1 files changed, 269 insertions, 0 deletions
diff --git a/arch/xtensa/include/asm/processor.h b/arch/xtensa/include/asm/processor.h
new file mode 100644
index 000000000..d008a153a
--- /dev/null
+++ b/arch/xtensa/include/asm/processor.h
@@ -0,0 +1,269 @@
+/*
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ *
+ * Copyright (C) 2001 - 2008 Tensilica Inc.
+ * Copyright (C) 2015 Cadence Design Systems Inc.
+ */
+
+#ifndef _XTENSA_PROCESSOR_H
+#define _XTENSA_PROCESSOR_H
+
+#include <asm/core.h>
+
+#include <linux/compiler.h>
+#include <linux/stringify.h>
+
+#include <asm/bootparam.h>
+#include <asm/ptrace.h>
+#include <asm/types.h>
+#include <asm/regs.h>
+
+#define ARCH_SLAB_MINALIGN XTENSA_STACK_ALIGNMENT
+
+/*
+ * User space process size: 1 GB.
+ * Windowed call ABI requires caller and callee to be located within the same
+ * 1 GB region. The C compiler places trampoline code on the stack for sources
+ * that take the address of a nested C function (a feature used by glibc), so
+ * the 1 GB requirement applies to the stack as well.
+ */
+
+#ifdef CONFIG_MMU
+#define TASK_SIZE	__XTENSA_UL_CONST(0x40000000)
+#else
+#define TASK_SIZE	__XTENSA_UL_CONST(0xffffffff)
+#endif
+
+#define STACK_TOP	TASK_SIZE
+#define STACK_TOP_MAX	STACK_TOP
+
+/*
+ * General exception cause assigned to fake NMI. Fake NMI needs to be handled
+ * differently from other interrupts, but it uses common kernel entry/exit
+ * code.
+ */
+
+#define EXCCAUSE_MAPPED_NMI	62
+
+/*
+ * General exception cause assigned to debug exceptions. Debug exceptions go
+ * to their own vector, rather than the general exception vectors (user,
+ * kernel, double); and their specific causes are reported via DEBUGCAUSE
+ * rather than EXCCAUSE.  However it is sometimes convenient to redirect debug
+ * exceptions to the general exception mechanism.  To do this, an otherwise
+ * unused EXCCAUSE value was assigned to debug exceptions for this purpose.
+ */
+
+#define EXCCAUSE_MAPPED_DEBUG	63
+
+/*
+ * We use DEPC also as a flag to distinguish between double and regular
+ * exceptions. For performance reasons, DEPC might contain the value of
+ * EXCCAUSE for regular exceptions, so we use this definition to mark a
+ * valid double exception address.
+ * (Note: We use it in bgeui, so it should be 64, 128, or 256)
+ */
+
+#define VALID_DOUBLE_EXCEPTION_ADDRESS	64
+
+#define XTENSA_INT_LEVEL(intno) _XTENSA_INT_LEVEL(intno)
+#define _XTENSA_INT_LEVEL(intno) XCHAL_INT##intno##_LEVEL
+
+#define XTENSA_INTLEVEL_MASK(level) _XTENSA_INTLEVEL_MASK(level)
+#define _XTENSA_INTLEVEL_MASK(level) (XCHAL_INTLEVEL##level##_MASK)
+
+#define XTENSA_INTLEVEL_ANDBELOW_MASK(l) _XTENSA_INTLEVEL_ANDBELOW_MASK(l)
+#define _XTENSA_INTLEVEL_ANDBELOW_MASK(l) (XCHAL_INTLEVEL##l##_ANDBELOW_MASK)
+
+#define PROFILING_INTLEVEL XTENSA_INT_LEVEL(XCHAL_PROFILING_INTERRUPT)
+
+/* LOCKLEVEL defines the interrupt level that masks all
+ * general-purpose interrupts.
