Messages in this thread | | | Date | Fri, 2 Sep 2011 13:12:06 +0800 | Subject | Re: [PATCH] EFI: Do not use __pa() to get the physical address of an ioremapped memory range | From | huang ying <> |
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On Thu, Sep 1, 2011 at 8:28 PM, Matt Fleming <matt@console-pimps.org> wrote: > On Thu, 2011-09-01 at 16:14 +0800, Zhang Rui wrote: >> On Thu, 2011-09-01 at 14:55 +0800, Zhang, Rui wrote: >> > From: Zhang Rui <rui.zhang@intel.com> >> > Date: Wed, 31 Aug 2011 09:59:01 +0800 >> > Subject: Do not use __pa() to get the physical address of an ioremapped memory range. >> > >> > set_memory_uc uses __pa() to translate the virtual address to the physical address. >> > This breaks a EFI_MEMORY_MAPPED_IO memory region in my case as it was ioremapped first. >> > >> oops, wrong patch was attached. >> >> here is the correct patch. >> >> From: Zhang Rui <rui.zhang@intel.com> >> Date: Wed, 31 Aug 2011 09:59:01 +0800 >> Subject: Do not use __pa() to get the physical address of an ioremapped memory range. >> >> set_memory_uc uses __pa() to translate the virtual address to the physical address. >> This breaks a EFI_MEMORY_MAPPED_IO memory region in my case as it was ioremapped first. > > Hmm.. does anyone know why we ioremap_cache() the memory on > CONFIG_X86_32 instead of ioremap_nocache()? In the case of > EFI_MEMORY_MAPPED_IO the memory really needs to be uncached. Then if > we've ioremap'd the memory we should skip set_memory_uc() altogether, > no?
Because whether the mapping should be cached is determined by md->attr instead of md->type. And besides UC, we may add WC, etc support.
Best Regards, Huang Ying
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