diff options
Diffstat (limited to 'recipes-extended/xen/files/xen-arm64-implement-atomic-fetch-add.patch')
| -rw-r--r-- | recipes-extended/xen/files/xen-arm64-implement-atomic-fetch-add.patch | 50 |
1 files changed, 0 insertions, 50 deletions
diff --git a/recipes-extended/xen/files/xen-arm64-implement-atomic-fetch-add.patch b/recipes-extended/xen/files/xen-arm64-implement-atomic-fetch-add.patch deleted file mode 100644 index 6e957a50..00000000 --- a/recipes-extended/xen/files/xen-arm64-implement-atomic-fetch-add.patch +++ /dev/null @@ -1,50 +0,0 @@ -From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001 -From: Christopher Clark <christopher.w.clark@gmail.com> -Date: Fri, 26 June 2020 16:34:00 -0800 -Subject: [PATCH] xen: implement atomic op to fix arm64 compilation - -Xen's ARM implementation of arch_fetch_and_add since f9cc3cd9 -uses a builtin, despite the build being performed with -fno-builtin. -With gcc 10.1.0, this now breaks prelinking spinlock.c, so -implement the one atomic operation that is required with logic -derived from Linux's atomic_ll_sc.h: ATOMIC_FETCH_OP and comparison with -the binary produced with and without the patch with gcc 9.2.0. - -Signed-off-by: Christopher Clark <christopher.w.clark@gmail.com> -diff --git a/xen/include/asm-arm/system.h b/xen/include/asm-arm/system.h -index e5d062667d..c46dd3ac71 100644 ---- a/xen/include/asm-arm/system.h -+++ b/xen/include/asm-arm/system.h -@@ -55,7 +55,32 @@ static inline int local_abort_is_enabled(void) - return !(flags & PSR_ABT_MASK); - } - -+#ifdef CONFIG_ARM_64 -+ -+/* see atomic_ll_sc.h: ATOMIC_FETCH_OP(name, mb, acq, rel, cl, op, asm_op, constraint) */ -+static inline int arch_fetch_and_add(unsigned int *ptr, unsigned long i) -+{ -+ int register lptr asm("x0"); -+ int register result asm("w1"); -+ int register newval asm("w2"); -+ int register status asm("w3"); -+ -+ asm volatile( -+ " mov %[lptr], %[ptr]\n" -+ "1: ldxr %w[result], [%[lptr]]\n" -+ " add %w[newval], %w[result], %w[i]\n" -+ " stlxr %w[status], %w[newval], [%[lptr]]\n" -+ " cbnz %w[status], 1b\n" -+ " dmb ish\n" -+ : [result] "=&r" (result), [lptr] "=&r" (lptr), [newval] "=&r" (newval), [status] "=&r" (status), [i] "+r" (i), "+Q" (*ptr) -+ : [ptr] "r" (ptr), "r" (i) -+ : "memory"); -+ -+ return result; -+} -+#else - #define arch_fetch_and_add(x, v) __sync_fetch_and_add(x, v) -+#endif - - extern struct vcpu *__context_switch(struct vcpu *prev, struct vcpu *next); - |