score: Add support for Sunplus S+core architecture

This is the complete set of new arch Score's files for linux.
Score instruction set support 16bits, 32bits and 64bits instruction,
Score SOC had been used in game machine and LCD TV.

Signed-off-by: Chen Liqin <liqin.chen@sunplusct.com>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

1 files changed, 235 insertions, 0 deletions

diff --git a/arch/score/mm/fault.c b/arch/score/mm/fault.c
new file mode 100644
index 000000000000..47b600e4b2c5
--- /dev/null
+++ b/arch/score/mm/fault.c
@@ -0,0 +1,235 @@
+/*
+ * arch/score/mm/fault.c
+ *
+ * Score Processor version.
+ *
+ * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
+ *  Lennox Wu <lennox.wu@sunplusct.com>
+ *  Chen Liqin <liqin.chen@sunplusct.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/mman.h>
+#include <linux/module.h>
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+
+/*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ */
+asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long write,
+				unsigned long address)
+{
+	struct vm_area_struct *vma = NULL;
+	struct task_struct *tsk = current;
+	struct mm_struct *mm = tsk->mm;
+	const int field = sizeof(unsigned long) * 2;
+	siginfo_t info;
+	int fault;
+
+	info.si_code = SEGV_MAPERR;
+
+	/*
+	* We fault-in kernel-space virtual memory on-demand. The
+	* 'reference' page table is init_mm.pgd.
+	*
+	* NOTE! We MUST NOT take any locks for this case. We may
+	* be in an interrupt or a critical region, and should
+	* only copy the information from the master page table,
+	* nothing more.
+	*/
+	if (unlikely(address >= VMALLOC_START && address <= VMALLOC_END))
+		goto vmalloc_fault;
+#ifdef MODULE_START
+	if (unlikely(address >= MODULE_START && address < MODULE_END))
+		goto vmalloc_fault;
+#endif
+
+	/*
+	* If we're in an interrupt or have no user
+	* context, we must not take the fault..
+	*/
+	if (in_atomic() || !mm)
+		goto bad_area_nosemaphore;
+
+	down_read(&mm->mmap_sem);
+	vma = find_vma(mm, address);
+	if (!vma)
+		goto bad_area;
+	if (vma->vm_start <= address)
+		goto good_area;
+	if (!(vma->vm_flags & VM_GROWSDOWN))
+		goto bad_area;
+	if (expand_stack(vma, address))
+		goto bad_area;
+	/*
+	* Ok, we have a good vm_area for this memory access, so
+	* we can handle it..
+	 */
+good_area:
+	info.si_code = SEGV_ACCERR;
+
+	if (write) {
+		if (!(vma->vm_flags & VM_WRITE))
+			goto bad_area;
+	} else {
+		if (!(vma->vm_flags & (VM_READ | VM_WRITE | VM_EXEC)))
+			goto bad_area;
+	}
+
+survive:
+	/*
+	* If for any reason at all we couldn't handle the fault,
+	* make sure we exit gracefully rather than endlessly redo
+	* the fault.
+	*/
+	fault = handle_mm_fault(mm, vma, address, write);
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		if (fault & VM_FAULT_OOM)
+			goto out_of_memory;
+		else if (fault & VM_FAULT_SIGBUS)
+			goto do_sigbus;
+		BUG();
+	}
+	if (fault & VM_FAULT_MAJOR)
+		tsk->maj_flt++;
+	else
+		tsk->min_flt++;
+
+	up_read(&mm->mmap_sem);
+	return;
+
+	/*
+	* Something tried to access memory that isn't in our memory map..
+	* Fix it, but check if it's kernel or user first..
+	 */
+bad_area:
+	up_read(&mm->mmap_sem);
+
+bad_area_nosemaphore:
+	/* User mode accesses just cause a SIGSEGV */
+	if (user_mode(regs)) {
+		tsk->thread.cp0_badvaddr = address;
+		tsk->thread.error_code = write;
+		info.si_signo = SIGSEGV;
+		info.si_errno = 0;
+		/* info.si_code has been set above */
+		info.si_addr = (void __user *) address;
+		force_sig_info(SIGSEGV, &info, tsk);
+		return;
+	}
+
+no_context:
+	/* Are we prepared to handle this kernel fault? */
+	if (fixup_exception(regs)) {
+		current->thread.cp0_baduaddr = address;
+		return;
+	}
+
+	/*
+	* Oops. The kernel tried to access some bad page. We'll have to
+	* terminate things with extreme prejudice.
+	*/
+	bust_spinlocks(1);
+
+	printk(KERN_ALERT "CPU %d Unable to handle kernel paging request at "
+			"virtual address %0*lx, epc == %0*lx, ra == %0*lx\n",
+			0, field, address, field, regs->cp0_epc,
+			field, regs->regs[3]);
+	die("Oops", regs);
+
+	/*
+	* We ran out of memory, or some other thing happened to us that made
+	* us unable to handle the page fault gracefully.
+	*/
+out_of_memory:
+	up_read(&mm->mmap_sem);
+	if (is_global_init(tsk)) {
+		yield();
+		down_read(&mm->mmap_sem);
+		goto survive;
+	}
+	printk("VM: killing process %s\n", tsk->comm);
+	if (user_mode(regs))
+		do_group_exit(SIGKILL);
+	goto no_context;
+
+do_sigbus:
+	up_read(&mm->mmap_sem);
+	/* Kernel mode? Handle exceptions or die */
+	if (!user_mode(regs))
+		goto no_context;
+	else
+	/*
+	* Send a sigbus, regardless of whether we were in kernel
+	* or user mode.
+	*/
+	tsk->thread.cp0_badvaddr = address;
+	info.si_signo = SIGBUS;
+	info.si_errno = 0;
+	info.si_code = BUS_ADRERR;
+	info.si_addr = (void __user *) address;
+	force_sig_info(SIGBUS, &info, tsk);
+	return;
+vmalloc_fault:
+	{
+		/*
+		* Synchronize this task's top level page-table
+		* with the 'reference' page table.
+		*
+		* Do _not_ use "tsk" here. We might be inside
+		* an interrupt in the middle of a task switch..
+		*/
+		int offset = __pgd_offset(address);
+		pgd_t *pgd, *pgd_k;
+		pud_t *pud, *pud_k;
+		pmd_t *pmd, *pmd_k;
+		pte_t *pte_k;
+
+		pgd = (pgd_t *) pgd_current + offset;
+		pgd_k = init_mm.pgd + offset;
+
+		if (!pgd_present(*pgd_k))
+			goto no_context;
+		set_pgd(pgd, *pgd_k);
+
+		pud = pud_offset(pgd, address);
+		pud_k = pud_offset(pgd_k, address);
+		if (!pud_present(*pud_k))
+			goto no_context;
+
+		pmd = pmd_offset(pud, address);
+		pmd_k = pmd_offset(pud_k, address);
+		if (!pmd_present(*pmd_k))
+			goto no_context;
+		set_pmd(pmd, *pmd_k);
+
+		pte_k = pte_offset_kernel(pmd_k, address);
+		if (!pte_present(*pte_k))
+			goto no_context;
+		return;
+	}
+}