sh: GUSA atomic rollback support.
This implements kernel-level atomic rollback built on top of gUSA,
as an alternative non-IRQ based atomicity method. This is generally
a faster method for platforms that are lacking the LL/SC pairs that
SH-4A and later use, and is only supportable on legacy cores.
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/include/asm-sh/atomic-grb.h b/include/asm-sh/atomic-grb.h
new file mode 100644
index 0000000..4c5b7db
--- /dev/null
+++ b/include/asm-sh/atomic-grb.h
@@ -0,0 +1,169 @@
+#ifndef __ASM_SH_ATOMIC_GRB_H
+#define __ASM_SH_ATOMIC_GRB_H
+
+static inline void atomic_add(int i, atomic_t *v)
+{
+ int tmp;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t" /* r0 = end point */
+ " mov r15, r1 \n\t" /* r1 = saved sp */
+ " mov #-6, r15 \n\t" /* LOGIN: r15 = size */
+ " mov.l @%1, %0 \n\t" /* load old value */
+ " add %2, %0 \n\t" /* add */
+ " mov.l %0, @%1 \n\t" /* store new value */
+ "1: mov r1, r15 \n\t" /* LOGOUT */
+ : "=&r" (tmp),
+ "+r" (v)
+ : "r" (i)
+ : "memory" , "r0", "r1");
+}
+
+static inline void atomic_sub(int i, atomic_t *v)
+{
+ int tmp;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t" /* r0 = end point */
+ " mov r15, r1 \n\t" /* r1 = saved sp */
+ " mov #-6, r15 \n\t" /* LOGIN: r15 = size */
+ " mov.l @%1, %0 \n\t" /* load old value */
+ " sub %2, %0 \n\t" /* sub */
+ " mov.l %0, @%1 \n\t" /* store new value */
+ "1: mov r1, r15 \n\t" /* LOGOUT */
+ : "=&r" (tmp),
+ "+r" (v)
+ : "r" (i)
+ : "memory" , "r0", "r1");
+}
+
+static inline int atomic_add_return(int i, atomic_t *v)
+{
+ int tmp;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t" /* r0 = end point */
+ " mov r15, r1 \n\t" /* r1 = saved sp */
+ " mov #-6, r15 \n\t" /* LOGIN: r15 = size */
+ " mov.l @%1, %0 \n\t" /* load old value */
+ " add %2, %0 \n\t" /* add */
+ " mov.l %0, @%1 \n\t" /* store new value */
+ "1: mov r1, r15 \n\t" /* LOGOUT */
+ : "=&r" (tmp),
+ "+r" (v)
+ : "r" (i)
+ : "memory" , "r0", "r1");
+
+ return tmp;
+}
+
+static inline int atomic_sub_return(int i, atomic_t *v)
+{
+ int tmp;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t" /* r0 = end point */
+ " mov r15, r1 \n\t" /* r1 = saved sp */
+ " mov #-6, r15 \n\t" /* LOGIN: r15 = size */
+ " mov.l @%1, %0 \n\t" /* load old value */
+ " sub %2, %0 \n\t" /* sub */
+ " mov.l %0, @%1 \n\t" /* store new value */
+ "1: mov r1, r15 \n\t" /* LOGOUT */
+ : "=&r" (tmp),
+ "+r" (v)
+ : "r" (i)
+ : "memory", "r0", "r1");
+
+ return tmp;
+}
+
+static inline void atomic_clear_mask(unsigned int mask, atomic_t *v)
+{
+ int tmp;
+ unsigned int _mask = ~mask;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t" /* r0 = end point */
+ " mov r15, r1 \n\t" /* r1 = saved sp */
+ " mov #-6, r15 \n\t" /* LOGIN: r15 = size */
+ " mov.l @%1, %0 \n\t" /* load old value */
+ " and %2, %0 \n\t" /* add */
+ " mov.l %0, @%1 \n\t" /* store new value */
+ "1: mov r1, r15 \n\t" /* LOGOUT */
+ : "=&r" (tmp),
+ "+r" (v)
+ : "r" (_mask)
+ : "memory" , "r0", "r1");
+}
+
+static inline void atomic_set_mask(unsigned int mask, atomic_t *v)
+{
+ int tmp;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t" /* r0 = end point */
+ " mov r15, r1 \n\t" /* r1 = saved sp */
+ " mov #-6, r15 \n\t" /* LOGIN: r15 = size */
+ " mov.l @%1, %0 \n\t" /* load old value */
+ " or %2, %0 \n\t" /* or */
+ " mov.l %0, @%1 \n\t" /* store new value */
+ "1: mov r1, r15 \n\t" /* LOGOUT */
+ : "=&r" (tmp),
+ "+r" (v)
+ : "r" (mask)
+ : "memory" , "r0", "r1");
+}
+
+static inline int atomic_cmpxchg(atomic_t *v, int old, int new)
+{
+ int ret;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t"
+ " nop \n\t"
+ " mov r15, r1 \n\t"
+ " mov #-8, r15 \n\t"
+ " mov.l @%1, %0 \n\t"
+ " cmp/eq %2, %0 \n\t"
+ " bf 1f \n\t"
+ " mov.l %3, @%1 \n\t"
+ "1: mov r1, r15 \n\t"
+ : "=&r" (ret)
+ : "r" (v), "r" (old), "r" (new)
+ : "memory" , "r0", "r1" , "t");
+
+ return ret;
+}
+
+static inline int atomic_add_unless(atomic_t *v, int a, int u)
+{
+ int ret;
+ unsigned long tmp;
+
+ __asm__ __volatile__ (
+ " .align 2 \n\t"
+ " mova 1f, r0 \n\t"
+ " nop \n\t"
+ " mov r15, r1 \n\t"
+ " mov #-12, r15 \n\t"
+ " mov.l @%2, %1 \n\t"
+ " mov %1, %0 \n\t"
+ " cmp/eq %4, %0 \n\t"
+ " bt/s 1f \n\t"
+ " add %3, %1 \n\t"
+ " mov.l %1, @%2 \n\t"
+ "1: mov r1, r15 \n\t"
+ : "=&r" (ret), "=&r" (tmp)
+ : "r" (v), "r" (a), "r" (u)
+ : "memory" , "r0", "r1" , "t");
+
+ return ret != u;
+}
+#endif /* __ASM_SH_ATOMIC_GRB_H */
