scsi: mpt3sas: Introduce function to clone mpi request.

1) Added function _base_clone_mpi_to_sys_mem to clone
MPI request into system BAR0 mapped region.

2) Separate out MPI Endpoint IO submissions to function
_base_put_smid_mpi_ep_scsi_io.

3) MPI EP requests are submitted in two 32 bit MMIO writes.
from _base_mpi_ep_writeq.

 For 32 bit Arch,_base_writeq function is identical
to _base_mpi_ep_writeq, Removed duplicate code as suggested.
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani@broadcom.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/mpt3sas/mpt3sas_base.c

@@ -125,6 +125,25 @@ _scsih_set_fwfault_debug(const char *val, const struct kernel_param *kp)
 module_param_call(mpt3sas_fwfault_debug, _scsih_set_fwfault_debug,
 	param_get_int, &mpt3sas_fwfault_debug, 0644);
 
+/**
+ * _base_clone_mpi_to_sys_mem - Writes/copies MPI frames
+ *				to system/BAR0 region.
+ *
+ * @dst_iomem: Pointer to the destinaltion location in BAR0 space.
+ * @src: Pointer to the Source data.
+ * @size: Size of data to be copied.
+ */
+static void
+_base_clone_mpi_to_sys_mem(void *dst_iomem, void *src, u32 size)
+{
+	int i;
+	u32 *src_virt_mem = (u32 *)src;
+
+	for (i = 0; i < size/4; i++)
+		writel((u32)src_virt_mem[i],
+				(void __iomem *)dst_iomem + (i * 4));
+}
+
 /**
  * _base_clone_to_sys_mem - Writes/copies data to system/BAR0 region
  *
@@ -3267,6 +3286,29 @@ mpt3sas_base_free_smid(struct MPT3SAS_ADAPTER *ioc, u16 smid)
 	spin_unlock_irqrestore(&ioc->scsi_lookup_lock, flags);
 }
 
+/**
+ * _base_mpi_ep_writeq - 32 bit write to MMIO
+ * @b: data payload
+ * @addr: address in MMIO space
+ * @writeq_lock: spin lock
+ *
+ * This special handling for MPI EP to take care of 32 bit
+ * environment where its not quarenteed to send the entire word
+ * in one transfer.
+ */
+static inline void
+_base_mpi_ep_writeq(__u64 b, volatile void __iomem *addr,
+					spinlock_t *writeq_lock)
+{
+	unsigned long flags;
+	__u64 data_out = cpu_to_le64(b);
+
+	spin_lock_irqsave(writeq_lock, flags);
+	writel((u32)(data_out), addr);
+	writel((u32)(data_out >> 32), (addr + 4));
+	spin_unlock_irqrestore(writeq_lock, flags);
+}
+
 /**
  * _base_writeq - 64 bit write to MMIO
  * @ioc: per adapter object
@@ -3288,16 +3330,40 @@ _base_writeq(__u64 b, volatile void __iomem *addr, spinlock_t *writeq_lock)
 static inline void
 _base_writeq(__u64 b, volatile void __iomem *addr, spinlock_t *writeq_lock)
 {
-	unsigned long flags;
-	__u64 data_out = cpu_to_le64(b);
-
-	spin_lock_irqsave(writeq_lock, flags);
-	writel((u32)(data_out), addr);
-	writel((u32)(data_out >> 32), (addr + 4));
-	spin_unlock_irqrestore(writeq_lock, flags);
+	_base_mpi_ep_writeq(b, addr, writeq_lock);
 }
 #endif
 
