m68k: merge the mmu and non-mmu versions of sys_m68k.c

There is a lot of common code in the sys_m68k.c files. The mmu and non-mmu
versions can easily be merged into a single file.

There is really only 2 functions that differ in the 2 cases. A single
ifdef on CONFIG_MMU can take care of this. Alternatively we could break
those 2 functions out and maintain sys_m68k_no.c and sys_m68k_mm.c with
just this code in it (Makefile could then just build the right one).
Does anyone have strong feelings on which way they want this done?

Signed-off-by: Greg Ungerer <gerg@uclinux.org>

1 files changed, 578 insertions, 3 deletions

diff --git a/arch/m68k/kernel/sys_m68k.c b/arch/m68k/kernel/sys_m68k.c
index 63013df33584..8623f8dc16f8 100644
--- a/arch/m68k/kernel/sys_m68k.c
+++ b/arch/m68k/kernel/sys_m68k.c
@@ -1,5 +1,580 @@
+/*
+ * linux/arch/m68k/kernel/sys_m68k.c
+ *
+ * This file contains various random system calls that
+ * have a non-standard calling sequence on the Linux/m68k
+ * platform.
+ */
+
+#include <linux/capability.h>
+#include <linux/errno.h>
+#include <linux/sched.h>
+#include <linux/mm.h>
+#include <linux/fs.h>
+#include <linux/smp.h>
+#include <linux/sem.h>
+#include <linux/msg.h>
+#include <linux/shm.h>
+#include <linux/stat.h>
+#include <linux/syscalls.h>
+#include <linux/mman.h>
+#include <linux/file.h>
+#include <linux/ipc.h>
+
+#include <asm/setup.h>
+#include <asm/uaccess.h>
+#include <asm/cachectl.h>
+#include <asm/traps.h>
+#include <asm/page.h>
+#include <asm/unistd.h>
+#include <asm/cacheflush.h>
+
 #ifdef CONFIG_MMU
-#include "sys_m68k_mm.c"
+
+#include <asm/tlb.h>
+
+asmlinkage int do_page_fault(struct pt_regs *regs, unsigned long address,
+			     unsigned long error_code);
+
+asmlinkage long sys_mmap2(unsigned long addr, unsigned long len,
+	unsigned long prot, unsigned long flags,
+	unsigned long fd, unsigned long pgoff)
+{
+	/*
+	 * This is wrong for sun3 - there PAGE_SIZE is 8Kb,
+	 * so we need to shift the argument down by 1; m68k mmap64(3)
+	 * (in libc) expects the last argument of mmap2 in 4Kb units.
+	 */
+	return sys_mmap_pgoff(addr, len, prot, flags, fd, pgoff);
+}
+
+/* Convert virtual (user) address VADDR to physical address PADDR */
+#define virt_to_phys_040(vaddr)						\
+({									\
+  unsigned long _mmusr, _paddr;						\
+									\
+  __asm__ __volatile__ (".chip 68040\n\t"				\
+			"ptestr (%1)\n\t"				\
+			"movec %%mmusr,%0\n\t"				\
+			".chip 68k"					\
+			: "=r" (_mmusr)					\
+			: "a" (vaddr));					\
+  _paddr = (_mmusr & MMU_R_040) ? (_mmusr & PAGE_MASK) : 0;		\
+  _paddr;								\
+})
+
+static inline int
+cache_flush_040 (unsigned long addr, int scope, int cache, unsigned long len)
+{
+  unsigned long paddr, i;