+ */
+#if defined(CONFIG_XTENSA_FAKE_NMI) && defined(XCHAL_PROFILING_INTERRUPT)
+#define LOCKLEVEL (PROFILING_INTLEVEL - 1)
+#else
+#define LOCKLEVEL XCHAL_EXCM_LEVEL
+#endif
+
+#define TOPLEVEL XCHAL_EXCM_LEVEL
+#define XTENSA_FAKE_NMI (LOCKLEVEL < TOPLEVEL)
+
+/* WSBITS and WBBITS are the width of the WINDOWSTART and WINDOWBASE
+ * registers
+ */
+#define WSBITS  (XCHAL_NUM_AREGS / 4)      /* width of WINDOWSTART in bits */
+#define WBBITS  (XCHAL_NUM_AREGS_LOG2 - 2) /* width of WINDOWBASE in bits */
+
+#if defined(__XTENSA_WINDOWED_ABI__)
+#define KERNEL_PS_WOE_MASK PS_WOE_MASK
+#elif defined(__XTENSA_CALL0_ABI__)
+#define KERNEL_PS_WOE_MASK 0
+#else
+#error Unsupported xtensa ABI
+#endif
+
+#ifndef __ASSEMBLY__
+
+#if defined(__XTENSA_WINDOWED_ABI__)
+
+/* Build a valid return address for the specified call winsize.
+ * winsize must be 1 (call4), 2 (call8), or 3 (call12)
+ */
+#define MAKE_RA_FOR_CALL(ra,ws)   (((ra) & 0x3fffffff) | (ws) << 30)
+
+/* Convert return address to a valid pc
+ * Note: We assume that the stack pointer is in the same 1GB ranges as the ra
+ */
+#define MAKE_PC_FROM_RA(ra,sp)    (((ra) & 0x3fffffff) | ((sp) & 0xc0000000))
+
+#elif defined(__XTENSA_CALL0_ABI__)
+
+/* Build a valid return address for the specified call winsize.
+ * winsize must be 1 (call4), 2 (call8), or 3 (call12)
+ */
+#define MAKE_RA_FOR_CALL(ra, ws)   (ra)
+
+/* Convert return address to a valid pc
+ * Note: We assume that the stack pointer is in the same 1GB ranges as the ra
+ */
+#define MAKE_PC_FROM_RA(ra, sp)    (ra)
+
+#else
+#error Unsupported Xtensa ABI
+#endif
+
+/* Spill slot location for the register reg in the spill area under the stack
+ * pointer sp. reg must be in the range [0..4).
+ */
+#define SPILL_SLOT(sp, reg) (*(((unsigned long *)(sp)) - 4 + (reg)))
+
+/* Spill slot location for the register reg in the spill area under the stack
+ * pointer sp for the call8. reg must be in the range [4..8).
+ */
+#define SPILL_SLOT_CALL8(sp, reg) (*(((unsigned long *)(sp)) - 12 + (reg)))
+
+/* Spill slot location for the register reg in the spill area under the stack
+ * pointer sp for the call12. reg must be in the range [4..12).
+ */
+#define SPILL_SLOT_CALL12(sp, reg) (*(((unsigned long *)(sp)) - 16 + (reg)))
+
+struct thread_struct {
+
+	/* kernel's return address and stack pointer for context switching */
+	unsigned long ra; /* kernel's a0: return address and window call size */
+	unsigned long sp; /* kernel's a1: stack pointer */
+
+#ifdef CONFIG_HAVE_HW_BREAKPOINT
+	struct perf_event *ptrace_bp[XCHAL_NUM_IBREAK];
+	struct perf_event *ptrace_wp[XCHAL_NUM_DBREAK];
+#endif
+	/* Make structure 16 bytes aligned. */
+	int align[0] __attribute__ ((aligned(16)));
+};
+
+/* This decides where the kernel will search for a free chunk of vm
+ * space during mmap's.
