From 5b10496b6e6577f65b032a5c4c97d0d3a841273c Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Mon, 11 Sep 2006 17:50:29 +0900 Subject: [PATCH] [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 Signed-off-by: Ralf Baechle --- arch/mips/kernel/genex.S | 63 ++++++++++++++++++++++++++++++++++++++++ arch/mips/kernel/traps.c | 15 +++++++++- 2 files changed, 77 insertions(+), 1 deletion(-) diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S index 5baca16993..aacd4a005c 100644 --- a/arch/mips/kernel/genex.S +++ b/arch/mips/kernel/genex.S @@ -19,6 +19,7 @@ #include #include #include +#include #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 9fda1b8be3..6eccfb49ae 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); -- 2.39.5