summaryrefslogtreecommitdiffstats
path: root/include/asm-m68k/processor.h
diff options
context:
space:
mode:
Diffstat (limited to 'include/asm-m68k/processor.h')
-rw-r--r--include/asm-m68k/processor.h92
1 files changed, 92 insertions, 0 deletions
diff --git a/include/asm-m68k/processor.h b/include/asm-m68k/processor.h
new file mode 100644
index 000000000..d228816af
--- /dev/null
+++ b/include/asm-m68k/processor.h
@@ -0,0 +1,92 @@
+/*
+ * include/asm-m68k/processor.h
+ *
+ * Copyright (C) 1995 Hamish Macdonald
+ */
+
+#ifndef __ASM_M68K_PROCESSOR_H
+#define __ASM_M68K_PROCESSOR_H
+
+#include <asm/segment.h>
+
+/*
+ * User space process size: 3.75GB. This is hardcoded into a few places,
+ * so don't change it unless you know what you are doing.
+ */
+#define TASK_SIZE (0xF0000000UL)
+
+/*
+ * Bus types
+ */
+#define EISA_bus 0
+#define MCA_bus 0
+
+/* MAX floating point unit state size (FSAVE/FRESTORE) */
+#define FPSTATESIZE (216/sizeof(unsigned char))
+
+/*
+ * if you change this structure, you must change the code and offsets
+ * in m68k/machasm.S
+ */
+
+struct thread_struct {
+ unsigned long ksp; /* kernel stack pointer */
+ unsigned long usp; /* user stack pointer */
+ unsigned short sr; /* saved status register */
+ unsigned short fs; /* saved fs (sfc, dfc) */
+ unsigned long crp[2]; /* cpu root pointer */
+ unsigned long esp0; /* points to SR of stack frame */
+ unsigned long fp[8*3];
+ unsigned long fpcntl[3]; /* fp control regs */
+ unsigned char fpstate[FPSTATESIZE]; /* floating point state */
+};
+
+#define INIT_MMAP { &init_mm, 0, 0x40000000, __pgprot(_PAGE_PRESENT|_PAGE_ACCESSED), VM_READ | VM_WRITE | VM_EXEC }
+
+#define INIT_TSS { \
+ sizeof(init_kernel_stack) + (long) init_kernel_stack, 0, \
+ PS_S, KERNEL_DS, \
+ {0, 0}, 0, {0,}, {0, 0, 0}, {0,}, \
+}
+
+#define alloc_kernel_stack() __get_free_page(GFP_KERNEL)
+#define free_kernel_stack(page) free_page((page))
+
+/*
+ * Do necessary setup to start up a newly executed thread.
+ */
+static inline void start_thread(struct pt_regs * regs, unsigned long pc,
+ unsigned long usp)
+{
+ unsigned long nilstate = 0;
+
+ /* clear floating point state */
+ __asm__ __volatile__ ("frestore %0@" : : "a" (&nilstate));
+
+ /* reads from user space */
+ set_fs(USER_DS);
+
+ regs->pc = pc;
+ regs->sr &= ~0x2000;
+ wrusp(usp);
+}
+
+/*
+ * Return saved PC of a blocked thread.
+ */
+extern inline unsigned long thread_saved_pc(struct thread_struct *t)
+{
+ return ((unsigned long *)((struct switch_stack *)t->ksp)->a6)[1];
+}
+
+/*
+ * Return_address is a replacement for __builtin_return_address(count)
+ * which on certain architectures cannot reasonably be implemented in GCC
+ * (MIPS, Alpha) or is unuseable with -fomit-frame-pointer (i386).
+ * Note that __builtin_return_address(x>=1) is forbidden because the GCC
+ * aborts compilation on some CPUs. It's simply not possible to unwind
+ * some CPU's stackframes.
+ */
+#define return_address() __builtin_return_address(0)
+
+#endif