Re: [V5 PATCH 2/5] arm64 : Introduce support for ACPI _CCA object

From: Suravee Suthikulanit
Date: Wed Jun 03 2015 - 10:37:42 EST


On 5/28/2015 9:38 PM, Mark Salter wrote:
On Wed, 2015-05-20 at 17:09 -0500, Suravee Suthikulpanit wrote:
>Fromhttp://www.uefi.org/sites/default/files/resources/ACPI_6.0.pdf,
>section 6.2.17 _CCA states that ARM platforms require ACPI _CCA
>object to be specified for DMA-cabpable devices. Therefore, this patch
>specifies ACPI_CCA_REQUIRED in arm64 Kconfig.
>
>In addition, to handle the case when _CCA is missing, arm64 would assign
>dummy_dma_ops to disable DMA capability of the device.
>
>Acked-by: Catalin Marinas<catalin.marinas@xxxxxxx>
>Signed-off-by: Mark Salter<msalter@xxxxxxxxxx>
>Signed-off-by: Suravee Suthikulpanit<Suravee.Suthikulpanit@xxxxxxx>
>---
> arch/arm64/Kconfig | 1 +
> arch/arm64/include/asm/dma-mapping.h | 18 ++++++-
> arch/arm64/mm/dma-mapping.c | 92 ++++++++++++++++++++++++++++++++++++
> 3 files changed, 109 insertions(+), 2 deletions(-)
>
>diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
>index 4269dba..95307b4 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
>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>
>
^^^ This hunk causes build issues with a couple of drivers:

drivers/scsi/megaraid/megaraid_sas_fp.c:69:0: warning: "FALSE" redefined [enabled by default]
#define FALSE 0
^
In file included from include/acpi/acpi.h:58:0,
from include/linux/acpi.h:37,
from ./arch/arm64/include/asm/dma-mapping.h:21,
from include/linux/dma-mapping.h:86,
from ./arch/arm64/include/asm/pci.h:7,
from include/linux/pci.h:1460,
from drivers/scsi/megaraid/megaraid_sas_fp.c:37:
include/acpi/actypes.h:433:0: note: this is the location of the previous definition
#define FALSE (1 == 0)
^


In file included from include/acpi/acpi.h:58:0,
from include/linux/acpi.h:37,
from ./arch/arm64/include/asm/dma-mapping.h:21,
from include/linux/dma-mapping.h:86,
from include/scsi/scsi_cmnd.h:4,
from drivers/scsi/ufs/ufshcd.h:60,
from drivers/scsi/ufs/ufshcd.c:43:
include/acpi/actypes.h:433:41: error: expected identifier before â(â token
#define FALSE (1 == 0)
^
drivers/scsi/ufs/unipro.h:203:2: note: in expansion of macro âFALSEâ
FALSE = 0,
^

This happens because the ACPI definitions of TRUE and FALSE conflict
with local definitions in megaraid and enum declaration in ufs.

Mark,

Thanks for pointing this out. Although, I would think that the megaraid_sas_fp.c should have had the #ifndef to check before defining the TRUE and FALSE as following.

#ifndef TRUE
#define TRUE 1
#endif
#ifndef FALSE
#define FALSE 0
#endif

This seems to be what other drivers are also doing. If this is okay, I can send out a fix-up patch for the megaraid driver.

Thanks,

Suravee

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