[PATCH v5 07/14] drivers: acpi: iort: add support for ARM SMMU platform devices creation
Hanjun Guo
hanjun.guo at linaro.org
Tue Sep 13 01:15:31 PDT 2016
On 2016/9/13 15:46, nwatters at codeaurora.org wrote:
> On 2016-09-09 10:23, 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.pieralisi at arm.com>
>> Cc: Hanjun Guo <hanjun.guo at linaro.org>
>> Cc: Tomasz Nowicki <tn at semihalf.com>
>> Cc: "Rafael J. Wysocki" <rjw at 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;
>> + }
>> +
>> + 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);
>> +
>> + 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);
>
> Since iort_scan_node() returns after the first successful match it finds,
> only the first SMMU_V3 in my IORT is being enumerated. I think you need
> to go back to the "iterator" like approach you had been using or make
> iort_match_iommu_callback() always return a non-AE_OK value so the scan
> continues and has a chance to visit all of the SMMU_V3 nodes.
Please use the updated version of IORT patch (aka Tomasz's v11)
then things will work fine.
Thanks
Hanjun
More information about the linux-arm-kernel
mailing list