static int crb_map_io()

in tpm/tpm_crb.c [502:657]

• 121 lines of code
• 26 McCabe index (conditional complexity)

static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
		      struct acpi_table_tpm2 *buf)
{
	struct list_head acpi_resource_list;
	struct resource iores_array[TPM_CRB_MAX_RESOURCES + 1] = { {0} };
	void __iomem *iobase_array[TPM_CRB_MAX_RESOURCES] = {NULL};
	struct device *dev = &device->dev;
	struct resource *iores;
	void __iomem **iobase_ptr;
	int i;
	u32 pa_high, pa_low;
	u64 cmd_pa;
	u32 cmd_size;
	__le64 __rsp_pa;
	u64 rsp_pa;
	u32 rsp_size;
	int ret;

	INIT_LIST_HEAD(&acpi_resource_list);
	ret = acpi_dev_get_resources(device, &acpi_resource_list,
				     crb_check_resource, iores_array);
	if (ret < 0)
		return ret;
	acpi_dev_free_resource_list(&acpi_resource_list);

	if (resource_type(iores_array) != IORESOURCE_MEM) {
		dev_err(dev, FW_BUG "TPM2 ACPI table does not define a memory resource\n");
		return -EINVAL;
	} else if (resource_type(iores_array + TPM_CRB_MAX_RESOURCES) ==
		IORESOURCE_MEM) {
		dev_warn(dev, "TPM2 ACPI table defines too many memory resources\n");
		memset(iores_array + TPM_CRB_MAX_RESOURCES,
		       0, sizeof(*iores_array));
		iores_array[TPM_CRB_MAX_RESOURCES].flags = 0;
	}

	iores = NULL;
	iobase_ptr = NULL;
	for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
		if (buf->control_address >= iores_array[i].start &&
		    buf->control_address + sizeof(struct crb_regs_tail) - 1 <=
		    iores_array[i].end) {
			iores = iores_array + i;
			iobase_ptr = iobase_array + i;
			break;
		}
	}

	priv->regs_t = crb_map_res(dev, iores, iobase_ptr, buf->control_address,
				   sizeof(struct crb_regs_tail));

	if (IS_ERR(priv->regs_t))
		return PTR_ERR(priv->regs_t);

	/* The ACPI IO region starts at the head area and continues to include
	 * the control area, as one nice sane region except for some older
	 * stuff that puts the control area outside the ACPI IO region.
	 */
	if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
	    (priv->sm == ACPI_TPM2_MEMORY_MAPPED)) {
		if (iores &&
		    buf->control_address == iores->start +
		    sizeof(*priv->regs_h))
			priv->regs_h = *iobase_ptr;
		else
			dev_warn(dev, FW_BUG "Bad ACPI memory layout");
	}

	ret = __crb_request_locality(dev, priv, 0);
	if (ret)
		return ret;

	/*
	 * PTT HW bug w/a: wake up the device to access
	 * possibly not retained registers.
	 */
	ret = __crb_cmd_ready(dev, priv);
	if (ret)
		goto out_relinquish_locality;

	pa_high = ioread32(&priv->regs_t->ctrl_cmd_pa_high);
	pa_low  = ioread32(&priv->regs_t->ctrl_cmd_pa_low);
	cmd_pa = ((u64)pa_high << 32) | pa_low;
	cmd_size = ioread32(&priv->regs_t->ctrl_cmd_size);

	iores = NULL;
	iobase_ptr = NULL;
	for (i = 0; iores_array[i].end; ++i) {
		if (cmd_pa >= iores_array[i].start &&
		    cmd_pa <= iores_array[i].end) {
			iores = iores_array + i;
			iobase_ptr = iobase_array + i;
			break;
		}
	}

	if (iores)
		cmd_size = crb_fixup_cmd_size(dev, iores, cmd_pa, cmd_size);

	dev_dbg(dev, "cmd_hi = %X cmd_low = %X cmd_size %X\n",
		pa_high, pa_low, cmd_size);

	priv->cmd = crb_map_res(dev, iores, iobase_ptr,	cmd_pa, cmd_size);
	if (IS_ERR(priv->cmd)) {
		ret = PTR_ERR(priv->cmd);
		goto out;
	}

	memcpy_fromio(&__rsp_pa, &priv->regs_t->ctrl_rsp_pa, 8);
	rsp_pa = le64_to_cpu(__rsp_pa);
	rsp_size = ioread32(&priv->regs_t->ctrl_rsp_size);

	iores = NULL;
	iobase_ptr = NULL;
	for (i = 0; resource_type(iores_array + i) == IORESOURCE_MEM; ++i) {
		if (rsp_pa >= iores_array[i].start &&
		    rsp_pa <= iores_array[i].end) {
			iores = iores_array + i;
			iobase_ptr = iobase_array + i;
			break;
		}
	}

	if (iores)
		rsp_size = crb_fixup_cmd_size(dev, iores, rsp_pa, rsp_size);

	if (cmd_pa != rsp_pa) {
		priv->rsp = crb_map_res(dev, iores, iobase_ptr,
					rsp_pa, rsp_size);
		ret = PTR_ERR_OR_ZERO(priv->rsp);
		goto out;
	}

	/* According to the PTP specification, overlapping command and response
	 * buffer sizes must be identical.
	 */
	if (cmd_size != rsp_size) {
		dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
		ret = -EINVAL;
		goto out;
	}

	priv->rsp = priv->cmd;

out:
	if (!ret)
		priv->cmd_size = cmd_size;

	__crb_go_idle(dev, priv);

out_relinquish_locality:

	__crb_relinquish_locality(dev, priv, 0);

	return ret;
}