+
+  switch (scope)
+    {
+    case FLUSH_SCOPE_ALL:
+      switch (cache)
+	{
+	case FLUSH_CACHE_DATA:
+	  /* This nop is needed for some broken versions of the 68040.  */
+	  __asm__ __volatile__ ("nop\n\t"
+				".chip 68040\n\t"
+				"cpusha %dc\n\t"
+				".chip 68k");
+	  break;
+	case FLUSH_CACHE_INSN:
+	  __asm__ __volatile__ ("nop\n\t"
+				".chip 68040\n\t"
+				"cpusha %ic\n\t"
+				".chip 68k");
+	  break;
+	default:
+	case FLUSH_CACHE_BOTH:
+	  __asm__ __volatile__ ("nop\n\t"
+				".chip 68040\n\t"
+				"cpusha %bc\n\t"
+				".chip 68k");
+	  break;
+	}
+      break;
+
+    case FLUSH_SCOPE_LINE:
+      /* Find the physical address of the first mapped page in the
+	 address range.  */
+      if ((paddr = virt_to_phys_040(addr))) {
+        paddr += addr & ~(PAGE_MASK | 15);
+        len = (len + (addr & 15) + 15) >> 4;
+      } else {
+	unsigned long tmp = PAGE_SIZE - (addr & ~PAGE_MASK);
+
+	if (len <= tmp)
+	  return 0;
+	addr += tmp;
+	len -= tmp;
+	tmp = PAGE_SIZE;
+	for (;;)
+	  {
+	    if ((paddr = virt_to_phys_040(addr)))
+	      break;
+	    if (len <= tmp)
+	      return 0;
+	    addr += tmp;
+	    len -= tmp;
+	  }
+	len = (len + 15) >> 4;
+      }
+      i = (PAGE_SIZE - (paddr & ~PAGE_MASK)) >> 4;
+      while (len--)
+	{
+	  switch (cache)
+	    {
+	    case FLUSH_CACHE_DATA:
+	      __asm__ __volatile__ ("nop\n\t"
+				    ".chip 68040\n\t"
+				    "cpushl %%dc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    case FLUSH_CACHE_INSN:
+	      __asm__ __volatile__ ("nop\n\t"
+				    ".chip 68040\n\t"
+				    "cpushl %%ic,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    default:
+	    case FLUSH_CACHE_BOTH:
+	      __asm__ __volatile__ ("nop\n\t"
+				    ".chip 68040\n\t"
+				    "cpushl %%bc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    }
+	  if (!--i && len)
+	    {
+	      /*
+	       * No need to page align here since it is done by
+	       * virt_to_phys_040().
+	       */
+	      addr += PAGE_SIZE;
+	      i = PAGE_SIZE / 16;
+	      /* Recompute physical address when crossing a page
+	         boundary. */
+	      for (;;)
+		{
+		  if ((paddr = virt_to_phys_040(addr)))
+		    break;
+		  if (len <= i)
+		    return 0;
+		  len -= i;
+		  addr += PAGE_SIZE;
+		}
+	    }
+	  else
+	    paddr += 16;
+	}
+      break;
+
+    default:
+    case FLUSH_SCOPE_PAGE:
+      len += (addr & ~PAGE_MASK) + (PAGE_SIZE - 1);
+      for (len >>= PAGE_SHIFT; len--; addr += PAGE_SIZE)
+	{
+	  if (!(paddr = virt_to_phys_040(addr)))
+	    continue;
+	  switch (cache)
+	    {
+	    case FLUSH_CACHE_DATA:
+	      __asm__ __volatile__ ("nop\n\t"
+				    ".chip 68040\n\t"
