[PATCH 1/3] MIPS: Add header for UHI semihosting defines

[Jiaxun Yang <jiaxun.yang@flygoat.com>]

Add a header for MIPS UHI semihosting defines.
Including calling number, data structures and functions
to do UHI calls.

Signed-off-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
---
 arch/mips/include/asm/uhi.h | 309 ++++++++++++++++++++++++++++++++++++
 1 file changed, 309 insertions(+)
 create mode 100644 arch/mips/include/asm/uhi.h

diff --git a/arch/mips/include/asm/uhi.h b/arch/mips/include/asm/uhi.h
new file mode 100644
index 000000000000..5e72fd5a67fb
--- /dev/null
+++ b/arch/mips/include/asm/uhi.h
@@ -0,0 +1,309 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * MIPS UHI semihosting define and helpers
+ *
+ * Based on MD01069 - Unified Hosting Interface Reference Manual
+ *
+ * Copyright (C) 2023 Jiaxun Yang <jiaxun.yang@flygoat.com>
+ */
+
+
+#ifndef _MIPS_UHI_H_
+#define _MIPS_UHI_H_
+
+#include <linux/compiler.h>
+#include <linux/types.h>
+
+#define UHI_NR_exit		1
+#define UHI_NR_open		2
+#define UHI_NR_close		3
+#define UHI_NR_read		4
+#define UHI_NR_write		5
+#define UHI_NR_lseek		6
+#define UHI_NR_unlink		7
+#define UHI_NR_fstat		8
+#define UHI_NR_argc		9
+#define UHI_NR_argnlen		10
+#define UHI_NR_argn		11
+#define UHI_NR_plog		13
+#define UHI_NR_assert		14
+#define UHI_NR_pread		19
+#define UHI_NR_pwrite		20
+#define UHI_NR_link		22
+#define UHI_NR_bootfailure	23
+
+/* For SDDBP code and R2 */
+#define UHI_CALL_CODE		"1"
+#define UHI_CALL_CODE_RAW	1
+
+struct uhi_stat {
+	int16_t st_dev;
+	uint16_t st_ino;
+	uint32_t st_mode;
+	uint16_t st_nlink;
+	uint16_t st_uid;
+	uint16_t st_gid;
+	int16_t st_rdev;
+	uint64_t st_size;
+	uint64_t st_atime;
+	uint64_t st_spare1;
+	uint64_t st_mtime;
+	uint64_t st_spare2;
+	uint64_t st_ctime;
+	uint64_t st_spare3;
+	uint64_t st_blksize;
+	uint64_t st_blocks;
+	uint64_t st_spare4[2];
+};
+
+#define UHI_O_RDONLY	0x0
+#define UHI_O_WRONLY	0x1
+#define UHI_O_RDWR	0x2
+#define UHI_O_APPEND	0x8
+#define UHI_O_CREAT	0x200
+#define UHI_O_TRUNC	0x400
+#define UHI_O_EXCL	0x800
+
+#define UHI_EACCESS		13
+#define UHI_EAGAIN		11
+#define UHI_EBADF		9
+#define UHI_EBADMSG		77
+#define UHI_EBUSY		16
+#define UHI_ECONNRESET		104
+#define UHI_EEXIST		17
+#define UHI_EFBIG		27
+#define UHI_EINTR		4
+#define UHI_EINVAL		22
+#define UHI_EIO			5
+#define UHI_EISDIR		21
+#define UHI_ELOOP		92
+#define UHI_EMFILE		24
+#define UHI_EMLINK		31
+#define UHI_ENAMETOOLONG	91
+#define UHI_ENETDOWN		115
+#define UHI_ENETUNREACH		114
+#define UHI_ENFILE		23
+#define UHI_ENOBUFS		105
+#define UHI_ENOENT		2
+#define UHI_ENOMEM		12
+#define UHI_ENOSPC		28
+#define UHI_ENOSR		63
+#define UHI_ENOTCONN		128
