[v5 03/14] mpt3sas: SGL to PRP Translation for I/Os to NVMe devices

Suganath Prabu S suganath-prabu.subramani at broadcom.com
Wed Aug 30 07:08:27 PDT 2017


* Added support for translating the SGLs associated with incoming
commands either to IEE SGL or NVMe PRPs for NVMe devices.

* The hardware translation of IEEE SGL to NVMe PRPs has limitation
and if a command cannot be translated by hardware then it will go
to firmware and the firmware needs to translate it. And this will
have a performance reduction. To avoid that driver proactively
checks whether the translation will be done in hardware or not,
if not then driver try to translate inside the driver.

v1 - v3: no change.
v3 - v4: Removed hole check as suggested by Martin.
With commit-id <5a8d75a1b8c99bdc926ba69b7b7dbe4fae81a5af> "block: 
fix bio_will_gap() for first bvec with offset" driver can always assume
that their won't be any holes in the data buffers pointed by SGE's and no
need to have extra checks for detecting the holes.
v4 - v5: Removed the check to find data transfer length exceeding MDTS,
as we are setting max I/O size to match MDTS in slave_configure.

Signed-off-by: Chaitra P B <chaitra.basappa at broadcom.com>
Signed-off-by: Suganath Prabu S <suganath-prabu.subramani at broadcom.com>
---
 drivers/scsi/mpt3sas/mpt3sas_base.c      | 590 ++++++++++++++++++++++++++++++-
 drivers/scsi/mpt3sas/mpt3sas_base.h      |  44 ++-
 drivers/scsi/mpt3sas/mpt3sas_ctl.c       |   1 +
 drivers/scsi/mpt3sas/mpt3sas_scsih.c     |  14 +-
 drivers/scsi/mpt3sas/mpt3sas_warpdrive.c |   2 +-
 5 files changed, 635 insertions(+), 16 deletions(-)

diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.c b/drivers/scsi/mpt3sas/mpt3sas_base.c
index 18039bb..dcf5157 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.c
@@ -59,6 +59,7 @@
 #include <linux/time.h>
 #include <linux/ktime.h>
 #include <linux/kthread.h>
+#include <asm/page.h>        /* To get host page size per arch */
 #include <linux/aer.h>
 
 
@@ -1347,6 +1348,469 @@ _base_build_sg(struct MPT3SAS_ADAPTER *ioc, void *psge,
 /* IEEE format sgls */
 