+				    "cpushp %%dc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    case FLUSH_CACHE_INSN:
+	      __asm__ __volatile__ ("nop\n\t"
+				    ".chip 68040\n\t"
+				    "cpushp %%ic,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    default:
+	    case FLUSH_CACHE_BOTH:
+	      __asm__ __volatile__ ("nop\n\t"
+				    ".chip 68040\n\t"
+				    "cpushp %%bc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    }
+	}
+      break;
+    }
+  return 0;
+}
+
+#define virt_to_phys_060(vaddr)				\
+({							\
+  unsigned long paddr;					\
+  __asm__ __volatile__ (".chip 68060\n\t"		\
+			"plpar (%0)\n\t"		\
+			".chip 68k"			\
+			: "=a" (paddr)			\
+			: "0" (vaddr));			\
+  (paddr); /* XXX */					\
+})
+
+static inline int
+cache_flush_060 (unsigned long addr, int scope, int cache, unsigned long len)
+{
+  unsigned long paddr, i;
+
+  /*
+   * 68060 manual says:
+   *  cpush %dc : flush DC, remains valid (with our %cacr setup)
+   *  cpush %ic : invalidate IC
+   *  cpush %bc : flush DC + invalidate IC
+   */
+  switch (scope)
+    {
+    case FLUSH_SCOPE_ALL:
+      switch (cache)
+	{
+	case FLUSH_CACHE_DATA:
+	  __asm__ __volatile__ (".chip 68060\n\t"
+				"cpusha %dc\n\t"
+				".chip 68k");
+	  break;
+	case FLUSH_CACHE_INSN:
+	  __asm__ __volatile__ (".chip 68060\n\t"
+				"cpusha %ic\n\t"
+				".chip 68k");
+	  break;
+	default:
+	case FLUSH_CACHE_BOTH:
+	  __asm__ __volatile__ (".chip 68060\n\t"
+				"cpusha %bc\n\t"
+				".chip 68k");
+	  break;
+	}
+      break;
+
+    case FLUSH_SCOPE_LINE:
+      /* Find the physical address of the first mapped page in the
+	 address range.  */
+      len += addr & 15;
+      addr &= -16;
+      if (!(paddr = virt_to_phys_060(addr))) {
+	unsigned long tmp = PAGE_SIZE - (addr & ~PAGE_MASK);
+
+	if (len <= tmp)
+	  return 0;
+	addr += tmp;
+	len -= tmp;
+	tmp = PAGE_SIZE;
+	for (;;)
+	  {
+	    if ((paddr = virt_to_phys_060(addr)))
+	      break;
+	    if (len <= tmp)
+	      return 0;
+	    addr += tmp;
+	    len -= tmp;
+	  }
+      }
+      len = (len + 15) >> 4;
+      i = (PAGE_SIZE - (paddr & ~PAGE_MASK)) >> 4;
+      while (len--)
+	{
+	  switch (cache)
+	    {
+	    case FLUSH_CACHE_DATA:
+	      __asm__ __volatile__ (".chip 68060\n\t"
+				    "cpushl %%dc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    case FLUSH_CACHE_INSN:
+	      __asm__ __volatile__ (".chip 68060\n\t"
+				    "cpushl %%ic,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    default:
+	    case FLUSH_CACHE_BOTH:
+	      __asm__ __volatile__ (".chip 68060\n\t"
+				    "cpushl %%bc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    }
+	  if (!--i && len)
+	    {
+
+	      /*
+	       * We just want to jump to the first cache line
+	       * in the next page.
