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authorAtsushi Nemoto <anemo@mba.ocn.ne.jp>2006-09-11 17:50:29 +0900
committerRalf Baechle <ralf@linux-mips.org>2006-11-30 01:14:44 +0000
commit5b10496b6e6577f65b032a5c4c97d0d3a841273c (patch)
tree996de253070623043619f893afe8aa244ae88e8a /arch
parent656be92f9ae194ed62bc81310a4589a7cd765f13 (diff)
[MIPS] Fast path for rdhwr emulation for TLS
Add special short path for emulationg RDHWR which is used to support TLS. Add an extra prologue for cpu_has_vtag_icache case. Signed-off-by: Atsushi Nemoto <anemo@mba.ocn.ne.jp> Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to 'arch')
-rw-r--r--arch/mips/kernel/genex.S63
-rw-r--r--arch/mips/kernel/traps.c15
2 files changed, 77 insertions, 1 deletions
diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S
index 5baca16993d..aacd4a005c5 100644
--- a/arch/mips/kernel/genex.S
+++ b/arch/mips/kernel/genex.S
@@ -19,6 +19,7 @@
#include <asm/mipsregs.h>
#include <asm/stackframe.h>
#include <asm/war.h>
+#include <asm/page.h>
#define PANIC_PIC(msg) \
.set push; \
@@ -378,6 +379,68 @@ NESTED(nmi_handler, PT_SIZE, sp)
BUILD_HANDLER dsp dsp sti silent /* #26 */
BUILD_HANDLER reserved reserved sti verbose /* others */
+ .align 5
+ LEAF(handle_ri_rdhwr_vivt)
+#ifdef CONFIG_MIPS_MT_SMTC
+ PANIC_PIC("handle_ri_rdhwr_vivt called")
+#else
+ .set push
+ .set noat
+ .set noreorder
+ /* check if TLB contains a entry for EPC */
+ MFC0 k1, CP0_ENTRYHI
+ andi k1, 0xff /* ASID_MASK */
+ MFC0 k0, CP0_EPC
+ PTR_SRL k0, PAGE_SHIFT + 1
+ PTR_SLL k0, PAGE_SHIFT + 1
+ or k1, k0
+ MTC0 k1, CP0_ENTRYHI
+ mtc0_tlbw_hazard
+ tlbp
+ tlb_probe_hazard
+ mfc0 k1, CP0_INDEX
+ .set pop
+ bltz k1, handle_ri /* slow path */
+ /* fall thru */
+#endif
+ END(handle_ri_rdhwr_vivt)
+
+ LEAF(handle_ri_rdhwr)
+ .set push
+ .set noat
+ .set noreorder
+ /* 0x7c03e83b: rdhwr v1,$29 */
+ MFC0 k1, CP0_EPC
+ lui k0, 0x7c03
+ lw k1, (k1)
+ ori k0, 0xe83b
+ .set reorder
+ bne k0, k1, handle_ri /* if not ours */
+ /* The insn is rdhwr. No need to check CAUSE.BD here. */
+ get_saved_sp /* k1 := current_thread_info */
+ .set noreorder
+ MFC0 k0, CP0_EPC
+#if defined(CONFIG_CPU_R3000) || defined(CONFIG_CPU_TX39XX)
+ ori k1, _THREAD_MASK
+ xori k1, _THREAD_MASK
+ LONG_L v1, TI_TP_VALUE(k1)
+ LONG_ADDIU k0, 4
+ jr k0
+ rfe
+#else
+ LONG_ADDIU k0, 4 /* stall on $k0 */
+ MTC0 k0, CP0_EPC
+ /* I hope three instructions between MTC0 and ERET are enough... */
+ ori k1, _THREAD_MASK
+ xori k1, _THREAD_MASK
+ LONG_L v1, TI_TP_VALUE(k1)
+ .set mips3
+ eret
+ .set mips0
+#endif
+ .set pop
+ END(handle_ri_rdhwr)
+
#ifdef CONFIG_64BIT
/* A temporary overflow handler used by check_daddi(). */
diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 9fda1b8be3a..6eccfb49ae6 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -54,6 +54,8 @@ extern asmlinkage void handle_dbe(void);
extern asmlinkage void handle_sys(void);
extern asmlinkage void handle_bp(void);
extern asmlinkage void handle_ri(void);
+extern asmlinkage void handle_ri_rdhwr_vivt(void);
+extern asmlinkage void handle_ri_rdhwr(void);
extern asmlinkage void handle_cpu(void);
extern asmlinkage void handle_ov(void);
extern asmlinkage void handle_tr(void);
@@ -1423,6 +1425,15 @@ void __init set_uncached_handler (unsigned long offset, void *addr, unsigned lon
memcpy((void *)(uncached_ebase + offset), addr, size);
}
+static int __initdata rdhwr_noopt;
+static int __init set_rdhwr_noopt(char *str)
+{
+ rdhwr_noopt = 1;
+ return 1;
+}
+
+__setup("rdhwr_noopt", set_rdhwr_noopt);
+
void __init trap_init(void)
{
extern char except_vec3_generic, except_vec3_r4000;
@@ -1502,7 +1513,9 @@ void __init trap_init(void)
set_except_vector(8, handle_sys);
set_except_vector(9, handle_bp);
- set_except_vector(10, handle_ri);
+ set_except_vector(10, rdhwr_noopt ? handle_ri :
+ (cpu_has_vtag_icache ?
+ handle_ri_rdhwr_vivt : handle_ri_rdhwr));
set_except_vector(11, handle_cpu);
set_except_vector(12, handle_ov);
set_except_vector(13, handle_tr);