Initial import

1 files changed, 549 insertions, 0 deletions

diff --git a/arch/m32r/mm/fault.c b/arch/m32r/mm/fault.c
new file mode 100644
index 000000000..e3d4d4890
--- /dev/null
+++ b/arch/m32r/mm/fault.c
@@ -0,0 +1,549 @@
+/*
+ *  linux/arch/m32r/mm/fault.c
+ *
+ *  Copyright (c) 2001, 2002  Hitoshi Yamamoto, and H. Kondo
+ *  Copyright (c) 2004  Naoto Sugai, NIIBE Yutaka
+ *
+ *  Some code taken from i386 version.
+ *    Copyright (C) 1995  Linus Torvalds
+ */
+
+#include <linux/signal.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/ptrace.h>
+#include <linux/mman.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/tty.h>
+#include <linux/vt_kern.h>		/* For unblank_screen() */
+#include <linux/highmem.h>
+#include <linux/module.h>
+
+#include <asm/m32r.h>
+#include <asm/uaccess.h>
+#include <asm/hardirq.h>
+#include <asm/mmu_context.h>
+#include <asm/tlbflush.h>
+
+extern void die(const char *, struct pt_regs *, long);
+
+#ifndef CONFIG_SMP
+asmlinkage unsigned int tlb_entry_i_dat;
+asmlinkage unsigned int tlb_entry_d_dat;
+#define tlb_entry_i tlb_entry_i_dat
+#define tlb_entry_d tlb_entry_d_dat
+#else
+unsigned int tlb_entry_i_dat[NR_CPUS];
+unsigned int tlb_entry_d_dat[NR_CPUS];
+#define tlb_entry_i tlb_entry_i_dat[smp_processor_id()]
+#define tlb_entry_d tlb_entry_d_dat[smp_processor_id()]
+#endif
+
+extern void init_tlb(void);
+
+/*======================================================================*
+ * do_page_fault()
+ *======================================================================*
+ * This routine handles page faults.  It determines the address,
+ * and the problem, and then passes it off to one of the appropriate
+ * routines.
+ *
+ * ARGUMENT:
+ *  regs       : M32R SP reg.
+ *  error_code : See below
+ *  address    : M32R MMU MDEVA reg. (Operand ACE)
+ *             : M32R BPC reg. (Instruction ACE)
+ *
+ * error_code :
+ *  bit 0 == 0 means no page found, 1 means protection fault
+ *  bit 1 == 0 means read, 1 means write
+ *  bit 2 == 0 means kernel, 1 means user-mode
+ *  bit 3 == 0 means data, 1 means instruction
+ *======================================================================*/
+#define ACE_PROTECTION		1
+#define ACE_WRITE		2
+#define ACE_USERMODE		4
+#define ACE_INSTRUCTION		8
+
+asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long error_code,
+  unsigned long address)
+{
+	struct task_struct *tsk;
+	struct mm_struct *mm;
+	struct vm_area_struct * vma;
+	unsigned long page, addr;
+	unsigned long flags = 0;
+	int fault;
+	siginfo_t info;
+
+	/*
+	 * If BPSW IE bit enable --> set PSW IE bit
+	 */
+	if (regs->psw & M32R_PSW_BIE)
+		local_irq_enable();
+
+	tsk = current;
+
+	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.
+	 *
+	 * This verifies that the fault happens in kernel space
+	 * (error_code & ACE_USERMODE) == 0, and that the fault was not a
+	 * protection error (error_code & ACE_PROTECTION) == 0.
+	 */
+	if (address >= TASK_SIZE && !(error_code & ACE_USERMODE))
+		goto vmalloc_fault;
+
+	mm = tsk->mm;
+
+	/*
+	 * If we're in an interrupt or have no user context or are running in an
+	 * atomic region then we must not take the fault..
+	 */
+	if (in_atomic() || !mm)
+		goto bad_area_nosemaphore;
+
+	if (error_code & ACE_USERMODE)
+		flags |= FAULT_FLAG_USER;
+
+	/* When running in the kernel we expect faults to occur only to
+	 * addresses in user space.  All other faults represent errors in the
+	 * kernel and should generate an OOPS.  Unfortunately, in the case of an
+	 * erroneous fault occurring in a code path which already holds mmap_sem
+	 * we will deadlock attempting to validate the fault against the
+	 * address space.  Luckily the kernel only validly references user
+	 * space from well defined areas of code, which are listed in the
+	 * exceptions table.
