Re: highmem pci dma mapping does not work, missing cast in asm-i386/pci.h

Jes Sorensen
2002-06-23T15:39:47Z

>>>>> "Ben" == Benjamin LaHaise <bcrl@redhat.com> writes:

Ben> Hello all, There's a missing cast in pci_map_page that causes 64
Ben> bit capable drivers to access the wrong memory for highmem pages.
Ben> Please include the patch below to fix it.

Looking at this one, I believe we need to do the same for
page_to_phys() - either by using dma_addr_t as the type or explicitly
going u64 #ifdef CONFIG_HIGHMEM.

Patch using dma_addr_t included relative to 2.4.18.

Btw. I noticed that in 2.5.24/ia32 we use CONFIG_HIGHMEM to declare
dma_addr_t as 64 bit but CONFIG_HIGHMEM64G to handle page_to_phys. Is
this just an oversight or on purpose?

Comments?

Jes

--- include/asm-i386/io.h~ Sun Jun 23 11:29:26 2002
+++ include/asm-i386/io.h Sun Jun 23 11:30:17 2002
@@ -2,6 +2,7 @@
#define _ASM_IO_H

#include <linux/config.h>
+#include <asm/types.h>

/*
* This file contains the definitions for the x86 IO instructions
@@ -76,7 +77,7 @@
/*
* Change "struct page" to physical address.
*/
-#define page_to_phys(page) ((page - mem_map) << PAGE_SHIFT)
+#define page_to_phys(page) ((dma_addr_t)(page - mem_map) << PAGE_SHIFT)

extern void * __ioremap(unsigned long offset, unsigned long size, unsigned long flags);