powerpc/pseries/svm: Add helpers for UV_SHARE_PAGE and UV_UNSHARE_PAGE

These functions are used when the guest wants to grant the hypervisor
access to certain pages.
Signed-off-by: Ram Pai <linuxram@us.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190820021326.6884-6-bauerman@linux.ibm.com

arch/powerpc/include/asm/ultravisor-api.h

@@ -26,5 +26,7 @@
 #define UV_WRITE_PATE			0xF104
 #define UV_RETURN			0xF11C
 #define UV_ESM				0xF110
+#define UV_SHARE_PAGE			0xF130
+#define UV_UNSHARE_PAGE			0xF134
 
 #endif /* _ASM_POWERPC_ULTRAVISOR_API_H */

arch/powerpc/include/asm/ultravisor.h

@@ -31,4 +31,14 @@ static inline int uv_register_pate(u64 lpid, u64 dw0, u64 dw1)
 	return ucall_norets(UV_WRITE_PATE, lpid, dw0, dw1);
 }
 
+static inline int uv_share_page(u64 pfn, u64 npages)
+{
+	return ucall_norets(UV_SHARE_PAGE, pfn, npages);
+}
+
+static inline int uv_unshare_page(u64 pfn, u64 npages)
+{
+	return ucall_norets(UV_UNSHARE_PAGE, pfn, npages);
+}
+
 #endif	/* _ASM_POWERPC_ULTRAVISOR_H */