[PATCHv4 17/18] x86/mm: Handle encrypted memory in page_to_virt() and __pa()

["Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>]

Per-KeyID direct mappings require changes into how we find the right
virtual address for a page and virt-to-phys address translations.

page_to_virt() definition overwrites default macros provided by
<linux/mm.h>. We only overwrite the macros if MTKME is enabled
compile-time.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
---
 arch/x86/include/asm/mktme.h   | 3 +++
 arch/x86/include/asm/page_64.h | 2 +-
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/mktme.h b/arch/x86/include/asm/mktme.h
index ba83fba4f9b3..dbfbd955da98 100644
--- a/arch/x86/include/asm/mktme.h
+++ b/arch/x86/include/asm/mktme.h
@@ -29,6 +29,9 @@ void arch_free_page(struct page *page, int order);
 
 int sync_direct_mapping(void);
 
+#define page_to_virt(x) \
+	(__va(PFN_PHYS(page_to_pfn(x))) + page_keyid(x) * direct_mapping_size)
+
 #else
 #define mktme_keyid_mask	((phys_addr_t)0)
 #define mktme_nr_keyids		0
diff --git a/arch/x86/include/asm/page_64.h b/arch/x86/include/asm/page_64.h
index 53c32af895ab..ffad496aadad 100644
--- a/arch/x86/include/asm/page_64.h
+++ b/arch/x86/include/asm/page_64.h
@@ -23,7 +23,7 @@ static inline unsigned long __phys_addr_nodebug(unsigned long x)
 	/* use the carry flag to determine if x was < __START_KERNEL_map */
 	x = y + ((x > y) ? phys_base : (__START_KERNEL_map - PAGE_OFFSET));
 
-	return x;
+	return x % direct_mapping_size;
 }
 
 #ifdef CONFIG_DEBUG_VIRTUAL
-- 
2.18.0