summaryrefslogtreecommitdiffstats
path: root/arch/tile/include/asm/spinlock_64.h
diff options
context:
space:
mode:
authorChris Metcalf <cmetcalf@tilera.com>2011-05-04 14:38:26 -0400
committerChris Metcalf <cmetcalf@tilera.com>2011-05-12 15:52:12 -0400
commit18aecc2b645bbb07851b196452a2af314222069b (patch)
tree959f765f69af01046c6e26db12b45c3390799d3e /arch/tile/include/asm/spinlock_64.h
parentbe84cb43833ee40a42e08f5425d20310f16229c7 (diff)
downloadblackbird-op-linux-18aecc2b645bbb07851b196452a2af314222069b.tar.gz
blackbird-op-linux-18aecc2b645bbb07851b196452a2af314222069b.zip
arch/tile: finish enabling support for TILE-Gx 64-bit chip
This support was partially present in the existing code (look for "__tilegx__" ifdefs) but with this change you can build a working kernel using the TILE-Gx toolchain and ARCH=tilegx. Most of these files are new, generally adding a foo_64.c file where previously there was just a foo_32.c file. The ARCH=tilegx directive redirects to arch/tile, not arch/tilegx, using the existing SRCARCH mechanism in the top-level Makefile. Changes to existing files: - <asm/bitops.h> and <asm/bitops_32.h> changed to factor the include of <asm-generic/bitops/non-atomic.h> in the common header. - <asm/compat.h> and arch/tile/kernel/compat.c changed to remove the "const" markers I had put on compat_sys_execve() when trying to match some recent similar changes to the non-compat execve. It turns out the compat version wasn't "upgraded" to use const. - <asm/opcode-tile_64.h> and <asm/opcode_constants_64.h> were previously included accidentally, with the 32-bit contents. Now they have the proper 64-bit contents. Finally, I had to hack the existing hacky drivers/input/input-compat.h to add yet another "#ifdef" for INPUT_COMPAT_TEST (same as x86_64). Signed-off-by: Chris Metcalf <cmetcalf@tilera.com> Acked-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> [drivers/input]
Diffstat (limited to 'arch/tile/include/asm/spinlock_64.h')
-rw-r--r--arch/tile/include/asm/spinlock_64.h161
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/tile/include/asm/spinlock_64.h b/arch/tile/include/asm/spinlock_64.h
new file mode 100644
index 000000000000..72be5904e020
--- /dev/null
+++ b/arch/tile/include/asm/spinlock_64.h
@@ -0,0 +1,161 @@
+/*
+ * Copyright 2011 Tilera Corporation. All Rights Reserved.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation, version 2.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for
+ * more details.
+ *
+ * 64-bit SMP ticket spinlocks, allowing only a single CPU anywhere
+ * (the type definitions are in asm/spinlock_types.h)
+ */
+
+#ifndef _ASM_TILE_SPINLOCK_64_H
+#define _ASM_TILE_SPINLOCK_64_H
+
+/* Shifts and masks for the various fields in "lock". */
+#define __ARCH_SPIN_CURRENT_SHIFT 17
+#define __ARCH_SPIN_NEXT_MASK 0x7fff
+#define __ARCH_SPIN_NEXT_OVERFLOW 0x8000
+
+/*
+ * Return the "current" portion of a ticket lock value,
+ * i.e. the number that currently owns the lock.
+ */
+static inline int arch_spin_current(u32 val)
+{
+ return val >> __ARCH_SPIN_CURRENT_SHIFT;
+}
+
+/*
+ * Return the "next" portion of a ticket lock value,
+ * i.e. the number that the next task to try to acquire the lock will get.
