| Message ID | E1V51J5-0006uq-1h@rmk-PC.arm.linux.org.uk (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Aug 1, 2013 at 5:25 PM, Santosh Shilimkar <santosh.shilimkar@ti.com> wrote: > Most of the kernel code assumes that max*pfn is maximum pfns because > the physical start of memory is expected to be PFN0. Since this > assumption is not true on ARM architectures, the meaning of max*pfn > is number of memory pages. This is done to keep drivers happy which > are making use of of these variable to calculate the dma bounce limit > using dma_mask. > > Now since we have a architecture override possibility for DMAable > maximum pfns, lets make meaning of max*pfns as maximum pnfs on ARM > as well. > > Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com> > Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk> > --- > arch/arm/include/asm/dma-mapping.h | 8 ++++++++ > arch/arm/mm/init.c | 10 ++++------ > 2 files changed, 12 insertions(+), 6 deletions(-) > > diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h > index 5b579b9..863cd84 100644 > --- a/arch/arm/include/asm/dma-mapping.h > +++ b/arch/arm/include/asm/dma-mapping.h > @@ -64,6 +64,7 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) > { > return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); > } > + > #else > static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn) > { > @@ -86,6 +87,13 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) > } > #endif > > +/* The ARM override for dma_max_pfn() */ > +static inline unsigned long dma_max_pfn(struct device *dev) > +{ > + return PHYS_PFN_OFFSET + dma_to_pfn(dev, *dev->dma_mask); Do we need to handle dev == NULL case? Rob
On Mon, Aug 05, 2013 at 10:15:11PM -0500, Rob Herring wrote: > On Thu, Aug 1, 2013 at 5:25 PM, Santosh Shilimkar > <santosh.shilimkar@ti.com> wrote: > > +/* The ARM override for dma_max_pfn() */ > > +static inline unsigned long dma_max_pfn(struct device *dev) > > +{ > > + return PHYS_PFN_OFFSET + dma_to_pfn(dev, *dev->dma_mask); > > Do we need to handle dev == NULL case? No, look at where it's used and the code it's replacing. You'll find that its callsites handle the dev = NULL case.
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h index 5b579b9..863cd84 100644 --- a/arch/arm/include/asm/dma-mapping.h +++ b/arch/arm/include/asm/dma-mapping.h @@ -64,6 +64,7 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) { return (dma_addr_t)__virt_to_bus((unsigned long)(addr)); } + #else static inline dma_addr_t pfn_to_dma(struct device *dev, unsigned long pfn) { @@ -86,6 +87,13 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr) } #endif +/* The ARM override for dma_max_pfn() */ +static inline unsigned long dma_max_pfn(struct device *dev) +{ + return PHYS_PFN_OFFSET + dma_to_pfn(dev, *dev->dma_mask); +} +#define dma_max_pfn(dev) dma_max_pfn(dev) + /* * DMA errors are defined by all-bits-set in the DMA address. */ diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c index b5b5836..2731dcf 100644 --- a/arch/arm/mm/init.c +++ b/arch/arm/mm/init.c @@ -422,12 +422,10 @@ void __init bootmem_init(void) * This doesn't seem to be used by the Linux memory manager any * more, but is used by ll_rw_block. If we can get rid of it, we * also get rid of some of the stuff above as well. - * - * Note: max_low_pfn and max_pfn reflect the number of _pages_ in - * the system, not the maximum PFN. */ - max_low_pfn = max_low - PHYS_PFN_OFFSET; - max_pfn = max_high - PHYS_PFN_OFFSET; + min_low_pfn = min; + max_low_pfn = max_low; + max_pfn = max_high; } /* @@ -533,7 +531,7 @@ static inline void free_area_high(unsigned long pfn, unsigned long end) static void __init free_highpages(void) { #ifdef CONFIG_HIGHMEM - unsigned long max_low = max_low_pfn + PHYS_PFN_OFFSET; + unsigned long max_low = max_low_pfn; struct memblock_region *mem, *res; /* set highmem page free */