xtensa: add support for the xtensa processor architecture [2/2]
The Xtensa processor architecture is a configurable, extensible,
and synthesizable 32-bit RISC processor core provided by Tensilica, inc.
This is the second part of the basic architecture port, adding the
'arch/xtensa' directory and a readme file.
Signed-off-by: Chris Zankel <chris@zankel.net>
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
diff --git a/arch/xtensa/include/asm/ptrace.h b/arch/xtensa/include/asm/ptrace.h
new file mode 100644
index 0000000..d187dbf
--- /dev/null
+++ b/arch/xtensa/include/asm/ptrace.h
@@ -0,0 +1,133 @@
+/*
+ * Copyright (C) 2001 - 2007 Tensilica Inc.
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#ifndef _XTENSA_PTRACE_H
+#define _XTENSA_PTRACE_H
+
+#include <compiler.h>
+
+/*
+ * Kernel stack
+ *
+ * +-----------------------+ -------- STACK_SIZE
+ * | register file | |
+ * +-----------------------+ |
+ * | struct pt_regs | |
+ * +-----------------------+ | ------ PT_REGS_OFFSET
+ * double : 16 bytes spill area : | ^
+ * exception :- - - - - - - - - - - -: | |
+ * frame : struct pt_regs : | |
+ * :- - - - - - - - - - - -: | |
+ * | | | |
+ * | memory stack | | |
+ * | | | |
+ * ~ ~ ~ ~
+ * ~ ~ ~ ~
+ * | | | |
+ * | | | |
+ * +-----------------------+ | | --- STACK_BIAS
+ * | struct task_struct | | | ^
+ * current --> +-----------------------+ | | |
+ * | struct thread_info | | | |
+ * +-----------------------+ --------
+ */
+
+#define KERNEL_STACK_SIZE (2 * PAGE_SIZE)
+
+/* Offsets for exception_handlers[] (3 x 64-entries x 4-byte tables) */
+
+#define EXC_TABLE_KSTK 0x004 /* Kernel Stack */
+#define EXC_TABLE_DOUBLE_SAVE 0x008 /* Double exception save area for a0 */
+#define EXC_TABLE_FIXUP 0x00c /* Fixup handler */
+#define EXC_TABLE_PARAM 0x010 /* For passing a parameter to fixup */
+#define EXC_TABLE_SYSCALL_SAVE 0x014 /* For fast syscall handler */
+#define EXC_TABLE_FAST_USER 0x100 /* Fast user exception handler */
+#define EXC_TABLE_FAST_KERNEL 0x200 /* Fast kernel exception handler */
+#define EXC_TABLE_DEFAULT 0x300 /* Default C-Handler */
+#define EXC_TABLE_SIZE 0x400
+
+/* Registers used by strace */
+
+#define REG_A_BASE 0xfc000000
+#define REG_AR_BASE 0x04000000
+#define REG_PC 0x14000000
+#define REG_PS 0x080000e6
+#define REG_WB 0x08000048
+#define REG_WS 0x08000049
+#define REG_LBEG 0x08000000
+#define REG_LEND 0x08000001
+#define REG_LCOUNT 0x08000002
+#define REG_SAR 0x08000003
+#define REG_DEPC 0x080000c0
+#define REG_EXCCAUSE 0x080000e8
+#define REG_EXCVADDR 0x080000ee
+#define SYSCALL_NR 0x1
+
+#define AR_REGNO_TO_A_REGNO(ar, wb) (ar - wb*4) & ~(XCHAL_NUM_AREGS - 1)
+
+/* Other PTRACE_ values defined in <linux/ptrace.h> using values 0-9,16,17,24 */
+
+#define PTRACE_GETREGS 12
+#define PTRACE_SETREGS 13
+#define PTRACE_GETFPREGS 14
+#define PTRACE_SETFPREGS 15
+#define PTRACE_GETFPREGSIZE 18
+
+#ifndef __ASSEMBLY__
+
+/*
+ * This struct defines the way the registers are stored on the
+ * kernel stack during a system call or other kernel entry.
+ */
+struct pt_regs {
+ unsigned long pc; /* 4 */
+ unsigned long ps; /* 8 */
+ unsigned long depc; /* 12 */
+ unsigned long exccause; /* 16 */
+ unsigned long excvaddr; /* 20 */
+ unsigned long debugcause; /* 24 */
+ unsigned long wmask; /* 28 */
+ unsigned long lbeg; /* 32 */
+ unsigned long lend; /* 36 */
+ unsigned long lcount; /* 40 */
+ unsigned long sar; /* 44 */
+ unsigned long windowbase; /* 48 */
+ unsigned long windowstart; /* 52 */
+ unsigned long syscall; /* 56 */
+ unsigned long icountlevel; /* 60 */
+ int reserved[1]; /* 64 */
+
+ /* Make sure the areg field is 16 bytes aligned */
+ int align[0] __aligned(16);
+
+ /* current register frame.
+ * Note: The ESF for kernel exceptions ends after 16 registers!
+ */
+ unsigned long areg[16]; /* 128 (64) */
+};
+
+#ifdef __KERNEL__
+
+# define task_pt_regs(tsk) ((struct pt_regs *) \
+ (task_stack_page(tsk) + KERNEL_STACK_SIZE - (XCHAL_NUM_AREGS-16)*4) - 1)
+# define user_mode(regs) (((regs)->ps & 0x00000020) != 0)
+# define instruction_pointer(regs) ((regs)->pc)
+void show_regs(struct pt_regs *);
+
+# ifndef CONFIG_SMP
+# define profile_pc(regs) instruction_pointer(regs)
+# endif
+#endif /* __KERNEL__ */
+
+#else /* __ASSEMBLY__ */
+
+#ifdef __KERNEL__
+# include <asm/asm-offsets.h>
+#define PT_REGS_OFFSET (KERNEL_STACK_SIZE - PT_USER_SIZE)
+#endif
+
+#endif /* !__ASSEMBLY__ */
+#endif /* _XTENSA_PTRACE_H */