Messages in this thread | | | Date | Thu, 14 Mar 2013 16:05:27 -0700 | From | Laura Abbott <> | Subject | gen_pool_add broken with LPAE based systems |
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Hi,
We use genalloc for managing certain pools of physical memory. genalloc currently uses unsigned long for virtual addresses and phys_addr_t for physical addresses. Our ARM LPAE systems have 64-bit physical addresses but unsigned long is still 32 bits. Using gen_pool_add breaks with addresses > 4G because gen_pool_add treats the address passed in as the virtual address. gen_pool allocates internally based on the 32 bit virtual address as well so everything is broken if we want to be able to manage the full address space after 4G. I see a couple of options:
1) Change gen_pool_add to use physical addresses and allocate based on physical addresses instead of virtual addresses 2) Change the virtual address to be a 64 bit type or something selectable to a 64 bit type. 3) Allow a flag per pool to select whether the allocator is virtual or physical and switch between those. 4) Split the APIs into virtual <-> physical and physical only and have separate types for each.
Any of these suggestions seem reasonable or is there another option to consider?
Thanks, Laura -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, hosted by The Linux Foundation
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