MIPS: Add GINVT instruction helpers

Add a family of ginvt_* functions making it easy to emit a GINVT
instruction to globally invalidate TLB entries. We make use of the
_ASM_MACRO infrastructure to support emitting the instructions even if
the assembler isn't new enough to support them natively.

An associated STYPE_GINV definition & sync_ginv() function are added to
emit a sync instruction of type 0x14, which operates as a completion
barrier for these new GINVT (and GINVI) instructions.

Signed-off-by: Paul Burton <paul.burton@mips.com>
Cc: linux-mips@vger.kernel.org

1 files changed, 56 insertions, 0 deletions

diff --git a/arch/mips/include/asm/ginvt.h b/arch/mips/include/asm/ginvt.h
new file mode 100644
index 000000000000..49c6dbe37338
--- /dev/null
+++ b/arch/mips/include/asm/ginvt.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __MIPS_ASM_GINVT_H__
+#define __MIPS_ASM_GINVT_H__
+
+#include <asm/mipsregs.h>
+
+enum ginvt_type {
+	GINVT_FULL,
+	GINVT_VA,
+	GINVT_MMID,
+};
+
+#ifdef TOOLCHAIN_SUPPORTS_GINV
+# define _ASM_SET_GINV	".set	ginv\n"
+#else
+_ASM_MACRO_1R1I(ginvt, rs, type,
+		_ASM_INSN_IF_MIPS(0x7c0000bd | (__rs << 21) | (\\type << 8))
+		_ASM_INSN32_IF_MM(0x0000717c | (__rs << 16) | (\\type << 9)));
+# define _ASM_SET_GINV
+#endif
+
+static inline void ginvt(unsigned long addr, enum ginvt_type type)
+{
+	asm volatile(
+		".set	push\n"
+		_ASM_SET_GINV
+		"	ginvt	%0, %1\n"
+		".set	pop"
+		: /* no outputs */
+		: "r"(addr), "i"(type)
+		: "memory");
+}
+
+static inline void ginvt_full(void)
+{
+	ginvt(0, GINVT_FULL);
+}
+
+static inline void ginvt_va(unsigned long addr)
+{
+	addr &= PAGE_MASK << 1;
+	ginvt(addr, GINVT_VA);
+}
+
+static inline void ginvt_mmid(void)
+{
+	ginvt(0, GINVT_MMID);
+}
+
+static inline void ginvt_va_mmid(unsigned long addr)
+{
+	addr &= PAGE_MASK << 1;
+	ginvt(addr, GINVT_VA | GINVT_MMID);
+}
+
+#endif /* __MIPS_ASM_GINVT_H__ */