+ */
+#define TASK_UNMAPPED_BASE	(TASK_SIZE / 2)
+
+#define INIT_THREAD  \
+{									\
+	ra:		0, 						\
+	sp:		sizeof(init_stack) + (long) &init_stack,	\
+}
+
+
+/*
+ * Do necessary setup to start up a newly executed thread.
+ * Note: When windowed ABI is used for userspace we set-up ps
+ *       as if we did a call4 to the new pc.
+ *       set_thread_state in signal.c depends on it.
+ */
+#if IS_ENABLED(CONFIG_USER_ABI_CALL0)
+#define USER_PS_VALUE ((USER_RING << PS_RING_SHIFT) |			\
+		       (1 << PS_UM_BIT) |				\
+		       (1 << PS_EXCM_BIT))
+#else
+#define USER_PS_VALUE (PS_WOE_MASK |					\
+		       (1 << PS_CALLINC_SHIFT) |			\
+		       (USER_RING << PS_RING_SHIFT) |			\
+		       (1 << PS_UM_BIT) |				\
+		       (1 << PS_EXCM_BIT))
+#endif
+
+/* Clearing a0 terminates the backtrace. */
+#define start_thread(regs, new_pc, new_sp) \
+	do { \
+		unsigned long syscall = (regs)->syscall; \
+		unsigned long current_aregs[16]; \
+		memcpy(current_aregs, (regs)->areg, sizeof(current_aregs)); \
+		memset((regs), 0, sizeof(*(regs))); \
+		(regs)->pc = (new_pc); \
+		(regs)->ps = USER_PS_VALUE; \
+		memcpy((regs)->areg, current_aregs, sizeof(current_aregs)); \
+		(regs)->areg[1] = (new_sp); \
+		(regs)->areg[0] = 0; \
+		(regs)->wmask = 1; \
+		(regs)->depc = 0; \
+		(regs)->windowbase = 0; \
+		(regs)->windowstart = 1; \
+		(regs)->syscall = syscall; \
+	} while (0)
+
+/* Forward declaration */
+struct task_struct;
+struct mm_struct;
+
+extern unsigned long __get_wchan(struct task_struct *p);
+
+void init_arch(bp_tag_t *bp_start);
+void do_notify_resume(struct pt_regs *regs);
+
+#define KSTK_EIP(tsk)		(task_pt_regs(tsk)->pc)
+#define KSTK_ESP(tsk)		(task_pt_regs(tsk)->areg[1])
+
+#define cpu_relax()  barrier()
+
+/* Special register access. */
+
+#define xtensa_set_sr(x, sr) \
+	({ \
+	 __asm__ __volatile__ ("wsr %0, "__stringify(sr) :: \
+			       "a"((unsigned int)(x))); \
+	 })
+
+#define xtensa_get_sr(sr) \
+	({ \
+	 unsigned int v; \
+	 __asm__ __volatile__ ("rsr %0, "__stringify(sr) : "=a"(v)); \
+	 v; \
+	 })
+
+#define xtensa_xsr(x, sr) \
+	({ \
+	 unsigned int __v__ = (unsigned int)(x); \
+	 __asm__ __volatile__ ("xsr %0, " __stringify(sr) : "+a"(__v__)); \
+	 __v__; \
+	 })
+
+#if XCHAL_HAVE_EXTERN_REGS
+
+static inline void set_er(unsigned long value, unsigned long addr)
+{
+	asm volatile ("wer %0, %1" : : "a" (value), "a" (addr) : "memory");
+}
+
+static inline unsigned long get_er(unsigned long addr)
+{
+	register unsigned long value;
+	asm volatile ("rer %0, %1" : "=a" (value) : "a" (addr) : "memory");
+	return value;
+}
+
+#endif /* XCHAL_HAVE_EXTERN_REGS */
+
+#endif	/* __ASSEMBLY__ */
+#endif	/* _XTENSA_PROCESSOR_H */