v4.19.13 snapshot.
diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
new file mode 100644
index 0000000..31733a9
--- /dev/null
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -0,0 +1,169 @@
+#ifndef _ASM_POWERPC_CODE_PATCHING_H
+#define _ASM_POWERPC_CODE_PATCHING_H
+
+/*
+ * Copyright 2008, Michael Ellerman, IBM Corporation.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version
+ * 2 of the License, or (at your option) any later version.
+ */
+
+#include <asm/types.h>
+#include <asm/ppc-opcode.h>
+#include <linux/string.h>
+#include <linux/kallsyms.h>
+#include <asm/asm-compat.h>
+
+/* Flags for create_branch:
+ * "b" == create_branch(addr, target, 0);
+ * "ba" == create_branch(addr, target, BRANCH_ABSOLUTE);
+ * "bl" == create_branch(addr, target, BRANCH_SET_LINK);
+ * "bla" == create_branch(addr, target, BRANCH_ABSOLUTE | BRANCH_SET_LINK);
+ */
+#define BRANCH_SET_LINK 0x1
+#define BRANCH_ABSOLUTE 0x2
+
+bool is_offset_in_branch_range(long offset);
+unsigned int create_branch(const unsigned int *addr,
+ unsigned long target, int flags);
+unsigned int create_cond_branch(const unsigned int *addr,
+ unsigned long target, int flags);
+int patch_branch(unsigned int *addr, unsigned long target, int flags);
+int patch_instruction(unsigned int *addr, unsigned int instr);
+int raw_patch_instruction(unsigned int *addr, unsigned int instr);
+int patch_instruction_site(s32 *addr, unsigned int instr);
+int patch_branch_site(s32 *site, unsigned long target, int flags);
+
+int instr_is_relative_branch(unsigned int instr);
+int instr_is_relative_link_branch(unsigned int instr);
+int instr_is_branch_to_addr(const unsigned int *instr, unsigned long addr);
+unsigned long branch_target(const unsigned int *instr);
+unsigned int translate_branch(const unsigned int *dest,
+ const unsigned int *src);
+extern bool is_conditional_branch(unsigned int instr);
+#ifdef CONFIG_PPC_BOOK3E_64
+void __patch_exception(int exc, unsigned long addr);
+#define patch_exception(exc, name) do { \
+ extern unsigned int name; \
+ __patch_exception((exc), (unsigned long)&name); \
+} while (0)
+#endif
+
+#define OP_RT_RA_MASK 0xffff0000UL
+#define LIS_R2 0x3c020000UL
+#define ADDIS_R2_R12 0x3c4c0000UL
+#define ADDI_R2_R2 0x38420000UL
+
+static inline unsigned long ppc_function_entry(void *func)
+{
+#ifdef PPC64_ELF_ABI_v2
+ u32 *insn = func;
+
+ /*
+ * A PPC64 ABIv2 function may have a local and a global entry
+ * point. We need to use the local entry point when patching
+ * functions, so identify and step over the global entry point
+ * sequence.
+ *
+ * The global entry point sequence is always of the form:
+ *
+ * addis r2,r12,XXXX
+ * addi r2,r2,XXXX
+ *
+ * A linker optimisation may convert the addis to lis:
+ *
+ * lis r2,XXXX
+ * addi r2,r2,XXXX
+ */
+ if ((((*insn & OP_RT_RA_MASK) == ADDIS_R2_R12) ||
+ ((*insn & OP_RT_RA_MASK) == LIS_R2)) &&
+ ((*(insn+1) & OP_RT_RA_MASK) == ADDI_R2_R2))
+ return (unsigned long)(insn + 2);
+ else
+ return (unsigned long)func;
+#elif defined(PPC64_ELF_ABI_v1)
+ /*
+ * On PPC64 ABIv1 the function pointer actually points to the
+ * function's descriptor. The first entry in the descriptor is the
+ * address of the function text.
+ */
+ return ((func_descr_t *)func)->entry;
+#else
+ return (unsigned long)func;
+#endif
+}
+
+static inline unsigned long ppc_global_function_entry(void *func)
+{
+#ifdef PPC64_ELF_ABI_v2
+ /* PPC64 ABIv2 the global entry point is at the address */
+ return (unsigned long)func;
+#else
+ /* All other cases there is no change vs ppc_function_entry() */
+ return ppc_function_entry(func);
+#endif
+}
+
+/*
+ * Wrapper around kallsyms_lookup() to return function entry address:
+ * - For ABIv1, we lookup the dot variant.
+ * - For ABIv2, we return the local entry point.
+ */
+static inline unsigned long ppc_kallsyms_lookup_name(const char *name)
+{
+ unsigned long addr;
+#ifdef PPC64_ELF_ABI_v1
+ /* check for dot variant */
+ char dot_name[1 + KSYM_NAME_LEN];
+ bool dot_appended = false;
+
+ if (strnlen(name, KSYM_NAME_LEN) >= KSYM_NAME_LEN)
+ return 0;
+
+ if (name[0] != '.') {
+ dot_name[0] = '.';
+ dot_name[1] = '\0';
+ strlcat(dot_name, name, sizeof(dot_name));
+ dot_appended = true;
+ } else {
+ dot_name[0] = '\0';
+ strlcat(dot_name, name, sizeof(dot_name));
+ }
+ addr = kallsyms_lookup_name(dot_name);
+ if (!addr && dot_appended)
+ /* Let's try the original non-dot symbol lookup */
+ addr = kallsyms_lookup_name(name);
+#elif defined(PPC64_ELF_ABI_v2)
+ addr = kallsyms_lookup_name(name);
+ if (addr)
+ addr = ppc_function_entry((void *)addr);
+#else
+ addr = kallsyms_lookup_name(name);
+#endif
+ return addr;
+}
+
+#ifdef CONFIG_PPC64
+/*
+ * Some instruction encodings commonly used in dynamic ftracing
+ * and function live patching.
+ */
+
+/* This must match the definition of STK_GOT in <asm/ppc_asm.h> */
+#ifdef PPC64_ELF_ABI_v2
+#define R2_STACK_OFFSET 24
+#else
+#define R2_STACK_OFFSET 40
+#endif
+
+#define PPC_INST_LD_TOC (PPC_INST_LD | ___PPC_RT(__REG_R2) | \
+ ___PPC_RA(__REG_R1) | R2_STACK_OFFSET)
+
+/* usually preceded by a mflr r0 */
+#define PPC_INST_STD_LR (PPC_INST_STD | ___PPC_RS(__REG_R0) | \
+ ___PPC_RA(__REG_R1) | PPC_LR_STKOFF)
+#endif /* CONFIG_PPC64 */
+
+#endif /* _ASM_POWERPC_CODE_PATCHING_H */