+	 *
+	 * As the vast majority of faults will be valid we will only perform
+	 * the source reference check when there is a possibility of a deadlock.
+	 * Attempt to lock the address space, if we cannot we then validate the
+	 * source.  If this is invalid we can skip the address space check,
+	 * thus avoiding the deadlock.
+	 */
+	if (!down_read_trylock(&mm->mmap_sem)) {
+		if ((error_code & ACE_USERMODE) == 0 &&
+		    !search_exception_tables(regs->psw))
+			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 (error_code & ACE_USERMODE) {
+		/*
+		 * accessing the stack below "spu" is always a bug.
+		 * The "+ 4" is there due to the push instruction
+		 * doing pre-decrement on the stack and that
+		 * doesn't show up until later..
+		 */
+		if (address + 4 < regs->spu)
+			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;
+	switch (error_code & (ACE_WRITE|ACE_PROTECTION)) {
+		default:	/* 3: write, present */
+			/* fall through */
+		case ACE_WRITE:	/* write, not present */
+			if (!(vma->vm_flags & VM_WRITE))
+				goto bad_area;
+			flags |= FAULT_FLAG_WRITE;
+			break;
+		case ACE_PROTECTION:	/* read, present */
+		case 0:		/* read, not present */
+			if (!(vma->vm_flags & (VM_READ | VM_EXEC)))
+				goto bad_area;
+	}
+
+	/*
+	 * For instruction access exception, check if the area is executable
+	 */
+	if ((error_code & ACE_INSTRUCTION) && !(vma->vm_flags & VM_EXEC))
+	  goto bad_area;
+
+	/*
+	 * If for any reason at all we couldn't handle the fault,
+	 * make sure we exit gracefully rather than endlessly redo
+	 * the fault.
+	 */
+	addr = (address & PAGE_MASK);
+	set_thread_fault_code(error_code);
+	fault = handle_mm_fault(mm, vma, addr, flags);
+	if (unlikely(fault & VM_FAULT_ERROR)) {
+		if (fault & VM_FAULT_OOM)
+			goto out_of_memory;
+		else if (fault & VM_FAULT_SIGSEGV)
+			goto bad_area;
+		else if (fault & VM_FAULT_SIGBUS)
+			goto do_sigbus;
+		BUG();
+	}
+	if (fault & VM_FAULT_MAJOR)
+		tsk->maj_flt++;
+	else
+		tsk->min_flt++;
+	set_thread_fault_code(0);
+	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 (error_code & ACE_USERMODE) {
+		tsk->thread.address = address;
+		tsk->thread.error_code = error_code | (address >= TASK_SIZE);
+		tsk->thread.trap_no = 14;
+		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))
+		return;
+
+/*
+ * Oops. The kernel tried to access some bad page. We'll have to
+ * terminate things with extreme prejudice.
+ */
+
+	bust_spinlocks(1);
+
+	if (address < PAGE_SIZE)
+		printk(KERN_ALERT "Unable to handle kernel NULL pointer dereference");
+	else
+		printk(KERN_ALERT "Unable to handle kernel paging request");
+	printk(" at virtual address %08lx\n",address);
+	printk(KERN_ALERT " printing bpc:\n");
+	printk("%08lx\n", regs->bpc);
+	page = *(unsigned long *)MPTB;
+	page = ((unsigned long *) page)[address >> PGDIR_SHIFT];
+	printk(KERN_ALERT "*pde = %08lx\n", page);
+	if (page & _PAGE_PRESENT) {
+		page &= PAGE_MASK;
+		address &= 0x003ff000;
+		page = ((unsigned long *) __va(page))[address >> PAGE_SHIFT];
+		printk(KERN_ALERT "*pte = %08lx\n", page);
+	}
+	die("Oops", regs, error_code);
+	bust_spinlocks(0);
+	do_exit(SIGKILL);
+
+/*
+ * 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 (!(error_code & ACE_USERMODE))
+		goto no_context;
+	pagefault_out_of_memory();
+	return;
+
+do_sigbus:
+	up_read(&mm->mmap_sem);
+
+	/* Kernel mode? Handle exception or die */
+	if (!(error_code & ACE_USERMODE))
+		goto no_context;
+
+	tsk->thread.address = address;
+	tsk->thread.error_code = error_code;
+	tsk->thread.trap_no = 14;
+	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_index(address);
+		pgd_t *pgd, *pgd_k;
+		pmd_t *pmd, *pmd_k;
+		pte_t *pte_k;
+
+		pgd = (pgd_t *)*(unsigned long *)MPTB;
+		pgd = offset + (pgd_t *)pgd;
+		pgd_k = init_mm.pgd + offset;
+
+		if (!pgd_present(*pgd_k))
+			goto no_context;
+
+		/*
+		 * set_pgd(pgd, *pgd_k); here would be useless on PAE
+		 * and redundant with the set_pmd() on non-PAE.
