Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 471 insertions, 0 deletions

diff --git a/arch/x86/include/asm/alternative.h b/arch/x86/include/asm/alternative.h
new file mode 100644
index 000000000..65f79092c
--- /dev/null
+++ b/arch/x86/include/asm/alternative.h
@@ -0,0 +1,471 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_X86_ALTERNATIVE_H
+#define _ASM_X86_ALTERNATIVE_H
+
+#include <linux/types.h>
+#include <linux/stringify.h>
+#include <asm/asm.h>
+
+#define ALT_FLAGS_SHIFT		16
+
+#define ALT_FLAG_NOT		(1 << 0)
+#define ALT_NOT(feature)	((ALT_FLAG_NOT << ALT_FLAGS_SHIFT) | (feature))
+
+#ifndef __ASSEMBLY__
+
+#include <linux/stddef.h>
+
+/*
+ * Alternative inline assembly for SMP.
+ *
+ * The LOCK_PREFIX macro defined here replaces the LOCK and
+ * LOCK_PREFIX macros used everywhere in the source tree.
+ *
+ * SMP alternatives use the same data structures as the other
+ * alternatives and the X86_FEATURE_UP flag to indicate the case of a
+ * UP system running a SMP kernel.  The existing apply_alternatives()
+ * works fine for patching a SMP kernel for UP.
+ *
+ * The SMP alternative tables can be kept after boot and contain both
+ * UP and SMP versions of the instructions to allow switching back to
+ * SMP at runtime, when hotplugging in a new CPU, which is especially
+ * useful in virtualized environments.
+ *
+ * The very common lock prefix is handled as special case in a
+ * separate table which is a pure address list without replacement ptr
+ * and size information.  That keeps the table sizes small.
+ */
+
+#ifdef CONFIG_SMP
+#define LOCK_PREFIX_HERE \
+		".pushsection .smp_locks,\"a\"\n"	\
+		".balign 4\n"				\
+		".long 671f - .\n" /* offset */		\
+		".popsection\n"				\
+		"671:"
+
+#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
+
+#else /* ! CONFIG_SMP */
+#define LOCK_PREFIX_HERE ""
+#define LOCK_PREFIX ""
+#endif
+
+/*
+ * objtool annotation to ignore the alternatives and only consider the original
+ * instruction(s).
+ */
+#define ANNOTATE_IGNORE_ALTERNATIVE				\
+	"999:\n\t"						\
+	".pushsection .discard.ignore_alts\n\t"			\
+	".long 999b\n\t"					\
+	".popsection\n\t"
+
+/*
+ * The patching flags are part of the upper bits of the @ft_flags parameter when
+ * specifying them. The split is currently like this:
+ *
+ * [31... flags ...16][15... CPUID feature bit ...0]
+ *
+ * but since this is all hidden in the macros argument being split, those fields can be
+ * extended in the future to fit in a u64 or however the need arises.
+ */
+struct alt_instr {
+	s32 instr_offset;	/* original instruction */
+	s32 repl_offset;	/* offset to replacement instruction */
+
+	union {
+		struct {
+			u32 cpuid: 16;	/* CPUID bit set for replacement */
+			u32 flags: 16;	/* patching control flags */
+		};
+		u32 ft_flags;
+	};
+
+	u8  instrlen;		/* length of original instruction */
+	u8  replacementlen;	/* length of new instruction */
+} __packed;
+
+/*
+ * Debug flag that can be tested to see whether alternative
+ * instructions were patched in already:
+ */
+extern int alternatives_patched;
+
+extern void alternative_instructions(void);
+extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
+extern void apply_retpolines(s32 *start, s32 *end);
+extern void apply_returns(s32 *start, s32 *end);
+extern void apply_seal_endbr(s32 *start, s32 *end);
+extern void apply_fineibt(s32 *start_retpoline, s32 *end_retpoine,
+			  s32 *start_cfi, s32 *end_cfi);
+
+struct module;
+struct paravirt_patch_site;
+
+struct callthunk_sites {
+	s32				*call_start, *call_end;
+	struct paravirt_patch_site	*pv_start, *pv_end;
+};
+
+#ifdef CONFIG_CALL_THUNKS
+extern void callthunks_patch_builtin_calls(void);
+extern void callthunks_patch_module_calls(struct callthunk_sites *sites,
+					  struct module *mod);
+extern void *callthunks_translate_call_dest(void *dest);
+extern int x86_call_depth_emit_accounting(u8 **pprog, void *func);
+#else
+static __always_inline void callthunks_patch_builtin_calls(void) {}
+static __always_inline void
+callthunks_patch_module_calls(struct callthunk_sites *sites,
+			      struct module *mod) {}
+static __always_inline void *callthunks_translate_call_dest(void *dest)
+{
+	return dest;
+}
+static __always_inline int x86_call_depth_emit_accounting(u8 **pprog,
+							  void *func)
+{
+	return 0;
+}
+#endif
+
+#ifdef CONFIG_SMP
+extern void alternatives_smp_module_add(struct module *mod, char *name,
+					void *locks, void *locks_end,
