[PATCH v2 0/4] MIPS DMA coherence fixes

[PATCH v2 0/4] MIPS DMA coherence fixes

[Jiaxun Yang]

Hi all,

This series fixes MIPS per-device DMA coherence support. It's mostly adjusting
Kconfig options.

The v1 series had some extra patches that fixing default coherency settings
for OF probing but I decided to send them as a dedicated series.

Thanks.
- Jiaxun

Jiaxun Yang (4):
  MIPS: Remove DMA_PERDEV_COHERENT
  MIPS: Always select ARCH_HAS_SETUP_DMA_OPS
  MIPS: Always select ARCH_HAS_SYNC_DMA_FOR_CPU for noncoherent
    platforms
  MIPS: c-r4k: Always install dma flush functions

 arch/mips/Kconfig    | 16 ++--------------
 arch/mips/mm/c-r4k.c | 12 +++---------
 2 files changed, 5 insertions(+), 23 deletions(-)

-- 
2.37.1 (Apple Git-137.1)

[PATCH v2 1/4] MIPS: Remove DMA_PERDEV_COHERENT

[Jiaxun Yang]

As now we are always managing DMA coherence on per dev bias,
there is no need to have such option. And it's not selected
by any platform.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
v2: Remove unrelated change.
---
 arch/mips/Kconfig | 5 -----
 1 file changed, 5 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 37072e15b263..a1170f0a0c04 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1080,11 +1080,6 @@ config FW_CFE
 config ARCH_SUPPORTS_UPROBES
 	bool
 
-config DMA_PERDEV_COHERENT
-	bool
-	select ARCH_HAS_SETUP_DMA_OPS
-	select DMA_NONCOHERENT
-
 config DMA_NONCOHERENT
 	bool
 	#
-- 
2.37.1 (Apple Git-137.1)

[PATCH v2 2/4] MIPS: Always select ARCH_HAS_SETUP_DMA_OPS

[Jiaxun Yang]

arch_setup_dma_ops on MIPS sets coherency information in struct device.
It's essential for per-device coherency to work.

Select it for all non-coherent platforms.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/Kconfig | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index a1170f0a0c04..dae894b7d857 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -134,7 +134,6 @@ choice
 
 config MIPS_GENERIC_KERNEL
 	bool "Generic board-agnostic MIPS kernel"
-	select ARCH_HAS_SETUP_DMA_OPS
 	select MIPS_GENERIC
 	select BOOT_RAW
 	select BUILTIN_DTB
@@ -1089,6 +1088,7 @@ config DMA_NONCOHERENT
 	# by pgprot_writcombine can be mixed, and the latter sometimes provides
 	# significant advantages.
 	#
+	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_DMA_WRITE_COMBINE
 	select ARCH_HAS_DMA_PREP_COHERENT
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
-- 
2.37.1 (Apple Git-137.1)

[PATCH v2 3/4] MIPS: Always select ARCH_HAS_SYNC_DMA_FOR_CPU for noncoherent platforms

[Jiaxun Yang]

As now we are telling the necessity of post DMA flush per CPU type,
there is no need to select ARCH_HAS_SYNC_DMA_FOR_CPU on per platform
bias, just select it unconditionally and we can sort it at runtime.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/Kconfig | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index dae894b7d857..bcca65b25f62 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -115,7 +115,6 @@ config MACH_INGENIC
 	select SYS_SUPPORTS_LITTLE_ENDIAN
 	select SYS_SUPPORTS_ZBOOT
 	select DMA_NONCOHERENT
-	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select IRQ_MIPS_CPU
 	select PINCTRL
 	select GPIOLIB
@@ -1091,6 +1090,7 @@ config DMA_NONCOHERENT
 	select ARCH_HAS_SETUP_DMA_OPS
 	select ARCH_HAS_DMA_WRITE_COMBINE
 	select ARCH_HAS_DMA_PREP_COHERENT
+	select ARCH_HAS_SYNC_DMA_FOR_CPU
 	select ARCH_HAS_SYNC_DMA_FOR_DEVICE
 	select ARCH_HAS_DMA_SET_UNCACHED
 	select DMA_NONCOHERENT_MMAP
@@ -1854,11 +1854,9 @@ config SYS_HAS_CPU_MIPS32_R3_5
 
 config SYS_HAS_CPU_MIPS32_R5
 	bool
-	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
 
 config SYS_HAS_CPU_MIPS32_R6
 	bool
-	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
 
 config SYS_HAS_CPU_MIPS64_R1
 	bool
@@ -1868,15 +1866,12 @@ config SYS_HAS_CPU_MIPS64_R2
 
 config SYS_HAS_CPU_MIPS64_R5
 	bool
-	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
 
 config SYS_HAS_CPU_MIPS64_R6
 	bool
-	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
 
 config SYS_HAS_CPU_P5600
 	bool
-	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
 
 config SYS_HAS_CPU_R3000
 	bool
@@ -1901,7 +1896,6 @@ config SYS_HAS_CPU_NEVADA
 
 config SYS_HAS_CPU_R10000
 	bool
-	select ARCH_HAS_SYNC_DMA_FOR_CPU if DMA_NONCOHERENT
 
 config SYS_HAS_CPU_RM7000
 	bool
@@ -1930,7 +1924,6 @@ config SYS_HAS_CPU_BMIPS4380
 config SYS_HAS_CPU_BMIPS5000
 	bool
 	select SYS_HAS_CPU_BMIPS
-	select ARCH_HAS_SYNC_DMA_FOR_CPU
 
