debugging: Add hacks.h

1 files changed, 130 insertions, 0 deletions

diff --git a/include/linux/hacks.h b/include/linux/hacks.h
new file mode 100644
index 0000000000000..76bcf290308c9
--- /dev/null
+++ b/include/linux/hacks.h
@@ -0,0 +1,130 @@
+#if !defined(LINUX_HACKS_H)
+#define LINUX_HACKS_H
+
+/*
+ * putc - output a char to the UART at ARM64_DEBUG_PORT.
+ * model_brk - Hard breakpoint for the Fast Model debugger.
+ * c_out - output a char using Model Semi-hosting.
+ * s_out - output a string using Model Semi-hosting.
+ */
+
+#define ARM64_DEBUG_PORT 0x1c090000
+
+#if defined(__ASSEMBLY__)
+
+.macro putc c:req
+	mov	x21, #ARM64_DEBUG_PORT
+	mov	x22, \c
+	str	x22, [x21]
+.endm
+
+.macro	model_brk
+	mov	x0, #0x18;     /* angel_SWIreason_ReportException */
+	mov	x1, #0x20000; 
+	add	x1, x1, #0x20; /* ADP_Stopped_BreakPoint */
+	hlt	#0xf000        /* A64 semihosting */
+.endm
+
+.macro	model_brk_2, r1=x21, r2=x22
+	mov	\r1, x0
+	mov	\r2, x1
+	mov	x0, #0x18;     /* angel_SWIreason_ReportException */
+	mov	x1, #0x20000;
+	add	x1, x1, #0x20; /* ADP_Stopped_BreakPoint */
+	hlt	#0xf000        /* A64 semihosting */
+	mov	x0, \r1
+	mov	x1, \r2
+.endm
+
+.macro	c_out, a
+	adr	x1, .debug_str
+	mov	w2, \a
+	strb	w2, [x1]
+	mov	x0, #3
+	hlt	#0xf000
+.endm
+
+.macro	s_out, a
+	adr	x1, \a
+	mov	x0, #4			/* SYS_WRITE0 */
+	hlt	#0xf000			/* A64 semihosting */
+.endm
+
+.macro	mmu_check, a
+	c_out	#(\a + '0')
+	mrs	x1, sctlr_el1
+	tbz	x1, #0, 1f
+	s_out	.debug_y
+	b	2f
+1:
+	s_out	.debug_n
+2:
+.endm
+
+.macro	out_data
+
+	.align 3
+
+	.debug_y:
+		.string	" debug_y\n"
+	.debug_n:
+		.string	" debug_n\n"
+
+	.align 3, 0
+	.debug_str:
+		.quad	0
+		.quad	0
+		.quad	0
+		.quad	0
+.endm
+
+#else
+
+#include <linux/kernel.h>
+#include <asm/compiler.h>
+
+static inline void model_brk(int line)
+{
+	asm volatile(
+		"mov x0, #0x18;"	/* angel_SWIreason_ReportException */
+		"mov x1, #0x20000;"
+		"add x1, x1, #0x20;"	/* ADP_Stopped_BreakPoint */
+		"hlt #0xf000\n"		/* A64 semihosting */
+		:
+		: "r" (line)
+		: "x0", "x1");
+}
+
+static inline void c_out(char c)
+{
+	asm volatile("mov  x1, %0\n"
+		     "mov  x0, #3\n"
+		     "hlt  0xf000\n"
+		     : : "r" (&c) : "x0", "x1", "memory");
+}
+
+static inline void s_out(const char *s)
+{
+	asm volatile("mov  x1, %0\n"
+		     "mov  x0, #4\n"
+		     "hlt  0xf000\n"
+		     : : "r" (s) : "x0", "x1", "memory");
+}
+
+#define S(x) #x
+#define S_(x) S(x)
+
+#define line_out(_s) s_out(__func__); s_out(":" S_(__LINE__) ": " _s)
+
+#define print_sctlr_el1() _print_sctlr_el1(__func__, __LINE__)
+static inline void _print_sctlr_el1(const char *func, int line)
+{
+	u32 val;
+
+	asm volatile("mrs %0,  sctlr_el1" : "=r" (val));
+
+	printk("%s:%d: sctlr_el1: %x - %s\n", func, line, val, (val & 1) ? "y" : "n");
+}
+
+#endif
+#endif /* LINUX_HACKS_H */