drivers/infiniband/hw/mthca/mthca_reset.c

Source file repositories/reference/linux-study-clean/drivers/infiniband/hw/mthca/mthca_reset.c

File Facts

System
Linux kernel
Corpus path
drivers/infiniband/hw/mthca/mthca_reset.c
Extension
.c
Size
7550 bytes
Lines
283
Domain
Driver Families
Bucket
drivers/infiniband
Inferred role
Driver Families: implementation source
Status
source implementation candidate

Why This File Exists

Repeatable hardware-adapter layer. Deep compatibility for every driver is out of scope; this atlas records patterns, probe lifecycles, bus glue, IRQ/DMA usage, and links back to core abstractions.

Dependency Surface

Detected Declarations

Annotated Snippet

if (!bridge) {
			/*
			 * Didn't find a bridge for a Tavor device --
			 * assume we're in no-bridge mode and hope for
			 * the best.
			 */
			mthca_warn(mdev, "No bridge found for %s\n",
				  pci_name(mdev->pdev));
		}

	}

	/* For Arbel do we need to save off the full 4K PCI Express header?? */
	hca_header = kmalloc(256, GFP_KERNEL);
	if (!hca_header) {
		err = -ENOMEM;
		goto put_dev;
	}

	for (i = 0; i < 64; ++i) {
		if (i == 22 || i == 23)
			continue;
		if (pci_read_config_dword(mdev->pdev, i * 4, hca_header + i)) {
			err = -ENODEV;
			mthca_err(mdev, "Couldn't save HCA "
				  "PCI header, aborting.\n");
			goto free_hca;
		}
	}

	hca_pcix_cap = pci_find_capability(mdev->pdev, PCI_CAP_ID_PCIX);
	hca_pcie_cap = pci_pcie_cap(mdev->pdev);

	if (bridge) {
		bridge_header = kmalloc(256, GFP_KERNEL);
		if (!bridge_header) {
			err = -ENOMEM;
			goto free_hca;
		}

		for (i = 0; i < 64; ++i) {
			if (i == 22 || i == 23)
				continue;
			if (pci_read_config_dword(bridge, i * 4, bridge_header + i)) {
				err = -ENODEV;
				mthca_err(mdev, "Couldn't save HCA bridge "
					  "PCI header, aborting.\n");
				goto free_bh;
			}
		}
		bridge_pcix_cap = pci_find_capability(bridge, PCI_CAP_ID_PCIX);
		if (!bridge_pcix_cap) {
				err = -ENODEV;
				mthca_err(mdev, "Couldn't locate HCA bridge "
					  "PCI-X capability, aborting.\n");
				goto free_bh;
		}
	}

	/* actually hit reset */
	{
		void __iomem *reset = ioremap(pci_resource_start(mdev->pdev, 0) +
					      MTHCA_RESET_OFFSET, 4);

		if (!reset) {
			err = -ENOMEM;
			mthca_err(mdev, "Couldn't map HCA reset register, "
				  "aborting.\n");
			goto free_bh;
		}

		writel(MTHCA_RESET_VALUE, reset);
		iounmap(reset);
	}

	/* Docs say to wait one second before accessing device */
	msleep(1000);

	/* Now wait for PCI device to start responding again */
	{
		u32 v;
		int c = 0;

		for (c = 0; c < 100; ++c) {
			if (pci_read_config_dword(bridge ? bridge : mdev->pdev, 0, &v)) {
				err = -ENODEV;
				mthca_err(mdev, "Couldn't access HCA after reset, "
					  "aborting.\n");
				goto free_bh;
			}

Annotation

Implementation Notes