Merge commit 'v2.6.28-rc6' into core/debug

1 files changed, 64 insertions, 17 deletions

diff --git a/arch/mips/kernel/traps.c b/arch/mips/kernel/traps.c
index 6bee29097a5..353056110f2 100644
--- a/arch/mips/kernel/traps.c
+++ b/arch/mips/kernel/traps.c
@@ -32,6 +32,7 @@
 #include <asm/cpu.h>
 #include <asm/dsp.h>
 #include <asm/fpu.h>
+#include <asm/fpu_emulator.h>
 #include <asm/mipsregs.h>
 #include <asm/mipsmtregs.h>
 #include <asm/module.h>
@@ -42,10 +43,14 @@
 #include <asm/tlbdebug.h>
 #include <asm/traps.h>
 #include <asm/uaccess.h>
+#include <asm/watch.h>
 #include <asm/mmu_context.h>
 #include <asm/types.h>
 #include <asm/stacktrace.h>
 
+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);
@@ -718,6 +723,21 @@ static void do_trap_or_bp(struct pt_regs *regs, unsigned int code,
 		die_if_kernel("Kernel bug detected", regs);
 		force_sig(SIGTRAP, current);
 		break;
+	case BRK_MEMU:
+		/*
+		 * Address errors may be deliberately induced by the FPU
+		 * emulator to retake control of the CPU after executing the
+		 * instruction in the delay slot of an emulated branch.
+		 *
+		 * Terminate if exception was recognized as a delay slot return
+		 * otherwise handle as normal.
+		 */
+		if (do_dsemulret(regs))
+			return;
+
+		die_if_kernel("Math emu break/trap", regs);
+		force_sig(SIGTRAP, current);
+		break;
 	default:
 		scnprintf(b, sizeof(b), "%s instruction in kernel code", str);
 		die_if_kernel(b, regs);
@@ -822,8 +842,10 @@ 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);
 		}
@@ -907,13 +929,26 @@ 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)
@@ -1251,6 +1286,9 @@ 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 +1296,11 @@ 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 +1310,7 @@ 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. */
 
@@ -1533,6 +1571,8 @@ void __cpuinit set_uncached_handler(unsigned long offset, void *addr,
 #ifdef CONFIG_64BIT
 	unsigned long uncached_ebase = TO_UNCAC(ebase);
 #endif
+	if (cpu_has_mips_r2)
+		ebase += (read_c0_ebase() & 0x3ffff000);
 
 	if (!addr)
 		panic(panic_null_cerr);
@@ -1554,6 +1594,10 @@ 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)
@@ -1562,8 +1606,11 @@ void __init trap_init(void)
 
 	if (cpu_has_veic || cpu_has_vint)
 		ebase = (unsigned long) alloc_bootmem_low_pages(0x200 + VECTORSPACING*64);
-	else
+	else {
 		ebase = CAC_BASE;
+		if (cpu_has_mips_r2)
+			ebase += (read_c0_ebase() & 0x3ffff000);
+	}
 
 	per_cpu_trap_init();
 
@@ -1618,7 +1665,7 @@ 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);
@@ -1671,11 +1718,11 @@ void __init trap_init(void)
 
 	if (cpu_has_vce)
 		/* Special exception: R4[04]00 uses also the divec space. */
-		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_r4000, 0x100);
+		memcpy((void *)(ebase + 0x180), &except_vec3_r4000, 0x100);
 	else if (cpu_has_4kex)
-		memcpy((void *)(CAC_BASE + 0x180), &except_vec3_generic, 0x80);
+		memcpy((void *)(ebase + 0x180), &except_vec3_generic, 0x80);
 	else
-		memcpy((void *)(CAC_BASE + 0x080), &except_vec3_generic, 0x80);
+		memcpy((void *)(ebase + 0x080), &except_vec3_generic, 0x80);
 
 	signal_init();
 #ifdef CONFIG_MIPS32_COMPAT