 /**
+ * _base_build_nvme_prp - This function is called for NVMe end devices to build
+ * a native SGL (NVMe PRP). The native SGL is built starting in the first PRP
+ * entry of the NVMe message (PRP1).  If the data buffer is small enough to be
+ * described entirely using PRP1, then PRP2 is not used.  If needed, PRP2 is
+ * used to describe a larger data buffer.  If the data buffer is too large to
+ * describe using the two PRP entriess inside the NVMe message, then PRP1
+ * describes the first data memory segment, and PRP2 contains a pointer to a PRP
+ * list located elsewhere in memory to describe the remaining data memory
+ * segments.  The PRP list will be contiguous.
+
+ * The native SGL for NVMe devices is a Physical Region Page (PRP).  A PRP
+ * consists of a list of PRP entries to describe a number of noncontigous
+ * physical memory segments as a single memory buffer, just as a SGL does.  Note
+ * however, that this function is only used by the IOCTL call, so the memory
+ * given will be guaranteed to be contiguous.  There is no need to translate
+ * non-contiguous SGL into a PRP in this case.  All PRPs will describe
+ * contiguous space that is one page size each.
+ *
+ * Each NVMe message contains two PRP entries.  The first (PRP1) either contains
+ * a PRP list pointer or a PRP element, depending upon the command.  PRP2
+ * contains the second PRP element if the memory being described fits within 2
+ * PRP entries, or a PRP list pointer if the PRP spans more than two entries.
+ *
+ * A PRP list pointer contains the address of a PRP list, structured as a linear
+ * array of PRP entries.  Each PRP entry in this list describes a segment of
+ * physical memory.
+ *
+ * Each 64-bit PRP entry comprises an address and an offset field.  The address
+ * always points at the beginning of a 4KB physical memory page, and the offset
+ * describes where within that 4KB page the memory segment begins.  Only the
+ * first element in a PRP list may contain a non-zero offest, implying that all
+ * memory segments following the first begin at the start of a 4KB page.
+ *
+ * Each PRP element normally describes 4KB of physical memory, with exceptions
+ * for the first and last elements in the list.  If the memory being described
+ * by the list begins at a non-zero offset within the first 4KB page, then the
+ * first PRP element will contain a non-zero offset indicating where the region
+ * begins within the 4KB page.  The last memory segment may end before the end
+ * of the 4KB segment, depending upon the overall size of the memory being
+ * described by the PRP list.
+ *
+ * Since PRP entries lack any indication of size, the overall data buffer length
+ * is used to determine where the end of the data memory buffer is located, and
+ * how many PRP entries are required to describe it.
+ *
+ * @ioc: per adapter object
+ * @smid: system request message index for getting asscociated SGL
+ * @nvme_encap_request: the NVMe request msg frame pointer
+ * @data_out_dma: physical address for WRITES
+ * @data_out_sz: data xfer size for WRITES
+ * @data_in_dma: physical address for READS
+ * @data_in_sz: data xfer size for READS
+ *
+ * Returns nothing.
+ */
+static void
+_base_build_nvme_prp(struct MPT3SAS_ADAPTER *ioc, u16 smid,
+	Mpi26NVMeEncapsulatedRequest_t *nvme_encap_request,
+	dma_addr_t data_out_dma, size_t data_out_sz, dma_addr_t data_in_dma,
+	size_t data_in_sz)
+{
+	int		prp_size = NVME_PRP_SIZE;
+	u64		*prp_entry, *prp1_entry, *prp2_entry, *prp_entry_phys;
+	u64		*prp_page, *prp_page_phys;
+	u32		offset, entry_len;
+	u32		page_mask_result, page_mask;
+	dma_addr_t	paddr;
+	size_t		length;
+
+	/*
+	 * Not all commands require a data transfer. If no data, just return
+	 * without constructing any PRP.
+	 */
+	if (!data_in_sz && !data_out_sz)
+		return;
+	/*
+	 * Set pointers to PRP1 and PRP2, which are in the NVMe command.
+	 * PRP1 is located at a 24 byte offset from the start of the NVMe
+	 * command.  Then set the current PRP entry pointer to PRP1.
+	 */
+	prp1_entry = (u64 *)(nvme_encap_request->NVMe_Command +
+	    NVME_CMD_PRP1_OFFSET);
+	prp2_entry = (u64 *)(nvme_encap_request->NVMe_Command +
+	    NVME_CMD_PRP2_OFFSET);
+	prp_entry = prp1_entry;
+	/*
+	 * For the PRP entries, use the specially allocated buffer of
+	 * contiguous memory.
+	 */
+	prp_page = (u64 *)mpt3sas_base_get_pcie_sgl(ioc, smid);
+	prp_page_phys = (u64 *)mpt3sas_base_get_pcie_sgl_dma(ioc, smid);
+
+	/*
+	 * Check if we are within 1 entry of a page boundary we don't
+	 * want our first entry to be a PRP List entry.
+	 */
+	page_mask = ioc->page_size - 1;
+	page_mask_result = (uintptr_t)((u8 *)prp_page + prp_size) & page_mask;
+	if (!page_mask_result) {
+		/* Bump up to next page boundary. */
+		prp_page = (u64 *)((u8 *)prp_page + prp_size);
+		prp_page_phys = (u64 *)((u8 *)prp_page_phys + prp_size);
+	}
+
+	/*
+	 * Set PRP physical pointer, which initially points to the current PRP
+	 * DMA memory page.
+	 */
+	prp_entry_phys = prp_page_phys;
+
+	/* Get physical address and length of the data buffer. */
+	if (data_in_sz) {
+		paddr = data_in_dma;
+		length = data_in_sz;
+	} else {
+		paddr = data_out_dma;
+		length = data_out_sz;
+	}
+
