Re: [PATCH v2 1/1] powerpc/papr_scm: Properly handle UUID types and API
From: Aneesh Kumar K.V <hidden>
Date: 2021-06-16 13:48:39
Also in:
linuxppc-dev
On 6/16/21 7:13 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 eliminate the direct strict types assignments.
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")Do we need the Fixes: there? It didn't change any functionality right? The format with which we stored cookie1 remains the same with older and newer code. The newer one is better? Reviewed-by: Aneesh Kumar K.V <redacted>
quoted hunk ↗ jump to hunk
Cc: Oliver O'Halloran <oohall@gmail.com> Cc: Aneesh Kumar K.V <redacted> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> --- v2: added missed header (Vaibhav), updated comment (Aneesh), rewrite part of the commit message to avoid mentioning the Sparse arch/powerpc/platforms/pseries/papr_scm.c | 27 +++++++++++++++-------- 1 file changed, 18 insertions(+), 9 deletions(-)diff --git a/arch/powerpc/platforms/pseries/papr_scm.c b/arch/powerpc/platforms/pseries/papr_scm.c index e2b69cc3beaf..b43be41e8ff7 100644 --- a/arch/powerpc/platforms/pseries/papr_scm.c +++ b/arch/powerpc/platforms/pseries/papr_scm.c@@ -18,6 +18,7 @@ #include <asm/plpar_wrappers.h> #include <asm/papr_pdsm.h> #include <asm/mce.h> +#include <asm/unaligned.h> #define BIND_ANY_ADDR (~0ul)@@ -1101,8 +1102,9 @@ 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 */@@ -1145,16 +1147,23 @@ 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 - * uuid str so that we can compare this with the label - * area cookie irrespective of the endian config with which - * the kernel is built. + * The cookie1 and cookie2 are not really little endian. + * We store a raw buffer representation of the + * uuid string so that we can compare this with the label + * area cookie irrespective of the endian configuration + * with which the kernel is built. + * + * Historically we stored the cookie in the below format. + * for a uuid string 72511b67-0b3b-42fd-8d1d-5be3cae8bcaa + * cookie1 was 0xfd423b0b671b5172 + * cookie2 was 0xaabce8cae35b1d8d */ - 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]); /* might be zero */ p->metadata_size = metadata_size;