patch-2.1.51 linux/arch/mips/mm/umap.c

• Lines: 217
• Date: Sat Aug 16 09:51:07 1997
• Orig file: v2.1.50/linux/arch/mips/mm/umap.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.1.50/linux/arch/mips/mm/umap.c linux/arch/mips/mm/umap.c
@@ -0,0 +1,216 @@
+/*
+ * arch/mips/mm/umap.c
+ *
+ * (C) Copyright 1994 Linus Torvalds
+ *
+ * Changes:
+ *
+ * Modified from Linus source to removing active mappings from any
+ * task.  This is required for implementing the virtual graphics
+ * interface for direct rendering on the SGI - miguel.
+ *
+ * Added a routine to map a vmalloc()ed area into user space, this one
+ * is required by the /dev/shmiq driver - miguel.
+ */
+#include <linux/stat.h>
+#include <linux/sched.h>
+#include <linux/kernel.h>
+#include <linux/mm.h>
+#include <linux/smp.h>
+#include <linux/smp_lock.h>
+#include <linux/shm.h>
+#include <linux/errno.h>
+#include <linux/mman.h>
+#include <linux/string.h>
+#include <linux/vmalloc.h>
+#include <linux/swap.h>
+
+#include <asm/system.h>
+#include <asm/pgtable.h>
+#include <asm/page.h>
+
+static inline void
+remove_mapping_pte_range (pmd_t *pmd, unsigned long address, unsigned long size)
+{
+	pte_t *pte;
+	unsigned long end;
+
+	if (pmd_none (*pmd))
+		return;
+	if (pmd_bad (*pmd)){
+		printk ("remove_graphics_pte_range: bad pmd (%08lx)\n", pmd_val (*pmd));
+		pmd_clear (pmd);
+		return;
+	}
+	pte = pte_offset (pmd, address);
+	address &= ~PMD_MASK;
+	end = address + size;
+	if (end > PMD_SIZE)
+		end = PMD_SIZE;
+	do {
+		pte_t entry = *pte;
+		if (pte_present (entry))
+			set_pte (pte, pte_modify (entry, PAGE_NONE));
+		address += PAGE_SIZE;
+		pte++;
+	} while (address < end);
+						  
+}
+
+static inline void
+remove_mapping_pmd_range (pgd_t *pgd, unsigned long address, unsigned long size)
+{
+	pmd_t *pmd;
+	unsigned long end;
+
+	if (pgd_none (*pgd))
+		return;
+
+	if (pgd_bad (*pgd)){
+		printk ("remove_graphics_pmd_range: bad pgd (%08lx)\n", pgd_val (*pgd));
+		pgd_clear (pgd);
+		return;
+	}
+	pmd = pmd_offset (pgd, address);
+	address &= ~PGDIR_MASK;
+	end = address + size;
+	if (end > PGDIR_SIZE)
+		end = PGDIR_SIZE;
+	do {
+		remove_mapping_pte_range (pmd, address, end - address);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address < end);
+		
+}
+
+/*
+ * This routine is called from the page fault handler to remove a
+ * range of active mappings at this point
+ */
+void
+remove_mapping (struct task_struct *task, unsigned long start, unsigned long end)
+{
+	unsigned long beg = start;
+	pgd_t *dir;
+
+	down (&task->mm->mmap_sem);
+	dir = pgd_offset (task->mm, start);
+	flush_cache_range (task->mm, beg, end);
+	while (start < end){
+		remove_mapping_pmd_range (dir, start, end - start);
+		start = (start + PGDIR_SIZE) & PGDIR_MASK;
+		dir++;
+	}
+	flush_tlb_range (task->mm, beg, end);
+	up (&task->mm->mmap_sem);
+}
+
+void *vmalloc_uncached (unsigned long size)
+{
+	return vmalloc_prot (size, PAGE_KERNEL_UNCACHED);
+}
+
+static inline void free_pte(pte_t page)
+{
+	if (pte_present(page)) {
+		unsigned long addr = pte_page(page);
+		if (MAP_NR(addr) >= max_mapnr || PageReserved(mem_map+MAP_NR(addr)))
+			return;
+		free_page(addr);
+		if (current->mm->rss <= 0)
+			return;
+		current->mm->rss--;
+		return;
+	}
+	swap_free(pte_val(page));
+}
+
+static inline void forget_pte(pte_t page)
+{
+	if (!pte_none(page)) {
+		printk("forget_pte: old mapping existed!\n");
+		free_pte(page);
+	}
+}
+
+/*
+ * maps a range of vmalloc()ed memory into the requested pages. the old
+ * mappings are removed. 
+ */
+static inline void
+vmap_pte_range (pte_t *pte, unsigned long address, unsigned long size, unsigned long vaddr)
+{
+	unsigned long end;
+	pgd_t *vdir;
+	pmd_t *vpmd;
+	pte_t *vpte;
+	
+	address &= ~PMD_MASK;
+	end = address + size;
+	if (end > PMD_SIZE)
+		end = PMD_SIZE;
+	do {
+		pte_t oldpage = *pte;
+		unsigned long page;
+		pte_clear(pte);
+
+		vdir = pgd_offset_k (vaddr);
+		vpmd = pmd_offset (vdir, vaddr);
+		vpte = pte_offset (vpmd, vaddr);
+		page = pte_page (*vpte);
+		
+		set_pte(pte, mk_pte_phys(page, PAGE_USERIO));
+		forget_pte(oldpage);
+		address += PAGE_SIZE;
+		vaddr += PAGE_SIZE;
+		pte++;
+	} while (address < end);
+}
+
+static inline int
+vmap_pmd_range (pmd_t *pmd, unsigned long address, unsigned long size, unsigned long vaddr)
+{
+	unsigned long end;
+
+	address &= ~PGDIR_MASK;
+	end = address + size;
+	if (end > PGDIR_SIZE)
+		end = PGDIR_SIZE;
+	vaddr -= address;
+	do {
+		pte_t * pte = pte_alloc(pmd, address);
+		if (!pte)
+			return -ENOMEM;
+		vmap_pte_range(pte, address, end - address, address + vaddr);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address < end);
+	return 0;
+}
+
+int
+vmap_page_range (unsigned long from, unsigned long size, unsigned long vaddr)
+{
+	int error = 0;
+	pgd_t * dir;
+	unsigned long beg = from;
+	unsigned long end = from + size;
+
+	vaddr -= from;
+	dir = pgd_offset(current->mm, from);
+	flush_cache_range(current->mm, beg, end);
+	while (from < end) {
+		pmd_t *pmd = pmd_alloc(dir, from);
+		error = -ENOMEM;
+		if (!pmd)
+			break;
+		error = vmap_pmd_range(pmd, from, end - from, vaddr + from);
+		if (error)
+			break;
+		from = (from + PGDIR_SIZE) & PGDIR_MASK;
+		dir++;
+	}
+	flush_tlb_range(current->mm, beg, end);
+	return error;
+}