+#define UHI_ENOTDIR		20
+#define UHI_ENXIO		6
+#define UHI_EOVERFLOW		139
+#define UHI_EPERM		1
+#define UHI_EPIPE		32
+#define UHI_ERANGE		34
+#define UHI_EROFS		30
+#define UHI_ESPIPE		29
+#define UHI_ETIMEDOUT		116
+#define UHI_ETXTBSY		26
+#define UHI_EWOULDBLOCK		11
+#define UHI_EXDEV		18
+
+
+struct uhi_gpctx {
+	unsigned long r[31];
+	unsigned long epc;
+	unsigned long badvaddr;
+	unsigned long hi;
+	unsigned long lo;
+	void *link;
+	uint32_t status;
+	uint32_t cause;
+	uint32_t badinstr;
+	uint32_t badpinstr;
+};
+
+static inline long __uhi_call0(long n)
+{
+	register long r2 __asm__("$2");
+	register long r25 __asm__("$25") = n;
+	register long r3 __asm__("$3");
+
+	__asm__ __volatile__ (
+		".set	push   \n"
+		".set	" MIPS_ISA_LEVEL " \n"
+		"addu $2,$0,%2 \n"
+		"sdbbp " UHI_CALL_CODE "   \n"
+		".set	pop	\n"
+		: "=&r"(r2), "=r"(r3)
+		: "ir"(UHI_CALL_CODE_RAW), "0"(r2), "r"(r25)
+		: "memory");
+
+	return r2 == -1 ? -r3 : r2;
+}
+
+static inline long __uhi_call1(long n, long a)
+{
+	register long r2 __asm__("$2");
+	register long r25 __asm__("$25") = n;
+	register long r4 __asm__("$4") = a;
+	register long r3 __asm__("$3");
+
+	__asm__ __volatile__ (
+		".set	push   \n"
+		".set	" MIPS_ISA_LEVEL " \n"
+		"addu $2,$0,%2 \n"
+		"sdbbp " UHI_CALL_CODE "   \n"
+		".set	pop	\n"
+		: "=&r"(r2), "=r"(r3)
+		: "ir"(UHI_CALL_CODE_RAW), "0"(r2), "r"(r25), "r"(r4)
+		: "memory");
+
+	return r2 == -1 ? -r3 : r2;
+}
+
+static inline long __uhi_call2(long n, long a, long b)
+{
+	register long r2 __asm__("$2");
+	register long r25 __asm__("$25") = n;
+	register long r4 __asm__("$4") = a;
+	register long r5 __asm__("$5") = b;
+	register long r3 __asm__("$3");
+
+	__asm__ __volatile__ (
+		".set	push   \n"
+		".set	" MIPS_ISA_LEVEL " \n"
+		"addu $2,$0,%2 \n"
+		"sdbbp " UHI_CALL_CODE "   \n"
+		".set	pop	\n"
+		: "=&r"(r2), "=r"(r3)
+		: "ir"(UHI_CALL_CODE_RAW), "0"(r2), "r"(r25), "r"(r4), "r"(r5)
+		: "memory");
+
+	return r2 == -1 ? -r3 : r2;
+}
+
+static inline long __uhi_call3(long n, long a, long b, long c)
+{
+	register long r2 __asm__("$2");
+	register long r25 __asm__("$25") = n;
+	register long r4 __asm__("$4") = a;
+	register long r5 __asm__("$5") = b;
+	register long r6 __asm__("$6") = c;
+	register long r3 __asm__("$3");
+
+	__asm__ __volatile__ (
+		".set	push   \n"
+		".set	" MIPS_ISA_LEVEL " \n"
+		"addu $2,$0,%2 \n"
+		"sdbbp " UHI_CALL_CODE "   \n"
+		".set	pop	\n"
+		: "=&r"(r2), "=r"(r3)
+		: "ir"(UHI_CALL_CODE_RAW), "0"(r2), "r"(r25), "r"(r4), "r"(r5), "r"(r6)
+		: "memory");
+
+	return r2 == -1 ? -r3 : r2;
+}
+
+static inline long __uhi_call4(long n, long a, long b, long c, long d)
+{
