From 1c787f0d396c309131d5f34939598d657ee2459f Mon Sep 17 00:00:00 2001
From: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
Date: Mon, 21 Aug 2006 20:38:57 +0200
Subject: Backwards compatibility code for ttms.

---
 linux-core/drm_compat.c | 140 ++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)
 create mode 100644 linux-core/drm_compat.c

(limited to 'linux-core/drm_compat.c')

diff --git a/linux-core/drm_compat.c b/linux-core/drm_compat.c
new file mode 100644
index 00000000..cdef4b97
--- /dev/null
+++ b/linux-core/drm_compat.c
@@ -0,0 +1,140 @@
+/**************************************************************************
+ * 
+ * This kernel module 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, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ * 
+ **************************************************************************/
+/*
+ * This code provides access to unexported mm kernel features. It is necessary
+ * to use the new DRM memory manager code with kernels that don't support it
+ * directly.
+ *
+ * Authors: Thomas Hellstrom <thomas-at-tungstengraphics-dot-com>
+ *          Linux kernel mm subsystem authors. 
+ *          (Most code taken from there).
+ */
+
+#include "drmP.h"
+#include <asm/pgtable.h>
+#include <asm/cacheflush.h>
+#include <asm/tlbflush.h>
+
+#ifdef MODULE
+void pgd_clear_bad(pgd_t * pgd)
+{
+	pgd_ERROR(*pgd);
+	pgd_clear(pgd);
+}
+
+void pud_clear_bad(pud_t * pud)
+{
+	pud_ERROR(*pud);
+	pud_clear(pud);
+}
+
+void pmd_clear_bad(pmd_t * pmd)
+{
+	pmd_ERROR(*pmd);
+	pmd_clear(pmd);
+}
+#endif
+
+static inline void change_pte_range(struct mm_struct *mm, pmd_t * pmd,
+				    unsigned long addr, unsigned long end)
+{
+	pte_t *pte;
+
+	pte = pte_offset_map(pmd, addr);
+	do {
+		if (pte_present(*pte)) {
+			pte_t ptent;
+			ptent = *pte;
+			ptep_get_and_clear(mm, addr, pte);
+			lazy_mmu_prot_update(ptent);
+		}
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+	pte_unmap(pte - 1);
+}
+
+static inline void change_pmd_range(struct mm_struct *mm, pud_t * pud,
+				    unsigned long addr, unsigned long end)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	pmd = pmd_offset(pud, addr);
+	do {
+		next = pmd_addr_end(addr, end);
+		if (pmd_none_or_clear_bad(pmd))
+			continue;
+		change_pte_range(mm, pmd, addr, next);
+	} while (pmd++, addr = next, addr != end);
+}
+
+static inline void change_pud_range(struct mm_struct *mm, pgd_t * pgd,
+				    unsigned long addr, unsigned long end)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	pud = pud_offset(pgd, addr);
+	do {
+		next = pud_addr_end(addr, end);
+		if (pud_none_or_clear_bad(pud))
+			continue;
+		change_pmd_range(mm, pud, addr, next);
+	} while (pud++, addr = next, addr != end);
+}
+
+/*
+ * This function should be called with all relevant spinlocks held.
+ */
+
+void drm_clear_vma(struct vm_area_struct *vma,
+		   unsigned long addr, unsigned long end)
+{
+	struct mm_struct *mm = vma->vm_mm;
+	pgd_t *pgd;
+	unsigned long next;
+#if defined(flush_tlb_mm) || !defined(MODULE)
+	unsigned long start = addr;
+#endif
+	BUG_ON(addr >= end);
+	pgd = pgd_offset(mm, addr);
+	flush_cache_range(vma, addr, end);
+	do {
+		next = pgd_addr_end(addr, end);
+		if (pgd_none_or_clear_bad(pgd))
+			continue;
+		change_pud_range(mm, pgd, addr, next);
+	} while (pgd++, addr = next, addr != end);
+#if defined(flush_tlb_mm) || !defined(MODULE)
+	flush_tlb_range(vma, addr, end);
+#endif
+}
+
+pgprot_t drm_prot_map(uint32_t flags)
+{
+#ifdef MODULE
+	static pgprot_t drm_protection_map[16] = {
+		__P000, __P001, __P010, __P011, __P100, __P101, __P110, __P111,
+		__S000, __S001, __S010, __S011, __S100, __S101, __S110, __S111
+	};
+
+	return drm_protection_map[flags & 0x0F];
+#else
+	extern pgprot_t protection_map[];
+	return protection_map[flags & 0x0F];
+#endif
+};
-- 
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