Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / arch / hexagon / include / asm / pgalloc.h

diff --git a/kernel/arch/hexagon/include/asm/pgalloc.h b/kernel/arch/hexagon/include/asm/pgalloc.h
new file mode 100644 (file)
index 0000000..77da3b0
--- /dev/null
+++ b/kernel/arch/hexagon/include/asm/pgalloc.h
@@ -0,0 +1,148 @@
+/*
+ * Page table support for the Hexagon architecture
+ *
+ * Copyright (c) 2010-2011, The Linux Foundation. All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 and
+ * only version 2 as published by the Free Software Foundation.
+ *
+ * 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, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ */
+
+#ifndef _ASM_PGALLOC_H
+#define _ASM_PGALLOC_H
+
+#include <asm/mem-layout.h>
+#include <asm/atomic.h>
+
+#define check_pgt_cache() do {} while (0)
+
+extern unsigned long long kmap_generation;
+
+/*
+ * Page table creation interface
+ */
+static inline pgd_t *pgd_alloc(struct mm_struct *mm)
+{
+       pgd_t *pgd;
+
+       pgd = (pgd_t *)__get_free_page(GFP_KERNEL | __GFP_ZERO);
+
+       /*
+        * There may be better ways to do this, but to ensure
+        * that new address spaces always contain the kernel
+        * base mapping, and to ensure that the user area is
+        * initially marked invalid, initialize the new map
+        * map with a copy of the kernel's persistent map.
+        */
+
+       memcpy(pgd, swapper_pg_dir, PTRS_PER_PGD*sizeof(pgd_t));
+       mm->context.generation = kmap_generation;
+
+       /* Physical version is what is passed to virtual machine on switch */
+       mm->context.ptbase = __pa(pgd);
+
+       return pgd;
+}
+
+static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
+{
+       free_page((unsigned long) pgd);
+}
+
+static inline struct page *pte_alloc_one(struct mm_struct *mm,
+                                        unsigned long address)
+{
+       struct page *pte;
+
+       pte = alloc_page(GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO);
+       if (!pte)
+               return NULL;
+       if (!pgtable_page_ctor(pte)) {
+               __free_page(pte);
+               return NULL;
+       }
+       return pte;
+}
+
+/* _kernel variant gets to use a different allocator */
+static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
+                                         unsigned long address)
+{
+       gfp_t flags =  GFP_KERNEL | __GFP_REPEAT | __GFP_ZERO;
+       return (pte_t *) __get_free_page(flags);
+}
+
+static inline void pte_free(struct mm_struct *mm, struct page *pte)
+{
+       pgtable_page_dtor(pte);
+       __free_page(pte);
+}
+
+static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
+{
+       free_page((unsigned long)pte);
+}
+
+static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd,
+                               pgtable_t pte)
+{
+       /*
+        * Conveniently, zero in 3 LSB means indirect 4K page table.
+        * Not so convenient when you're trying to vary the page size.
+        */
+       set_pmd(pmd, __pmd(((unsigned long)page_to_pfn(pte) << PAGE_SHIFT) |
+               HEXAGON_L1_PTE_SIZE));
+}
+
+/*
+ * Other architectures seem to have ways of making all processes
+ * share the same pmd's for their kernel mappings, but the v0.3
+ * Hexagon VM spec has a "monolithic" L1 table for user and kernel
+ * segments.  We track "generations" of the kernel map to minimize
+ * overhead, and update the "slave" copies of the kernel mappings
+ * as part of switch_mm.  However, we still need to update the
+ * kernel map of the active thread who's calling pmd_populate_kernel...
+ */
+static inline void pmd_populate_kernel(struct mm_struct *mm, pmd_t *pmd,
+                                      pte_t *pte)
+{
+       extern spinlock_t kmap_gen_lock;
+       pmd_t *ppmd;
+       int pmdindex;
+
+       spin_lock(&kmap_gen_lock);
+       kmap_generation++;
+       mm->context.generation = kmap_generation;
+       current->active_mm->context.generation = kmap_generation;
+       spin_unlock(&kmap_gen_lock);
+
+       set_pmd(pmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
+
+       /*
+        * Now the "slave" copy of the current thread.
+        * This is pointer arithmetic, not byte addresses!
+        */
+       pmdindex = (pgd_t *)pmd - mm->pgd;
+       ppmd = (pmd_t *)current->active_mm->pgd + pmdindex;
+       set_pmd(ppmd, __pmd(((unsigned long)__pa(pte)) | HEXAGON_L1_PTE_SIZE));
+       if (pmdindex > max_kernel_seg)
+               max_kernel_seg = pmdindex;
+}
+
+#define __pte_free_tlb(tlb, pte, addr)         \
+do {                                           \
+       pgtable_page_dtor((pte));               \
+       tlb_remove_page((tlb), (pte));          \
+} while (0)
+
+#endif