		.of_match_table = sdma_of_match,
+	},
+};
+
+static int __init sdma_driver_init(void)
+{
+	return platform_driver_register(&sdma_driver);
+}
+module_init(sdma_driver_init);
+
+static void sdma_driver_exit(void)
+{
+	platform_driver_unregister(&sdma_driver);
+}
+module_exit(sdma_driver_exit);
module_platform_driver


Best regards,
Krzysztof

.

Hi

Thank you for carefully reviewing this patch and give all these advices.

I had sent a version 2 of the patch and fixed these points in dts bindings and driver code.

If any thing else is wrong, please let me know.


Best regards,

Guo Mengqi




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