compilation fixes for i460 with 2.5.1[5-7] kernels

PATCH In review Peter Chubb 2 participants 2 messages May 24, 2002 Char and misc drivers

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Peter Chubb

author

2002-05-24 05:26 UTC #0 lore raw

PATCH 1/1 compilation fixes for i460 with 2.5.1[5-7] kernels

Since 2.5.15, a few interfaces are no longer exported from filemap.c --- which means the code for getting and releasing locked pages in files .../agp/agpgart_be.c, .../drm/radeon.c, and .../drm/r128_cce.c has to be changed.

Question: Is it *really* necessary to lock these pages? As they're grabbed from the freepage list, they're not backed by a file, so noone else will ever try to get the page. (Or have I misunderstood completely what's going on here?) So what's it locking against?

# This is a BitKeeper generated patch for the following project:
# Project Name: Linux kernel tree
# This patch format is intended for GNU patch command version 2.5 or higher.
# This patch includes the following deltas:
# ChangeSet 1.540 -> 1.541
# drivers/char/agp/agpgart_be.c 1.30 -> 1.31
# drivers/char/drm/r128_cce.c 1.6 -> 1.7
# drivers/char/drm/radeon_cp.c 1.7 -> 1.8
# drivers/char/drm/r128_drv.h 1.5 -> 1.6
#
# The following is the BitKeeper ChangeSet Log
# --------------------------------------------
# 02/05/24 [email protected] 1.541
# Replace explicit bit twiddling in struct page with calls to the correct interface functions

# in IA64-specific parts of the DRM/AGP stuff.
# 
# wake_up_page() is no longer available (as of 2.5.15)
# 
# Clean up r128_cce.c
# --------------------------------------------
#
diff -Nru a/drivers/char/agp/agpgart_be.c b/drivers/char/agp/agpgart_be.c
--- a/drivers/char/agp/agpgart_be.c	Fri May 24 15:31:15 2002
+++ b/drivers/char/agp/agpgart_be.c	Fri May 24 15:31:15 2002
@@ -1739,8 +1739,8 @@
 	bp_end = bp + ((PAGE_SIZE * (1 << (intel_i460_pageshift - PAGE_SHIFT))) - 1);

for (page = virt_to_page(bp); page <= virt_to_page(bp_end); page++) {
- atomic_inc(&page->count);
- set_bit(PG_locked, &page->flags);
+ get_page(page);
+ lock_page(page);
atomic_inc(&agp_bridge.current_memory_agp);
}
return bp;
@@ -1758,9 +1758,8 @@
i460_pg_detail[pg_num] = NULL;

for (page = virt_to_page(bp); page < virt_to_page(bp_end); page++) {
- atomic_dec(&page->count);
- clear_bit(PG_locked, &page->flags);
- wake_up_page(page);
+ put_page(page);
+ unlock_page(page);
atomic_dec(&agp_bridge.current_memory_agp);
}

drivers/char/drm/r128_cce.c +20 -7

diff -Nru a/drivers/char/drm/r128_cce.c b/drivers/char/drm/r128_cce.c
@@ -36,6 +36,11 @@
 #include <linux/interrupt.h>	/* For task queue support */
 #include <linux/delay.h>
 
+
+#ifdef CONFIG_AGP_I460
+# include <linux/pagemap.h> /* for unlock_page */
+#endif
+
 #define R128_FIFO_DEBUG		0

@@ -229,7 +234,7 @@
 		 * a better solution.
 		 */
  		if ( GET_RING_HEAD( &dev_priv->ring ) = dev_priv->ring.tail
-		     || ( dev->agp->agp_info.chipset = INTEL_460GX
+		     || ( dev_priv->cce_is_i460
 			  && ( dev_priv->ring.tail - GET_RING_HEAD( &dev_priv->ring ) ) = 2 ) )
 		{
 #endif

@@ -369,8 +374,10 @@
 			unsigned long alt_rh_off;
 
 			alt_rh_off = __get_free_page(GFP_KERNEL | GFP_DMA);
-			atomic_inc(&virt_to_page(alt_rh_off)->count);
-			set_bit(PG_locked, &virt_to_page(alt_rh_off)->flags);
+			if (alt_rh_off = 0UL)
+				BUG();
+			get_page(virt_to_page(alt_rh_off));
+			SetPageLocked(virt_to_page(alt_rh_off));
 
 			dev_priv->ring.head = (__volatile__ u32 *) alt_rh_off;
 			SET_RING_HEAD( &dev_priv->ring, 0 );

@@ -431,6 +438,10 @@
 	memset( dev_priv, 0, sizeof(drm_r128_private_t) );
 
 	dev_priv->is_pci = init->is_pci;
+#ifdef CONFIG_AGP_I460
+	dev_priv->cce_is_i460 = dev->agp->agp_info.chipset = INTEL_460GX;
+#endif
+
 
 	if ( dev_priv->is_pci && !dev->sg ) {
 		DRM_ERROR( "PCI GART memory not allocated!\n" );

