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

[Mark Salter <msalter@redhat.com>]

On Wed, 2015-06-03 at 09:37 -0500, Suravee Suthikulanit wrote:
> 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@arm.com>
> >> >Signed-off-by: Mark Salter<msalter@redhat.com>
> >> >Signed-off-by: Suravee Suthikulpanit<Suravee.Suthikulpanit@amd.com>
> >> >---
> >> >  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 ‘(’ token
> >   #define FALSE                           (1 == 0)
> >                                           ^
> > drivers/scsi/ufs/unipro.h:203:2: note: in expansion of macro ‘FALSE’
> >    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.
> 

Yeah, or #undef them if defined so megaraid defines them as desired.
And #undef if defined would work for unipro.h as well.