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-rw-r--r--arch/loongarch/include/asm/percpu.h236
1 files changed, 236 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/percpu.h b/arch/loongarch/include/asm/percpu.h
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+++ b/arch/loongarch/include/asm/percpu.h
@@ -0,0 +1,236 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ */
+#ifndef __ASM_PERCPU_H
+#define __ASM_PERCPU_H
+
+#include <asm/cmpxchg.h>
+#include <asm/loongarch.h>
+
+/*
+ * The "address" (in fact, offset from $r21) of a per-CPU variable is close to
+ * the loading address of main kernel image, but far from where the modules are
+ * loaded. Tell the compiler this fact when using explicit relocs.
+ */
+#if defined(MODULE) && defined(CONFIG_AS_HAS_EXPLICIT_RELOCS)
+# if __has_attribute(model)
+# define PER_CPU_ATTRIBUTES __attribute__((model("extreme")))
+# else
+# error compiler support for the model attribute is necessary when a recent assembler is used
+# endif
+#endif
+
+/* Use r21 for fast access */
+register unsigned long __my_cpu_offset __asm__("$r21");
+
+static inline void set_my_cpu_offset(unsigned long off)
+{
+ __my_cpu_offset = off;
+ csr_write64(off, PERCPU_BASE_KS);
+}
+#define __my_cpu_offset __my_cpu_offset
+
+#define PERCPU_OP(op, asm_op, c_op) \
+static __always_inline unsigned long __percpu_##op(void *ptr, \
+ unsigned long val, int size) \
+{ \
+ unsigned long ret; \
+ \
+ switch (size) { \
+ case 4: \
+ __asm__ __volatile__( \
+ "am"#asm_op".w" " %[ret], %[val], %[ptr] \n" \
+ : [ret] "=&r" (ret), [ptr] "+ZB"(*(u32 *)ptr) \
+ : [val] "r" (val)); \
+ break; \
+ case 8: \
+ __asm__ __volatile__( \
+ "am"#asm_op".d" " %[ret], %[val], %[ptr] \n" \
+ : [ret] "=&r" (ret), [ptr] "+ZB"(*(u64 *)ptr) \
+ : [val] "r" (val)); \
+ break; \
+ default: \
+ ret = 0; \
+ BUILD_BUG(); \
+ } \
+ \
+ return ret c_op val; \
+}
+
+PERCPU_OP(add, add, +)
+PERCPU_OP(and, and, &)
+PERCPU_OP(or, or, |)
+#undef PERCPU_OP
+
+static __always_inline unsigned long __percpu_read(void *ptr, int size)
+{
+ unsigned long ret;
+
+ switch (size) {
+ case 1:
+ __asm__ __volatile__ ("ldx.b %[ret], $r21, %[ptr] \n"
+ : [ret] "=&r"(ret)
+ : [ptr] "r"(ptr)
+ : "memory");
+ break;
+ case 2:
+ __asm__ __volatile__ ("ldx.h %[ret], $r21, %[ptr] \n"
+ : [ret] "=&r"(ret)
+ : [ptr] "r"(ptr)
+ : "memory");
+ break;
+ case 4:
+ __asm__ __volatile__ ("ldx.w %[ret], $r21, %[ptr] \n"
+ : [ret] "=&r"(ret)
+ : [ptr] "r"(ptr)
+ : "memory");
+ break;
+ case 8:
+ __asm__ __volatile__ ("ldx.d %[ret], $r21, %[ptr] \n"
+ : [ret] "=&r"(ret)
+ : [ptr] "r"(ptr)
+ : "memory");
+ break;
+ default:
+ ret = 0;
+ BUILD_BUG();
+ }
+
+ return ret;
+}
+
+static __always_inline void __percpu_write(void *ptr, unsigned long val, int size)
+{
+ switch (size) {
+ case 1:
+ __asm__ __volatile__("stx.b %[val], $r21, %[ptr] \n"
+ :
+ : [val] "r" (val), [ptr] "r" (ptr)
+ : "memory");
+ break;
+ case 2:
+ __asm__ __volatile__("stx.h %[val], $r21, %[ptr] \n"
+ :
+ : [val] "r" (val), [ptr] "r" (ptr)
+ : "memory");
+ break;
+ case 4:
+ __asm__ __volatile__("stx.w %[val], $r21, %[ptr] \n"
+ :
