From: Miles Chen <[email protected]>
This change exports dma_alloc_from_contiguous and
dma_release_from_contiguous to modules.
Currently, we can add a reserve a memory node in dts files, make
it a CMA memory by setting compatible = "shared-dma-pool",
and setup the dev->cma_area by using of_reserved_mem_device_init_by_idx().
Export dma_alloc_from_contiguous and dma_release_from_contiguous, so we
can allocate/free from/to dev->cma_area in kernel modules.
Signed-off-by: Miles Chen <[email protected]>
---
kernel/dma/contiguous.c | 2 ++
1 file changed, 2 insertions(+)
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index b2a87905846d..d5920bdedc77 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -197,6 +197,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
}
+EXPORT_SYMBOL_GPL(dma_alloc_from_contiguous);
/**
* dma_release_from_contiguous() - release allocated pages
@@ -213,6 +214,7 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
{
return cma_release(dev_get_cma_area(dev), pages, count);
}
+EXPORT_SYMBOL_GPL(dma_release_from_contiguous);
/*
* Support for reserved memory regions defined in device tree
--
2.18.0
On 11/07/2019 06:33, [email protected] wrote:
> From: Miles Chen <[email protected]>
>
> This change exports dma_alloc_from_contiguous and
> dma_release_from_contiguous to modules.
>
> Currently, we can add a reserve a memory node in dts files, make
> it a CMA memory by setting compatible = "shared-dma-pool",
> and setup the dev->cma_area by using of_reserved_mem_device_init_by_idx().
>
> Export dma_alloc_from_contiguous and dma_release_from_contiguous, so we
> can allocate/free from/to dev->cma_area in kernel modules.
As far as I understand, this was never intended for drivers to call
directly. If a device has its own private CMA area, then regular
dma_alloc_attrs() should allocate from that automatically; if that's not
happening already, then there's a bug somewhere.
Robin.
> Signed-off-by: Miles Chen <[email protected]>
> ---
> kernel/dma/contiguous.c | 2 ++
> 1 file changed, 2 insertions(+)
>
> diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> index b2a87905846d..d5920bdedc77 100644
> --- a/kernel/dma/contiguous.c
> +++ b/kernel/dma/contiguous.c
> @@ -197,6 +197,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
>
> return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
> }
> +EXPORT_SYMBOL_GPL(dma_alloc_from_contiguous);
>
> /**
> * dma_release_from_contiguous() - release allocated pages
> @@ -213,6 +214,7 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
> {
> return cma_release(dev_get_cma_area(dev), pages, count);
> }
> +EXPORT_SYMBOL_GPL(dma_release_from_contiguous);
>
> /*
> * Support for reserved memory regions defined in device tree
>
On Thu, Jul 11, 2019 at 09:50:58AM +0100, Robin Murphy wrote:
> On 11/07/2019 06:33, [email protected] wrote:
>> From: Miles Chen <[email protected]>
>>
>> This change exports dma_alloc_from_contiguous and
>> dma_release_from_contiguous to modules.
>>
>> Currently, we can add a reserve a memory node in dts files, make
>> it a CMA memory by setting compatible = "shared-dma-pool",
>> and setup the dev->cma_area by using of_reserved_mem_device_init_by_idx().
>>
>> Export dma_alloc_from_contiguous and dma_release_from_contiguous, so we
>> can allocate/free from/to dev->cma_area in kernel modules.
>
> As far as I understand, this was never intended for drivers to call
> directly. If a device has its own private CMA area, then regular
> dma_alloc_attrs() should allocate from that automatically; if that's not
> happening already, then there's a bug somewhere.
Agreed.
On Thu, 2019-07-11 at 09:50 +0100, Robin Murphy wrote:
> On 11/07/2019 06:33, [email protected] wrote:
> > From: Miles Chen <[email protected]>
> >
> > This change exports dma_alloc_from_contiguous and
> > dma_release_from_contiguous to modules.
> >
> > Currently, we can add a reserve a memory node in dts files, make
> > it a CMA memory by setting compatible = "shared-dma-pool",
> > and setup the dev->cma_area by using of_reserved_mem_device_init_by_idx().
> >
> > Export dma_alloc_from_contiguous and dma_release_from_contiguous, so we
> > can allocate/free from/to dev->cma_area in kernel modules.
>
> As far as I understand, this was never intended for drivers to call
> directly. If a device has its own private CMA area, then regular
> dma_alloc_attrs() should allocate from that automatically; if that's not
> happening already, then there's a bug somewhere.
>
> Robin.
Thanks for your comment.
After using dma_direct_ops, dma_alloc_attrs() works fine now.
Miles
>
> > Signed-off-by: Miles Chen <[email protected]>
> > ---
> > kernel/dma/contiguous.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
> > index b2a87905846d..d5920bdedc77 100644
> > --- a/kernel/dma/contiguous.c
> > +++ b/kernel/dma/contiguous.c
> > @@ -197,6 +197,7 @@ struct page *dma_alloc_from_contiguous(struct device *dev, size_t count,
> >
> > return cma_alloc(dev_get_cma_area(dev), count, align, no_warn);
> > }
> > +EXPORT_SYMBOL_GPL(dma_alloc_from_contiguous);
> >
> > /**
> > * dma_release_from_contiguous() - release allocated pages
> > @@ -213,6 +214,7 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
> > {
> > return cma_release(dev_get_cma_area(dev), pages, count);
> > }
> > +EXPORT_SYMBOL_GPL(dma_release_from_contiguous);
> >
> > /*
> > * Support for reserved memory regions defined in device tree
> >