+	/* Loop while the length is not zero. */
+	while (length) {
+		/*
+		 * Check if we need to put a list pointer here if we are at
+		 * page boundary - prp_size (8 bytes).
+		 */
+		page_mask_result =
+		    (uintptr_t)((u8 *)prp_entry_phys + prp_size) & page_mask;
+		if (!page_mask_result) {
+			/*
+			 * This is the last entry in a PRP List, so we need to
+			 * put a PRP list pointer here.  What this does is:
+			 *   - bump the current memory pointer to the next
+			 *     address, which will be the next full page.
+			 *   - set the PRP Entry to point to that page.  This
+			 *     is now the PRP List pointer.
+			 *   - bump the PRP Entry pointer the start of the
+			 *     next page.  Since all of this PRP memory is
+			 *     contiguous, no need to get a new page - it's
+			 *     just the next address.
+			 */
+			prp_entry_phys++;
+			*prp_entry = cpu_to_le64((uintptr_t)prp_entry_phys);
+			prp_entry++;
+		}
+
+		/* Need to handle if entry will be part of a page. */
+		offset = (u32)paddr & page_mask;
+		entry_len = ioc->page_size - offset;
+
+		if (prp_entry == prp1_entry) {
+			/*
+			 * Must fill in the first PRP pointer (PRP1) before
+			 * moving on.
+			 */
+			*prp1_entry = cpu_to_le64((u64)paddr);
+
+			/*
+			 * Now point to the second PRP entry within the
+			 * command (PRP2).
+			 */
+			prp_entry = prp2_entry;
+		} else if (prp_entry == prp2_entry) {
+			/*
+			 * Should the PRP2 entry be a PRP List pointer or just
+			 * a regular PRP pointer?  If there is more than one
+			 * more page of data, must use a PRP List pointer.
+			 */
+			if (length > ioc->page_size) {
+				/*
+				 * PRP2 will contain a PRP List pointer because
+				 * more PRP's are needed with this command. The
+				 * list will start at the beginning of the
+				 * contiguous buffer.
+				 */
+				*prp2_entry =
+				    cpu_to_le64((uintptr_t)prp_entry_phys);
+
+				/*
+				 * The next PRP Entry will be the start of the
+				 * first PRP List.
+				 */
+				prp_entry = prp_page;
+			} else {
+				/*
+				 * After this, the PRP Entries are complete.
+				 * This command uses 2 PRP's and no PRP list.
+				 */
+				*prp2_entry = cpu_to_le64((u64)paddr);
+			}
+		} else {
+			/*
+			 * Put entry in list and bump the addresses.
+			 *
+			 * After PRP1 and PRP2 are filled in, this will fill in
+			 * all remaining PRP entries in a PRP List, one per
+			 * each time through the loop.
+			 */
+			*prp_entry = cpu_to_le64((u64)paddr);
+			prp_entry++;
+			prp_entry_phys++;
+		}
+
+		/*
+		 * Bump the phys address of the command's data buffer by the
+		 * entry_len.
+		 */
+		paddr += entry_len;
+
+		/* Decrement length accounting for last partial page. */
+		if (entry_len > length)
+			length = 0;
+		else
+			length -= entry_len;
+	}
+}
+
+/**
+ * base_make_prp_nvme -
+ * Prepare PRPs(Physical Region Page)- SGLs specific to NVMe drives only
+ *
+ * @ioc:		per adapter object
+ * @scmd:		SCSI command from the mid-layer
+ * @mpi_request:	mpi request
+ * @smid:		msg Index
+ * @sge_count:		scatter gather element count.
+ *
+ * Returns:		true: PRPs are built
+ *			false: IEEE SGLs needs to be built
+ */
+void
+base_make_prp_nvme(struct MPT3SAS_ADAPTER *ioc,
+		struct scsi_cmnd *scmd,
+		Mpi25SCSIIORequest_t *mpi_request,
+		u16 smid, int sge_count)
+{
+	int sge_len, offset, num_prp_in_chain = 0;
+	Mpi25IeeeSgeChain64_t *main_chain_element, *ptr_first_sgl;
+	u64 *curr_buff;
+	dma_addr_t msg_phys;
+	u64 sge_addr;
+	u32 page_mask, page_mask_result;
+	struct scatterlist *sg_scmd;
+	u32 first_prp_len;
+	int data_len = scsi_bufflen(scmd);
+	u32 nvme_pg_size;
+
+	nvme_pg_size = max_t(u32, ioc->page_size, NVME_PRP_PAGE_SIZE);
+	/*
+	 * Nvme has a very convoluted prp format.  One prp is required
+	 * for each page or partial page. Driver need to split up OS sg_list
+	 * entries if it is longer than one page or cross a page
+	 * boundary.  Driver also have to insert a PRP list pointer entry as
+	 * the last entry in each physical page of the PRP list.
+	 *
+	 * NOTE: The first PRP "entry" is actually placed in the first
+	 * SGL entry in the main message as IEEE 64 format.  The 2nd
+	 * entry in the main message is the chain element, and the rest
+	 * of the PRP entries are built in the contiguous pcie buffer.
+	 */
+	page_mask = nvme_pg_size - 1;
+
+	/*
+	 * Native SGL is needed.
+	 * Put a chain element in main message frame that points to the first
+	 * chain buffer.
+	 *
+	 * NOTE:  The ChainOffset field must be 0 when using a chain pointer to
+	 *        a native SGL.
+	 */
+
+	/* Set main message chain element pointer */
+	main_chain_element = (pMpi25IeeeSgeChain64_t)&mpi_request->SGL;
+	/*
+	 * For NVMe the chain element needs to be the 2nd SG entry in the main
+	 * message.
+	 */
+	main_chain_element = (Mpi25IeeeSgeChain64_t *)
+		((u8 *)main_chain_element + sizeof(MPI25_IEEE_SGE_CHAIN64));
+
+	/*
+	 * For the PRP entries, use the specially allocated buffer of
+	 * contiguous memory.  Normal chain buffers can't be used
+	 * because each chain buffer would need to be the size of an OS
+	 * page (4k).
+	 */
+	curr_buff = mpt3sas_base_get_pcie_sgl(ioc, smid);
+	msg_phys = (dma_addr_t)mpt3sas_base_get_pcie_sgl_dma(ioc, smid);
+
+	main_chain_element->Address = cpu_to_le64(msg_phys);
