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authoradrian <adrian@FreeBSD.org>2013-10-09 00:27:12 +0000
committeradrian <adrian@FreeBSD.org>2013-10-09 00:27:12 +0000
commit2d83a106ef6be8c710efe1d9b7af3cd23e360ce6 (patch)
tree9cce3bc17b5281dca851c18f69eafd859cb22d9f /sys/mips/include/cpuregs.h
parentce0fc242f77ded919627602c30b5a37691f3d60b (diff)
downloadFreeBSD-src-2d83a106ef6be8c710efe1d9b7af3cd23e360ce6.zip
FreeBSD-src-2d83a106ef6be8c710efe1d9b7af3cd23e360ce6.tar.gz
Add "better" MIPS24k and MIPS74k barriers.
* the mips74k cores only need EHB (which is 'sll $0, $0, 3') here; NOPs don't actually work. * add EHB as the last NOP for the default barriers/hazards; that is "better" behaviour and should work on a wider variety of processors. This allows the existing (icky) TLB code to work, allowing the AR9344 SoC (mips74k) to actually get through kernel startup. Tested: * AR9344 SoC - (mips74k) * AR9331 SoC - (mips24k) TODO: * test on mips4k CPUs, just to be sure. * document that sll $0, $0, 3 is actually "EHB" and that it falls back to being a NOP for pre-mips32r1. * mips24k has an errata that we currently don't correctly explicitly state - ie, that after DERET/ERET, the only valid instruction is a NOP. Reviewed by: imp@ Approved by: re@ (gjb)
Diffstat (limited to 'sys/mips/include/cpuregs.h')
-rw-r--r--sys/mips/include/cpuregs.h9
1 files changed, 8 insertions, 1 deletions
diff --git a/sys/mips/include/cpuregs.h b/sys/mips/include/cpuregs.h
index 436a980..be8414f 100644
--- a/sys/mips/include/cpuregs.h
+++ b/sys/mips/include/cpuregs.h
@@ -149,6 +149,11 @@
#define MIPS_CCA_CC 0x05 /* Cacheable Coherent. */
#endif
+#if defined(CPU_MIPS74KC)
+#define MIPS_CCA_UNCACHED 0x02
+#define MIPS_CCA_CACHED 0x00
+#endif
+
#ifndef MIPS_CCA_UNCACHED
#define MIPS_CCA_UNCACHED MIPS_CCA_UC
#endif
@@ -204,12 +209,14 @@
#define COP0_SYNC .word 0xc0 /* ehb */
#elif defined(CPU_SB1)
#define COP0_SYNC ssnop; ssnop; ssnop; ssnop; ssnop; ssnop; ssnop; ssnop; ssnop
+#elif defined(CPU_MIPS74KC)
+#define COP0_SYNC .word 0xc0 /* ehb */
#else
/*
* Pick a reasonable default based on the "typical" spacing described in the
* "CP0 Hazards" chapter of MIPS Architecture Book Vol III.
*/
-#define COP0_SYNC ssnop; ssnop; ssnop; ssnop; ssnop
+#define COP0_SYNC ssnop; ssnop; ssnop; ssnop; .word 0xc0;
#endif
#define COP0_HAZARD_FPUENABLE nop; nop; nop; nop;
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