Subject: cache coherent io on au1500

From: Bruno Randolf <[email-masked]>
Date: Thu, 11 Sep 2003 16:05:12 +0200

hello!

i have an Au1500, silicon stepping AD (mtx-1 board) which as far as i 
understand should be able to do cache coherent io. but if i change 
CONFIG_NONCOHERENT_IO to "n" compilation of 2.4.21 fails with 

mipsel-linux-gcc -D__KERNEL__ -I/data/kernel/mtx-2.4.21/include -Wall 
- -Wstrict-prototypes -Wno-trigraphs -O2 -fno-strict-aliasing -fno-common 
- -fomit-frame-pointer -I /data/kernel/mtx-2.4.21/include/asm/gcc -G 0 
- -mno-abicalls -fno-pic -pipe -mcpu=r4600 -mips2 -Wa,--trap   -nostdinc 
- -iwithprefix include -DKBUILD_BASENAME=fork  -c -o fork.o fork.c
In file included from fork.c:20:
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h: In function `vmalloc':
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h:36: `_CACHE_CACHABLE_COW' 
undeclared (first use in this function)
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h:36: (Each undeclared 
identifier is reported only once
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h:36: for each function it 
appears in.)
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h: In function `vmalloc_dma':
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h:45: `_CACHE_CACHABLE_COW' 
undeclared (first use in this function)
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h: In function `vmalloc_32':
/data/kernel/mtx-2.4.21/include/linux/vmalloc.h:54: `_CACHE_CACHABLE_COW' 
undeclared (first use in this function)
make[2]: *** [fork.o] Error 1

how could i fix that?

thanks,
bruno

---

From: Pete Popov <[email-masked]>
Date: 11 Sep 2003 09:58:40 -0700

Take a look at ftp.linux-mips.org:/pub/linux/mips/people/ppopov.
There's a README there that describes patches that are not in the tree.
One of them is a tiny patch called coherent_cow.patch that fixes the
compilation problem below. Ralf was looking for a more permanent fix, so
he hasn't applied this patch.

Pete

On Thu, 2003-09-11 at 07:05, Bruno Randolf wrote:
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