+	main_chain_element->NextChainOffset = 0;
+	main_chain_element->Flags = MPI2_IEEE_SGE_FLAGS_CHAIN_ELEMENT |
+			MPI2_IEEE_SGE_FLAGS_SYSTEM_ADDR |
+			MPI26_IEEE_SGE_FLAGS_NSF_NVME_PRP;
+
+	/* Build first prp, sge need not to be page aligned*/
+	ptr_first_sgl = (pMpi25IeeeSgeChain64_t)&mpi_request->SGL;
+	sg_scmd = scsi_sglist(scmd);
+	sge_addr = sg_dma_address(sg_scmd);
+	sge_len = sg_dma_len(sg_scmd);
+
+	offset = (u32)(sge_addr & page_mask);
+	first_prp_len = nvme_pg_size - offset;
+
+	ptr_first_sgl->Address = cpu_to_le64(sge_addr);
+	ptr_first_sgl->Length = cpu_to_le32(first_prp_len);
+
+	data_len -= first_prp_len;
+
+	if (sge_len > first_prp_len) {
+		sge_addr += first_prp_len;
+		sge_len -= first_prp_len;
+	} else if (sge_len == first_prp_len) {
+		sg_scmd = sg_next(sg_scmd);
+		sge_addr = sg_dma_address(sg_scmd);
+		sge_len = sg_dma_len(sg_scmd);
+	}
+
+	for (;;) {
+		offset = (u32)(sge_addr & page_mask);
+
+		/* Put PRP pointer due to page boundary*/
+		page_mask_result = (uintptr_t)(curr_buff + 1) & page_mask;
+		if (unlikely(!page_mask_result)) {
+			scmd_printk(KERN_NOTICE,
+				scmd, "page boundary curr_buff: 0x%p\n",
+				curr_buff);
+			msg_phys += 8;
+			*curr_buff = cpu_to_le64(msg_phys);
+			curr_buff++;
+			num_prp_in_chain++;
+		}
+
+		*curr_buff = cpu_to_le64(sge_addr);
+		curr_buff++;
+		msg_phys += 8;
+		num_prp_in_chain++;
+
+		sge_addr += nvme_pg_size;
+		sge_len -= nvme_pg_size;
+		data_len -= nvme_pg_size;
+
+		if (data_len <= 0)
+			break;
+
+		if (sge_len > 0)
+			continue;
+
+		sg_scmd = sg_next(sg_scmd);
+		sge_addr = sg_dma_address(sg_scmd);
+		sge_len = sg_dma_len(sg_scmd);
+	}
+
+	main_chain_element->Length =
+		cpu_to_le32(num_prp_in_chain * sizeof(u64));
+	return;
+}
+
+static bool
+base_is_prp_possible(struct MPT3SAS_ADAPTER *ioc,
+	struct _pcie_device *pcie_device, struct scsi_cmnd *scmd, int sge_count)
+{
+	u32 i;
+	u32 data_length = 0;
+	struct scatterlist *sg_scmd;
+	bool build_prp = false;
+	u32 nvme_pg_size, page_mask;
+	u32 first_page_offset, first_page_data_size, end_residual;
+	u64 *msg_phys;
+
+	nvme_pg_size = max_t(u32, ioc->page_size,
+			NVME_PRP_PAGE_SIZE);
+	data_length = cpu_to_le32(scsi_bufflen(scmd));
+	sg_scmd = scsi_sglist(scmd);
+
+	/* Create page_mask (to get offset within page) */
+	page_mask = ioc->page_size - 1;
+
+	/*
+	 ** NVMe uses one PRP for each page (or part of a page)
+	 ** look at the data length - if 4 pages or less then IEEE is OK
+	 ** if  > 5 pages then we need to build a native SGL
+	 ** if > 4 and <= 5 pages, then check physical address of 1st SG entry
+	 ** if this first size in the page is >= the residual beyond 4 pages
+	 ** then use IEEE, otherwise use native SGL
+	 **/
+
+	if (data_length > (nvme_pg_size * 5)) {
+		build_prp = true;
+	} else if ((data_length > (nvme_pg_size * 4)) &&
+				(data_length <= (nvme_pg_size * 5)))  {
+		msg_phys = (u64 *) sg_dma_address(sg_scmd);
+		first_page_offset = ((u32)(u64)msg_phys & page_mask);
+		first_page_data_size = ioc->page_size -
+						first_page_offset;
+		end_residual = data_length % ioc->page_size;
+		/*
+		 ** If offset into first page pushes the end of
+		 ** the data beyond end of the 5th page, we need
+		 ** the extra PRP list
+		 **/
+		if (first_page_data_size < end_residual)
+			build_prp = true;
+
+		/* check if 1st SG entry size is < residual beyond 4 pages */
+		if (sg_dma_len(sg_scmd) < (data_length - (nvme_pg_size * 4)))
+			build_prp = true;
+	}
+	return build_prp;
+}
+
+/**
+ * _base_check_pcie_native_sgl - This function is called for PCIe end devices to
+ * determine if the driver needs to build a native SGL.  If so, that native
+ * SGL is built in the special contiguous buffers allocated especially for
+ * PCIe SGL creation.  If the driver will not build a native SGL, return
+ * TRUE and a normal IEEE SGL will be built.  Currently this routine
+ * supports NVMe.
+ * @ioc: per adapter object
+ * @mpi_request: mf request pointer
+ * @smid: system request message index
+ * @scmd: scsi command
+ * @pcie_device: points to the PCIe device's info
+ *
+ * Returns 0 if native SGL was built, 1 if no SGL was built
+ */
+static int
+_base_check_pcie_native_sgl(struct MPT3SAS_ADAPTER *ioc,
+	Mpi25SCSIIORequest_t *mpi_request, u16 smid, struct scsi_cmnd *scmd,
+	struct _pcie_device *pcie_device)
+{
+	struct scatterlist *sg_scmd;
+	int sges_left;
+
+	/* Get the SG list pointer and info. */
+	sg_scmd = scsi_sglist(scmd);
+	sges_left = scsi_dma_map(scmd);
+	if (sges_left < 0) {
+		sdev_printk(KERN_ERR, scmd->device,
+			"scsi_dma_map failed: request for %d bytes!\n",
+			scsi_bufflen(scmd));
+		return 1;
+	}
+
+	/* Check if we need to build a native SG list. */
+	if (base_is_prp_possible(ioc, pcie_device,
+				scmd, sges_left) == 0) {
+		/* We built a native SG list, just return. */
+		goto out;
+	}
+
+	/*
+	 * Build native NVMe PRP.
+	 */
+	base_make_prp_nvme(ioc, scmd, mpi_request,
+			smid, sges_left);
+
+	return 0;
+out:
+	scsi_dma_unmap(scmd);
+	return 1;
+}
+
+/**
  * _base_add_sg_single_ieee - add sg element for IEEE format
  * @paddr: virtual address for SGE
  * @flags: SGE flags
@@ -1391,9 +1855,11 @@ _base_build_zero_len_sge_ieee(struct MPT3SAS_ADAPTER *ioc, void *paddr)
 
