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/xtensa/include/asm/cmpxchg.h | 113 +++++++++++++++++++++++++++++++++++++++++++-------------
1 files changed, 87 insertions(+), 26 deletions(-)
diff --git a/kernel/arch/xtensa/include/asm/cmpxchg.h b/kernel/arch/xtensa/include/asm/cmpxchg.h
index 201e900..a175f8a 100644
--- a/kernel/arch/xtensa/include/asm/cmpxchg.h
+++ b/kernel/arch/xtensa/include/asm/cmpxchg.h
@@ -13,6 +13,7 @@
#ifndef __ASSEMBLY__
+#include <linux/bits.h>
#include <linux/stringify.h>
/*
@@ -22,12 +23,29 @@
static inline unsigned long
__cmpxchg_u32(volatile int *p, int old, int new)
{
-#if XCHAL_HAVE_S32C1I
+#if XCHAL_HAVE_EXCLUSIVE
+ unsigned long tmp, result;
+
__asm__ __volatile__(
- " wsr %2, scompare1\n"
- " s32c1i %0, %1, 0\n"
- : "+a" (new)
- : "a" (p), "a" (old)
+ "1: l32ex %[result], %[addr]\n"
+ " bne %[result], %[cmp], 2f\n"
+ " mov %[tmp], %[new]\n"
+ " s32ex %[tmp], %[addr]\n"
+ " getex %[tmp]\n"
+ " beqz %[tmp], 1b\n"
+ "2:\n"
+ : [result] "=&a" (result), [tmp] "=&a" (tmp)
+ : [new] "a" (new), [addr] "a" (p), [cmp] "a" (old)
+ : "memory"
+ );
+
+ return result;
+#elif XCHAL_HAVE_S32C1I
+ __asm__ __volatile__(
+ " wsr %[cmp], scompare1\n"
+ " s32c1i %[new], %[mem]\n"
+ : [new] "+a" (new), [mem] "+m" (*p)
+ : [cmp] "a" (old)
: "memory"
);
@@ -35,14 +53,14 @@
#else
__asm__ __volatile__(
" rsil a15, "__stringify(TOPLEVEL)"\n"
- " l32i %0, %1, 0\n"
- " bne %0, %2, 1f\n"
- " s32i %3, %1, 0\n"
+ " l32i %[old], %[mem]\n"
+ " bne %[old], %[cmp], 1f\n"
+ " s32i %[new], %[mem]\n"
"1:\n"
" wsr a15, ps\n"
" rsync\n"
- : "=&a" (old)
- : "a" (p), "a" (old), "r" (new)
+ : [old] "=&a" (old), [mem] "+m" (*p)
+ : [cmp] "a" (old), [new] "r" (new)
: "a15", "memory");
return old;
#endif
@@ -107,16 +125,32 @@
static inline unsigned long xchg_u32(volatile int * m, unsigned long val)
{
-#if XCHAL_HAVE_S32C1I
+#if XCHAL_HAVE_EXCLUSIVE
+ unsigned long tmp, result;
+
+ __asm__ __volatile__(
+ "1: l32ex %[result], %[addr]\n"
+ " mov %[tmp], %[val]\n"
+ " s32ex %[tmp], %[addr]\n"
+ " getex %[tmp]\n"
+ " beqz %[tmp], 1b\n"
+ : [result] "=&a" (result), [tmp] "=&a" (tmp)
+ : [val] "a" (val), [addr] "a" (m)
+ : "memory"
+ );
+
+ return result;
+#elif XCHAL_HAVE_S32C1I
unsigned long tmp, result;
__asm__ __volatile__(
- "1: l32i %1, %2, 0\n"
- " mov %0, %3\n"
- " wsr %1, scompare1\n"
- " s32c1i %0, %2, 0\n"
- " bne %0, %1, 1b\n"
- : "=&a" (result), "=&a" (tmp)
- : "a" (m), "a" (val)
+ "1: l32i %[tmp], %[mem]\n"
+ " mov %[result], %[val]\n"
+ " wsr %[tmp], scompare1\n"
+ " s32c1i %[result], %[mem]\n"
+ " bne %[result], %[tmp], 1b\n"
+ : [result] "=&a" (result), [tmp] "=&a" (tmp),
+ [mem] "+m" (*m)
+ : [val] "a" (val)
: "memory"
);
return result;
@@ -124,12 +158,12 @@
unsigned long tmp;
__asm__ __volatile__(
" rsil a15, "__stringify(TOPLEVEL)"\n"
- " l32i %0, %1, 0\n"
- " s32i %2, %1, 0\n"
+ " l32i %[tmp], %[mem]\n"
+ " s32i %[val], %[mem]\n"
" wsr a15, ps\n"
" rsync\n"
- : "=&a" (tmp)
- : "a" (m), "a" (val)
+ : [tmp] "=&a" (tmp), [mem] "+m" (*m)
+ : [val] "a" (val)
: "a15", "memory");
return tmp;
#endif
@@ -137,6 +171,28 @@
#define xchg(ptr,x) \
((__typeof__(*(ptr)))__xchg((unsigned long)(x),(ptr),sizeof(*(ptr))))
+
+static inline u32 xchg_small(volatile void *ptr, u32 x, int size)
+{
+ int off = (unsigned long)ptr % sizeof(u32);
+ volatile u32 *p = ptr - off;
+#ifdef __BIG_ENDIAN
+ int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
+#else
+ int bitoff = off * BITS_PER_BYTE;
+#endif
+ u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff;
+ u32 oldv, newv;
+ u32 ret;
+
+ do {
+ oldv = READ_ONCE(*p);
+ ret = (oldv & bitmask) >> bitoff;
+ newv = (oldv & ~bitmask) | (x << bitoff);
+ } while (__cmpxchg_u32(p, oldv, newv) != oldv);
+
+ return ret;
+}
/*
* This only works if the compiler isn't horribly bad at optimizing.
@@ -150,11 +206,16 @@
__xchg(unsigned long x, volatile void * ptr, int size)
{
switch (size) {
- case 4:
- return xchg_u32(ptr, x);
+ case 1:
+ return xchg_small(ptr, x, 1);
+ case 2:
+ return xchg_small(ptr, x, 2);
+ case 4:
+ return xchg_u32(ptr, x);
+ default:
+ __xchg_called_with_bad_pointer();
+ return x;
}
- __xchg_called_with_bad_pointer();
- return x;
}
#endif /* __ASSEMBLY__ */
--
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