Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 239 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/code-patching.h b/arch/powerpc/include/asm/code-patching.h
new file mode 100644
index 000000000..1c6316ec4
--- /dev/null
+++ b/arch/powerpc/include/asm/code-patching.h
@@ -0,0 +1,239 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _ASM_POWERPC_CODE_PATCHING_H
+#define _ASM_POWERPC_CODE_PATCHING_H
+
+/*
+ * Copyright 2008, Michael Ellerman, IBM Corporation.
+ */
+
+#include <asm/types.h>
+#include <asm/ppc-opcode.h>
+#include <linux/string.h>
+#include <linux/kallsyms.h>
+#include <asm/asm-compat.h>
+#include <asm/inst.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
+
+DECLARE_STATIC_KEY_FALSE(init_mem_is_free);
+
+/*
+ * Powerpc branch instruction is :
+ *
+ *  0         6                 30   31
+ *  +---------+----------------+---+---+
+ *  | opcode  |     LI         |AA |LK |
+ *  +---------+----------------+---+---+
+ *  Where AA = 0 and LK = 0
+ *
+ * LI is a signed 24 bits integer. The real branch offset is computed
+ * by: imm32 = SignExtend(LI:'0b00', 32);
+ *
+ * So the maximum forward branch should be:
+ *   (0x007fffff << 2) = 0x01fffffc =  0x1fffffc
+ * The maximum backward branch should be:
+ *   (0xff800000 << 2) = 0xfe000000 = -0x2000000
+ */
+static inline bool is_offset_in_branch_range(long offset)
+{
+	return (offset >= -0x2000000 && offset <= 0x1fffffc && !(offset & 0x3));
+}
+
+static inline bool is_offset_in_cond_branch_range(long offset)
+{
+	return offset >= -0x8000 && offset <= 0x7fff && !(offset & 0x3);
+}
+
+static inline int create_branch(ppc_inst_t *instr, const u32 *addr,
+				unsigned long target, int flags)
+{
+	long offset;
+
+	*instr = ppc_inst(0);
+	offset = target;
+	if (! (flags & BRANCH_ABSOLUTE))
+		offset = offset - (unsigned long)addr;
+
+	/* Check we can represent the target in the instruction format */
+	if (!is_offset_in_branch_range(offset))
+		return 1;
+
+	/* Mask out the flags and target, so they don't step on each other. */
+	*instr = ppc_inst(0x48000000 | (flags & 0x3) | (offset & 0x03FFFFFC));
+
+	return 0;
+}
+
+int create_cond_branch(ppc_inst_t *instr, const u32 *addr,
+		       unsigned long target, int flags);
+int patch_branch(u32 *addr, unsigned long target, int flags);
+int patch_instruction(u32 *addr, ppc_inst_t instr);
+int raw_patch_instruction(u32 *addr, ppc_inst_t instr);
+
+static inline unsigned long patch_site_addr(s32 *site)
+{
+	return (unsigned long)site + *site;
+}
+
+static inline int patch_instruction_site(s32 *site, ppc_inst_t instr)
+{
+	return patch_instruction((u32 *)patch_site_addr(site), instr);
+}
+
+static inline int patch_branch_site(s32 *site, unsigned long target, int flags)
+{
+	return patch_branch((u32 *)patch_site_addr(site), target, flags);
+}
+
+static inline int modify_instruction(unsigned int *addr, unsigned int clr,
+				     unsigned int set)
+{
+	return patch_instruction(addr, ppc_inst((*addr & ~clr) | set));
+}
+
+static inline int modify_instruction_site(s32 *site, unsigned int clr, unsigned int set)
+{
+	return modify_instruction((unsigned int *)patch_site_addr(site), clr, set);
+}
+
+static inline unsigned int branch_opcode(ppc_inst_t instr)
+{
+	return ppc_inst_primary_opcode(instr) & 0x3F;
+}
+
+static inline int instr_is_branch_iform(ppc_inst_t instr)
+{
+	return branch_opcode(instr) == 18;
+}
+
+static inline int instr_is_branch_bform(ppc_inst_t instr)
+{
+	return branch_opcode(instr) == 16;
+}
+
+int instr_is_relative_branch(ppc_inst_t instr);
+int instr_is_relative_link_branch(ppc_inst_t instr);
+unsigned long branch_target(const u32 *instr);
+int translate_branch(ppc_inst_t *instr, const u32 *dest, const u32 *src);
+bool is_conditional_branch(ppc_inst_t instr);
+
+#define OP_RT_RA_MASK	0xffff0000UL
+#define LIS_R2		(PPC_RAW_LIS(_R2, 0))
+#define ADDIS_R2_R12	(PPC_RAW_ADDIS(_R2, _R12, 0))
+#define ADDI_R2_R2	(PPC_RAW_ADDI(_R2, _R2, 0))
+
+
+static inline unsigned long ppc_function_entry(void *func)
+{
+#ifdef CONFIG_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(CONFIG_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 ((struct func_desc *)func)->addr;
+#else
+	return (unsigned long)func;
+#endif
+}
+
+static inline unsigned long ppc_global_function_entry(void *func)
+{
+#ifdef CONFIG_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 CONFIG_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(CONFIG_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;
+}
+
+/*
+ * 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 CONFIG_PPC64_ELF_ABI_V2
+#define R2_STACK_OFFSET         24
+#else
+#define R2_STACK_OFFSET         40
+#endif
+
+#define PPC_INST_LD_TOC		PPC_RAW_LD(_R2, _R1, R2_STACK_OFFSET)
+
+/* usually preceded by a mflr r0 */
+#define PPC_INST_STD_LR		PPC_RAW_STD(_R0, _R1, PPC_LR_STKOFF)
+
+#endif /* _ASM_POWERPC_CODE_PATCHING_H */