[PATCH 7/7] of: address: Use dma_default_coherent to determine default coherency

[Jiaxun Yang]

As for now all arches have dma_default_coherent matched with default
DMA coherency for of devices, so there is no need to have a standalone
config option.

This also fixes a case that for some MIPS platforms, coherency information
is not carried in devicetree and kernel will override dma_default_coherent
at early boot.

Note for PowerPC: CONFIG_OF_DMA_DEFUALT_COHERENT was only selected when
CONFIG_NOT_COHERENT_CACHE is false, in this case dma_default_coherent will
be ture, so we don't need to select CONFIG_ARCH_DMA_DEFAULT_COHERENT for
PowerPC.

Signed-off-by: Jiaxun Yang <jiaxun.y...@flygoat.com>
---
 arch/powerpc/Kconfig | 1 -
 arch/riscv/Kconfig   | 1 -
 drivers/of/Kconfig   | 4 ----
 drivers/of/address.c | 2 +-
 4 files changed, 1 insertion(+), 7 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a27fea39413e..2cfee7ba2e6a 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -271,7 +271,6 @@ config PPC
        select NEED_PER_CPU_PAGE_FIRST_CHUNK    if PPC64
        select NEED_SG_DMA_LENGTH
        select OF
-       select OF_DMA_DEFAULT_COHERENT          if !NOT_COHERENT_CACHE
        select OF_EARLY_FLATTREE
        select OLD_SIGACTION                    if PPC32
        select OLD_SIGSUSPEND
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index c1327309e0f6..e69e69b9cfd4 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -120,7 +120,6 @@ config RISCV
        select MODULES_USE_ELF_RELA if MODULES
        select MODULE_SECTIONS if MODULES
        select OF
-       select OF_DMA_DEFAULT_COHERENT
        select OF_EARLY_FLATTREE
        select OF_IRQ
        select PCI_DOMAINS_GENERIC if PCI
diff --git a/drivers/of/Kconfig b/drivers/of/Kconfig
index 80b5fd44ab1c..e040837e5537 100644
--- a/drivers/of/Kconfig
+++ b/drivers/of/Kconfig
@@ -90,8 +90,4 @@ config OF_OVERLAY
 config OF_NUMA
        bool
 
-config OF_DMA_DEFAULT_COHERENT
-       # arches should select this if DMA is coherent by default for OF devices
-       bool
-
 endif # OF
diff --git a/drivers/of/address.c b/drivers/of/address.c
index c34ac33b7338..8e17adb10f20 100644
--- a/drivers/of/address.c
+++ b/drivers/of/address.c
@@ -1053,7 +1053,7 @@ phys_addr_t __init of_dma_get_max_cpu_address(struct 
device_node *np)
 bool of_dma_is_coherent(struct device_node *np)
 {
        struct device_node *node;
-       bool is_coherent = IS_ENABLED(CONFIG_OF_DMA_DEFAULT_COHERENT);
+       bool is_coherent = dma_default_coherent;
 
        node = of_node_get(np);
 
-- 
2.37.1 (Apple Git-137.1)