From: Julien Grall Date: Fri, 7 Aug 2015 16:34:36 +0000 (+0100) Subject: arm/xen: implement correctly pfn_to_mfn X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=5192b35de47e47a0f736fe30da199f32030680e7;p=GitHub%2Fmoto-9609%2Fandroid_kernel_motorola_exynos9610.git arm/xen: implement correctly pfn_to_mfn After the commit introducing convertion between DMA and guest addresses, all the callers of pfn_to_mfn are expecting to get a GFN (Guest Frame Number). On ARM, all the guests are auto-translated so the GFN is equal to the Linux PFN (Pseudo-physical Frame Number). The current implementation may return an MFN if the caller is passing a PFN associated to a mapped foreign grant. In pratice, I haven't seen the problem on running guest but we should fix it for the sake of correctness. Correct the implementation by always returning the pfn passed in parameter. A follow-up patch will take care to rename pfn_to_mfn to a suitable name. Signed-off-by: Julien Grall Reviewed-by: Stefano Stabellini Signed-off-by: David Vrabel --- diff --git a/arch/arm/include/asm/xen/page.h b/arch/arm/include/asm/xen/page.h index 5f76a9e7ef1b..911d62b4df26 100644 --- a/arch/arm/include/asm/xen/page.h +++ b/arch/arm/include/asm/xen/page.h @@ -36,14 +36,6 @@ extern struct rb_root phys_to_mach; static inline unsigned long pfn_to_mfn(unsigned long pfn) { - unsigned long mfn; - - if (phys_to_mach.rb_node != NULL) { - mfn = __pfn_to_mfn(pfn); - if (mfn != INVALID_P2M_ENTRY) - return mfn; - } - return pfn; }