+	       */
+	      addr += PAGE_SIZE;
+	      addr &= PAGE_MASK;
+
+	      i = PAGE_SIZE / 16;
+	      /* Recompute physical address when crossing a page
+	         boundary. */
+	      for (;;)
+	        {
+	          if ((paddr = virt_to_phys_060(addr)))
+	            break;
+	          if (len <= i)
+	            return 0;
+	          len -= i;
+	          addr += PAGE_SIZE;
+	        }
+	    }
+	  else
+	    paddr += 16;
+	}
+      break;
+
+    default:
+    case FLUSH_SCOPE_PAGE:
+      len += (addr & ~PAGE_MASK) + (PAGE_SIZE - 1);
+      addr &= PAGE_MASK;	/* Workaround for bug in some
+				   revisions of the 68060 */
+      for (len >>= PAGE_SHIFT; len--; addr += PAGE_SIZE)
+	{
+	  if (!(paddr = virt_to_phys_060(addr)))
+	    continue;
+	  switch (cache)
+	    {
+	    case FLUSH_CACHE_DATA:
+	      __asm__ __volatile__ (".chip 68060\n\t"
+				    "cpushp %%dc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    case FLUSH_CACHE_INSN:
+	      __asm__ __volatile__ (".chip 68060\n\t"
+				    "cpushp %%ic,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    default:
+	    case FLUSH_CACHE_BOTH:
+	      __asm__ __volatile__ (".chip 68060\n\t"
+				    "cpushp %%bc,(%0)\n\t"
+				    ".chip 68k"
+				    : : "a" (paddr));
+	      break;
+	    }
+	}
+      break;
+    }
+  return 0;
+}
+
+/* sys_cacheflush -- flush (part of) the processor cache.  */
+asmlinkage int
+sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
+{
+	struct vm_area_struct *vma;
+	int ret = -EINVAL;
+
+	if (scope < FLUSH_SCOPE_LINE || scope > FLUSH_SCOPE_ALL ||
+	    cache & ~FLUSH_CACHE_BOTH)
+		goto out;
+
+	if (scope == FLUSH_SCOPE_ALL) {
+		/* Only the superuser may explicitly flush the whole cache. */
+		ret = -EPERM;
+		if (!capable(CAP_SYS_ADMIN))
+			goto out;
+	} else {
+		/*
+		 * Verify that the specified address region actually belongs
+		 * to this process.
+		 */
+		vma = find_vma (current->mm, addr);
+		ret = -EINVAL;
+		/* Check for overflow.  */
+		if (addr + len < addr)
+			goto out;
+		if (vma == NULL || addr < vma->vm_start || addr + len > vma->vm_end)
+			goto out;
+	}
+
+	if (CPU_IS_020_OR_030) {
+		if (scope == FLUSH_SCOPE_LINE && len < 256) {
+			unsigned long cacr;
+			__asm__ ("movec %%cacr, %0" : "=r" (cacr));
+			if (cache & FLUSH_CACHE_INSN)
+				cacr |= 4;
+			if (cache & FLUSH_CACHE_DATA)
+				cacr |= 0x400;
+			len >>= 2;
+			while (len--) {
+				__asm__ __volatile__ ("movec %1, %%caar\n\t"
+						      "movec %0, %%cacr"
+						      : /* no outputs */
+						      : "r" (cacr), "r" (addr));
+				addr += 4;
+			}
+		} else {
+			/* Flush the whole cache, even if page granularity requested. */
+			unsigned long cacr;
+			__asm__ ("movec %%cacr, %0" : "=r" (cacr));
+			if (cache & FLUSH_CACHE_INSN)
+				cacr |= 8;
+			if (cache & FLUSH_CACHE_DATA)
+				cacr |= 0x800;
+			__asm__ __volatile__ ("movec %0, %%cacr" : : "r" (cacr));
+		}
+		ret = 0;
+		goto out;
+	} else {
+	    /*
+	     * 040 or 060: don't blindly trust 'scope', someone could
+	     * try to flush a few megs of memory.
