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authorLinus Torvalds <torvalds@linux-foundation.org>2026-09-20 08:15:23 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-09-20 08:15:23 -0700
commitbdab18633a302c82b5e5d5dbc4e38b0baf9c0837 (patch)
tree0446500af9a76d4e8b2a72a0a41391ceede73a10 /arch/mips/lib/delay.c
downloadlinux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.tar.gz
linux-stable-bdab18633a302c82b5e5d5dbc4e38b0baf9c0837.zip
Merge tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipgrafted
Pull futex fix from Ingo Molnar: - Also allocate a default private futex hash on vfork() as well, to avoid races with (private) futex waiters (Peter Zijlstra) * tag 'locking-urgent-2026-09-20' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: futex: Also allocate private hash on vfork()
Diffstat (limited to 'arch/mips/lib/delay.c')
-rw-r--r--arch/mips/lib/delay.c68
1 files changed, 68 insertions, 0 deletions
diff --git a/arch/mips/lib/delay.c b/arch/mips/lib/delay.c
new file mode 100644
index 000000000..ccdb1fc1e
--- /dev/null
+++ b/arch/mips/lib/delay.c
@@ -0,0 +1,68 @@
+/*
+ * 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 by Waldorf Electronics
+ * Copyright (C) 1995 - 2000, 01, 03 by Ralf Baechle
+ * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
+ * Copyright (C) 2007, 2014 Maciej W. Rozycki
+ */
+#include <linux/delay.h>
+#include <linux/export.h>
+#include <linux/param.h>
+#include <linux/smp.h>
+#include <linux/stringify.h>
+
+#include <asm/asm.h>
+#include <asm/compiler.h>
+
+#ifndef CONFIG_CPU_DADDI_WORKAROUNDS
+#define GCC_DADDI_IMM_ASM() "I"
+#else
+#define GCC_DADDI_IMM_ASM() "r"
+#endif
+
+#ifndef CONFIG_HAVE_PLAT_DELAY
+
+void __delay(unsigned long loops)
+{
+ __asm__ __volatile__ (
+ " .set noreorder \n"
+ " .align 3 \n"
+ "1: bnez %0, 1b \n"
+ " " __stringify(LONG_SUBU) " %0, %1 \n"
+ " .set reorder \n"
+ : "=r" (loops)
+ : GCC_DADDI_IMM_ASM() (1), "0" (loops));
+}
+EXPORT_SYMBOL(__delay);
+
+/*
+ * Division by multiplication: you don't have to worry about
+ * loss of precision.
+ *
+ * Use only for very small delays ( < 1 msec). Should probably use a
+ * lookup table, really, as the multiplications take much too long with
+ * short delays. This is a "reasonable" implementation, though (and the
+ * first constant multiplications gets optimized away if the delay is
+ * a constant)
+ */
+
+void __udelay(unsigned long us)
+{
+ unsigned int lpj = raw_current_cpu_data.udelay_val;
+
+ __delay((us * 0x000010c7ull * HZ * lpj) >> 32);
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long ns)
+{
+ unsigned int lpj = raw_current_cpu_data.udelay_val;
+
+ __delay((ns * 0x00000005ull * HZ * lpj) >> 32);
+}
+EXPORT_SYMBOL(__ndelay);
+
+#endif