[PATCH 5.13 753/800] powerpc/papr_scm: Properly handle UUID types and API

From: Greg Kroah-Hartman
Date: Mon Jul 12 2021 - 05:05:01 EST


From: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>

[ Upstream commit 0e8554b5d7801b0aebc6c348a0a9f7706aa17b3b ]

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")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210616134303.58185-1-andriy.shevchenko@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 ef26fe40efb0..8335e13836db 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)

@@ -1094,8 +1095,9 @@ 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 */
@@ -1138,16 +1140,23 @@ 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;
--
2.30.2