On 06/06/11 14:21, Sebastian Andrzej Siewior wrote:

Suzuki Poulose wrote:

quoted

Could you please let me know your thoughts/comments about this patch ?

I'm mostly fine with it.

Maaxim copied fs2dt.c from ppc64 to ppc. So I guess ppc64 has the same
problem.

Yes, you are right. Porting this patch over to ppc64 is in my TODO list.

ARM and MIPS is soon having DT support and kexec is probably also
on their list so I would hate to see them to either copy the DT parsing
file or having their own implementation.

Maybe we should try to use libfdt for dt parsing. It has /proc import
support so it should be fine for our needs. It is already in tree and used
by ppc32 if a basic dtb is specified. I'm not sure if the /proc interface
is part of dtc or libfdt.

I'm not saying this has to be done now but maybe later before ARM and/or
MIPS comes along needs something similar for their needs. If the libfdt is
too complex for sucking in the dtb from /proc then maybe something else
that generic and can be shared between booth ppc architectures and the
other ones.

OK

quoted

quoted

Index: kexec-tools-2.0.4/kexec/arch/ppc/kexec-ppc.c
===================================================================

--- kexec-tools-2.0.4.orig/kexec/arch/ppc/kexec-ppc.c
+++ kexec-tools-2.0.4/kexec/arch/ppc/kexec-ppc.c

@@ -34,6 +35,92 @@ unsigned int rtas_base, rtas_size;

int max_memory_ranges;
const char *ramdisk;

+/*
+ * Reads the #address-cells and #size-cells on this platform.
+ * This is used to parse the memory/reg info from the device-tree
+ */
+int init_memory_region_info()
+{
+ size_t res = 0;
+ FILE *fp;
+ char *file;
+
+ file = "/proc/device-tree/#address-cells";
+ fp = fopen(file, "r");
+ if (!fp) {
+ fprintf(stderr,"Unable to open %s\n", file);
+ return -1;
+ }
+
+ res = fread(&dt_address_cells,sizeof(unsigned long),1,fp);
+ if (res != 1) {
+ fprintf(stderr,"Error reading %s\n", file);
+ return -1;
+ }
+ fclose(fp);
+ dt_address_cells *= sizeof(unsigned long);

This should be sizeof(unsigned int). I know we on 32bit.

OK. I was using (unsigned long) to get the word size on the machine. Given
this code is duplicated in ppc64, thought of having a generic code which works
fine for all ppcXX. As you mentioned, if we go about moving to a single copy of
fdt code, using long would help us.

quoted

quoted

+ file = "/proc/device-tree/#size-cells";
+ fp = fopen(file, "r");
+ if (!fp) {
+ fprintf(stderr,"Unable to open %s\n", file);
+ return -1;
+ }
+
+ res = fread(&dt_size_cells,sizeof(unsigned long),1,fp);
+ if (res != 1) {
+ fprintf(stderr,"Error reading %s\n", file);
+ return -1;
+ }
+ fclose(fp);
+ dt_size_cells *= sizeof(unsigned long);

same here.

Thanks
Suzuki