 /**
  * _base_build_sg_scmd - main sg creation routine
+ *		pcie_device is unused here!
  * @ioc: per adapter object
  * @scmd: scsi command
  * @smid: system request message index
+ * @unused: unused pcie_device pointer
  * Context: none.
  *
  * The main routine that builds scatter gather table from a given
@@ -1403,7 +1869,7 @@ _base_build_zero_len_sge_ieee(struct MPT3SAS_ADAPTER *ioc, void *paddr)
  */
 static int
 _base_build_sg_scmd(struct MPT3SAS_ADAPTER *ioc,
-		struct scsi_cmnd *scmd, u16 smid)
+	struct scsi_cmnd *scmd, u16 smid, struct _pcie_device *unused)
 {
 	Mpi2SCSIIORequest_t *mpi_request;
 	dma_addr_t chain_dma;
@@ -1537,6 +2003,8 @@ _base_build_sg_scmd(struct MPT3SAS_ADAPTER *ioc,
  * @ioc: per adapter object
  * @scmd: scsi command
  * @smid: system request message index
+ * @pcie_device: Pointer to pcie_device. If set, the pcie native sgl will be
+ * constructed on need.
  * Context: none.
  *
  * The main routine that builds scatter gather table from a given
@@ -1546,9 +2014,9 @@ _base_build_sg_scmd(struct MPT3SAS_ADAPTER *ioc,
  */
 static int
 _base_build_sg_scmd_ieee(struct MPT3SAS_ADAPTER *ioc,
-	struct scsi_cmnd *scmd, u16 smid)
+	struct scsi_cmnd *scmd, u16 smid, struct _pcie_device *pcie_device)
 {
-	Mpi2SCSIIORequest_t *mpi_request;
+	Mpi25SCSIIORequest_t *mpi_request;
 	dma_addr_t chain_dma;
 	struct scatterlist *sg_scmd;
 	void *sg_local, *chain;
@@ -1571,6 +2039,13 @@ _base_build_sg_scmd_ieee(struct MPT3SAS_ADAPTER *ioc,
 	chain_sgl_flags = MPI2_IEEE_SGE_FLAGS_CHAIN_ELEMENT |
 	    MPI2_IEEE_SGE_FLAGS_SYSTEM_ADDR;
 