+					void *text, void *text_end);
+extern void alternatives_smp_module_del(struct module *mod);
+extern void alternatives_enable_smp(void);
+extern int alternatives_text_reserved(void *start, void *end);
+extern bool skip_smp_alternatives;
+#else
+static inline void alternatives_smp_module_add(struct module *mod, char *name,
+					       void *locks, void *locks_end,
+					       void *text, void *text_end) {}
+static inline void alternatives_smp_module_del(struct module *mod) {}
+static inline void alternatives_enable_smp(void) {}
+static inline int alternatives_text_reserved(void *start, void *end)
+{
+	return 0;
+}
+#endif	/* CONFIG_SMP */
+
+#define b_replacement(num)	"664"#num
+#define e_replacement(num)	"665"#num
+
+#define alt_end_marker		"663"
+#define alt_slen		"662b-661b"
+#define alt_total_slen		alt_end_marker"b-661b"
+#define alt_rlen(num)		e_replacement(num)"f-"b_replacement(num)"f"
+
+#define OLDINSTR(oldinstr, num)						\
+	"# ALT: oldnstr\n"						\
+	"661:\n\t" oldinstr "\n662:\n"					\
+	"# ALT: padding\n"						\
+	".skip -(((" alt_rlen(num) ")-(" alt_slen ")) > 0) * "		\
+		"((" alt_rlen(num) ")-(" alt_slen ")),0x90\n"		\
+	alt_end_marker ":\n"
+
+/*
+ * gas compatible max based on the idea from:
+ * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
+ *
+ * The additional "-" is needed because gas uses a "true" value of -1.
+ */
+#define alt_max_short(a, b)	"((" a ") ^ (((" a ") ^ (" b ")) & -(-((" a ") < (" b ")))))"
+
+/*
+ * Pad the second replacement alternative with additional NOPs if it is
+ * additionally longer than the first replacement alternative.
+ */
+#define OLDINSTR_2(oldinstr, num1, num2) \
+	"# ALT: oldinstr2\n"									\
+	"661:\n\t" oldinstr "\n662:\n"								\
+	"# ALT: padding2\n"									\
+	".skip -((" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")) > 0) * "	\
+		"(" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")), 0x90\n"	\
+	alt_end_marker ":\n"
+
+#define OLDINSTR_3(oldinsn, n1, n2, n3)								\
+	"# ALT: oldinstr3\n"									\
+	"661:\n\t" oldinsn "\n662:\n"								\
+	"# ALT: padding3\n"									\
+	".skip -((" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3))	\
+		" - (" alt_slen ")) > 0) * "							\
+		"(" alt_max_short(alt_max_short(alt_rlen(n1), alt_rlen(n2)), alt_rlen(n3))	\
+		" - (" alt_slen ")), 0x90\n"							\
+	alt_end_marker ":\n"
+
+#define ALTINSTR_ENTRY(ft_flags, num)					      \
+	" .long 661b - .\n"				/* label           */ \
+	" .long " b_replacement(num)"f - .\n"		/* new instruction */ \
+	" .4byte " __stringify(ft_flags) "\n"		/* feature + flags */ \
+	" .byte " alt_total_slen "\n"			/* source len      */ \
+	" .byte " alt_rlen(num) "\n"			/* replacement len */
+
+#define ALTINSTR_REPLACEMENT(newinstr, num)		/* replacement */	\
+	"# ALT: replacement " #num "\n"						\
+	b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n"
+
+/* alternative assembly primitive: */
+#define ALTERNATIVE(oldinstr, newinstr, ft_flags)			\
+	OLDINSTR(oldinstr, 1)						\
+	".pushsection .altinstructions,\"a\"\n"				\
+	ALTINSTR_ENTRY(ft_flags, 1)					\
+	".popsection\n"							\
+	".pushsection .altinstr_replacement, \"ax\"\n"			\
+	ALTINSTR_REPLACEMENT(newinstr, 1)				\
+	".popsection\n"
+
+#define ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \
+	OLDINSTR_2(oldinstr, 1, 2)					\
+	".pushsection .altinstructions,\"a\"\n"				\
+	ALTINSTR_ENTRY(ft_flags1, 1)					\
+	ALTINSTR_ENTRY(ft_flags2, 2)					\
+	".popsection\n"							\
+	".pushsection .altinstr_replacement, \"ax\"\n"			\
+	ALTINSTR_REPLACEMENT(newinstr1, 1)				\
+	ALTINSTR_REPLACEMENT(newinstr2, 2)				\
+	".popsection\n"
+
+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
+#define ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) \
+	ALTERNATIVE_2(oldinstr, newinstr_no, X86_FEATURE_ALWAYS,	\
+		      newinstr_yes, ft_flags)
+
+#define ALTERNATIVE_3(oldinsn, newinsn1, ft_flags1, newinsn2, ft_flags2, \
+			newinsn3, ft_flags3)				\
+	OLDINSTR_3(oldinsn, 1, 2, 3)					\
+	".pushsection .altinstructions,\"a\"\n"				\
+	ALTINSTR_ENTRY(ft_flags1, 1)					\
+	ALTINSTR_ENTRY(ft_flags2, 2)					\
+	ALTINSTR_ENTRY(ft_flags3, 3)					\
+	".popsection\n"							\
+	".pushsection .altinstr_replacement, \"ax\"\n"			\
+	ALTINSTR_REPLACEMENT(newinsn1, 1)				\
+	ALTINSTR_REPLACEMENT(newinsn2, 2)				\
+	ALTINSTR_REPLACEMENT(newinsn3, 3)				\
+	".popsection\n"
+
+/*
+ * Alternative instructions for different CPU types or capabilities.
