On Thu, Mar 6, 2014 at 3:19 AM, Santosh Shilimkar
<santosh.shilimkar@xxxxxx> wrote:
> The of_dma_is_coherent() helper parses the given DT device
> node to see if the "dma-coherent" property is supported and
> returns true or false accordingly.
>
> For the architectures which are fully dma coherent and don't need per device
> property, it can enable CONFIG_ARCH_IS_DMA_COHERENT config option which
> enables DMA coherent for all devices by default.
This worries me. I killed off arch_is_coherent() for arm. Now we're
adding something back. Also, we already have HAVE_GENERIC_DMA_COHERENT
which is different, but the names will be confusing. MIPS also has
DMA_NONCOHERENT.
>
> Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
> Cc: Russell King <linux@xxxxxxxxxxxxxxxx>
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Olof Johansson <olof@xxxxxxxxx>
> Cc: Grant Likely <grant.likely@xxxxxxxxxx>
> Cc: Rob Herring <robh+dt@xxxxxxxxxx>
> Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
> Cc: Linus Walleij <linus.walleij@xxxxxxxxxx>
> Signed-off-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> ---
> drivers/of/platform.c | 31 +++++++++++++++++++++++++++++++
> include/linux/of_platform.h | 6 ++++++
> 2 files changed, 37 insertions(+)
>
> diff --git a/drivers/of/platform.c b/drivers/of/platform.c
> index 2265a55..bd080db 100644
> --- a/drivers/of/platform.c
> +++ b/drivers/of/platform.c
> @@ -570,4 +570,35 @@ out:
> return ret;
> }
> EXPORT_SYMBOL_GPL(of_dma_get_range);
> +
> +/**
> + * of_dma_is_coherent - Check if device is coherent
> + * @np: device node
> + *
> + * It returns true if "dma-coherent" property was found
> + * for this device in DT.
> + */
> +#ifndef CONFIG_ARCH_IS_DMA_COHERENT
> +bool of_dma_is_coherent(struct device_node *np)
> +{
> + struct device_node *node = np;
> +
> + while (node) {
This screams for a for_each_parent_of_node helper.
> + if (of_property_read_bool(node, "dma-coherent")) {
> + of_node_put(node);
> + return true;
> + }
> + node = of_get_next_parent(node);
> + }
> + return false;
> +}
> +EXPORT_SYMBOL_GPL(of_dma_is_coherent);
> +#else
> +inline bool of_dma_is_coherent(struct device_node *np)
This is in the header and should not be here.
> +{
> + /* ARCH is fully dma coherent and don't need per device control */
> + return true;
> +}
> +EXPORT_SYMBOL_GPL(of_dma_is_coherent);
> +#endif
> #endif /* CONFIG_OF_ADDRESS */
> diff --git a/include/linux/of_platform.h b/include/linux/of_platform.h
> index ba7d3dc..48e0748 100644
> --- a/include/linux/of_platform.h
> +++ b/include/linux/of_platform.h
> @@ -74,6 +74,7 @@ extern int of_platform_populate(struct device_node *root,
> struct device *parent);
> extern int of_dma_get_range(struct device_node *np, dma_addr_t *dma_addr,
> phys_addr_t *paddr, phys_addr_t *size);
> +extern bool of_dma_is_coherent(struct device_node *np);
> #else
> static inline int of_platform_populate(struct device_node *root,
> const struct of_device_id *matches,
> @@ -88,6 +89,11 @@ static inline int of_dma_get_range(struct device_node *np, dma_addr_t *dma_addr,
> {
> return -ENODEV;
> }
> +
> +static inline bool of_dma_is_coherent(struct device_node *np)
> +{
> + return false;
> +}
> #endif
I don't think you have the ifdefs right here.
Rob
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