On 09/09/16 15:23, Lorenzo Pieralisi wrote:
> In ARM ACPI systems, IOMMU components are specified through static
> IORT table entries. In order to create platform devices for the
> corresponding ARM SMMU components, IORT kernel code should be made
> able to parse IORT table entries and create platform devices
> dynamically.
>
> This patch adds the generic IORT infrastructure required to create
> platform devices for ARM SMMUs.
>
> ARM SMMU versions have different resources requirement therefore this
> patch also introduces an IORT specific structure (ie iort_iommu_config)
> that contains hooks (to be defined when the corresponding ARM SMMU
> driver support is added to the kernel) to be used to define the
> platform devices names, init the IOMMUs, count their resources and
> finally initialize them.
>
> Signed-off-by: Lorenzo Pieralisi <lorenzo.pieral...@arm.com>
> Cc: Hanjun Guo <hanjun....@linaro.org>
> Cc: Tomasz Nowicki <t...@semihalf.com>
> Cc: "Rafael J. Wysocki" <r...@rjwysocki.net>
> ---
> drivers/acpi/arm64/iort.c | 131
> ++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 131 insertions(+)
>
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index b89b3d3..e0a9b16 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -22,6 +22,7 @@
> #include <linux/kernel.h>
> #include <linux/list.h>
> #include <linux/pci.h>
> +#include <linux/platform_device.h>
> #include <linux/slab.h>
>
> struct iort_its_msi_chip {
> @@ -424,6 +425,135 @@ struct irq_domain *iort_get_device_domain(struct device
> *dev, u32 req_id)
> return irq_find_matching_fwnode(handle, DOMAIN_BUS_PCI_MSI);
> }
>
> +struct iort_iommu_config {
> + const char *name;
> + int (*iommu_init)(struct acpi_iort_node *node);
> + bool (*iommu_is_coherent)(struct acpi_iort_node *node);
> + int (*iommu_count_resources)(struct acpi_iort_node *node);
> + void (*iommu_init_resources)(struct resource *res,
> + struct acpi_iort_node *node);
> +};
> +
> +static __init
> +const struct iort_iommu_config *iort_get_iommu_cfg(struct acpi_iort_node
> *node)
> +{
> + return NULL;
> +}
> +
> +/**
> + * iort_add_smmu_platform_device() - Allocate a platform device for SMMU
> + * @fwnode: IORT node associated fwnode handle
> + * @node: Pointer to SMMU ACPI IORT node
> + *
> + * Returns: 0 on success, <0 failure
> + */
> +static int __init iort_add_smmu_platform_device(struct fwnode_handle *fwnode,
> + struct acpi_iort_node *node)
> +{
> + struct platform_device *pdev;
> + struct resource *r;
> + enum dev_dma_attr attr;
> + int ret, count;
> + const struct iort_iommu_config *ops = iort_get_iommu_cfg(node);
> +
> + if (!ops)
> + return -ENODEV;
> +
> + pdev = platform_device_alloc(ops->name, PLATFORM_DEVID_AUTO);
> + if (!pdev)
> + return PTR_ERR(pdev);
> +
> + count = ops->iommu_count_resources(node);
> +
> + r = kcalloc(count, sizeof(*r), GFP_KERNEL);
> + if (!r) {
> + ret = -ENOMEM;
> + goto dev_put;
> + }
> +
> + ops->iommu_init_resources(r, node);
> +
> + ret = platform_device_add_resources(pdev, r, count);
> + /*
> + * Resources are duplicated in platform_device_add_resources,
> + * free their allocated memory
> + */
> + kfree(r);
> +
> + if (ret)
> + goto dev_put;
> +
> + /*
> + * Add a copy of IORT node pointer to platform_data to
> + * be used to retrieve IORT data information.
> + */
> + ret = platform_device_add_data(pdev, &node, sizeof(node));
> + if (ret)
> + goto dev_put;
> +
> + pdev->dev.dma_mask = kmalloc(sizeof(*pdev->dev.dma_mask), GFP_KERNEL);
> + if (!pdev->dev.dma_mask) {
> + ret = -ENOMEM;
> + goto dev_put;
> + }
Since this is exclusively for creating SMMUs, and we know they should
never have weird shenanigans going on requiring different masks, I'd be
inclined to just point dev.dma_mask at dev.coherent_dma_mask and be done
with it.
> +
> + pdev->dev.fwnode = fwnode;
> +
> + /*
> + * Set default dma mask value for the table walker,
> + * to be overridden on probing with correct value.
> + */
> + *pdev->dev.dma_mask = DMA_BIT_MASK(32);
> + pdev->dev.coherent_dma_mask = *pdev->dev.dma_mask;
> +
> + attr = ops->iommu_is_coherent(node) ?
> + DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
> +
> + /* Configure DMA for the page table walker */
> + acpi_dma_configure(&pdev->dev, attr);
Oh look, some more code which would be simpler if acpi_dma_configure()
set the default mask itself ;)
Robin.
> +
> + ret = platform_device_add(pdev);
> + if (ret)
> + goto dma_deconfigure;
> +
> + return 0;
> +
> +dma_deconfigure:
> + acpi_dma_deconfigure(&pdev->dev);
> + kfree(pdev->dev.dma_mask);
> +
> +dev_put:
> + platform_device_put(pdev);
> +
> + return ret;
> +}
> +
> +static acpi_status __init iort_match_iommu_callback(struct acpi_iort_node
> *node,
> + void *context)
> +{
> + int ret;
> + struct fwnode_handle *fwnode;
> +
> + fwnode = iort_get_fwnode(node);
> +
> + if (!fwnode)
> + return AE_NOT_FOUND;
> +
> + ret = iort_add_smmu_platform_device(fwnode, node);
> + if (ret) {
> + pr_err("Error in platform device creation\n");
> + return AE_ERROR;
> + }
> +
> + return AE_OK;
> +}
> +
> +static void __init iort_smmu_init(void)
> +{
> + iort_scan_node(ACPI_IORT_NODE_SMMU, iort_match_iommu_callback, NULL);
> + iort_scan_node(ACPI_IORT_NODE_SMMU_V3, iort_match_iommu_callback, NULL);
> +}
> +
> void __init acpi_iort_init(void)
> {
> acpi_status status;
> @@ -436,4 +566,5 @@ void __init acpi_iort_init(void)
> }
>
> acpi_probe_device_table(iort);
> + iort_smmu_init();
> }
>
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