+ : [val] "r" (val), [ptr] "r" (ptr)
+ : "memory");
+ break;
+ case 8:
+ __asm__ __volatile__("stx.d %[val], $r21, %[ptr] \n"
+ :
+ : [val] "r" (val), [ptr] "r" (ptr)
+ : "memory");
+ break;
+ default:
+ BUILD_BUG();
+ }
+}
+
+static __always_inline unsigned long __percpu_xchg(void *ptr, unsigned long val,
+ int size)
+{
+ switch (size) {
+ case 1:
+ case 2:
+ return __xchg_small((volatile void *)ptr, val, size);
+
+ case 4:
+ return __xchg_asm("amswap.w", (volatile u32 *)ptr, (u32)val);
+
+ case 8:
+ return __xchg_asm("amswap.d", (volatile u64 *)ptr, (u64)val);
+
+ default:
+ BUILD_BUG();
+ }
+
+ return 0;
+}
+
+/* this_cpu_cmpxchg */
+#define _protect_cmpxchg_local(pcp, o, n) \
+({ \
+ typeof(*raw_cpu_ptr(&(pcp))) __ret; \
+ preempt_disable_notrace(); \
+ __ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \
+ preempt_enable_notrace(); \
+ __ret; \
+})
+
+#define _percpu_read(pcp) \
+({ \
+ typeof(pcp) __retval; \
+ __retval = (typeof(pcp))__percpu_read(&(pcp), sizeof(pcp)); \
+ __retval; \
+})
+
+#define _percpu_write(pcp, val) \
+do { \
+ __percpu_write(&(pcp), (unsigned long)(val), sizeof(pcp)); \
+} while (0) \
+
+#define _pcp_protect(operation, pcp, val) \
+({ \
+ typeof(pcp) __retval; \
+ preempt_disable_notrace(); \
+ __retval = (typeof(pcp))operation(raw_cpu_ptr(&(pcp)), \
+ (val), sizeof(pcp)); \
+ preempt_enable_notrace(); \
+ __retval; \
+})
+
+#define _percpu_add(pcp, val) \
+ _pcp_protect(__percpu_add, pcp, val)
+
+#define _percpu_add_return(pcp, val) _percpu_add(pcp, val)
+
+#define _percpu_and(pcp, val) \
+ _pcp_protect(__percpu_and, pcp, val)
+
+#define _percpu_or(pcp, val) \
+ _pcp_protect(__percpu_or, pcp, val)
+
+#define _percpu_xchg(pcp, val) ((typeof(pcp)) \
+ _pcp_protect(__percpu_xchg, pcp, (unsigned long)(val)))
+
+#define this_cpu_add_4(pcp, val) _percpu_add(pcp, val)
+#define this_cpu_add_8(pcp, val) _percpu_add(pcp, val)
+
+#define this_cpu_add_return_4(pcp, val) _percpu_add_return(pcp, val)
+#define this_cpu_add_return_8(pcp, val) _percpu_add_return(pcp, val)
+
+#define this_cpu_and_4(pcp, val) _percpu_and(pcp, val)
+#define this_cpu_and_8(pcp, val) _percpu_and(pcp, val)
+
+#define this_cpu_or_4(pcp, val) _percpu_or(pcp, val)
+#define this_cpu_or_8(pcp, val) _percpu_or(pcp, val)
+
+#define this_cpu_read_1(pcp) _percpu_read(pcp)
+#define this_cpu_read_2(pcp) _percpu_read(pcp)
+#define this_cpu_read_4(pcp) _percpu_read(pcp)
+#define this_cpu_read_8(pcp) _percpu_read(pcp)
+
+#define this_cpu_write_1(pcp, val) _percpu_write(pcp, val)
+#define this_cpu_write_2(pcp, val) _percpu_write(pcp, val)
+#define this_cpu_write_4(pcp, val) _percpu_write(pcp, val)
+#define this_cpu_write_8(pcp, val) _percpu_write(pcp, val)
+
+#define this_cpu_xchg_1(pcp, val) _percpu_xchg(pcp, val)
+#define this_cpu_xchg_2(pcp, val) _percpu_xchg(pcp, val)
+#define this_cpu_xchg_4(pcp, val) _percpu_xchg(pcp, val)
+#define this_cpu_xchg_8(pcp, val) _percpu_xchg(pcp, val)
+
+#define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+#define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n)
+
+#include <asm-generic/percpu.h>
+
+#endif /* __ASM_PERCPU_H */