Hi Rafael, On 5/15/2015 6:53 PM, Rafael J. Wysocki wrote:
On Friday, May 15, 2015 04:23:09 PM Suravee Suthikulpanit wrote:[...] diff --git a/drivers/acpi/acpi_platform.c b/drivers/acpi/acpi_platform.c index 4bf7559..f6bc438 100644 --- a/drivers/acpi/acpi_platform.c +++ b/drivers/acpi/acpi_platform.c @@ -103,14 +103,18 @@ struct platform_device *acpi_create_platform_device(struct acpi_device *adev) pdevinfo.res = resources; pdevinfo.num_res = count; pdevinfo.fwnode = acpi_fwnode_handle(adev); - pdevinfo.dma_mask = DMA_BIT_MASK(32); + pdevinfo.dma_mask = acpi_dma_is_supported(adev) ? DMA_BIT_MASK(32) : 0; pdev = platform_device_register_full(&pdevinfo); - if (IS_ERR(pdev)) + if (IS_ERR(pdev)) { dev_err(&adev->dev, "platform device creation failed: %ld\n", PTR_ERR(pdev)); - else + } else { + if (acpi_dma_is_supported(adev)) + arch_setup_dma_ops(&pdev->dev, 0, 0, NULL, + acpi_dma_is_coherent(adev));Shouldn't we generally do that in acpi_bind_one() for all bus types that don't have specific handling rather than here?
I think that would also work, and makes sense. However, I'm not sure if this would help in the case when we are creating PCI end-point devices, since the CCA is specified at the host bridge node, and there is no ACPI companion for the end-point devices. It seems that patch 3/6 of this series is still needed.
diff --git a/drivers/acpi/scan.c b/drivers/acpi/scan.c index 849b699..c56e66a 100644 --- a/drivers/acpi/scan.c +++ b/drivers/acpi/scan.c @@ -11,6 +11,7 @@ #include <linux/kthread.h> #include <linux/dmi.h> #include <linux/nls.h> +#include <linux/dma-mapping.h> #include <asm/pgtable.h> @@ -2137,6 +2138,44 @@ void acpi_free_pnp_ids(struct acpi_device_pnp *pnp) kfree(pnp->unique_id); } +static void acpi_init_coherency(struct acpi_device *adev) +{ + unsigned long long cca = 0; + acpi_status status; + struct acpi_device *parent = adev->parent; + struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; + + if (parent && parent->flags.cca_seen) { + /* + * From ACPI spec, OSPM will ignore _CCA if an ancestor + * already saw one. + */ + adev->flags.cca_seen = 1; + cca = acpi_dma_is_coherent(parent);Shouldn't the device's own _CCA take precedence?
According to the ACPI specification, the parent's _CCA take precedence.
+ } else { + status = acpi_evaluate_integer(adev->handle, "_CCA", + NULL, &cca); + if (ACPI_SUCCESS(status)) { + adev->flags.cca_seen = 1; + } else if (!IS_ENABLED(CONFIG_ACPI_CCA_REQUIRED)) { + /* + * If architecture does not specify that _CCA is + * required for DMA-able devices (e.g. x86), + * we default to _CCA=1. + */ + cca = 1; + } else {What about using acpi_handle_debug() here?
Ok I can do that.
[...] diff --git a/include/acpi/acpi_bus.h b/include/acpi/acpi_bus.h index 8de4fa9..2a05ffb 100644 --- a/include/acpi/acpi_bus.h +++ b/include/acpi/acpi_bus.h @@ -208,7 +208,9 @@ struct acpi_device_flags { u32 visited:1; u32 hotplug_notify:1; u32 is_dock_station:1; - u32 reserved:23; + u32 is_coherent:1;I'd prefer to call this 'coherent_dma'.
OK. Thanks, Suravee -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