+	/* Check if we need to build a native SG list. */
+	if ((pcie_device) && (_base_check_pcie_native_sgl(ioc, mpi_request,
+			smid, scmd, pcie_device) == 0)) {
+		/* We built a native SG list, just return. */
+		return 0;
+	}
+
 	sg_scmd = scsi_sglist(scmd);
 	sges_left = scsi_dma_map(scmd);
 	if (sges_left < 0) {
@@ -1582,12 +2057,12 @@ _base_build_sg_scmd_ieee(struct MPT3SAS_ADAPTER *ioc,
 
 	sg_local = &mpi_request->SGL;
 	sges_in_segment = (ioc->request_sz -
-	    offsetof(Mpi2SCSIIORequest_t, SGL))/ioc->sge_size_ieee;
+		   offsetof(Mpi25SCSIIORequest_t, SGL))/ioc->sge_size_ieee;
 	if (sges_left <= sges_in_segment)
 		goto fill_in_last_segment;
 
 	mpi_request->ChainOffset = (sges_in_segment - 1 /* chain element */) +
-	    (offsetof(Mpi2SCSIIORequest_t, SGL)/ioc->sge_size_ieee);
+	    (offsetof(Mpi25SCSIIORequest_t, SGL)/ioc->sge_size_ieee);
 
