From 748e4f3d702def1a4bff191e0cf93b6a05340f01 Mon Sep 17 00:00:00 2001
From: hc <hc@nodka.com>
Date: Fri, 10 May 2024 07:41:34 +0000
Subject: [PATCH] add gpio led uart
---
kernel/arch/x86/include/asm/qspinlock.h | 35 ++++++++++++++++++++++++-----------
1 files changed, 24 insertions(+), 11 deletions(-)
diff --git a/kernel/arch/x86/include/asm/qspinlock.h b/kernel/arch/x86/include/asm/qspinlock.h
index 055c60a..d86ab94 100644
--- a/kernel/arch/x86/include/asm/qspinlock.h
+++ b/kernel/arch/x86/include/asm/qspinlock.h
@@ -11,20 +11,17 @@
#define _Q_PENDING_LOOPS (1 << 9)
#define queued_fetch_set_pending_acquire queued_fetch_set_pending_acquire
-
-static __always_inline bool __queued_RMW_btsl(struct qspinlock *lock)
-{
- GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter,
- "I", _Q_PENDING_OFFSET, "%0", c);
-}
-
static __always_inline u32 queued_fetch_set_pending_acquire(struct qspinlock *lock)
{
- u32 val = 0;
+ u32 val;
- if (__queued_RMW_btsl(lock))
- val |= _Q_PENDING_VAL;
-
+ /*
+ * We can't use GEN_BINARY_RMWcc() inside an if() stmt because asm goto
+ * and CONFIG_PROFILE_ALL_BRANCHES=y results in a label inside a
+ * statement expression, which GCC doesn't like.
+ */
+ val = GEN_BINARY_RMWcc(LOCK_PREFIX "btsl", lock->val.counter, c,
+ "I", _Q_PENDING_OFFSET) * _Q_PENDING_VAL;
val |= atomic_read(&lock->val) & ~_Q_PENDING_MASK;
return val;
@@ -35,6 +32,7 @@
extern void __pv_init_lock_hash(void);
extern void __pv_queued_spin_lock_slowpath(struct qspinlock *lock, u32 val);
extern void __raw_callee_save___pv_queued_spin_unlock(struct qspinlock *lock);
+extern bool nopvspin;
#define queued_spin_unlock queued_spin_unlock
/**
@@ -66,10 +64,25 @@
#endif
#ifdef CONFIG_PARAVIRT
+/*
+ * virt_spin_lock_key - enables (by default) the virt_spin_lock() hijack.
+ *
+ * Native (and PV wanting native due to vCPU pinning) should disable this key.
+ * It is done in this backwards fashion to only have a single direction change,
+ * which removes ordering between native_pv_spin_init() and HV setup.
+ */
DECLARE_STATIC_KEY_TRUE(virt_spin_lock_key);
void native_pv_lock_init(void) __init;
+/*
+ * Shortcut for the queued_spin_lock_slowpath() function that allows
+ * virt to hijack it.
+ *
+ * Returns:
+ * true - lock has been negotiated, all done;
+ * false - queued_spin_lock_slowpath() will do its thing.
+ */
#define virt_spin_lock virt_spin_lock
static inline bool virt_spin_lock(struct qspinlock *lock)
{
--
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