+ */
+static inline int arch_spin_next(u32 val)
+{
+ return val & __ARCH_SPIN_NEXT_MASK;
+}
+
+/* The lock is locked if a task would have to wait to get it. */
+static inline int arch_spin_is_locked(arch_spinlock_t *lock)
+{
+ u32 val = lock->lock;
+ return arch_spin_current(val) != arch_spin_next(val);
+}
+
+/* Bump the current ticket so the next task owns the lock. */
+static inline void arch_spin_unlock(arch_spinlock_t *lock)
+{
+ wmb(); /* guarantee anything modified under the lock is visible */
+ __insn_fetchadd4(&lock->lock, 1U << __ARCH_SPIN_CURRENT_SHIFT);
+}
+
+void arch_spin_unlock_wait(arch_spinlock_t *lock);
+
+void arch_spin_lock_slow(arch_spinlock_t *lock, u32 val);
+
+/* Grab the "next" ticket number and bump it atomically.
+ * If the current ticket is not ours, go to the slow path.
+ * We also take the slow path if the "next" value overflows.
+ */
+static inline void arch_spin_lock(arch_spinlock_t *lock)
+{
+ u32 val = __insn_fetchadd4(&lock->lock, 1);
+ u32 ticket = val & (__ARCH_SPIN_NEXT_MASK | __ARCH_SPIN_NEXT_OVERFLOW);
+ if (unlikely(arch_spin_current(val) != ticket))
+ arch_spin_lock_slow(lock, ticket);
+}
+
+/* Try to get the lock, and return whether we succeeded. */
+int arch_spin_trylock(arch_spinlock_t *lock);
+
+/* We cannot take an interrupt after getting a ticket, so don't enable them. */
+#define arch_spin_lock_flags(lock, flags) arch_spin_lock(lock)
+
+/*
+ * Read-write spinlocks, allowing multiple readers
+ * but only one writer.
+ *
+ * We use fetchadd() for readers, and fetchor() with the sign bit
+ * for writers.
+ */
+
+#define __WRITE_LOCK_BIT (1 << 31)
+
+static inline int arch_write_val_locked(int val)
+{
+ return val < 0; /* Optimize "val & __WRITE_LOCK_BIT". */
+}
+
+/**
+ * read_can_lock - would read_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+static inline int arch_read_can_lock(arch_rwlock_t *rw)
+{
+ return !arch_write_val_locked(rw->lock);
+}
+
+/**
+ * write_can_lock - would write_trylock() succeed?
+ * @lock: the rwlock in question.
+ */
+static inline int arch_write_can_lock(arch_rwlock_t *rw)
+{
+ return rw->lock == 0;
+}
+
+extern void __read_lock_failed(arch_rwlock_t *rw);
+
+static inline void arch_read_lock(arch_rwlock_t *rw)
+{
+ u32 val = __insn_fetchaddgez4(&rw->lock, 1);
+ if (unlikely(arch_write_val_locked(val)))
+ __read_lock_failed(rw);
+}
+
+extern void __write_lock_failed(arch_rwlock_t *rw, u32 val);
+
+static inline void arch_write_lock(arch_rwlock_t *rw)
+{
+ u32 val = __insn_fetchor4(&rw->lock, __WRITE_LOCK_BIT);
+ if (unlikely(val != 0))
+ __write_lock_failed(rw, val);
+}
+
+static inline void arch_read_unlock(arch_rwlock_t *rw)
+{
+ __insn_mf();
+ __insn_fetchadd4(&rw->lock, -1);
+}
+
+static inline void arch_write_unlock(arch_rwlock_t *rw)
+{
+ __insn_mf();
+ rw->lock = 0;
+}
+
+static inline int arch_read_trylock(arch_rwlock_t *rw)
+{
+ return !arch_write_val_locked(__insn_fetchaddgez4(&rw->lock, 1));
+}
+
+static inline int arch_write_trylock(arch_rwlock_t *rw)
+{
+ u32 val = __insn_fetchor4(&rw->lock, __WRITE_LOCK_BIT);
+ if (likely(val == 0))
+ return 1;
+ if (!arch_write_val_locked(val))
+ __insn_fetchand4(&rw->lock, ~__WRITE_LOCK_BIT);
+ return 0;
+}
+
+#define arch_read_lock_flags(lock, flags) arch_read_lock(lock)
+#define arch_write_lock_flags(lock, flags) arch_write_lock(lock)
+
+#endif /* _ASM_TILE_SPINLOCK_64_H */
OpenPOWER on IntegriCloud