+ *
+ * This allows to use optimized instructions even on generic binary
+ * kernels.
+ *
+ * length of oldinstr must be longer or equal the length of newinstr
+ * It can be padded with nops as needed.
+ *
+ * For non barrier like inlines please define new variants
+ * without volatile and memory clobber.
+ */
+#define alternative(oldinstr, newinstr, ft_flags)			\
+	asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags) : : : "memory")
+
+#define alternative_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) \
+	asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2) ::: "memory")
+
+#define alternative_ternary(oldinstr, ft_flags, newinstr_yes, newinstr_no) \
+	asm_inline volatile(ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) ::: "memory")
+
+/*
+ * Alternative inline assembly with input.
+ *
+ * Peculiarities:
+ * No memory clobber here.
+ * Argument numbers start with 1.
+ * Leaving an unused argument 0 to keep API compatibility.
+ */
+#define alternative_input(oldinstr, newinstr, ft_flags, input...)	\
+	asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags)	\
+		: : "i" (0), ## input)
+
+/*
+ * This is similar to alternative_input. But it has two features and
+ * respective instructions.
+ *
+ * If CPU has feature2, newinstr2 is used.
+ * Otherwise, if CPU has feature1, newinstr1 is used.
+ * Otherwise, oldinstr is used.
+ */
+#define alternative_input_2(oldinstr, newinstr1, ft_flags1, newinstr2,	     \
+			   ft_flags2, input...)				     \
+	asm_inline volatile(ALTERNATIVE_2(oldinstr, newinstr1, ft_flags1,     \
+		newinstr2, ft_flags2)					     \
+		: : "i" (0), ## input)
+
+/* Like alternative_input, but with a single output argument */
+#define alternative_io(oldinstr, newinstr, ft_flags, output, input...)	\
+	asm_inline volatile (ALTERNATIVE(oldinstr, newinstr, ft_flags)	\
+		: output : "i" (0), ## input)
+
+/* Like alternative_io, but for replacing a direct call with another one. */
+#define alternative_call(oldfunc, newfunc, ft_flags, output, input...)	\
+	asm_inline volatile (ALTERNATIVE("call %P[old]", "call %P[new]", ft_flags) \
+		: output : [old] "i" (oldfunc), [new] "i" (newfunc), ## input)
+
+/*
+ * Like alternative_call, but there are two features and respective functions.
+ * If CPU has feature2, function2 is used.
+ * Otherwise, if CPU has feature1, function1 is used.
+ * Otherwise, old function is used.
+ */
+#define alternative_call_2(oldfunc, newfunc1, ft_flags1, newfunc2, ft_flags2,   \
+			   output, input...)				      \
+	asm_inline volatile (ALTERNATIVE_2("call %P[old]", "call %P[new1]", ft_flags1,\
+		"call %P[new2]", ft_flags2)				      \
+		: output, ASM_CALL_CONSTRAINT				      \
+		: [old] "i" (oldfunc), [new1] "i" (newfunc1),		      \
+		  [new2] "i" (newfunc2), ## input)
+
+/*
+ * use this macro(s) if you need more than one output parameter
+ * in alternative_io
+ */
+#define ASM_OUTPUT2(a...) a
+
+/*
+ * use this macro if you need clobbers but no inputs in
+ * alternative_{input,io,call}()
+ */
+#define ASM_NO_INPUT_CLOBBER(clbr...) "i" (0) : clbr
+
+#else /* __ASSEMBLY__ */
+
+#ifdef CONFIG_SMP
+	.macro LOCK_PREFIX
+672:	lock
+	.pushsection .smp_locks,"a"
+	.balign 4
+	.long 672b - .