 	/* fill in main message segment when there is a chain following */
 	while (sges_in_segment > 1) {
@@ -2267,6 +2742,33 @@ mpt3sas_base_get_sense_buffer_dma(struct MPT3SAS_ADAPTER *ioc, u16 smid)
 }
 
 /**
+ * mpt3sas_base_get_pcie_sgl - obtain a PCIe SGL virt addr
+ * @ioc: per adapter object
+ * @smid: system request message index
+ *
+ * Returns virt pointer to a PCIe SGL.
+ */
+void *
+mpt3sas_base_get_pcie_sgl(struct MPT3SAS_ADAPTER *ioc, u16 smid)
+{
+	return (void *)(ioc->scsi_lookup[smid - 1].pcie_sg_list.pcie_sgl);
+}
+
+/**
+ * mpt3sas_base_get_pcie_sgl_dma - obtain a PCIe SGL dma addr
+ * @ioc: per adapter object
+ * @smid: system request message index
+ *
+ * Returns phys pointer to the address of the PCIe buffer.
+ */
+void *
+mpt3sas_base_get_pcie_sgl_dma(struct MPT3SAS_ADAPTER *ioc, u16 smid)
+{
+	return (void *)(uintptr_t)
+		(ioc->scsi_lookup[smid - 1].pcie_sg_list.pcie_sgl_dma);
+}
+
+/**
  * mpt3sas_base_get_reply_virt_addr - obtain reply frames virt address
  * @ioc: per adapter object
  * @phys_addr: lower 32 physical addr of the reply
@@ -2945,6 +3447,11 @@ _base_display_ioc_capabilities(struct MPT3SAS_ADAPTER *ioc)
 
 	_base_display_OEMs_branding(ioc);
 
+	if (ioc->facts.ProtocolFlags & MPI2_IOCFACTS_PROTOCOL_NVME_DEVICES) {
+		pr_info("%sNVMe", i ? "," : "");
+		i++;
+	}
+
 	pr_info(MPT3SAS_FMT "Protocol=(", ioc->name);
 
 	if (ioc->facts.ProtocolFlags & MPI2_IOCFACTS_PROTOCOL_SCSI_INITIATOR) {
@@ -3249,6 +3756,17 @@ _base_release_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 		kfree(ioc->reply_post);
 	}
 
