ref: f17a5cc2cf345921f9036e23dfd895a9ee68a0e5
parent: 2ee4c089741823aae794eaa2eb53780f65019981
author: cinap_lenrek <[email protected]>
date: Sun Oct 28 02:05:43 EDT 2018
bcm: fix l2 cache maintenance routines for raspi3 (armv8) armv8 has 16-way l2, so adjust shift for the set-way cache tag format.
--- a/sys/src/9/bcm/cache.v7.s
+++ b/sys/src/9/bcm/cache.v7.s
@@ -132,17 +132,6 @@
MOVW.P 8(R13), R15
/*
- * these shift values are for the Cortex-A8 L1 cache (A=2, L=6) and
- * the Cortex-A8 L2 cache (A=3, L=6).
- * A = log2(# of ways), L = log2(bytes per cache line).
- * see armv7 arch ref p. 1403.
- */
-#define L1WAYSH 30
-#define L1SETSH 6
-#define L2WAYSH 29
-#define L2SETSH 6
-
-/*
* callers are assumed to be the above l1 and l2 ops.
* R0 is the function to call in the innermost loop.
* R8 is the cache level (one-origin: 1 or 2).
@@ -184,11 +173,12 @@
ADD $1, R2 /* R2 (sets) = ((R0 >> 13) & MASK(15)) + 1 */
/* precompute set/way shifts for inner loop */
+ MOVW $6, R4
CMP $0, R8 /* cache == 1? */
- MOVW.EQ $L1WAYSH, R3 /* yes */
- MOVW.EQ $L1SETSH, R4
- MOVW.NE $L2WAYSH, R3 /* no */
- MOVW.NE $L2SETSH, R4
+ MOVW.EQ $30, R3 /* l1 */
+ MOVW.NE $29, R3 /* l2 */
+ CMP $16, R5 /* armv8 has 16-way l2, adjust shift */
+ MOVW.EQ $28, R3
/* iterate over ways */
MOVW $0, R7 /* R7: way */