Messages in this thread | | | Subject | Re: [PATCH v1 1/1] powerpc/papr_scm: Properly handle UUID types and API | From | "Aneesh Kumar K.V" <> | Date | Fri, 16 Apr 2021 15:05:31 +0530 |
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On 4/16/21 2:39 PM, Andy Shevchenko wrote: > On Fri, Apr 16, 2021 at 01:28:21PM +0530, Aneesh Kumar K.V wrote: >> On 4/15/21 7:16 PM, Andy Shevchenko wrote: >>> Parse to and export from UUID own type, before dereferencing. >>> This also fixes wrong comment (Little Endian UUID is something else) >>> and should fix Sparse warnings about assigning strict types to POD. >>> >>> Fixes: 43001c52b603 ("powerpc/papr_scm: Use ibm,unit-guid as the iset cookie") >>> Fixes: 259a948c4ba1 ("powerpc/pseries/scm: Use a specific endian format for storing uuid from the device tree") >>> Cc: Oliver O'Halloran <oohall@gmail.com> >>> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> >>> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> >>> --- >>> Not tested >>> arch/powerpc/platforms/pseries/papr_scm.c | 13 ++++++++----- >>> 1 file changed, 8 insertions(+), 5 deletions(-) >>> >>> diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c >>> index ae6f5d80d5ce..4366e1902890 100644 >>> --- a/arch/powerpc/platforms/pseries/papr_scm.c >>> +++ b/arch/powerpc/platforms/pseries/papr_scm.c >>> @@ -1085,8 +1085,9 @@ static int papr_scm_probe(struct platform_device *pdev) >>> u32 drc_index, metadata_size; >>> u64 blocks, block_size; >>> struct papr_scm_priv *p; >>> + u8 uuid_raw[UUID_SIZE]; >>> const char *uuid_str; >>> - u64 uuid[2]; >>> + uuid_t uuid; >>> int rc; >>> /* check we have all the required DT properties */ >>> @@ -1129,16 +1130,18 @@ static int papr_scm_probe(struct platform_device *pdev) >>> p->hcall_flush_required = of_property_read_bool(dn, "ibm,hcall-flush-required"); >>> /* We just need to ensure that set cookies are unique across */ >>> - uuid_parse(uuid_str, (uuid_t *) uuid); >>> + uuid_parse(uuid_str, &uuid); >>> + >>> /* >>> * cookie1 and cookie2 are not really little endian >>> - * we store a little endian representation of the >>> + * we store a raw buffer representation of the >>> * uuid str so that we can compare this with the label >>> * area cookie irrespective of the endian config with which >>> * the kernel is built. >>> */ >>> - p->nd_set.cookie1 = cpu_to_le64(uuid[0]); >>> - p->nd_set.cookie2 = cpu_to_le64(uuid[1]); >>> + export_uuid(uuid_raw, &uuid); >>> + p->nd_set.cookie1 = get_unaligned_le64(&uuid_raw[0]); >>> + p->nd_set.cookie2 = get_unaligned_le64(&uuid_raw[8]); >> >> ok that does the equivalent of cpu_to_le64 there. So we are good. But the >> comment update is missing the details why we did that get_unaligned_le64. >> Maybe raw buffer representation is the correct term? >> Should we add an example in the comment. ie, > >> /* >> * Historically we stored the cookie in the below format. >> for a uuid str 72511b67-0b3b-42fd-8d1d-5be3cae8bcaa >> cookie1 was 0xfd423b0b671b5172 cookie2 was 0xaabce8cae35b1d8d >> */ > > I'm fine with the comment. At least it will shed a light on the byte ordering > we are expecting. >
Will you be sending an update? Also it will be good to list the sparse warning in the commit message?
-aneesh
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