2 messages, 2 authors, 2016-06-30 · open the first message on its own page
From: Masahiro Yamada <hidden>
Date: 2016-06-30 11:10:42
Hello. Which memory attribute will ARM/ARM64 Linux set to the memory region reserved by /memreserve/ of Device Tree? Normal memory non-cacheable? Or, cacheable? Or, not defined? Perhaps actual behavior depends on whether the reserved area is located in the low-memory region? Thanks, -- Best Regards Masahiro Yamada
From: Robin Murphy <robin.murphy@arm.com>
Date: 2016-06-30 11:39:03
On 30/06/16 12:10, Masahiro Yamada wrote:
Hello. Which memory attribute will ARM/ARM64 Linux set to the memory region reserved by /memreserve/ of Device Tree? Normal memory non-cacheable? Or, cacheable? Or, not defined? Perhaps actual behavior depends on whether the reserved area is located in the low-memory region?
Isn't the point of memreserve that the kernel avoids mapping it at all? If a reserved region is later mapped in by a driver using dma_declare_coherent_memory(), ioremap(), memremap() or whatever else, then the attributes will vary depending on the exact method used. Robin.
Thanks,