Re: [PATCH 8/8] dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP

2019-08-09 Thread Geert Uytterhoeven
Hi Christoph,

On Thu, Aug 8, 2019 at 6:01 PM Christoph Hellwig  wrote:
> CONFIG_ARCH_NO_COHERENT_DMA_MMAP is now functionally identical to
> !CONFIG_MMU, so remove the separate symbol.  The only difference is that
> arm did not set it for !CONFIG_MMU, but arm uses a separate dma mapping
> implementation including its own mmap method, which is handled by moving
> the CONFIG_MMU check in dma_can_mmap so that is only applies to the
> dma-direct case, just as the other ifdefs for it.
>
> Signed-off-by: Christoph Hellwig 

>  arch/m68k/Kconfig   |  1 -

For m68k:
Acked-by: Geert Uytterhoeven 

Gr{oetje,eeting}s,

Geert

-- 
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- ge...@linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds


[PATCH 8/8] dma-mapping: remove CONFIG_ARCH_NO_COHERENT_DMA_MMAP

2019-08-08 Thread Christoph Hellwig
CONFIG_ARCH_NO_COHERENT_DMA_MMAP is now functionally identical to
!CONFIG_MMU, so remove the separate symbol.  The only difference is that
arm did not set it for !CONFIG_MMU, but arm uses a separate dma mapping
implementation including its own mmap method, which is handled by moving
the CONFIG_MMU check in dma_can_mmap so that is only applies to the
dma-direct case, just as the other ifdefs for it.

Signed-off-by: Christoph Hellwig 
---
 arch/Kconfig|  3 ---
 arch/c6x/Kconfig|  1 -
 arch/m68k/Kconfig   |  1 -
 arch/microblaze/Kconfig |  1 -
 arch/sh/Kconfig |  1 -
 arch/xtensa/Kconfig |  1 -
 kernel/dma/mapping.c| 12 +---
 7 files changed, 5 insertions(+), 15 deletions(-)

diff --git a/arch/Kconfig b/arch/Kconfig
index a7b57dd42c26..ec2834206d08 100644
--- a/arch/Kconfig
+++ b/arch/Kconfig
@@ -790,9 +790,6 @@ config COMPAT_32BIT_TIME
  This is relevant on all 32-bit architectures, and 64-bit architectures
  as part of compat syscall handling.
 
-config ARCH_NO_COHERENT_DMA_MMAP
-   bool
-
 config ARCH_NO_PREEMPT
bool
 
diff --git a/arch/c6x/Kconfig b/arch/c6x/Kconfig
index b4fb61c83494..e65e8d82442a 100644
--- a/arch/c6x/Kconfig
+++ b/arch/c6x/Kconfig
@@ -20,7 +20,6 @@ config C6X
select OF_EARLY_FLATTREE
select GENERIC_CLOCKEVENTS
select MODULES_USE_ELF_RELA
-   select ARCH_NO_COHERENT_DMA_MMAP
select MMU_GATHER_NO_RANGE if MMU
 
 config MMU
diff --git a/arch/m68k/Kconfig b/arch/m68k/Kconfig
index c518d695c376..614b355ae338 100644
--- a/arch/m68k/Kconfig
+++ b/arch/m68k/Kconfig
@@ -8,7 +8,6 @@ config M68K
select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE
select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA
select ARCH_MIGHT_HAVE_PC_PARPORT if ISA
-   select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select ARCH_NO_PREEMPT if !COLDFIRE
select BINFMT_FLAT_ARGVP_ENVP_ON_STACK
select DMA_DIRECT_REMAP if HAS_DMA && MMU && !COLDFIRE
diff --git a/arch/microblaze/Kconfig b/arch/microblaze/Kconfig
index d411de05b628..632c9477a0f6 100644
--- a/arch/microblaze/Kconfig
+++ b/arch/microblaze/Kconfig
@@ -9,7 +9,6 @@ config MICROBLAZE
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_MIGHT_HAVE_PC_PARPORT
-   select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select ARCH_WANT_IPC_PARSE_VERSION
select BUILDTIME_EXTABLE_SORT
select TIMER_OF
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 6b1b5941b618..f356ee674d89 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -5,7 +5,6 @@ config SUPERH
select ARCH_HAS_PTE_SPECIAL
select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
select ARCH_MIGHT_HAVE_PC_PARPORT
-   select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select HAVE_PATA_PLATFORM
select CLKDEV_LOOKUP
select DMA_DECLARE_COHERENT
diff --git a/arch/xtensa/Kconfig b/arch/xtensa/Kconfig
index ebc135bda921..70653aed3005 100644
--- a/arch/xtensa/Kconfig
+++ b/arch/xtensa/Kconfig
@@ -5,7 +5,6 @@ config XTENSA
select ARCH_HAS_BINFMT_FLAT if !MMU
select ARCH_HAS_SYNC_DMA_FOR_CPU
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
-   select ARCH_NO_COHERENT_DMA_MMAP if !MMU
select ARCH_USE_QUEUED_RWLOCKS
select ARCH_USE_QUEUED_SPINLOCKS
select ARCH_WANT_FRAME_POINTERS
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c
index 64d1de59e133..fc17016b0871 100644
--- a/kernel/dma/mapping.c
+++ b/kernel/dma/mapping.c
@@ -186,7 +186,7 @@ int dma_common_mmap(struct device *dev, struct 
vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
unsigned long attrs)
 {
-#ifndef CONFIG_ARCH_NO_COHERENT_DMA_MMAP
+#ifdef CONFIG_MMU
unsigned long user_count = vma_pages(vma);
unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
unsigned long off = vma->vm_pgoff;
@@ -217,7 +217,7 @@ int dma_common_mmap(struct device *dev, struct 
vm_area_struct *vma,
user_count << PAGE_SHIFT, vma->vm_page_prot);
 #else
return -ENXIO;
-#endif /* !CONFIG_ARCH_NO_COHERENT_DMA_MMAP */
+#endif /* CONFIG_MMU */
 }
 
 /**
@@ -231,12 +231,10 @@ bool dma_can_mmap(struct device *dev)
 {
const struct dma_map_ops *ops = get_dma_ops(dev);
 
-   if (IS_ENABLED(CONFIG_ARCH_NO_COHERENT_DMA_MMAP))
-   return false;
-
if (dma_is_direct(ops)) {
-   return dev_is_dma_coherent(dev) ||
-   IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN);
+   return IS_ENABLED(CONFIG_MMU) &&
+  (dev_is_dma_coherent(dev) ||
+   IS_ENABLED(CONFIG_ARCH_HAS_DMA_COHERENT_TO_PFN));
}
 
return ops->mmap != NULL;
-- 
2.20.1