Re: [PATCH v2 03/10] DMA, CMA: separate core cma management codes from DMA APIs

Joonsoo Kim
2014-06-16T05:24:50Z

On Thu, Jun 12, 2014 at 02:37:43PM +0900, Minchan Kim wrote:
> On Thu, Jun 12, 2014 at 12:21:40PM +0900, Joonsoo Kim wrote:
> > To prepare future generalization work on cma area management code,
> > we need to separate core cma management codes from DMA APIs.
> > We will extend these core functions to cover requirements of
> > ppc kvm's cma area management functionality in following patches.
> > This separation helps us not to touch DMA APIs while extending
> > core functions.
> >
> > Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com>
> >
> > diff --git a/drivers/base/dma-contiguous.c b/drivers/base/dma-contiguous.c
> > index fb0cdce..8a44c82 100644
> > --- a/drivers/base/dma-contiguous.c
> > +++ b/drivers/base/dma-contiguous.c
> > @@ -231,9 +231,9 @@ core_initcall(cma_init_reserved_areas);
> > * If @fixed is true, reserve contiguous area at exactly @base. If false,
> > * reserve in range from @base to @limit.
> > */
> > -int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
> > - phys_addr_t limit, struct cma **res_cma,
> > - bool fixed)
> > +static int __init __dma_contiguous_reserve_area(phys_addr_t size,
> > + phys_addr_t base, phys_addr_t limit,
> > + struct cma **res_cma, bool fixed)
> > {
> > struct cma *cma = &cma_areas[cma_area_count];
> > phys_addr_t alignment;
> > @@ -288,16 +288,30 @@ int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
> >
> > pr_info("%s(): reserved %ld MiB at %08lx\n",
> > __func__, (unsigned long)size / SZ_1M, (unsigned long)base);
> > -
> > - /* Architecture specific contiguous memory fixup. */
> > - dma_contiguous_early_fixup(base, size);
> > return 0;
> > +
> > err:
> > pr_err("%s(): failed to reserve %ld MiB\n",
> > __func__, (unsigned long)size / SZ_1M);
> > return ret;
> > }
> >
> > +int __init dma_contiguous_reserve_area(phys_addr_t size, phys_addr_t base,
> > + phys_addr_t limit, struct cma **res_cma,
> > + bool fixed)
> > +{
> > + int ret;
> > +
> > + ret = __dma_contiguous_reserve_area(size, base, limit, res_cma, fixed);
> > + if (ret)
> > + return ret;
> > +
> > + /* Architecture specific contiguous memory fixup. */
> > + dma_contiguous_early_fixup(base, size);
>
> In old, base and size are aligned with alignment and passed into arch fixup
> but your patch is changing it.
> I didn't look at what kinds of side effect it makes but just want to confirm.

Good catch!!!
I will fix it.

> > +
> > + return 0;
> > +}
> > +
> > static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count)
> > {
> > mutex_lock(&cma->lock);
> > @@ -316,20 +330,16 @@ static void clear_cma_bitmap(struct cma *cma, unsigned long pfn, int count)
> > * global one. Requires architecture specific dev_get_cma_area() helper
> > * function.
> > */
> > -struct page *dma_alloc_from_contiguous(struct device *dev, int count,
> > +static struct page *__dma_alloc_from_contiguous(struct cma *cma, int count,
> > unsigned int align)
> > {
> > unsigned long mask, pfn, pageno, start = 0;
> > - struct cma *cma = dev_get_cma_area(dev);
> > struct page *page = NULL;
> > int ret;
> >
> > if (!cma || !cma->count)
> > return NULL;
> >
> > - if (align > CONFIG_CMA_ALIGNMENT)
> > - align = CONFIG_CMA_ALIGNMENT;
> > -
> > pr_debug("%s(cma %p, count %d, align %d)\n", __func__, (void *)cma,
> > count, align);
> >
> > @@ -377,6 +387,17 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
> > return page;
> > }
> >
>
> Please move the description in __dma_alloc_from_contiguous to here exported API.
>

Okay.

> > +struct page *dma_alloc_from_contiguous(struct device *dev, int count,
> > + unsigned int align)
> > +{
> > + struct cma *cma = dev_get_cma_area(dev);
> > +
> > + if (align > CONFIG_CMA_ALIGNMENT)
> > + align = CONFIG_CMA_ALIGNMENT;
> > +
> > + return __dma_alloc_from_contiguous(cma, count, align);
> > +}
> > +
> > /**
> > * dma_release_from_contiguous() - release allocated pages
> > * @dev: Pointer to device for which the pages were allocated.
> > @@ -387,10 +408,9 @@ struct page *dma_alloc_from_contiguous(struct device *dev, int count,
> > * It returns false when provided pages do not belong to contiguous area and
> > * true otherwise.
> > */
> > -bool dma_release_from_contiguous(struct device *dev, struct page *pages,
> > +static bool __dma_release_from_contiguous(struct cma *cma, struct page *pages,
> > int count)
> > {
> > - struct cma *cma = dev_get_cma_area(dev);
> > unsigned long pfn;
> >
> > if (!cma || !pages)
> > @@ -410,3 +430,11 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
> >
> > return true;
> > }
> > +
>
> Ditto.
>
Okay.

Thanks.