+	     */
+
+	    if (len>=3*PAGE_SIZE && scope<FLUSH_SCOPE_PAGE)
+	        scope=FLUSH_SCOPE_PAGE;
+	    if (len>=10*PAGE_SIZE && scope<FLUSH_SCOPE_ALL)
+	        scope=FLUSH_SCOPE_ALL;
+	    if (CPU_IS_040) {
+		ret = cache_flush_040 (addr, scope, cache, len);
+	    } else if (CPU_IS_060) {
+		ret = cache_flush_060 (addr, scope, cache, len);
+	    }
+	}
+out:
+	return ret;
+}
+
+/* This syscall gets its arguments in A0 (mem), D2 (oldval) and
+   D1 (newval).  */
+asmlinkage int
+sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
+		      unsigned long __user * mem)
+{
+	/* This was borrowed from ARM's implementation.  */
+	for (;;) {
+		struct mm_struct *mm = current->mm;
+		pgd_t *pgd;
+		pmd_t *pmd;
+		pte_t *pte;
+		spinlock_t *ptl;
+		unsigned long mem_value;
+
+		down_read(&mm->mmap_sem);
+		pgd = pgd_offset(mm, (unsigned long)mem);
+		if (!pgd_present(*pgd))
+			goto bad_access;
+		pmd = pmd_offset(pgd, (unsigned long)mem);
+		if (!pmd_present(*pmd))
+			goto bad_access;
+		pte = pte_offset_map_lock(mm, pmd, (unsigned long)mem, &ptl);
+		if (!pte_present(*pte) || !pte_dirty(*pte)
+		    || !pte_write(*pte)) {
+			pte_unmap_unlock(pte, ptl);
+			goto bad_access;
+		}
+
+		mem_value = *mem;
+		if (mem_value == oldval)
+			*mem = newval;
+
+		pte_unmap_unlock(pte, ptl);
+		up_read(&mm->mmap_sem);
+		return mem_value;
+
+	      bad_access:
+		up_read(&mm->mmap_sem);
+		/* This is not necessarily a bad access, we can get here if
+		   a memory we're trying to write to should be copied-on-write.
+		   Make the kernel do the necessary page stuff, then re-iterate.
+		   Simulate a write access fault to do that.  */
+		{
+			/* The first argument of the function corresponds to
+			   D1, which is the first field of struct pt_regs.  */
+			struct pt_regs *fp = (struct pt_regs *)&newval;
+
+			/* '3' is an RMW flag.  */
+			if (do_page_fault(fp, (unsigned long)mem, 3))
+				/* If the do_page_fault() failed, we don't
+				   have anything meaningful to return.
+				   There should be a SIGSEGV pending for
+				   the process.  */
+				return 0xdeadbeef;
+		}
+	}
+}
+
 #else
-#include "sys_m68k_no.c"
-#endif
+
+/* sys_cacheflush -- flush (part of) the processor cache.  */
+asmlinkage int
+sys_cacheflush (unsigned long addr, int scope, int cache, unsigned long len)
+{
+	flush_cache_all();
+	return 0;
+}
+
+/* This syscall gets its arguments in A0 (mem), D2 (oldval) and
+   D1 (newval).  */
+asmlinkage int
+sys_atomic_cmpxchg_32(unsigned long newval, int oldval, int d3, int d4, int d5,
+		      unsigned long __user * mem)
+{
+	struct mm_struct *mm = current->mm;
+	unsigned long mem_value;
+
+	down_read(&mm->mmap_sem);
+
+	mem_value = *mem;
+	if (mem_value == oldval)
+		*mem = newval;
+
+	up_read(&mm->mmap_sem);
+	return mem_value;
+}
+
+#endif /* CONFIG_MMU */
+
+asmlinkage int sys_getpagesize(void)
+{
+	return PAGE_SIZE;
+}
+
+/*
+ * Do a system call from kernel instead of calling sys_execve so we
+ * end up with proper pt_regs.
+ */
+int kernel_execve(const char *filename,
+		  const char *const argv[],
+		  const char *const envp[])
+{
+	register long __res asm ("%d0") = __NR_execve;
+	register long __a asm ("%d1") = (long)(filename);
+	register long __b asm ("%d2") = (long)(argv);
+	register long __c asm ("%d3") = (long)(envp);
+	asm volatile ("trap  #0" : "+d" (__res)
+			: "d" (__a), "d" (__b), "d" (__c));
+	return __res;
+}
+
+asmlinkage unsigned long sys_get_thread_area(void)
+{
+	return current_thread_info()->tp_value;
+}
+
+asmlinkage int sys_set_thread_area(unsigned long tp)
+{
+	current_thread_info()->tp_value = tp;
+	return 0;
+}
+
+asmlinkage int sys_atomic_barrier(void)
+{
+	/* no code needed for uniprocs */
+	return 0;
+}