[PATCH v2 2/6] arm64: Add level-hinted TLB invalidation helper

From: Zhenyu Ye
Date: Thu Apr 23 2020 - 09:59:59 EST


From: Marc Zyngier <maz@xxxxxxxxxx>

Add a level-hinted TLB invalidation helper that only gets used if
ARMv8.4-TTL gets detected.

When ARMv8.4-TTL is implemented, the operand for TLBIs looks like
below:

* +----------+-------+----------------------+
* | ASID | TTL | BADDR |
* +----------+-------+----------------------+
* |63 48|47 44|43 0|

Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
Signed-off-by: Zhenyu Ye <yezhenyu2@xxxxxxxxxx>
---
arch/arm64/include/asm/tlbflush.h | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index bc3949064725..5f9f189bc6d2 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -10,6 +10,7 @@

#ifndef __ASSEMBLY__

+#include <linux/bitfield.h>
#include <linux/mm_types.h>
#include <linux/sched.h>
#include <asm/cputype.h>
@@ -59,6 +60,35 @@
__ta; \
})

+#define TLBI_TTL_MASK GENMASK_ULL(47, 44)
+
+#define __tlbi_level(op, addr, level) \
+ do { \
+ u64 arg = addr; \
+ \
+ if (cpus_have_const_cap(ARM64_HAS_ARMv8_4_TTL) && \
+ level) { \
+ u64 ttl = level; \
+ \
+ switch (PAGE_SIZE) { \
+ case SZ_4K: \
+ ttl |= 1 << 2; \
+ break; \
+ case SZ_16K: \
+ ttl |= 2 << 2; \
+ break; \
+ case SZ_64K: \
+ ttl |= 3 << 2; \
+ break; \
+ } \
+ \
+ arg &= ~TLBI_TTL_MASK; \
+ arg |= FIELD_PREP(TLBI_TTL_MASK, ttl); \
+ } \
+ \
+ __tlbi(op, arg); \
+ } while (0)
+
/*
* TLB Invalidation
* ================
--
2.19.1