On Wed, Oct 16, 2013 at 11:33:43AM +0200, Laurent Dufour wrote: > On 16/10/2013 09:28, Simon Horman wrote: > > On Tue, Oct 15, 2013 at 07:05:28PM +0200, Laurent Dufour wrote: > >> While reviewing fs2dt.c in the common kexec directory, in order to use it > >> to > >> support little endian ppc64 architecture, I found some endianess > >> conversion's issues. > >> > >> In dt_reserve, dt_base is a pointer and thus should not be converted. > >> > >> In checkprop, values read from the device tree are big endian encoded and > >> should be converted if CPU is running in little endian mode. > >> > >> In add_dyn_reconf_usable_mem_property__, fix extraneous endianess > >> conversion > >> of rlen which should be natively used to increase the dt pointer. > > > > These changes seem logical to me. > > > > However, I'm unsure how the code might have worked as-is. > > In particular I'm pretty sure ARM was running in little endian > > mode when I worked on DT support for it. Perhaps these code > > paths were not executed. Or the errors cancelled themselves out somehow? > > I've to admit that I don't know how this has worked for ARM. > I run this patch with a set of change I'm working on to support PPC64 > little endian architecture. My tests were done with kexec-tools built in > little endian mode, using this fs2dt.c file and I need this fix to build > a valid device tree. > > The fix is dt_reserve is hit unless the device tree is large enough. I > had to reduce INIT_TREE_WORDS to hit it. > > I think the ones in checkprop, add_dyn_reconf_usable_mem_property__ are > Power specific since RTAS and 'ibm,dynamic-memory' are required to hit them. > > This may explain why this issue are not seen in ARM mode.
Perhaps, its a bit of a mystery. I think that I will apply your change as it does seem to be correct. > > This being said, I wondering if the files fs2dt.c defined in the > arch/ppc64 and arch/ppc directories need to be kept. What do you think > about removing those files and belong on the common kexec/fs2dt.c file > for all the supported architecture ? I haven't examined the details but that sounds like a good idea to me. > > Cheers, > Laurent. > > >> > >> Signed-off-by: Laurent Dufour <[email protected]> > >> --- > >> kexec/fs2dt.c | 19 +++++++++++-------- > >> 1 file changed, 11 insertions(+), 8 deletions(-) > >> > >> diff --git a/kexec/fs2dt.c b/kexec/fs2dt.c > >> index 242a15e..5d774ae 100644 > >> --- a/kexec/fs2dt.c > >> +++ b/kexec/fs2dt.c > >> @@ -84,7 +84,7 @@ static void dt_reserve(unsigned **dt_ptr, unsigned words) > >> offset = *dt_ptr - dt_base; > >> dt_base = new_dt; > >> dt_cur_size = new_size; > >> - *dt_ptr = cpu_to_be32((unsigned)dt_base + offset); > >> + *dt_ptr = dt_base + offset; > >> memset(*dt_ptr, 0, (new_size - offset)*4); > >> } > >> } > >> @@ -112,19 +112,22 @@ static void checkprop(char *name, unsigned *data, > >> int len) > >> if ((data == NULL) && (base || size || end)) > >> die("unrecoverable error: no property data"); > >> else if (!strcmp(name, "linux,rtas-base")) > >> - base = *data; > >> + base = be32_to_cpu(*data); > >> else if (!strcmp(name, "linux,tce-base")) > >> - base = *(unsigned long long *) data; > >> + base = be64_to_cpu(*(unsigned long long *) data); > >> else if (!strcmp(name, "rtas-size") || > >> !strcmp(name, "linux,tce-size")) > >> - size = *data; > >> + size = be32_to_cpu(*data); > >> else if (reuse_initrd && !strcmp(name, "linux,initrd-start")) > >> if (len == 8) > >> - base = *(unsigned long long *) data; > >> + base = be64_to_cpu(*(unsigned long long *) data); > >> else > >> - base = *data; > >> + base = be32_to_cpu(*data); > >> else if (reuse_initrd && !strcmp(name, "linux,initrd-end")) > >> - end = *(unsigned long long *) data; > >> + if (len == 8) > >> + end = be64_to_cpu(*(unsigned long long *) data); > >> + else > >> + end = be32_to_cpu(*data); > >> > >> if (size && end) > >> die("unrecoverable error: size and end set at same time\n"); > >> @@ -267,7 +270,7 @@ static void add_dyn_reconf_usable_mem_property__(int > >> fd) > >> pad_structure_block(rlen); > >> memcpy(dt, ranges, rlen); > >> free(ranges); > >> - dt += cpu_to_be32((rlen + 3)/4); > >> + dt += (rlen + 3)/4; > >> } > >> > >> static void add_dyn_reconf_usable_mem_property(struct dirent *dp, int fd) > >> > > > _______________________________________________ kexec mailing list [email protected] http://lists.infradead.org/mailman/listinfo/kexec