+		 */
+
+		pmd = pmd_offset(pgd, address);
+		pmd_k = pmd_offset(pgd_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;
+
+		addr = (address & PAGE_MASK);
+		set_thread_fault_code(error_code);
+		update_mmu_cache(NULL, addr, pte_k);
+		set_thread_fault_code(0);
+		return;
+	}
+}
+
+/*======================================================================*
+ * update_mmu_cache()
+ *======================================================================*/
+#define TLB_MASK	(NR_TLB_ENTRIES - 1)
+#define ITLB_END	(unsigned long *)(ITLB_BASE + (NR_TLB_ENTRIES * 8))
+#define DTLB_END	(unsigned long *)(DTLB_BASE + (NR_TLB_ENTRIES * 8))
+void update_mmu_cache(struct vm_area_struct *vma, unsigned long vaddr,
+	pte_t *ptep)
+{
+	volatile unsigned long *entry1, *entry2;
+	unsigned long pte_data, flags;
+	unsigned int *entry_dat;
+	int inst = get_thread_fault_code() & ACE_INSTRUCTION;
+	int i;
+
+	/* Ptrace may call this routine. */
+	if (vma && current->active_mm != vma->vm_mm)
+		return;
+
+	local_irq_save(flags);
+
+	vaddr = (vaddr & PAGE_MASK) | get_asid();
+
+	pte_data = pte_val(*ptep);
+
+#ifdef CONFIG_CHIP_OPSP
+	entry1 = (unsigned long *)ITLB_BASE;
+	for (i = 0; i < NR_TLB_ENTRIES; i++) {
+		if (*entry1++ == vaddr) {
+			set_tlb_data(entry1, pte_data);
+			break;
+		}
+		entry1++;
+	}
+	entry2 = (unsigned long *)DTLB_BASE;
+	for (i = 0; i < NR_TLB_ENTRIES; i++) {
+		if (*entry2++ == vaddr) {
+			set_tlb_data(entry2, pte_data);
+			break;
+		}
+		entry2++;
+	}
+#else
+	/*
+	 * Update TLB entries
+	 *  entry1: ITLB entry address
+	 *  entry2: DTLB entry address
+	 */
+	__asm__ __volatile__ (
+		"seth	%0, #high(%4)	\n\t"
+		"st	%2, @(%5, %0)	\n\t"
+		"ldi	%1, #1		\n\t"
+		"st	%1, @(%6, %0)	\n\t"
+		"add3	r4, %0, %7	\n\t"
+		".fillinsn		\n"
+		"1:			\n\t"
+		"ld	%1, @(%6, %0)	\n\t"
+		"bnez	%1, 1b		\n\t"
+		"ld	%0, @r4+	\n\t"
+		"ld	%1, @r4		\n\t"
+		"st	%3, @+%0	\n\t"
+		"st	%3, @+%1	\n\t"
+		: "=&r" (entry1), "=&r" (entry2)
+		: "r" (vaddr), "r" (pte_data), "i" (MMU_REG_BASE),
+		"i" (MSVA_offset), "i" (MTOP_offset), "i" (MIDXI_offset)
+		: "r4", "memory"
+	);
+#endif
+
+	if ((!inst && entry2 >= DTLB_END) || (inst && entry1 >= ITLB_END))
+		goto notfound;
+
+found:
+	local_irq_restore(flags);
+
+	return;
+
+	/* Valid entry not found */
+notfound:
+	/*
+	 * Update ITLB or DTLB entry
+	 *  entry1: TLB entry address
+	 *  entry2: TLB base address
+	 */
+	if (!inst) {
+		entry2 = (unsigned long *)DTLB_BASE;
+		entry_dat = &tlb_entry_d;
+	} else {
+		entry2 = (unsigned long *)ITLB_BASE;
+		entry_dat = &tlb_entry_i;
+	}
+	entry1 = entry2 + (((*entry_dat - 1) & TLB_MASK) << 1);
+
+	for (i = 0 ; i < NR_TLB_ENTRIES ; i++) {
+		if (!(entry1[1] & 2))	/* Valid bit check */
+			break;
+
+		if (entry1 != entry2)
+			entry1 -= 2;
+		else
+			entry1 += TLB_MASK << 1;
+	}
+
+	if (i >= NR_TLB_ENTRIES) {	/* Empty entry not found */
+		entry1 = entry2 + (*entry_dat << 1);
+		*entry_dat = (*entry_dat + 1) & TLB_MASK;
