[PATCH v6 5/9] csky: Convert custom spinlock/rwlock to generic qspinlock/qrwlock

guoren
2021-03-31T14:32:46Z

From: Guo Ren <guoren@linux.alibaba.com>

Update the C-SKY port to use the generic qspinlock and qrwlock.

C-SKY only support ldex.w/stex.w with word(double word) size &
align access. So it must select XCHG32 to let qspinlock only use
word atomic xchg_tail.

Default is still ticket lock.

Signed-off-by: Guo Ren <guoren@linux.alibaba.com>
Cc: Waiman Long <longman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
---
arch/csky/Kconfig | 8 ++++++++
arch/csky/include/asm/Kbuild | 2 ++
arch/csky/include/asm/spinlock.h | 4 ++++
arch/csky/include/asm/spinlock_types.h | 4 ++++
4 files changed, 18 insertions(+)

diff --git a/arch/csky/Kconfig b/arch/csky/Kconfig
index 34e91224adc3..ae12332edb7b 100644
--- a/arch/csky/Kconfig
+++ b/arch/csky/Kconfig
@@ -8,6 +8,8 @@ config CSKY
select ARCH_HAS_SYNC_DMA_FOR_DEVICE
select ARCH_USE_BUILTIN_BSWAP
select ARCH_USE_QUEUED_RWLOCKS
+ select ARCH_USE_QUEUED_SPINLOCKS if !CSKY_TICKET_LOCK
+ select ARCH_USE_QUEUED_SPINLOCKS_XCHG32
select ARCH_WANT_FRAME_POINTERS if !CPU_CK610
select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT
select COMMON_CLK
@@ -304,6 +306,12 @@ config NR_CPUS
depends on SMP
default "4"

+config CSKY_TICKET_LOCK
+ bool "Ticket-based spin-locking"
+ default y
+ help
+ Say Y here to use ticket-based spin-locking.
+
config HIGHMEM
bool "High Memory Support"
depends on !CPU_CK610
diff --git a/arch/csky/include/asm/Kbuild b/arch/csky/include/asm/Kbuild
index cc24bb8e539f..2a2d09963bb9 100644
--- a/arch/csky/include/asm/Kbuild
+++ b/arch/csky/include/asm/Kbuild
@@ -2,6 +2,8 @@
generic-y += asm-offsets.h
generic-y += gpio.h
generic-y += kvm_para.h
+generic-y += mcs_spinlock.h
generic-y += qrwlock.h
+generic-y += qspinlock.h
generic-y += user.h
generic-y += vmlinux.lds.h
diff --git a/arch/csky/include/asm/spinlock.h b/arch/csky/include/asm/spinlock.h
index 69677167977a..fe98ad8ece51 100644
--- a/arch/csky/include/asm/spinlock.h
+++ b/arch/csky/include/asm/spinlock.h
@@ -6,6 +6,7 @@
#include <linux/spinlock_types.h>
#include <asm/barrier.h>

+#ifdef CONFIG_CSKY_TICKET_LOCK
/*
* Ticket-based spin-locking.
*/
@@ -80,6 +81,9 @@ static inline int arch_spin_is_contended(arch_spinlock_t *lock)
return (tickets.next - tickets.owner) > 1;
}
#define arch_spin_is_contended arch_spin_is_contended
+#else /* CONFIG_CSKY_TICKET_LOCK */
+#include <asm/qspinlock.h>
+#endif /* CONFIG_CSKY_TICKET_LOCK */

#include <asm/qrwlock.h>

diff --git a/arch/csky/include/asm/spinlock_types.h b/arch/csky/include/asm/spinlock_types.h
index 8ff0f6ff3a00..547f035f6dd5 100644
--- a/arch/csky/include/asm/spinlock_types.h
+++ b/arch/csky/include/asm/spinlock_types.h
@@ -7,6 +7,7 @@
# error "please don't include this file directly"
#endif

+#ifdef CONFIG_CSKY_TICKET_LOCK
#define TICKET_NEXT 16

typedef struct {
@@ -21,6 +22,9 @@ typedef struct {
} arch_spinlock_t;

#define __ARCH_SPIN_LOCK_UNLOCKED { { 0 } }
+#else
+#include <asm-generic/qspinlock_types.h>
+#endif

#include <asm-generic/qrwlock_types.h>