Adding upstream version 6.6.15.upstream/6.6.15

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

1 files changed, 111 insertions, 0 deletions

diff --git a/arch/loongarch/include/asm/alternative.h b/arch/loongarch/include/asm/alternative.h
new file mode 100644
index 0000000000..cee7b29785
--- /dev/null
+++ b/arch/loongarch/include/asm/alternative.h
@@ -0,0 +1,111 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_ALTERNATIVE_H
+#define _ASM_ALTERNATIVE_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/types.h>
+#include <linux/stddef.h>
+#include <linux/stringify.h>
+#include <asm/asm.h>
+
+struct alt_instr {
+	s32 instr_offset;	/* offset to original instruction */
+	s32 replace_offset;	/* offset to replacement instruction */
+	u16 feature;		/* feature bit set for replacement */
+	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 struct alt_instr __alt_instructions[], __alt_instructions_end[];
+
+extern void alternative_instructions(void);
+extern void apply_alternatives(struct alt_instr *start, struct alt_instr *end);
+
+#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)					\
+	"661:\n\t" oldinstr "\n662:\n"					\
+	".fill -(((" alt_rlen(num) ")-(" alt_slen ")) > 0) * "		\
+		"((" alt_rlen(num) ")-(" alt_slen ")) / 4, 4, 0x03400000\n"
+
+#define OLDINSTR(oldinstr, num)						\
+	__OLDINSTR(oldinstr, num)					\
+	alt_end_marker ":\n"
+
+#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) \
+	"661:\n\t" oldinstr "\n662:\n"								\
+	".fill -((" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")) > 0) * "	\
+		"(" alt_max_short(alt_rlen(num1), alt_rlen(num2)) " - (" alt_slen ")) / 4, "	\
+		"4, 0x03400000\n"	\
+	alt_end_marker ":\n"
+
+#define ALTINSTR_ENTRY(feature, num)					      \
+	" .long 661b - .\n"				/* label           */ \
+	" .long " b_replacement(num)"f - .\n"		/* new instruction */ \
+	" .short " __stringify(feature) "\n"		/* feature bit     */ \
+	" .byte " alt_total_slen "\n"			/* source len      */ \
+	" .byte " alt_rlen(num) "\n"			/* replacement len */
+
+#define ALTINSTR_REPLACEMENT(newinstr, feature, num)	/* replacement */     \
+	b_replacement(num)":\n\t" newinstr "\n" e_replacement(num) ":\n\t"
+
+/* alternative assembly primitive: */
+#define ALTERNATIVE(oldinstr, newinstr, feature)			\
+	OLDINSTR(oldinstr, 1)						\
+	".pushsection .altinstructions,\"a\"\n"				\
+	ALTINSTR_ENTRY(feature, 1)					\
+	".popsection\n"							\
+	".subsection 1\n" \
+	ALTINSTR_REPLACEMENT(newinstr, feature, 1)			\
+	".previous\n"
+
+#define ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2)\
+	OLDINSTR_2(oldinstr, 1, 2)					\
+	".pushsection .altinstructions,\"a\"\n"				\
+	ALTINSTR_ENTRY(feature1, 1)					\
+	ALTINSTR_ENTRY(feature2, 2)					\
+	".popsection\n"							\
+	".subsection 1\n" \
+	ALTINSTR_REPLACEMENT(newinstr1, feature1, 1)			\
+	ALTINSTR_REPLACEMENT(newinstr2, feature2, 2)			\
+	".previous\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, feature)			\
+	(asm volatile (ALTERNATIVE(oldinstr, newinstr, feature) : : : "memory"))
+
+#define alternative_2(oldinstr, newinstr1, feature1, newinstr2, feature2) \
+	(asm volatile(ALTERNATIVE_2(oldinstr, newinstr1, feature1, newinstr2, feature2) ::: "memory"))
+
+#endif /* __ASSEMBLY__ */
+
+#endif /* _ASM_ALTERNATIVE_H */