kernel header usage fix needed on ppc

[Jack Howarth <howarth at bromo dot med dot uc dot edu>]

Hi,
   As I said before, Paul Mackerras <paulus@linuxcare.com>, has decided
to wrap the asm-ppc kernel headers in Linux 2.4 tightly with an
#ifdef __KERNEL__/#endif /* __KERNEL__ */ wrapper. This is because 
we have been told that all kernel header usage by userland should be
considered as breakage. That being the case, I have found that glibc
2.1.95 has a build problem on linuxppc against these new strict kernel
headers. The file sysdeps/unix/sysv/linux/powerpc/mmap64.c has
asm/page.h included which now under the current bitkeeper linuxppc_2_3
tree no longer provides the needed declarations. I have managed to build
glibc 2.1.95 with the following patch...

--- glibc-2.1.95/sysdeps/unix/sysv/linux/powerpc/mmap64.c	Tue Sep 19 12:55:38 2000
+++ glibc-2.1.95.new/sysdeps/unix/sysv/linux/powerpc/mmap64.c	Sat Oct 21 14:15:55 2000
@@ -25,8 +25,12 @@
 #include <sys/syscall.h>
 #include <bp-checks.h>
 
-#include <asm/page.h>
 #include "kernel-features.h"
+
+/* PAGE_SHIFT determines the page size */
+#define PAGE_SHIFT	12
+#define PAGE_SIZE	(1UL << PAGE_SHIFT)
+#define PAGE_MASK	(~(PAGE_SIZE-1))
 
 #ifdef __NR_mmap2
 extern void *__unbounded __syscall_mmap2(void *__unbounded, size_t,

...It is unclear to me if we can do this in a better way using
getpagesize to calculate this stuff as in this test program...

--------------------------------------------------------------
#include <stdio.h>
#include <sys/shm.h>

#define PAGE_SHIFT	12
#define PAGE_SIZE	(1UL << PAGE_SHIFT)
#define PAGE_MASK	(~(PAGE_SIZE-1))


int i,pagesize,pageshift,pagemask;

main()
{
pagesize=__getpagesize();

for(i=1; i <= 8*sizeof(int); i++) {
  if( pagesize & (1UL << i)) {
    pageshift += i;
  }
}
pagemask=(~(pagesize-1));

printf("pagesize is %d\n",pagesize);
printf("pagesize is %d\n",PAGE_SIZE);
printf("pageshift is %d\n",pageshift);
printf("pageshift is %d\n",PAGE_SHIFT);
printf("pagemask is %x\n",pagemask);
printf("pagemask is %x\n",PAGE_MASK);

}

------------------------------------------------------
I am afraid to try this because it seems that perhaps
getpagesize uses mmap64.c and we will create a recursive
loop. I would appreciate if someone could either add
this change or create a better fix.
                           Jack Howarth