nvme-core: choose PIF from QPIF if QPIFS supports and PIF is QTYPE

As per TP4141a:
"If the Qualified Protection Information Format Support(QPIFS) bit is
set to 1 and the Protection Information Format(PIF) field is set to 11b
(i.e., Qualified Type), then the pif is as defined in the Qualified
Protection Information Format (QPIF) field."
So, choose PIF from QPIF if QPIFS supports and PIF is QTYPE.

Signed-off-by: Francis Pravin <francis.p@samsung.com>
Reviewed-by: Sagi Grimberg <sagi@grimberg.me>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>

Author: francispravin5

drivers/nvme/host/core.c

@@ -1875,12 +1875,18 @@ static void nvme_configure_pi_elbas(struct nvme_ns_head *head,
 		struct nvme_id_ns *id, struct nvme_id_ns_nvm *nvm)
 {
 	u32 elbaf = le32_to_cpu(nvm->elbaf[nvme_lbaf_index(id->flbas)]);
+	u8 guard_type;
 
 	/* no support for storage tag formats right now */
 	if (nvme_elbaf_sts(elbaf))
 		return;
 
-	head->guard_type = nvme_elbaf_guard_type(elbaf);
+	guard_type = nvme_elbaf_guard_type(elbaf);
+	if ((nvm->pic & NVME_ID_NS_NVM_QPIFS) &&
+	     guard_type == NVME_NVM_NS_QTYPE_GUARD)
+		guard_type = nvme_elbaf_qualified_guard_type(elbaf);
+
+	head->guard_type = guard_type;
 	switch (head->guard_type) {
 	case NVME_NVM_NS_64B_GUARD:
 		head->pi_size = sizeof(struct crc64_pi_tuple);

include/linux/nvme.h

@@ -483,6 +483,9 @@ enum {
 	NVME_ID_NS_NVM_STS_MASK		= 0x7f,
 	NVME_ID_NS_NVM_GUARD_SHIFT	= 7,
 	NVME_ID_NS_NVM_GUARD_MASK	= 0x3,
+	NVME_ID_NS_NVM_QPIF_SHIFT	= 9,
+	NVME_ID_NS_NVM_QPIF_MASK	= 0xf,
+	NVME_ID_NS_NVM_QPIFS		= 1 << 3,
 };
 
 static inline __u8 nvme_elbaf_sts(__u32 elbaf)
@@ -495,6 +498,11 @@ static inline __u8 nvme_elbaf_guard_type(__u32 elbaf)
 	return (elbaf >> NVME_ID_NS_NVM_GUARD_SHIFT) & NVME_ID_NS_NVM_GUARD_MASK;
 }
 
+static inline __u8 nvme_elbaf_qualified_guard_type(__u32 elbaf)
+{
+	return (elbaf >> NVME_ID_NS_NVM_QPIF_SHIFT) & NVME_ID_NS_NVM_QPIF_MASK;
+}
+
 struct nvme_id_ctrl_nvm {
 	__u8	vsl;
 	__u8	wzsl;
@@ -574,6 +582,7 @@ enum {
 	NVME_NVM_NS_16B_GUARD	= 0,
 	NVME_NVM_NS_32B_GUARD	= 1,
 	NVME_NVM_NS_64B_GUARD	= 2,
+	NVME_NVM_NS_QTYPE_GUARD	= 3,
 };
 
 static inline __u8 nvme_lbaf_index(__u8 flbas)