9os

commit fcc54cb0d2de6d363e9bcf39d085ddc61960c451
parent d120ce85422a76ce88a6f9be7d5123bc42bb21b5
Author: Roberto E. Vargas Caballero <k0ga@shike2.com>
Date:   Sun,  1 Nov 2020 10:00:03 +0100

os9/arm64: Convert between physical and virtual mem

When we deal with the page table we have to be careful of
transforming between physical and virtual memory.

Change-Id: If8999b5d837d92c390d2f886e3847b33eabea987

Diffstat:
M
include/os9/os9.h
 | 
2
++
M
src/os9/arch/arm64/mmu.c
 | 
22
+++++++++++++---------
M
src/os9/arch/arm64/trap.c
 | 
2
+-

3 files changed, 16 insertions(+), 10 deletions(-)
diff --git a/include/os9/os9.h b/include/os9/os9.h
@@ -24,6 +24,8 @@
 #define MiB (1024u * KiB)
 #define GiB (1024ul * MiB)
 
+#define VMEM(x) ((void *) ((char *) (x) + mach.kzero))
+#define PMEM(x) ((void *) ((char *) (x) - mach.kzero))
 #define PAGESIZE (4 * KiB)
 #define ENABLE   1
 #define DISABLE  0
diff --git a/src/os9/arch/arm64/mmu.c b/src/os9/arch/arm64/mmu.c
@@ -139,13 +139,16 @@
 int inlowmem = 1;
 
 static pte_t
-newpage(void)
+newtable(void)
 {
-	void *bp;
+	char *bp;
 
 	bp = allocb(1);
 	memset(bp, 0, PAGESIZE);
 
+	if (!inlowmem)
+		bp = PMEM(bp);
+
 	return (pte_t) bp;
 }
 
@@ -165,11 +168,13 @@ walker(uintptr_t va)
 
 		e = bp[n];
 		if (e == INVALID) {
-			e = newpage();
+			e = newtable();
 			bp[n] = e | TABLE;
 			barrier(DATA);
 		}
 		bp = (pte_t *) MASK(e);
+		if (!inlowmem)
+			bp = VMEM(bp);
 	}
 
 	return &bp[TINDEX(3, va)];
@@ -237,12 +242,11 @@ mapseg(Map *mp)
 	pa = mp->pa;	
 	va = mp->va;
 
-	n =  (mp->siz + 4*KiB-1)/(4*KiB);
-
+	n =  (mp->siz + PAGESIZE-1)/PAGESIZE;
 	for (i = 0; i < n; i++) {
 		vmap(pa, va, mp->perm);
-		pa += 4*KiB;
-		va += 4*KiB;
+		pa += PAGESIZE;
+		va += PAGESIZE;
 	}
 }
 
@@ -278,7 +282,7 @@ kernelmap(void)
 	 * FIXME: We are using a full page when
 	 * we only need 16 bytes with 16 byte alignment.
 	 */
-	syswr(TTBR1_EL1, newpage());
+	syswr(TTBR1_EL1, newtable());
 
 	dbg("TTBR1_EL1=%llx\n", sysrd(TTBR1_EL1));
 
@@ -302,7 +306,7 @@ initmap(void)
 	syswr(TCR_EL1, tcr);
 	barrier(CODE);
 
-	tbl = newpage();
+	tbl = newtable();
 	bp = (pte_t *) tbl;
 	for (pa = 0; pa < 4*GiB; pa += 1*GiB)
 		*bp++ = pa | attr;
diff --git a/src/os9/arch/arm64/trap.c b/src/os9/arch/arm64/trap.c
@@ -24,7 +24,7 @@ trap(Context *ctx)
 	if (ec != SVC || inlowmem) {
 		msg = (ec < NR_EC_VALS) ? ecstr[ec] : "unknown reason";
 		if (inlowmem)
-			msg -= mach.kzero;
+			msg = PMEM(msg);
 		fault(msg, ctx);
 	}