[Linux-mips-commits]CVS: linux/drivers/video epson1356fb.c,1.8,1.9

[Pete P. <pp...@us...>]

Update of /cvsroot/linux-mips/linux/drivers/video
In directory usw-pr-cvs1:/tmp/cvs-serv29502/drivers/video

Modified Files:
	epson1356fb.c 
Log Message:
Current linux generic remap_page_range does not support higher than
32 bit physical addresses on a 32 bit kernel.  In order to use the
epson driver with a 36 bit MIPS32 chip select, I had to copy a few of
the remap_page_range routines and modify them accorindly, in my local 
copy. This was tested on the Alchemy MIPS32 part which supports 36
bit phys addr.


Index: epson1356fb.c
===================================================================
RCS file: /cvsroot/linux-mips/linux/drivers/video/epson1356fb.c,v
retrieving revision 1.8
retrieving revision 1.9
diff -u -d -r1.8 -r1.9
--- epson1356fb.c	7 Mar 2002 23:30:22 -0000	1.8
+++ epson1356fb.c	12 Apr 2002 22:58:28 -0000	1.9
@@ -42,7 +42,7 @@
 #include <linux/string.h>
 #include <linux/mm.h>
 #include <linux/tty.h>
-#include <linux/malloc.h>
+#include <linux/slab.h>
 #include <linux/vmalloc.h>
 #include <linux/delay.h>
 #include <linux/interrupt.h>
@@ -57,6 +57,11 @@
 #include <asm/io.h>
 #include <asm/uaccess.h>
 #include <linux/timer.h>
+#include <linux/pagemap.h>
+
+#include <asm/pgalloc.h>
+#include <asm/uaccess.h>
+#include <asm/tlb.h>
 
 #ifdef CONFIG_MTRR
 #include <asm/mtrr.h>
@@ -210,6 +215,8 @@
 static struct e1356fb_fix boot_fix; // boot options
 static struct e1356fb_par boot_par; // boot options
 
+static int e1356_remap_page_range(unsigned long from, phys_t phys_addr, unsigned long size, pgprot_t prot);
+
 
 /* ------------------------------------------------------------------------- 
  *                      Hardware-specific funcions
@@ -2071,7 +2078,11 @@
 {
 	struct fb_info_e1356 *info = (struct fb_info_e1356*)fb;
 	unsigned int len;
+#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
+	u64 start=0, off;
+#else
 	unsigned long start=0, off;
+#endif
 
 	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT)) {
 		DPRINTK("invalid vma->vm_pgoff\n");
@@ -2152,10 +2163,17 @@
 	if (info->fix.mmunalign)
 		vma->vm_start += 2;
 	
+#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
+	if (e1356_remap_page_range(vma->vm_start, off,
+				vma->vm_end - vma->vm_start,
+				vma->vm_page_prot))
+		return -EAGAIN;
+#else
 	if (io_remap_page_range(vma->vm_start, off,
 				vma->vm_end - vma->vm_start,
 				vma->vm_page_prot))
 		return -EAGAIN;
+#endif
 
 	info->mmaped = 1;
 	return 0;
@@ -3042,3 +3060,99 @@
 	printk("e1356fb: reserving 1024 bytes for the hwcursor at %p\n",
 	       fb_info.membase_virt + fb_info.fb_size);
 }
+
+#if defined(CONFIG_64BIT_PHYS_ADDR) && defined(CONFIG_CPU_MIPS32)
+
+/*
+ * Return indicates whether a page was freed so caller can adjust rss
+ */
+static inline void forget_pte(pte_t page)
+{
+	if (!pte_none(page)) {
+		printk("forget_pte: old mapping existed!\n");
+		BUG();
+	}
+}
+
+/*
+ * maps a range of physical memory into the requested pages. the old
+ * mappings are removed. any references to nonexistent pages results
+ * in null mappings (currently treated as "copy-on-access")
+ */
+static inline void e1356_remap_pte_range(pte_t * pte, unsigned long address, unsigned long size,
+	phys_t phys_addr, pgprot_t prot)
+{
+	unsigned long end;
+
+	address &= ~PMD_MASK;
+	end = address + size;
+	if (end > PMD_SIZE)
+		end = PMD_SIZE;
+	do {
+		struct page *page;
+		pte_t oldpage;
+		oldpage = ptep_get_and_clear(pte);
+
+		page = virt_to_page(__va(phys_addr));
+		if ((!VALID_PAGE(page)) || PageReserved(page))
+ 			set_pte(pte, mk_pte_phys(phys_addr, prot));
+		forget_pte(oldpage);
+		address += PAGE_SIZE;
+		phys_addr += PAGE_SIZE;
+		pte++;
+	} while (address && (address < end));
+}
+
+static inline int e1356_remap_pmd_range(struct mm_struct *mm, pmd_t * pmd, unsigned long address, unsigned long size,
+	phys_t phys_addr, pgprot_t prot)
+{
+	unsigned long end;
+
+	address &= ~PGDIR_MASK;
+	end = address + size;
+	if (end > PGDIR_SIZE)
+		end = PGDIR_SIZE;
+	phys_addr -= address;
+	do {
+		pte_t * pte = pte_alloc(mm, pmd, address);
+		if (!pte)
+			return -ENOMEM;
+		e1356_remap_pte_range(pte, address, end - address, address + phys_addr, prot);
+		address = (address + PMD_SIZE) & PMD_MASK;
+		pmd++;
+	} while (address && (address < end));
+	return 0;
+}
+
+/*  Note: this is only safe if the mm semaphore is held when called. */
+static int e1356_remap_page_range(unsigned long from, phys_t phys_addr, unsigned long size, pgprot_t prot)
+{
+	int error = 0;
+	pgd_t * dir;
+	phys_t beg = from;
+	phys_t end = from + size;
+	struct mm_struct *mm = current->mm;
+
+	phys_addr -= from;
+	dir = pgd_offset(mm, from);
+	flush_cache_range(mm, beg, end);
+	if (from >= end)
+		BUG();
+
+	spin_lock(&mm->page_table_lock);
+	do {
+		pmd_t *pmd = pmd_alloc(mm, dir, from);
+		error = -ENOMEM;
+		if (!pmd)
+			break;
+		error = e1356_remap_pmd_range(mm, pmd, from, end - from, phys_addr + from, prot);
+		if (error)
+			break;
+		from = (from + PGDIR_SIZE) & PGDIR_MASK;
+		dir++;
+	} while (from && (from < end));
+	spin_unlock(&mm->page_table_lock);
+	flush_tlb_range(mm, beg, end);
+	return error;
+}
+#endif