1 files changed, 183 insertions, 0 deletions

diff --git a/arch/blackfin/include/asm/mmu_context.h b/arch/blackfin/include/asm/mmu_context.h
new file mode 100644
index 000000000000..8529552a981f
--- /dev/null
+++ b/arch/blackfin/include/asm/mmu_context.h
@@ -0,0 +1,183 @@
+/*
+ * File:         include/asm-blackfin/mmu_context.h
+ * Based on:
+ * Author:
+ *
+ * Created:
+ * Description:
+ *
+ * Modified:
+ *               Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * 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
+ */
+
+#ifndef __BLACKFIN_MMU_CONTEXT_H__
+#define __BLACKFIN_MMU_CONTEXT_H__
+
+#include <linux/gfp.h>
+#include <linux/sched.h>
+#include <asm/setup.h>
+#include <asm/page.h>
+#include <asm/pgalloc.h>
+#include <asm/cplbinit.h>
+
+extern void *current_l1_stack_save;
+extern int nr_l1stack_tasks;
+extern void *l1_stack_base;
+extern unsigned long l1_stack_len;
+
+extern int l1sram_free(const void*);
+extern void *l1sram_alloc_max(void*);
+
+static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
+{
+}
+
+/* Called when creating a new context during fork() or execve().  */
+static inline int
+init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+#ifdef CONFIG_MPU
+        unsigned long p = __get_free_pages(GFP_KERNEL, page_mask_order);
+        mm->context.page_rwx_mask = (unsigned long *)p;
+        memset(mm->context.page_rwx_mask, 0,
+               page_mask_nelts * 3 * sizeof(long));
+#endif
+        return 0;
+}
+
+static inline void free_l1stack(void)
+{
+        nr_l1stack_tasks--;
+        if (nr_l1stack_tasks == 0)
+                l1sram_free(l1_stack_base);
+}
+static inline void destroy_context(struct mm_struct *mm)
+{
+        struct sram_list_struct *tmp;
+
+        if (current_l1_stack_save == mm->context.l1_stack_save)
+                current_l1_stack_save = NULL;
+        if (mm->context.l1_stack_save)
+                free_l1stack();
+
+        while ((tmp = mm->context.sram_list)) {
+                mm->context.sram_list = tmp->next;
+                sram_free(tmp->addr);
+                kfree(tmp);
+        }
+#ifdef CONFIG_MPU
+        if (current_rwx_mask == mm->context.page_rwx_mask)
+                current_rwx_mask = NULL;
+        free_pages((unsigned long)mm->context.page_rwx_mask, page_mask_order);
+#endif
+}
+
+static inline unsigned long
+alloc_l1stack(unsigned long length, unsigned long *stack_base)
+{
+        if (nr_l1stack_tasks == 0) {
+                l1_stack_base = l1sram_alloc_max(&l1_stack_len);
+                if (!l1_stack_base)
+                        return 0;
+        }
+
+        if (l1_stack_len < length) {
+                if (nr_l1stack_tasks == 0)
+                        l1sram_free(l1_stack_base);
+                return 0;
+        }
+        *stack_base = (unsigned long)l1_stack_base;
+        nr_l1stack_tasks++;
+        return l1_stack_len;
+}
+
+static inline int
+activate_l1stack(struct mm_struct *mm, unsigned long sp_base)
+{
+        if (current_l1_stack_save)
+                memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
+        mm->context.l1_stack_save = current_l1_stack_save = (void*)sp_base;
+        memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
+        return 1;
+}
+
+#define deactivate_mm(tsk,mm)   do { } while (0)
+
+#define activate_mm(prev, next) switch_mm(prev, next, NULL)
+
+static inline void switch_mm(struct mm_struct *prev_mm, struct mm_struct *next_mm,
+                             struct task_struct *tsk)
+{
+        if (prev_mm == next_mm)
+                return;
+#ifdef CONFIG_MPU
+        if (prev_mm->context.page_rwx_mask == current_rwx_mask) {
+                flush_switched_cplbs();
+                set_mask_dcplbs(next_mm->context.page_rwx_mask);
+        }
+#endif
+
+        /* L1 stack switching.  */
+        if (!next_mm->context.l1_stack_save)
+                return;
+        if (next_mm->context.l1_stack_save == current_l1_stack_save)
+                return;
+        if (current_l1_stack_save) {
+                memcpy(current_l1_stack_save, l1_stack_base, l1_stack_len);
+        }
+        current_l1_stack_save = next_mm->context.l1_stack_save;
+        memcpy(l1_stack_base, current_l1_stack_save, l1_stack_len);
+}
+
+#ifdef CONFIG_MPU
+static inline void protect_page(struct mm_struct *mm, unsigned long addr,
+                                unsigned long flags)
+{
+        unsigned long *mask = mm->context.page_rwx_mask;
+        unsigned long page = addr >> 12;
+        unsigned long idx = page >> 5;
+        unsigned long bit = 1 << (page & 31);
+
+        if (flags & VM_MAYREAD)
+                mask[idx] |= bit;
+        else
+                mask[idx] &= ~bit;
+        mask += page_mask_nelts;
+        if (flags & VM_MAYWRITE)
+                mask[idx] |= bit;
+        else
+                mask[idx] &= ~bit;
+        mask += page_mask_nelts;
+        if (flags & VM_MAYEXEC)
+                mask[idx] |= bit;
+        else
+                mask[idx] &= ~bit;
+}
+
+static inline void update_protections(struct mm_struct *mm)
+{
+        if (mm->context.page_rwx_mask == current_rwx_mask) {
+                flush_switched_cplbs();
+                set_mask_dcplbs(mm->context.page_rwx_mask);
+        }
+}
+#endif
+
+#endif