+	register long r2 __asm__("$2");
+	register long r25 __asm__("$25") = n;
+	register long r4 __asm__("$4") = a;
+	register long r5 __asm__("$5") = b;
+	register long r6 __asm__("$6") = c;
+	register long r7 __asm__("$7") = d;
+	register long r3 __asm__("$3");
+
+	__asm__ __volatile__ (
+		".set	push   \n"
+		".set	" MIPS_ISA_LEVEL " \n"
+		"addu $2,$0,%2 \n"
+		"sdbbp " UHI_CALL_CODE "   \n"
+		".set	pop	\n"
+		: "=&r"(r2), "=r"(r3)
+		: "ir"(UHI_CALL_CODE_RAW), "0"(r2), "r"(r25), "r"(r4), "r"(r5), "r"(r6), "r"(r7)
+		: "memory");
+
+	return r2 == -1 ? -r3 : r2;
+}
+
+static inline int32_t uhi_exit(int32_t code)
+{
+	return __uhi_call1(UHI_NR_exit, code);
+}
+
+static inline int32_t uhi_open(const char *path, int32_t flags, int32_t mode)
+{
+	return __uhi_call3(UHI_NR_open, (long)path, flags, mode);
+}
+
+static inline int32_t uhi_close(int32_t fd)
+{
+	return __uhi_call1(UHI_NR_close, fd);
+}
+
+static inline int32_t uhi_read(int32_t fd, char *buf, long num)
+{
+	return __uhi_call3(UHI_NR_read, fd, (long)buf, num);
+}
+
+static inline long uhi_write(int32_t fd, const char *buf, long num)
+{
+	return __uhi_call3(UHI_NR_write, fd, (long)buf, num);
+}
+
+static inline int32_t uhi_lseek(int32_t fd, long offset, int32_t whence)
+{
+	return __uhi_call3(UHI_NR_lseek, fd, offset, whence);
+}
+
+static inline int32_t uhi_unlink(const char *path)
+{
+	return __uhi_call1(UHI_NR_unlink, (long)path);
+}
+
+static inline int32_t uhi_fstat(int32_t fd, struct uhi_stat *buf)
+{
+	return __uhi_call2(UHI_NR_fstat, fd, (long)buf);
+}
+
+static inline int32_t uhi_argc(void)
+{
+	return __uhi_call0(UHI_NR_argc);
+}
+
+static inline int32_t uhi_argnlen(int32_t n)
+{
+	return __uhi_call1(UHI_NR_argnlen, n);
+}
+
+static inline int32_t uhi_argn(int32_t n, char *buf, int32_t num)
+{
+	return __uhi_call3(UHI_NR_argn, n, (long)buf, num);
+}
+
+static inline int32_t uhi_plog(const char *buf, int32_t num)
+{
+	return __uhi_call2(UHI_NR_plog, (long)buf, num);
+}
+
+static inline void uhi_assert(const char *msg, const char *file, int32_t line)
+{
+	__uhi_call3(UHI_NR_assert, (long)msg, (long)file, line);
+}
+
+static inline int32_t uhi_link(const char *oldpath, const char *newpath)
+{
+	return __uhi_call2(UHI_NR_link, (long)oldpath, (long)newpath);
+}
+
+static inline int32_t uhi_pread(int32_t fd, char *buf, long num, long offset)
+{
+	return __uhi_call4(UHI_NR_pread, fd, (long)buf, num, offset);
+}
+
+static inline int32_t uhi_pwrite(int32_t fd, const char *buf, long num, long offset)
+{
+	return __uhi_call4(UHI_NR_pwrite, fd, (long)buf, num, offset);
+}
+
+static inline void uhi_bootfailure(int reason)
+{
+	__uhi_call1(UHI_NR_bootfailure, reason);
+}
+
+#endif
-- 
2.34.1