Re: [PATCH v3 1/3] acpi: arm64: add iort support for PMCG

[Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>]

On Fri, Sep 21, 2018 at 04:08:01PM +0100, Shameer Kolothum wrote:
> From: Neil Leeder <nleeder@codeaurora.org>
> 
> Add support for the SMMU Performance Monitor Counter Group
> information from ACPI. This is in preparation for its use
> in the SMMUv3 PMU driver.
> 
> Signed-off-by: Neil Leeder <nleeder@codeaurora.org>
> Signed-off-by: Hanjun Guo <guohanjun@huawei.com>
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  drivers/acpi/arm64/iort.c | 78 +++++++++++++++++++++++++++++++++++++++--------
>  1 file changed, 66 insertions(+), 12 deletions(-)
> 
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 08f26db..b979c86 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -356,7 +356,8 @@ static struct acpi_iort_node *iort_node_get_id(struct acpi_iort_node *node,
>  	if (map->flags & ACPI_IORT_ID_SINGLE_MAPPING) {
>  		if (node->type == ACPI_IORT_NODE_NAMED_COMPONENT ||
>  		    node->type == ACPI_IORT_NODE_PCI_ROOT_COMPLEX ||
> -		    node->type == ACPI_IORT_NODE_SMMU_V3) {
> +		    node->type == ACPI_IORT_NODE_SMMU_V3 ||
> +		    node->type == ACPI_IORT_NODE_PMCG) {
>  			*id_out = map->output_base;
>  			return parent;
>  		}
> @@ -394,6 +395,8 @@ static int iort_get_id_mapping_index(struct acpi_iort_node *node)
>  		}
>  
>  		return smmu->id_mapping_index;
> +	case ACPI_IORT_NODE_PMCG:
> +		return 0;
>  	default:
>  		return -EINVAL;
>  	}
> @@ -1309,6 +1312,50 @@ static bool __init arm_smmu_is_coherent(struct acpi_iort_node *node)
>  	return smmu->flags & ACPI_IORT_SMMU_COHERENT_WALK;
>  }
>  
> +static void __init arm_smmu_common_dma_configure(struct device *dev,
> +						enum dev_dma_attr attr)
> +{
> +	/* We expect the dma masks to be equivalent for all SMMUs set-ups */
> +	dev->dma_mask = &dev->coherent_dma_mask;
> +
> +	/* Configure DMA for the page table walker */
> +	acpi_dma_configure(dev, attr);
> +}

It looks like we can't get rid of this acpi_dma_configure() call
given that the platform device we create has no ACPI companion
(and I am not looking forward to fabricating one to make the
code homogeneous :)).

Still, having two methods per IORT node type (dev_is_coherent() and
dev_dma_configure()) does not make much sense, we can merge it into one
I think.

