2 * This file is subject to the terms and conditions of the GNU General Public
3 * License. See the file "COPYING" in the main directory of this archive
6 * Copyright (C) 2002 by Ralf Baechle
11 #include <linux/config.h>
14 * Pleassures of the R4600 V1.x. Cite from the IDT R4600 V1.7 errata:
16 * 18. The CACHE instructions Hit_Writeback_Invalidate_D, Hit_Writeback_D,
17 * Hit_Invalidate_D and Create_Dirty_Excl_D should only be
18 * executed if there is no other dcache activity. If the dcache is
19 * accessed for another instruction immeidately preceding when these
20 * cache instructions are executing, it is possible that the dcache
21 * tag match outputs used by these cache instructions will be
22 * incorrect. These cache instructions should be preceded by at least
23 * four instructions that are not any kind of load or store
26 * This is not allowed: lw
30 * cache Hit_Writeback_Invalidate_D
37 * cache Hit_Writeback_Invalidate_D
39 #undef R4600_V1_HIT_DCACHE_WAR /* Not used yet in 64-bit kernel */
43 * Writeback and invalidate the primary cache dcache before DMA.
45 * R4600 v2.0 bug: "The CACHE instructions Hit_Writeback_Inv_D,
46 * Hit_Writeback_D, Hit_Invalidate_D and Create_Dirty_Exclusive_D will only
47 * operate correctly if the internal data cache refill buffer is empty. These
48 * CACHE instructions should be separated from any potential data cache miss
49 * by a load instruction to an uncached address to empty the response buffer."
50 * (Revision 2.0 device errata from IDT available on http://www.idt.com/
53 #undef R4600_V2_HIT_CACHEOP_WAR /* Not used yet in 64-bit kernel */
55 #ifdef CONFIG_CPU_R5432
58 * When an interrupt happens on a CP0 register read instruction, CPU may
59 * lock up or read corrupted values of CP0 registers after it enters
60 * the exception handler.
62 * This workaround makes sure that we read a "safe" CP0 register as the
63 * first thing in the exception handler, which breaks one of the
64 * pre-conditions for this problem.
66 #define R5432_CP0_INTERRUPT_WAR
70 #endif /* _ASM_WAR_H */