 #
 # CPU may reorder R->R, R->W, W->R, W->W
-- 
2.37.1 (Apple Git-137.1)

[PATCH v2 4/4] MIPS: c-r4k: Always install dma flush functions

[Jiaxun Yang]

As nowadays DMA coherence is managed per device, it is possible
to have a system that is defaulted to coherent dma but still
have noncoherent device that needs to use those flush functions.

Just install them unconditionally.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/mm/c-r4k.c | 12 +++---------
 1 file changed, 3 insertions(+), 9 deletions(-)

diff --git a/arch/mips/mm/c-r4k.c b/arch/mips/mm/c-r4k.c
index a549fa98c2f4..7d447050a20b 100644
--- a/arch/mips/mm/c-r4k.c
+++ b/arch/mips/mm/c-r4k.c
@@ -1867,15 +1867,9 @@ void r4k_cache_init(void)
 	__local_flush_icache_user_range	= local_r4k_flush_icache_user_range;
 
 #ifdef CONFIG_DMA_NONCOHERENT
-	if (dma_default_coherent) {
-		_dma_cache_wback_inv	= (void *)cache_noop;
-		_dma_cache_wback	= (void *)cache_noop;
-		_dma_cache_inv		= (void *)cache_noop;
-	} else {
-		_dma_cache_wback_inv	= r4k_dma_cache_wback_inv;
-		_dma_cache_wback	= r4k_dma_cache_wback_inv;
-		_dma_cache_inv		= r4k_dma_cache_inv;
-	}
+	_dma_cache_wback_inv	= r4k_dma_cache_wback_inv;
+	_dma_cache_wback	= r4k_dma_cache_wback_inv;
+	_dma_cache_inv		= r4k_dma_cache_inv;
 #endif /* CONFIG_DMA_NONCOHERENT */
 
 	build_clear_page();
-- 
2.37.1 (Apple Git-137.1)

Re: [PATCH v2 1/4] MIPS: Remove DMA_PERDEV_COHERENT

[Philippe Mathieu-Daudé]

On 22/2/23 14:24, Jiaxun Yang wrote:
> As now we are always managing DMA coherence on per dev bias,
> there is no need to have such option. And it's not selected
> by any platform.

Leftover from 4e0664416c70 ("MIPS: remove CONFIG_DMA_PERDEV_COHERENT").

> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
> v2: Remove unrelated change.
> ---
>   arch/mips/Kconfig | 5 -----
>   1 file changed, 5 deletions(-)

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>

Re: [PATCH v2 1/4] MIPS: Remove DMA_PERDEV_COHERENT

[Thomas Bogendoerfer]

On Wed, Feb 22, 2023 at 01:24:22PM +0000, Jiaxun Yang wrote:
> As now we are always managing DMA coherence on per dev bias,
> there is no need to have such option. And it's not selected
> by any platform.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
> v2: Remove unrelated change.
> ---
>  arch/mips/Kconfig | 5 -----
>  1 file changed, 5 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v2 2/4] MIPS: Always select ARCH_HAS_SETUP_DMA_OPS

[Thomas Bogendoerfer]

On Wed, Feb 22, 2023 at 01:24:23PM +0000, Jiaxun Yang wrote:
> arch_setup_dma_ops on MIPS sets coherency information in struct device.
> It's essential for per-device coherency to work.
> 
> Select it for all non-coherent platforms.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/Kconfig | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v2 3/4] MIPS: Always select ARCH_HAS_SYNC_DMA_FOR_CPU for noncoherent platforms

[Thomas Bogendoerfer]

On Wed, Feb 22, 2023 at 01:24:24PM +0000, Jiaxun Yang wrote:
> As now we are telling the necessity of post DMA flush per CPU type,
> there is no need to select ARCH_HAS_SYNC_DMA_FOR_CPU on per platform
> bias, just select it unconditionally and we can sort it at runtime.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/Kconfig | 9 +--------
>  1 file changed, 1 insertion(+), 8 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]

Re: [PATCH v2 4/4] MIPS: c-r4k: Always install dma flush functions

[Thomas Bogendoerfer]

On Wed, Feb 22, 2023 at 01:24:25PM +0000, Jiaxun Yang wrote:
> As nowadays DMA coherence is managed per device, it is possible
> to have a system that is defaulted to coherent dma but still
> have noncoherent device that needs to use those flush functions.
> 
> Just install them unconditionally.
> 
> Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
> ---
>  arch/mips/mm/c-r4k.c | 12 +++---------
>  1 file changed, 3 insertions(+), 9 deletions(-)

applied to mips-next.

Thomas.

-- 
Crap can work. Given enough thrust pigs will fly, but it's not necessarily a
good idea.                                                [ RFC1925, 2.3 ]