[PATCH v1 01/13] arm64: mm: Re-implement the __tlbi_level macro as a C function

Ryan Roberts posted 13 patches 2 days, 8 hours ago
[PATCH v1 01/13] arm64: mm: Re-implement the __tlbi_level macro as a C function
Posted by Ryan Roberts 2 days, 8 hours ago
As part of efforts to reduce our reliance on complex preprocessor macros
for TLB invalidation routines, convert the __tlbi_level macro to a C
function for by-level TLB invalidation.

Each specific tlbi level op is implemented as a C function and the
appropriate function pointer is passed to __tlbi_level(). Since
everything is declared inline and is statically resolvable, the compiler
will convert the indirect function call to a direct inline execution.

Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
 arch/arm64/include/asm/tlbflush.h | 69 +++++++++++++++++++++++++------
 1 file changed, 56 insertions(+), 13 deletions(-)

diff --git a/arch/arm64/include/asm/tlbflush.h b/arch/arm64/include/asm/tlbflush.h
index a2d65d7d6aae..13a59cf28943 100644
--- a/arch/arm64/include/asm/tlbflush.h
+++ b/arch/arm64/include/asm/tlbflush.h
@@ -105,19 +105,62 @@ static inline unsigned long get_trans_granule(void)
 
 #define TLBI_TTL_UNKNOWN	INT_MAX
 
-#define __tlbi_level(op, addr, level) do {				\
-	u64 arg = addr;							\
-									\
-	if (alternative_has_cap_unlikely(ARM64_HAS_ARMv8_4_TTL) &&	\
-	    level >= 0 && level <= 3) {					\
-		u64 ttl = level & 3;					\
-		ttl |= get_trans_granule() << 2;			\
-		arg &= ~TLBI_TTL_MASK;					\
-		arg |= FIELD_PREP(TLBI_TTL_MASK, ttl);			\
-	}								\
-									\
-	__tlbi(op, arg);						\
-} while(0)
+typedef void (*tlbi_op)(u64 arg);
+
+static __always_inline void vae1is(u64 arg)
+{
+	__tlbi(vae1is, arg);
+}
+
+static __always_inline void vae2is(u64 arg)
+{
+	__tlbi(vae2is, arg);
+}
+
+static __always_inline void vale1(u64 arg)
+{
+	__tlbi(vale1, arg);
+	__tlbi_user(vale1, arg);
+}
+
+static __always_inline void vale1is(u64 arg)
+{
+	__tlbi(vale1is, arg);
+}
+
+static __always_inline void vale2is(u64 arg)
+{
+	__tlbi(vale2is, arg);
+}
+
+static __always_inline void vaale1is(u64 arg)
+{
+	__tlbi(vaale1is, arg);
+}
+
+static __always_inline void ipas2e1(u64 arg)
+{
+	__tlbi(ipas2e1, arg);
+}
+
+static __always_inline void ipas2e1is(u64 arg)
+{
+	__tlbi(ipas2e1is, arg);
+}
+
+static __always_inline void __tlbi_level(tlbi_op op, u64 addr, u32 level)
+{
+	u64 arg = addr;
+
+	if (alternative_has_cap_unlikely(ARM64_HAS_ARMv8_4_TTL) && level <= 3) {
+		u64 ttl = level | (get_trans_granule() << 2);
+
+		arg &= ~TLBI_TTL_MASK;
+		arg |= FIELD_PREP(TLBI_TTL_MASK, ttl);
+	}
+
+	op(arg);
+}
 
 #define __tlbi_user_level(op, arg, level) do {				\
 	if (arm64_kernel_unmapped_at_el0())				\
-- 
2.43.0
Re: [PATCH v1 01/13] arm64: mm: Re-implement the __tlbi_level macro as a C function
Posted by Jonathan Cameron 2 days, 5 hours ago
On Tue, 16 Dec 2025 14:45:46 +0000
Ryan Roberts <ryan.roberts@arm.com> wrote:

> As part of efforts to reduce our reliance on complex preprocessor macros
> for TLB invalidation routines, convert the __tlbi_level macro to a C
> function for by-level TLB invalidation.
> 
> Each specific tlbi level op is implemented as a C function and the
> appropriate function pointer is passed to __tlbi_level(). Since
> everything is declared inline and is statically resolvable, the compiler
> will convert the indirect function call to a direct inline execution.
> 
> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
> ---

> +static __always_inline void __tlbi_level(tlbi_op op, u64 addr, u32 level)
> +{
> +	u64 arg = addr;
> +
> +	if (alternative_has_cap_unlikely(ARM64_HAS_ARMv8_4_TTL) && level <= 3) {
> +		u64 ttl = level | (get_trans_granule() << 2);
> +
> +		arg &= ~TLBI_TTL_MASK;
> +		arg |= FIELD_PREP(TLBI_TTL_MASK, ttl);

Probably don't care, but I think you could do
		FIELD_MODIFY(TLBI_TTL_MASK, &arg, ttl);
instead of those two lines. Code generation hopefully similar?
So depends on which macros you find more readable.

> +	}
> +
> +	op(arg);
> +}
>  
>  #define __tlbi_user_level(op, arg, level) do {				\
>  	if (arm64_kernel_unmapped_at_el0())				\