+	}
+	*entry1++ = vaddr;	/* Set TLB tag */
+	set_tlb_data(entry1, pte_data);
+
+	goto found;
+}
+
+/*======================================================================*
+ * flush_tlb_page() : flushes one page
+ *======================================================================*/
+void local_flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	if (vma->vm_mm && mm_context(vma->vm_mm) != NO_CONTEXT) {
+		unsigned long flags;
+
+		local_irq_save(flags);
+		page &= PAGE_MASK;
+		page |= (mm_context(vma->vm_mm) & MMU_CONTEXT_ASID_MASK);
+		__flush_tlb_page(page);
+		local_irq_restore(flags);
+	}
+}
+
+/*======================================================================*
+ * flush_tlb_range() : flushes a range of pages
+ *======================================================================*/
+void local_flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+	unsigned long end)
+{
+	struct mm_struct *mm;
+
+	mm = vma->vm_mm;
+	if (mm_context(mm) != NO_CONTEXT) {
+		unsigned long flags;
+		int size;
+
+		local_irq_save(flags);
+		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+		if (size > (NR_TLB_ENTRIES / 4)) { /* Too many TLB to flush */
+			mm_context(mm) = NO_CONTEXT;
+			if (mm == current->mm)
+				activate_context(mm);
+		} else {
+			unsigned long asid;
+
+			asid = mm_context(mm) & MMU_CONTEXT_ASID_MASK;
+			start &= PAGE_MASK;
+			end += (PAGE_SIZE - 1);
+			end &= PAGE_MASK;
+
+			start |= asid;
+			end   |= asid;
+			while (start < end) {
+				__flush_tlb_page(start);
+				start += PAGE_SIZE;
+			}
+		}
+		local_irq_restore(flags);
+	}
+}
+
+/*======================================================================*
+ * flush_tlb_mm() : flushes the specified mm context TLB's
+ *======================================================================*/
+void local_flush_tlb_mm(struct mm_struct *mm)
+{
+	/* Invalidate all TLB of this process. */
+	/* Instead of invalidating each TLB, we get new MMU context. */
+	if (mm_context(mm) != NO_CONTEXT) {
+		unsigned long flags;
+
+		local_irq_save(flags);
+		mm_context(mm) = NO_CONTEXT;
+		if (mm == current->mm)
+			activate_context(mm);
+		local_irq_restore(flags);
+	}
+}
+
+/*======================================================================*
+ * flush_tlb_all() : flushes all processes TLBs
+ *======================================================================*/
+void local_flush_tlb_all(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	__flush_tlb_all();
+	local_irq_restore(flags);
+}
+
+/*======================================================================*
+ * init_mmu()
+ *======================================================================*/
+void __init init_mmu(void)
+{
+	tlb_entry_i = 0;
+	tlb_entry_d = 0;
+	mmu_context_cache = MMU_CONTEXT_FIRST_VERSION;
+	set_asid(mmu_context_cache & MMU_CONTEXT_ASID_MASK);
+	*(volatile unsigned long *)MPTB = (unsigned long)swapper_pg_dir;
+}