+/**
+ * _base_put_smid_mpi_ep_scsi_io - send SCSI_IO request to firmware
+ * @ioc: per adapter object
+ * @smid: system request message index
+ * @handle: device handle
+ *
+ * Return nothing.
+ */
+static void
+_base_put_smid_mpi_ep_scsi_io(struct MPT3SAS_ADAPTER *ioc, u16 smid, u16 handle)
+{
+	Mpi2RequestDescriptorUnion_t descriptor;
+	u64 *request = (u64 *)&descriptor;
+	void *mpi_req_iomem;
+	__le32 *mfp = (__le32 *)mpt3sas_base_get_msg_frame(ioc, smid);
+
+	_clone_sg_entries(ioc, (void *) mfp, smid);
+	mpi_req_iomem = (void *)ioc->chip +
+			MPI_FRAME_START_OFFSET + (smid * ioc->request_sz);
+	_base_clone_mpi_to_sys_mem(mpi_req_iomem, (void *)mfp,
+					ioc->request_sz);
+	descriptor.SCSIIO.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_SCSI_IO;
+	descriptor.SCSIIO.MSIxIndex =  _base_get_msix_index(ioc);
+	descriptor.SCSIIO.SMID = cpu_to_le16(smid);
+	descriptor.SCSIIO.DevHandle = cpu_to_le16(handle);
+	descriptor.SCSIIO.LMID = 0;
+	_base_mpi_ep_writeq(*request, &ioc->chip->RequestDescriptorPostLow,
+	    &ioc->scsi_lookup_lock);
+}
+
 /**
  * _base_put_smid_scsi_io - send SCSI_IO request to firmware
  * @ioc: per adapter object
@@ -3359,7 +3425,23 @@ _base_put_smid_hi_priority(struct MPT3SAS_ADAPTER *ioc, u16 smid,
 	u16 msix_task)
 {
 	Mpi2RequestDescriptorUnion_t descriptor;
-	u64 *request = (u64 *)&descriptor;
+	void *mpi_req_iomem;
+	u64 *request;
+
+	if (ioc->is_mcpu_endpoint) {
+		MPI2RequestHeader_t *request_hdr;
+
+		__le32 *mfp = (__le32 *)mpt3sas_base_get_msg_frame(ioc, smid);
+
+		request_hdr = (MPI2RequestHeader_t *)mfp;
+		/* TBD 256 is offset within sys register. */
+		mpi_req_iomem = (void *)ioc->chip + MPI_FRAME_START_OFFSET
+					+ (smid * ioc->request_sz);
+		_base_clone_mpi_to_sys_mem(mpi_req_iomem, (void *)mfp,
+							ioc->request_sz);
+	}
+
+	request = (u64 *)&descriptor;
 
 	descriptor.HighPriority.RequestFlags =
 	    MPI2_REQ_DESCRIPT_FLAGS_HIGH_PRIORITY;
@@ -3367,6 +3449,11 @@ _base_put_smid_hi_priority(struct MPT3SAS_ADAPTER *ioc, u16 smid,
 	descriptor.HighPriority.SMID = cpu_to_le16(smid);
 	descriptor.HighPriority.LMID = 0;
 	descriptor.HighPriority.Reserved1 = 0;
+	if (ioc->is_mcpu_endpoint)
+		_base_mpi_ep_writeq(*request,
+				&ioc->chip->RequestDescriptorPostLow,
+				&ioc->scsi_lookup_lock);
+	else
 		_base_writeq(*request, &ioc->chip->RequestDescriptorPostLow,
 		    &ioc->scsi_lookup_lock);
 }
@@ -3406,13 +3493,33 @@ static void
 _base_put_smid_default(struct MPT3SAS_ADAPTER *ioc, u16 smid)
 {
 	Mpi2RequestDescriptorUnion_t descriptor;
-	u64 *request = (u64 *)&descriptor;
+	void *mpi_req_iomem;
+	u64 *request;
+	MPI2RequestHeader_t *request_hdr;
+
+	if (ioc->is_mcpu_endpoint) {
+		__le32 *mfp = (__le32 *)mpt3sas_base_get_msg_frame(ioc, smid);
+
+		request_hdr = (MPI2RequestHeader_t *)mfp;
 
+		_clone_sg_entries(ioc, (void *) mfp, smid);
+		/* TBD 256 is offset within sys register */
+		mpi_req_iomem = (void *)ioc->chip +
+			MPI_FRAME_START_OFFSET + (smid * ioc->request_sz);
+		_base_clone_mpi_to_sys_mem(mpi_req_iomem, (void *)mfp,
+							ioc->request_sz);
+	}
+	request = (u64 *)&descriptor;
 	descriptor.Default.RequestFlags = MPI2_REQ_DESCRIPT_FLAGS_DEFAULT_TYPE;
 	descriptor.Default.MSIxIndex =  _base_get_msix_index(ioc);
 	descriptor.Default.SMID = cpu_to_le16(smid);
 	descriptor.Default.LMID = 0;
 	descriptor.Default.DescriptorTypeDependent = 0;
+	if (ioc->is_mcpu_endpoint)
+		_base_mpi_ep_writeq(*request,
+				&ioc->chip->RequestDescriptorPostLow,
+				&ioc->scsi_lookup_lock);
+	else
 		_base_writeq(*request, &ioc->chip->RequestDescriptorPostLow,
 				&ioc->scsi_lookup_lock);
 }
@@ -6333,6 +6440,9 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
 		ioc->put_smid_nvme_encap = &_base_put_smid_nvme_encap_atomic;
 	} else {
 		ioc->put_smid_default = &_base_put_smid_default;
+		if (ioc->is_mcpu_endpoint)
+			ioc->put_smid_scsi_io = &_base_put_smid_mpi_ep_scsi_io;
+		else
 			ioc->put_smid_scsi_io = &_base_put_smid_scsi_io;
 		ioc->put_smid_fast_path = &_base_put_smid_fast_path;
 		ioc->put_smid_hi_priority = &_base_put_smid_hi_priority;