@@ -687,10 +698,12 @@
 			unsigned long alt_rh_off  				(unsigned long) dev_priv->ring.head;
 
-			atomic_dec(&virt_to_page(alt_rh_off)->count);
-			clear_bit(PG_locked, &virt_to_page(alt_rh_off)->flags);
-			wake_up(&virt_to_page(alt_rh_off)->wait);
-			free_page(alt_rh_off);
+			if (alt_rh_off) {
+				struct page *p = virt_to_page(alt_rh_off);
+				put_page(p);
+				unlock_page(p);
+				__free_page(p);
+			}
 		}
 #endif

drivers/char/drm/r128_drv.h +3 -1

diff -Nru a/drivers/char/drm/r128_drv.h b/drivers/char/drm/r128_drv.h
@@ -65,7 +65,9 @@
 	int cce_mode;
 	int cce_fifo_size;
 	int cce_running;
-
+#ifdef CONFIG_AGP_I460
+	int is_i460;
+#endif
    	drm_r128_freelist_t *head;
    	drm_r128_freelist_t *tail;

drivers/char/drm/radeon_cp.c +15 -8

diff -Nru a/drivers/char/drm/radeon_cp.c b/drivers/char/drm/radeon_cp.c
@@ -36,6 +36,10 @@
 #include <linux/interrupt.h>	/* For task queue support */
 #include <linux/delay.h>
 
+#ifdef CONFIG_AGP_I460
+# include <linux/pagemap.h> /* for unlock_page */
+#endif
+
 #define RADEON_FIFO_DEBUG	0
 
 #if defined(__alpha__)

@@ -624,8 +628,10 @@
 			unsigned long alt_rh_off;
 
 			alt_rh_off = __get_free_page(GFP_KERNEL | GFP_DMA);
-			atomic_inc(&virt_to_page(alt_rh_off)->count);
-			set_bit(PG_locked, &virt_to_page(alt_rh_off)->flags);
+			if (alt_rh_off = 0UL)
+				BUG();
+			get_page(virt_to_page(alt_rh_off));
+			SetPageLocked(virt_to_page(alt_rh_off));
 
 			dev_priv->ring.head = (__volatile__ u32 *) alt_rh_off;
 			*dev_priv->ring.head = cur_read_ptr;

@@ -650,7 +656,7 @@
 #else
 		RADEON_WRITE( RADEON_CP_RB_RPTR_ADDR,
 			     entry->busaddr[page_ofs]);
-		DRM_DEBUG( "ring rptr: offset=0x%08x handle=0x%08lx\n",
+		DRM_DEBUG( "ring rptr: offset=%08lx handle=0x%08lx\n",
 			   entry->busaddr[page_ofs],
 			   entry->handle + tmp_ofs );
 #endif

@@ -1027,11 +1033,12 @@
 		 */
 		if( !dev_priv->is_pci && dev->agp->agp_info.chipset = INTEL_460GX ) {
 			unsigned long alt_rh_off = (unsigned long) dev_priv->ring.head;
-
-			atomic_dec(&virt_to_page(alt_rh_off)->count);
-			clear_bit(PG_locked, &virt_to_page(alt_rh_off)->flags);
-			wake_up(&virt_to_page(alt_rh_off)->wait);
-			free_page(alt_rh_off);
+			if (alt_rh_off) {
+				struct page *p = virt_to_page(alt_rh_off);
+				put_page(p);
+				unlock_page(p);
+				__free_page(p);
+			}
 		}
 #endif
 		DRM(free)( dev->dev_private, sizeof(drm_radeon_private_t), DRM_MEM_DRIVER );

David Mosberger

2002-05-24 18:00 UTC #1 lore raw

Quoted 1 line

Quoted 1 line
Quoted 1 line
Quoted 1 line
Quoted 1 line · Peter Chubb

Peter> Since 2.5.15, a few interfaces are no longer exported from Peter> filemap.c --- which means the code for getting and releasing Peter> locked pages in files .../agp/agpgart_be.c, .../drm/radeon.c, Peter> and .../drm/r128_cce.c has to be changed.

Peter> Question: Is it *really* necessary to lock these pages? As Peter> they're grabbed from the freepage list, they're not backed by Peter> a file, so noone else will ever try to get the page. (Or Peter> have I misunderstood completely what's going on here?) So Peter> what's it locking against?

I believe the locking is bogus. I'm no AGP expert, but my understanding is that what's going on there is that the agp code is allocating an scatter/gather table which is accessed by the GART ("AGP's DMA engine"). This table can be mapped into user level. I suspect the intent of the original code was to prevent swap-outs etc. on those pages. However, that's already taken care of by the vm-area which is used to map the memory into user level: it has the VM_RESERVED flag set (see drm_vm.h).

BTW: I'm finally back to working on the 2.5 tree. I hope to have a (preliminary) 2.5.17 patch sometime today.

	--david