+	.popsection
+	.endm
+#else
+	.macro LOCK_PREFIX
+	.endm
+#endif
+
+/*
+ * objtool annotation to ignore the alternatives and only consider the original
+ * instruction(s).
+ */
+.macro ANNOTATE_IGNORE_ALTERNATIVE
+	.Lannotate_\@:
+	.pushsection .discard.ignore_alts
+	.long .Lannotate_\@
+	.popsection
+.endm
+
+/*
+ * Issue one struct alt_instr descriptor entry (need to put it into
+ * the section .altinstructions, see below). This entry contains
+ * enough information for the alternatives patching code to patch an
+ * instruction. See apply_alternatives().
+ */
+.macro altinstr_entry orig alt ft_flags orig_len alt_len
+	.long \orig - .
+	.long \alt - .
+	.4byte \ft_flags
+	.byte \orig_len
+	.byte \alt_len
+.endm
+
+/*
+ * Define an alternative between two instructions. If @feature is
+ * present, early code in apply_alternatives() replaces @oldinstr with
+ * @newinstr. ".skip" directive takes care of proper instruction padding
+ * in case @newinstr is longer than @oldinstr.
+ */
+.macro ALTERNATIVE oldinstr, newinstr, ft_flags
+140:
+	\oldinstr
+141:
+	.skip -(((144f-143f)-(141b-140b)) > 0) * ((144f-143f)-(141b-140b)),0x90
+142:
+
+	.pushsection .altinstructions,"a"
+	altinstr_entry 140b,143f,\ft_flags,142b-140b,144f-143f
+	.popsection
+
+	.pushsection .altinstr_replacement,"ax"
+143:
+	\newinstr
+144:
+	.popsection
+.endm
+
+#define old_len			141b-140b
+#define new_len1		144f-143f
+#define new_len2		145f-144f
+#define new_len3		146f-145f
+
+/*
+ * gas compatible max based on the idea from:
+ * http://graphics.stanford.edu/~seander/bithacks.html#IntegerMinOrMax
+ *
+ * The additional "-" is needed because gas uses a "true" value of -1.
+ */
+#define alt_max_2(a, b)		((a) ^ (((a) ^ (b)) & -(-((a) < (b)))))
+#define alt_max_3(a, b, c)	(alt_max_2(alt_max_2(a, b), c))
+
+
+/*
+ * Same as ALTERNATIVE macro above but for two alternatives. If CPU
+ * has @feature1, it replaces @oldinstr with @newinstr1. If CPU has
+ * @feature2, it replaces @oldinstr with @feature2.
+ */
+.macro ALTERNATIVE_2 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2
+140:
+	\oldinstr
+141:
+	.skip -((alt_max_2(new_len1, new_len2) - (old_len)) > 0) * \
+		(alt_max_2(new_len1, new_len2) - (old_len)),0x90
+142:
+
+	.pushsection .altinstructions,"a"
+	altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f
+	altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f
+	.popsection
+
+	.pushsection .altinstr_replacement,"ax"
+143:
+	\newinstr1
+144:
+	\newinstr2
+145:
+	.popsection
+.endm
+
+.macro ALTERNATIVE_3 oldinstr, newinstr1, ft_flags1, newinstr2, ft_flags2, newinstr3, ft_flags3
+140:
+	\oldinstr
+141:
+	.skip -((alt_max_3(new_len1, new_len2, new_len3) - (old_len)) > 0) * \
+		(alt_max_3(new_len1, new_len2, new_len3) - (old_len)),0x90
+142:
+
+	.pushsection .altinstructions,"a"
+	altinstr_entry 140b,143f,\ft_flags1,142b-140b,144f-143f
+	altinstr_entry 140b,144f,\ft_flags2,142b-140b,145f-144f
+	altinstr_entry 140b,145f,\ft_flags3,142b-140b,146f-145f
+	.popsection
+
+	.pushsection .altinstr_replacement,"ax"
+143:
+	\newinstr1
+144:
+	\newinstr2
+145:
+	\newinstr3
+146:
+	.popsection
+.endm
+
+/* If @feature is set, patch in @newinstr_yes, otherwise @newinstr_no. */
+#define ALTERNATIVE_TERNARY(oldinstr, ft_flags, newinstr_yes, newinstr_no) \
+	ALTERNATIVE_2 oldinstr, newinstr_no, X86_FEATURE_ALWAYS,	\
+	newinstr_yes, ft_flags
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_X86_ALTERNATIVE_H */