Thanks,
Lorenzo

> +static int __init arm_smmu_v3_pmcg_count_resources(struct acpi_iort_node *node)
> +{
> +	struct acpi_iort_pmcg *pmcg;
> +
> +	/* Retrieve PMCG specific data */
> +	pmcg = (struct acpi_iort_pmcg *)node->node_data;
> +
> +	/*
> +	 * There are always 2 memory resources.
> +	 * If the overflow_gsiv is present then add that for a total of 3.
> +	 */
> +	return pmcg->overflow_gsiv ? 3 : 2;
> +}
> +
> +static void __init arm_smmu_v3_pmcg_init_resources(struct resource *res,
> +					       struct acpi_iort_node *node)
> +{
> +	struct acpi_iort_pmcg *pmcg;
> +
> +	/* Retrieve PMCG specific data */
> +	pmcg = (struct acpi_iort_pmcg *)node->node_data;
> +
> +	res[0].start = pmcg->page0_base_address;
> +	res[0].end = pmcg->page0_base_address + SZ_4K - 1;
> +	res[0].flags = IORESOURCE_MEM;
> +	res[1].start = pmcg->page1_base_address;
> +	res[1].end = pmcg->page1_base_address + SZ_4K - 1;
> +	res[1].flags = IORESOURCE_MEM;
> +
> +	if (pmcg->overflow_gsiv)
> +		acpi_iort_register_irq(pmcg->overflow_gsiv, "overflow",
> +				       ACPI_EDGE_SENSITIVE, &res[2]);
> +}
> +
>  struct iort_dev_config {
>  	const char *name;
>  	int (*dev_init)(struct acpi_iort_node *node);
> @@ -1318,6 +1365,8 @@ struct iort_dev_config {
>  				     struct acpi_iort_node *node);
>  	void (*dev_set_proximity)(struct device *dev,
>  				    struct acpi_iort_node *node);
> +	void (*dev_dma_configure)(struct device *dev,
> +					enum dev_dma_attr attr);
>  };
>  
>  static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {
> @@ -1326,23 +1375,34 @@ static const struct iort_dev_config iort_arm_smmu_v3_cfg __initconst = {
>  	.dev_count_resources = arm_smmu_v3_count_resources,
>  	.dev_init_resources = arm_smmu_v3_init_resources,
>  	.dev_set_proximity = arm_smmu_v3_set_proximity,
> +	.dev_dma_configure = arm_smmu_common_dma_configure,
>  };
>  
>  static const struct iort_dev_config iort_arm_smmu_cfg __initconst = {
>  	.name = "arm-smmu",
>  	.dev_is_coherent = arm_smmu_is_coherent,
>  	.dev_count_resources = arm_smmu_count_resources,
> -	.dev_init_resources = arm_smmu_init_resources
> +	.dev_init_resources = arm_smmu_init_resources,
> +	.dev_dma_configure = arm_smmu_common_dma_configure,
> +};
> +
> +static const struct iort_dev_config iort_arm_smmu_v3_pmcg_cfg __initconst = {
> +	.name = "arm-smmu-v3-pmu",
> +	.dev_count_resources = arm_smmu_v3_pmcg_count_resources,
> +	.dev_init_resources = arm_smmu_v3_pmcg_init_resources,
>  };
>  
>  static __init const struct iort_dev_config *iort_get_dev_cfg(
>  			struct acpi_iort_node *node)
>  {
> +
>  	switch (node->type) {
>  	case ACPI_IORT_NODE_SMMU_V3:
>  		return &iort_arm_smmu_v3_cfg;
>  	case ACPI_IORT_NODE_SMMU:
>  		return &iort_arm_smmu_cfg;
> +	case ACPI_IORT_NODE_PMCG:
> +		return &iort_arm_smmu_v3_pmcg_cfg;
>  	default:
>  		return NULL;
>  	}
> @@ -1398,12 +1458,6 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,
>  	if (ret)
>  		goto dev_put;
>  
> -	/*
> -	 * We expect the dma masks to be equivalent for
> -	 * all SMMUs set-ups
> -	 */
> -	pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
> -
>  	fwnode = iort_get_fwnode(node);
>  
>  	if (!fwnode) {
> @@ -1413,11 +1467,11 @@ static int __init iort_add_platform_device(struct acpi_iort_node *node,
>  
>  	pdev->dev.fwnode = fwnode;
>  
> -	attr = ops->dev_is_coherent && ops->dev_is_coherent(node) ?
> +	if (ops->dev_dma_configure) {
> +		attr = ops->dev_is_coherent && ops->dev_is_coherent(node) ?
>  			DEV_DMA_COHERENT : DEV_DMA_NON_COHERENT;
> -
> -	/* Configure DMA for the page table walker */
> -	acpi_dma_configure(&pdev->dev, attr);
> +		ops->dev_dma_configure(&pdev->dev, attr);
> +	}
>  
>  	iort_set_device_domain(&pdev->dev, node);
>  
> -- 
> 2.7.4
> 
>