Messages in this thread | | | Date | Fri, 11 Nov 2011 11:46:14 +0000 | From | Catalin Marinas <> | Subject | Re: [PATCH v8 16/16] ARM: LPAE: Add the Kconfig entries |
| |
On Thu, Nov 10, 2011 at 10:57:37PM +0000, Russell King - ARM Linux wrote: > On Mon, Nov 07, 2011 at 04:16:58PM +0000, Catalin Marinas wrote: > > +config ARCH_PHYS_ADDR_T_64BIT > > + def_bool ARM_LPAE > > + > > +config ARCH_DMA_ADDR_T_64BIT > > + def_bool ARM_LPAE > > + > > I still say this shouldn't depend on the host page table format. LPAE > itself has nothing to do with whether 64-bit DMA addresses are supported > by the system.
So we could change this to:
config ARCH_DMA_ADDR_T_64BIT depends on ARM_LPAE
and let platforms select it.
The x86 approach is to have another HIGHMEM64G config option for systems with more than 4GB of RAM and ARCH_DMA_ADDR_T_64BIT is selected automatically. But this comes under the assumption that there is a 1:1 mapping between phys and bus addresses.
-- Catalin
| |