9os

commit c32c2be34af08d1916382f329931866548e5cded
parent aff04880be7d7c5e6ee9efcfec213d12148c99bd
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sat, 24 Oct 2020 09:25:07 +0200

os9/arm64: Improve break-before-make

This implementation ensures the correct break-before-make.

Change-Id: I2c7b79bc6b583e0c4890b7981da8727b6876994c

Diffstat:
M
src/os9/arch/arm64/arch.s
 | 
1
-
M
src/os9/arch/arm64/mmu.c
 | 
6
+++---

2 files changed, 3 insertions(+), 4 deletions(-)
diff --git a/src/os9/arch/arm64/arch.s b/src/os9/arch/arm64/arch.s
@@ -39,7 +39,6 @@ invtlb:
 	LSR	X9,X0,#12
 	DSB	ISHST
 	TLBI	VAE1,X9
-//	DC	CVAU,X0	// FIXME: line commented because it generates an exception
 	DSB	ISH
 	RET
 
diff --git a/src/os9/arch/arm64/mmu.c b/src/os9/arch/arm64/mmu.c
@@ -183,6 +183,7 @@ vmap(phyaddr_t pa, uintptr_t va, int perm)
 		attr |= EL0;
 
 	/*
+	 * TODO: It does not need locking, it needs a exclusive load
 	 * locking is needed if we are in a system
 	 * with SMMUv3 and page tables are shared.
 	 */
@@ -195,13 +196,12 @@ vmap(phyaddr_t pa, uintptr_t va, int perm)
 	 * in multi processor systems.
 	 */
 	*p = INVALID;
+	invtlb(va);
 	barrier(DATA);
+	barrier(CODE);
 
 	*p = MASK(pa) | attr;
 	barrier(DATA);
-	barrier(CODE);
-
-	invtlb(va);
 	unlock(&m);
 
 	dbg("page %p: %llx\n", p, MASK(pa) | attr);