1 files changed, 187 insertions, 0 deletions
diff --git a/arch/powerpc/mm/mmu_context_book3s64.c b/arch/powerpc/mm/mmu_context_book3s64.c
new file mode 100644
index 000000000000..227b2a6c4544
--- /dev/null
+++ b/arch/powerpc/mm/mmu_context_book3s64.c
@@ -0,0 +1,187 @@
+/*
+ *  MMU context allocation for 64-bit kernels.
+ *
+ *  Copyright (C) 2004 Anton Blanchard, IBM Corp. <anton@samba.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.
+ *
+ */
+
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/string.h>
+#include <linux/types.h>
+#include <linux/mm.h>
+#include <linux/spinlock.h>
+#include <linux/idr.h>
+#include <linux/export.h>
+#include <linux/gfp.h>
+#include <linux/slab.h>
+
+#include <asm/mmu_context.h>
+#include <asm/pgalloc.h>
+
+#include "icswx.h"
+
+static DEFINE_SPINLOCK(mmu_context_lock);
+static DEFINE_IDA(mmu_context_ida);
+
+int __init_new_context(void)
+{
+	int index;
+	int err;
+
+again:
+	if (!ida_pre_get(&mmu_context_ida, GFP_KERNEL))
+		return -ENOMEM;
+
+	spin_lock(&mmu_context_lock);
+	err = ida_get_new_above(&mmu_context_ida, 1, &index);
+	spin_unlock(&mmu_context_lock);
+
+	if (err == -EAGAIN)
+		goto again;
+	else if (err)
+		return err;
+
+	if (index > MAX_USER_CONTEXT) {
+		spin_lock(&mmu_context_lock);
+		ida_remove(&mmu_context_ida, index);
+		spin_unlock(&mmu_context_lock);
+		return -ENOMEM;
+	}
+
+	return index;
+}
+EXPORT_SYMBOL_GPL(__init_new_context);
+static int radix__init_new_context(struct mm_struct *mm, int index)
+{
+	unsigned long rts_field;
+
+	/*
+	 * set the process table entry,
+	 */
+	rts_field = 3ull << PPC_BITLSHIFT(2);
+	process_tb[index].prtb0 = cpu_to_be64(rts_field | __pa(mm->pgd) | RADIX_PGD_INDEX_SIZE);
+	return 0;
+}
+
+int init_new_context(struct task_struct *tsk, struct mm_struct *mm)
+{
+	int index;
+
+	index = __init_new_context();
+	if (index < 0)
+		return index;
+
+	if (radix_enabled()) {
+		radix__init_new_context(mm, index);
+	} else {
+
+		/* The old code would re-promote on fork, we don't do that
+		 * when using slices as it could cause problem promoting slices
+		 * that have been forced down to 4K
+		 *
+		 * For book3s we have MMU_NO_CONTEXT set to be ~0. Hence check
+		 * explicitly against context.id == 0. This ensures that we
+		 * properly initialize context slice details for newly allocated
+		 * mm's (which will have id == 0) and don't alter context slice
+		 * inherited via fork (which will have id != 0).
+		 *
+		 * We should not be calling init_new_context() on init_mm. Hence a
+		 * check against 0 is ok.
+		 */
+		if (mm->context.id == 0)
+			slice_set_user_psize(mm, mmu_virtual_psize);
+		subpage_prot_init_new_context(mm);
+	}
+	mm->context.id = index;
+#ifdef CONFIG_PPC_ICSWX
+	mm->context.cop_lockp = kmalloc(sizeof(spinlock_t), GFP_KERNEL);
+	if (!mm->context.cop_lockp) {
+		__destroy_context(index);
+		subpage_prot_free(mm);
+		mm->context.id = MMU_NO_CONTEXT;
+		return -ENOMEM;
+	}
+	spin_lock_init(mm->context.cop_lockp);
+#endif /* CONFIG_PPC_ICSWX */
+
+#ifdef CONFIG_PPC_64K_PAGES
+	mm->context.pte_frag = NULL;
+#endif
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+	mm_iommu_init(&mm->context);
+#endif
+	return 0;
+}
+
+void __destroy_context(int context_id)
+{
+	spin_lock(&mmu_context_lock);
+	ida_remove(&mmu_context_ida, context_id);
+	spin_unlock(&mmu_context_lock);
+}
+EXPORT_SYMBOL_GPL(__destroy_context);
+
+#ifdef CONFIG_PPC_64K_PAGES
+static void destroy_pagetable_page(struct mm_struct *mm)
+{
+	int count;
+	void *pte_frag;
+	struct page *page;
+
+	pte_frag = mm->context.pte_frag;
+	if (!pte_frag)
+		return;
+
+	page = virt_to_page(pte_frag);
+	/* drop all the pending references */
+	count = ((unsigned long)pte_frag & ~PAGE_MASK) >> PTE_FRAG_SIZE_SHIFT;
+	/* We allow PTE_FRAG_NR fragments from a PTE page */
+	if (page_ref_sub_and_test(page, PTE_FRAG_NR - count)) {
+		pgtable_page_dtor(page);
+		free_hot_cold_page(page, 0);
+	}
+}
+
+#else
+static inline void destroy_pagetable_page(struct mm_struct *mm)
+{
+	return;
+}
+#endif
+
+
+void destroy_context(struct mm_struct *mm)
+{
+#ifdef CONFIG_SPAPR_TCE_IOMMU
+	mm_iommu_cleanup(&mm->context);
+#endif
+
+#ifdef CONFIG_PPC_ICSWX
+	drop_cop(mm->context.acop, mm);
+	kfree(mm->context.cop_lockp);
+	mm->context.cop_lockp = NULL;
+#endif /* CONFIG_PPC_ICSWX */
+
+	if (radix_enabled())
+		process_tb[mm->context.id].prtb1 = 0;
+	else
+		subpage_prot_free(mm);
+	destroy_pagetable_page(mm);
+	__destroy_context(mm->context.id);
+	mm->context.id = MMU_NO_CONTEXT;
+}
+
+#ifdef CONFIG_PPC_RADIX_MMU
+void radix__switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
+{
+	mtspr(SPRN_PID, next->context.id);
+	asm volatile("isync": : :"memory");
+}
+#endif