From c65a5480ff29198c241f11d39d9e34ab22c72c69 Mon Sep 17 00:00:00 2001 From: Atsushi Nemoto Date: Mon, 12 Nov 2007 02:05:18 +0900 Subject: [MIPS] Fix potential latency problem due to non-atomic cpu_wait. If an interrupt happened between checking of NEED_RESCHED and WAIT instruction, adjust EPC to restart from checking of NEED_RESCHED. Signed-off-by: Atsushi Nemoto Signed-off-by: Ralf Baechle --- arch/mips/kernel/traps.c | 22 ++++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) (limited to 'arch/mips/kernel/traps.c') diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 6bee29097a5..5fd0cd020af 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -46,6 +46,9 @@ #include #include +extern void check_wait(void); +extern asmlinkage void r4k_wait(void); +extern asmlinkage void rollback_handle_int(void); extern asmlinkage void handle_int(void); extern asmlinkage void handle_tlbm(void); extern asmlinkage void handle_tlbl(void); @@ -1251,6 +1254,9 @@ static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs) extern char except_vec_vi, except_vec_vi_lui; extern char except_vec_vi_ori, except_vec_vi_end; + extern char rollback_except_vec_vi; + char *vec_start = (cpu_wait == r4k_wait) ? + &rollback_except_vec_vi : &except_vec_vi; #ifdef CONFIG_MIPS_MT_SMTC /* * We need to provide the SMTC vectored interrupt handler @@ -1258,11 +1264,11 @@ static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs) * Status.IM bit to be masked before going there. */ extern char except_vec_vi_mori; - const int mori_offset = &except_vec_vi_mori - &except_vec_vi; + const int mori_offset = &except_vec_vi_mori - vec_start; #endif /* CONFIG_MIPS_MT_SMTC */ - const int handler_len = &except_vec_vi_end - &except_vec_vi; - const int lui_offset = &except_vec_vi_lui - &except_vec_vi; - const int ori_offset = &except_vec_vi_ori - &except_vec_vi; + const int handler_len = &except_vec_vi_end - vec_start; + const int lui_offset = &except_vec_vi_lui - vec_start; + const int ori_offset = &except_vec_vi_ori - vec_start; if (handler_len > VECTORSPACING) { /* @@ -1272,7 +1278,7 @@ static void *set_vi_srs_handler(int n, vi_handler_t addr, int srs) panic("VECTORSPACING too small"); } - memcpy(b, &except_vec_vi, handler_len); + memcpy(b, vec_start, handler_len); #ifdef CONFIG_MIPS_MT_SMTC BUG_ON(n > 7); /* Vector index %d exceeds SMTC maximum. */ @@ -1554,6 +1560,10 @@ void __init trap_init(void) extern char except_vec3_generic, except_vec3_r4000; extern char except_vec4; unsigned long i; + int rollback; + + check_wait(); + rollback = (cpu_wait == r4k_wait); #if defined(CONFIG_KGDB) if (kgdb_early_setup) @@ -1618,7 +1628,7 @@ void __init trap_init(void) if (board_be_init) board_be_init(); - set_except_vector(0, handle_int); + set_except_vector(0, rollback ? rollback_handle_int : handle_int); set_except_vector(1, handle_tlbm); set_except_vector(2, handle_tlbl); set_except_vector(3, handle_tlbs); -- cgit v1.2.3-70-g09d2 From 9cc123631b6630948eb5059d218f44424888daa7 Mon Sep 17 00:00:00 2001 From: "Kevin D. Kissell" Date: Tue, 9 Sep 2008 21:33:36 +0200 Subject: [MIPS] SMTC: Fix holes in SMTC and FPU affinity support. Signed-off-by: Kevin D. Kissell Signed-off-by: Ralf Baechle --- arch/mips/kernel/mips-mt-fpaff.c | 2 +- arch/mips/kernel/process.c | 19 +++++++++---------- arch/mips/kernel/traps.c | 6 ++++-- 3 files changed, 14 insertions(+), 13 deletions(-) (limited to 'arch/mips/kernel/traps.c') diff --git a/arch/mips/kernel/mips-mt-fpaff.c b/arch/mips/kernel/mips-mt-fpaff.c index df4d3f2f740..dc9eb72ed9d 100644 --- a/arch/mips/kernel/mips-mt-fpaff.c +++ b/arch/mips/kernel/mips-mt-fpaff.c @@ -159,7 +159,7 @@ __setup("fpaff=", fpaff_thresh); /* * FPU Use Factor empirically derived from experiments on 34K */ -#define FPUSEFACTOR 333 +#define FPUSEFACTOR 2000 static __init int mt_fp_affinity_init(void) { diff --git a/arch/mips/kernel/process.c b/arch/mips/kernel/process.c index ce7684335a4..22fc19bbe87 100644 --- a/arch/mips/kernel/process.c +++ b/arch/mips/kernel/process.c @@ -55,7 +55,7 @@ void __noreturn cpu_idle(void) while (1) { tick_nohz_stop_sched_tick(1); while (!need_resched()) { -#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG +#ifdef CONFIG_MIPS_MT_SMTC extern void smtc_idle_loop_hook(void); smtc_idle_loop_hook(); @@ -145,19 +145,18 @@ int copy_thread(int nr, unsigned long clone_flags, unsigned long usp, */ p->thread.cp0_status = read_c0_status() & ~(ST0_CU2|ST0_CU1); childregs->cp0_status &= ~(ST0_CU2|ST0_CU1); + +#ifdef CONFIG_MIPS_MT_SMTC + /* + * SMTC restores TCStatus after Status, and the CU bits + * are aliased there. + */ + childregs->cp0_tcstatus &= ~(ST0_CU2|ST0_CU1); +#endif clear_tsk_thread_flag(p, TIF_USEDFPU); #ifdef CONFIG_MIPS_MT_FPAFF clear_tsk_thread_flag(p, TIF_FPUBOUND); - - /* - * FPU affinity support is cleaner if we track the - * user-visible CPU affinity from the very beginning. - * The generic cpus_allowed mask will already have - * been copied from the parent before copy_thread - * is invoked. - */ - p->thread.user_cpus_allowed = p->cpus_allowed; #endif /* CONFIG_MIPS_MT_FPAFF */ if (clone_flags & CLONE_SETTLS) diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index 5fd0cd020af..b602ac6eb47 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -825,8 +825,10 @@ static void mt_ase_fp_affinity(void) if (cpus_intersects(current->cpus_allowed, mt_fpu_cpumask)) { cpumask_t tmask; - cpus_and(tmask, current->thread.user_cpus_allowed, - mt_fpu_cpumask); + current->thread.user_cpus_allowed + = current->cpus_allowed; + cpus_and(tmask, current->cpus_allowed, + mt_fpu_cpumask); set_cpus_allowed(current, tmask); set_thread_flag(TIF_FPUBOUND); } -- cgit v1.2.3-70-g09d2 From b67b2b703047bfaf62687ca64c9486599b609ef0 Mon Sep 17 00:00:00 2001 From: David Daney Date: Tue, 23 Sep 2008 00:08:45 -0700 Subject: MIPS: Watch exception handling for HARDWARE_WATCHPOINTS. Here we hook up the watch exception handler so that it sends SIGTRAP when the hardware watch registers are triggered. Signed-off-by: David Daney Signed-off-by: Ralf Baechle --- arch/mips/kernel/genex.S | 4 ++++ arch/mips/kernel/traps.c | 24 +++++++++++++++++++----- 2 files changed, 23 insertions(+), 5 deletions(-) (limited to 'arch/mips/kernel/traps.c') diff --git a/arch/mips/kernel/genex.S b/arch/mips/kernel/genex.S index 01dcbe38fa0..757d48f0d80 100644 --- a/arch/mips/kernel/genex.S +++ b/arch/mips/kernel/genex.S @@ -453,7 +453,11 @@ NESTED(nmi_handler, PT_SIZE, sp) BUILD_HANDLER tr tr sti silent /* #13 */ BUILD_HANDLER fpe fpe fpe silent /* #15 */ BUILD_HANDLER mdmx mdmx sti silent /* #22 */ +#ifdef CONFIG_HARDWARE_WATCHPOINTS + BUILD_HANDLER watch watch sti silent /* #23 */ +#else BUILD_HANDLER watch watch sti verbose /* #23 */ +#endif BUILD_HANDLER mcheck mcheck cli verbose /* #24 */ BUILD_HANDLER mt mt sti silent /* #25 */ BUILD_HANDLER dsp dsp sti silent /* #26 */ diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c index b602ac6eb47..80b9e070c20 100644 --- a/arch/mips/kernel/traps.c +++ b/arch/mips/kernel/traps.c @@ -42,6 +42,7 @@ #include #include #include +#include #include #include #include @@ -912,13 +913,26 @@ asmlinkage void do_mdmx(struct pt_regs *regs) asmlinkage void do_watch(struct pt_regs *regs) { + u32 cause; + /* - * We use the watch exception where available to detect stack - * overflows. + * Clear WP (bit 22) bit of cause register so we don't loop + * forever. */ - dump_tlb_all(); - show_regs(regs); - panic("Caught WATCH exception - probably caused by stack overflow."); + cause = read_c0_cause(); + cause &= ~(1 << 22); + write_c0_cause(cause); + + /* + * If the current thread has the watch registers loaded, save + * their values and send SIGTRAP. Otherwise another thread + * left the registers set, clear them and continue. + */ + if (test_tsk_thread_flag(current, TIF_LOAD_WATCH)) { + mips_read_watch_registers(); + force_sig(SIGTRAP, current); + } else + mips_clear_watch_registers(); } asmlinkage void do_mcheck(struct pt_regs *regs) -- cgit v1.2.3-70-g09d2