lkml.org 
[lkml]   [2015]   [May]   [11]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [V3 PATCH 2/5] arm64 : Introduce support for ACPI _CCA object
On Thu, May 07, 2015 at 07:37:13PM -0500, Suravee Suthikulpanit wrote:
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 4269dba..c7227e8 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -1,5 +1,6 @@
> config ARM64
> def_bool y
> + select ACPI_CCA_REQUIRED if ACPI
> select ACPI_GENERIC_GSI if ACPI
> select ACPI_REDUCED_HARDWARE_ONLY if ACPI
> select ARCH_HAS_ATOMIC64_DEC_IF_POSITIVE
> @@ -19,6 +20,7 @@ config ARM64
> select ARM_GIC_V2M if PCI_MSI
> select ARM_GIC_V3
> select ARM_GIC_V3_ITS if PCI_MSI
> + select ARM64_SUPPORT_ACPI_CCA_ZERO if ACPI

As per the other sub-thread, I don't think we need this option at all.

> diff --git a/arch/arm64/include/asm/dma-mapping.h b/arch/arm64/include/asm/dma-mapping.h
> index 9437e3d..f0d6d0b 100644
> --- a/arch/arm64/include/asm/dma-mapping.h
> +++ b/arch/arm64/include/asm/dma-mapping.h
> @@ -18,6 +18,7 @@
>
> #ifdef __KERNEL__
>
> +#include <linux/acpi.h>
> #include <linux/types.h>
> #include <linux/vmalloc.h>
>
> @@ -28,13 +29,23 @@
>
> #define DMA_ERROR_CODE (~(dma_addr_t)0)
> extern struct dma_map_ops *dma_ops;
> +extern struct dma_map_ops dummy_dma_ops;
>
> static inline struct dma_map_ops *__generic_dma_ops(struct device *dev)
> {
> - if (unlikely(!dev) || !dev->archdata.dma_ops)
> + if (unlikely(!dev))
> return dma_ops;
> - else
> + else if (dev->archdata.dma_ops)
> return dev->archdata.dma_ops;
> + else if (acpi_disabled)
> + return dma_ops;
> +
> + /*
> + * When ACPI is enabled, if arch_set_dma_ops is not called,
> + * we will disable device DMA capability by setting it
> + * to dummy_dma_ops.
> + */
> + return &dummy_dma_ops;
> }

The code looks fine to me but Arnd had some comments that I didn't fully
understand (dropping dummy_map_ops in favour of simply setting dma_mask
to NULL; I don't think the existing swiotlb ops would behave in a way
that always return NULL).

--
Catalin


\
 
 \ /
  Last update: 2015-05-11 19:41    [W:0.075 / U:0.944 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site