| Message ID | 20190711053343.28873-1-miles.chen@mediatek.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | kernel/dma: export dma_alloc_from_contiguous to modules | expand |
On 11/07/2019 06:33, miles.chen@mediatek.com wrote: > From: Miles Chen <miles.chen@mediatek.com> > > 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 <miles.chen@mediatek.com> > --- > 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, miles.chen@mediatek.com wrote: >> From: Miles Chen <miles.chen@mediatek.com> >> >> 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, miles.chen@mediatek.com wrote: > > From: Miles Chen <miles.chen@mediatek.com> > > > > 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 <miles.chen@mediatek.com> > > --- > > 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 > >
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