Hi Catalin,

On Mon, Aug 05, 2019 at 06:26:43PM +0100, Catalin Marinas wrote:

On Mon, Jul 29, 2019 at 05:21:12PM +0100, Steve Capper wrote:

quoted

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index a8a91a573bff..93341f4fe840 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h

@@ -37,8 +37,6 @@
  * VA_START - the first kernel virtual address.
  */
 #define VA_BITS			(CONFIG_ARM64_VA_BITS)
-#define VA_START		(UL(0xffffffffffffffff) - \
-	(UL(1) << (VA_BITS - 1)) + 1)
 #define PAGE_OFFSET		(UL(0xffffffffffffffff) - \
 	(UL(1) << VA_BITS) + 1)
 #define KIMAGE_VADDR		(MODULES_END)

@@ -166,10 +164,14 @@
 #endif
 
 #ifndef __ASSEMBLY__
+extern u64			vabits_actual;
+#define VA_BITS_ACTUAL		({vabits_actual;})

Why not use the variable vabits_actual directly instead of defining a
macro?

I thought that it would look better to have an uppercase name for the
actual VA bits to match the existing code style for VA_BITS.

I can just rename vabits_actual => VA_BITS_ACTUAL and get rid of the
macro?

quoted

diff --git a/arch/arm64/kernel/head.S b/arch/arm64/kernel/head.S
index ac58c69993ec..6dc7349868d9 100644
--- a/arch/arm64/kernel/head.S
+++ b/arch/arm64/kernel/head.S

@@ -321,6 +321,11 @@ __create_page_tables:
 	dmb	sy
 	dc	ivac, x6		// Invalidate potentially stale cache line
 
+	adr_l	x6, vabits_actual
+	str	x5, [x6]
+	dmb	sy
+	dc	ivac, x6		// Invalidate potentially stale cache line

Can we not replace vabits_user with vabits_actual and have a single
write? Maybe not in this patch but once the series is applied, they are
practically the same. It could be an additional patch (or define a
vabits_user macro as vabits_actual).

Thanks, I think it may be better to consolidate these in an extra patch (just
before the documentation patch). I'll add this to the series.

Cheers,
-- 
Steve

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