Adding upstream version 6.1.76.upstream/6.1.76upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 142 insertions, 0 deletions

diff --git a/arch/mips/include/asm/switch_to.h b/arch/mips/include/asm/switch_to.h
new file mode 100644
index 000000000..a4374b4cb
--- /dev/null
+++ b/arch/mips/include/asm/switch_to.h
@@ -0,0 +1,142 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 1994, 95, 96, 97, 98, 99, 2003, 06 by Ralf Baechle
+ * Copyright (C) 1996 by Paul M. Antoine
+ * Copyright (C) 1999 Silicon Graphics
+ * Kevin D. Kissell, kevink@mips.org and Carsten Langgaard, carstenl@mips.com
+ * Copyright (C) 2000 MIPS Technologies, Inc.
+ */
+#ifndef _ASM_SWITCH_TO_H
+#define _ASM_SWITCH_TO_H
+
+#include <asm/cpu-features.h>
+#include <asm/watch.h>
+#include <asm/dsp.h>
+#include <asm/cop2.h>
+#include <asm/fpu.h>
+
+struct task_struct;
+
+/**
+ * resume - resume execution of a task
+ * @prev:	The task previously executed.
+ * @next:	The task to begin executing.
+ * @next_ti:	task_thread_info(next).
+ *
+ * This function is used whilst scheduling to save the context of prev & load
+ * the context of next. Returns prev.
+ */
+extern asmlinkage struct task_struct *resume(struct task_struct *prev,
+		struct task_struct *next, struct thread_info *next_ti);
+
+extern unsigned int ll_bit;
+extern struct task_struct *ll_task;
+
+#ifdef CONFIG_MIPS_MT_FPAFF
+
+/*
+ * Handle the scheduler resume end of FPU affinity management.	We do this
+ * inline to try to keep the overhead down. If we have been forced to run on
+ * a "CPU" with an FPU because of a previous high level of FP computation,
+ * but did not actually use the FPU during the most recent time-slice (CU1
+ * isn't set), we undo the restriction on cpus_mask.
+ *
+ * We're not calling set_cpus_allowed() here, because we have no need to
+ * force prompt migration - we're already switching the current CPU to a
+ * different thread.
+ */
+
+#define __mips_mt_fpaff_switch_to(prev)					\
+do {									\
+	struct thread_info *__prev_ti = task_thread_info(prev);		\
+									\
+	if (cpu_has_fpu &&						\
+	    test_ti_thread_flag(__prev_ti, TIF_FPUBOUND) &&		\
+	    (!(KSTK_STATUS(prev) & ST0_CU1))) {				\
+		clear_ti_thread_flag(__prev_ti, TIF_FPUBOUND);		\
+		prev->cpus_mask = prev->thread.user_cpus_allowed;	\
+	}								\
+	next->thread.emulated_fp = 0;					\
+} while(0)
+
+#else
+#define __mips_mt_fpaff_switch_to(prev) do { (void) (prev); } while (0)
+#endif
+
+/*
+ * Clear LLBit during context switches on MIPSr5+ such that eretnc can be used
+ * unconditionally when returning to userland in entry.S.
+ */
+#define __clear_r5_hw_ll_bit() do {					\
+	if (cpu_has_mips_r5 || cpu_has_mips_r6)				\
+		write_c0_lladdr(0);					\
+} while (0)
+
+#define __clear_software_ll_bit() do {					\
+	if (!__builtin_constant_p(cpu_has_llsc) || !cpu_has_llsc)	\
+		ll_bit = 0;						\
+} while (0)
+
+/*
+ * Check FCSR for any unmasked exceptions pending set with `ptrace',
+ * clear them and send a signal.
+ */
+#ifdef CONFIG_MIPS_FP_SUPPORT
+# define __sanitize_fcr31(next)						\
+do {									\
+	unsigned long fcr31 = mask_fcr31_x(next->thread.fpu.fcr31);	\
+	void __user *pc;						\
+									\
+	if (unlikely(fcr31)) {						\
+		pc = (void __user *)task_pt_regs(next)->cp0_epc;	\
+		next->thread.fpu.fcr31 &= ~fcr31;			\
+		force_fcr31_sig(fcr31, pc, next);			\
+	}								\
+} while (0)
+#else
+# define __sanitize_fcr31(next)
+#endif
+
+/*
+ * For newly created kernel threads switch_to() will return to
+ * ret_from_kernel_thread, newly created user threads to ret_from_fork.
+ * That is, everything following resume() will be skipped for new threads.
+ * So everything that matters to new threads should be placed before resume().
+ */
+#define switch_to(prev, next, last)					\
+do {									\
+	__mips_mt_fpaff_switch_to(prev);				\
+	lose_fpu_inatomic(1, prev);					\
+	if (tsk_used_math(next))					\
+		__sanitize_fcr31(next);					\
+	if (cpu_has_dsp) {						\
+		__save_dsp(prev);					\
+		__restore_dsp(next);					\
+	}								\
+	if (cop2_present) {						\
+		u32 status = read_c0_status();				\
+									\
+		set_c0_status(ST0_CU2);					\
+		if ((KSTK_STATUS(prev) & ST0_CU2)) {			\
+			if (cop2_lazy_restore)				\
+				KSTK_STATUS(prev) &= ~ST0_CU2;		\
+			cop2_save(prev);				\
+		}							\
+		if (KSTK_STATUS(next) & ST0_CU2 &&			\
+		    !cop2_lazy_restore) {				\
+			cop2_restore(next);				\
+		}							\
+		write_c0_status(status);				\
+	}								\
+	__clear_r5_hw_ll_bit();						\
+	__clear_software_ll_bit();					\
+	if (cpu_has_userlocal)						\
+		write_c0_userlocal(task_thread_info(next)->tp_value);	\
+	__restore_watch(next);						\
+	(last) = resume(prev, next, task_thread_info(next));		\
+} while (0)
+
+#endif /* _ASM_SWITCH_TO_H */