+	if (ioc->pcie_sgl_dma_pool) {
+		for (i = 0; i < ioc->scsiio_depth; i++) {
+			if (ioc->scsi_lookup[i].pcie_sg_list.pcie_sgl)
+				pci_pool_free(ioc->pcie_sgl_dma_pool,
+				ioc->scsi_lookup[i].pcie_sg_list.pcie_sgl,
+				ioc->scsi_lookup[i].pcie_sg_list.pcie_sgl_dma);
+		}
+		if (ioc->pcie_sgl_dma_pool)
+			pci_pool_destroy(ioc->pcie_sgl_dma_pool);
+	}
+
 	if (ioc->config_page) {
 		dexitprintk(ioc, pr_info(MPT3SAS_FMT
 		    "config_page(0x%p): free\n", ioc->name,
@@ -3291,7 +3809,7 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 	u16 chains_needed_per_io;
 	u32 sz, total_sz, reply_post_free_sz;
 	u32 retry_sz;
-	u16 max_request_credit;
+	u16 max_request_credit, nvme_blocks_needed;
 	unsigned short sg_tablesize;
 	u16 sge_size;
 	int i;
@@ -3627,7 +4145,52 @@ _base_allocate_memory_pools(struct MPT3SAS_ADAPTER *ioc)
 		"internal(0x%p): depth(%d), start smid(%d)\n",
 		ioc->name, ioc->internal,
 	    ioc->internal_depth, ioc->internal_smid));
+	/*
+	 * The number of NVMe page sized blocks needed is:
+	 *     (((sg_tablesize * 8) - 1) / (page_size - 8)) + 1
+	 * ((sg_tablesize * 8) - 1) is the max PRP's minus the first PRP entry
+	 * that is placed in the main message frame.  8 is the size of each PRP
+	 * entry or PRP list pointer entry.  8 is subtracted from page_size
+	 * because of the PRP list pointer entry at the end of a page, so this
+	 * is not counted as a PRP entry.  The 1 added page is a round up.
+	 *
+	 * To avoid allocation failures due to the amount of memory that could
+	 * be required for NVMe PRP's, only each set of NVMe blocks will be
+	 * contiguous, so a new set is allocated for each possible I/O.
+	 */
+	if (ioc->facts.ProtocolFlags & MPI2_IOCFACTS_PROTOCOL_NVME_DEVICES) {
+		nvme_blocks_needed =
+			(ioc->shost->sg_tablesize * NVME_PRP_SIZE) - 1;
+		nvme_blocks_needed /= (ioc->page_size - NVME_PRP_SIZE);
+		nvme_blocks_needed++;
+
+		sz = nvme_blocks_needed * ioc->page_size;
+		ioc->pcie_sgl_dma_pool =
+			pci_pool_create("PCIe SGL pool", ioc->pdev, sz, 16, 0);
+		if (!ioc->pcie_sgl_dma_pool) {
+			pr_info(MPT3SAS_FMT
+			    "PCIe SGL pool: pci_pool_create failed\n",
+			    ioc->name);
+			goto out;
+		}
+		for (i = 0; i < ioc->scsiio_depth; i++) {
+			ioc->scsi_lookup[i].pcie_sg_list.pcie_sgl =
+					pci_pool_alloc(ioc->pcie_sgl_dma_pool,
+					GFP_KERNEL,
+				&ioc->scsi_lookup[i].pcie_sg_list.pcie_sgl_dma);
+			if (!ioc->scsi_lookup[i].pcie_sg_list.pcie_sgl) {
+				pr_info(MPT3SAS_FMT
+				    "PCIe SGL pool: pci_pool_alloc failed\n",
+				    ioc->name);
+				goto out;
+			}
+		}
 
+		dinitprintk(ioc, pr_info(MPT3SAS_FMT "PCIe sgl pool depth(%d), "
+			"element_size(%d), pool_size(%d kB)\n", ioc->name,
+			ioc->scsiio_depth, sz, (sz * ioc->scsiio_depth)/1024));
+		total_sz += sz * ioc->scsiio_depth;
+	}
 	/* sense buffers, 4 byte align */
 	sz = ioc->scsiio_depth * SCSI_SENSE_BUFFERSIZE;
 	ioc->sense_dma_pool = pci_pool_create("sense pool", ioc->pdev, sz, 4,
@@ -4472,6 +5035,19 @@ _base_get_ioc_facts(struct MPT3SAS_ADAPTER *ioc)
 	    le16_to_cpu(mpi_reply.HighPriorityCredit);
 	facts->ReplyFrameSize = mpi_reply.ReplyFrameSize;
 	facts->MaxDevHandle = le16_to_cpu(mpi_reply.MaxDevHandle);
+	facts->CurrentHostPageSize = mpi_reply.CurrentHostPageSize;
+
+	/*
+	 * Get the Page Size from IOC Facts. If it's 0, default to 4k.
+	 */
+	ioc->page_size = 1 << facts->CurrentHostPageSize;
+	if (ioc->page_size == 1) {
+		pr_info(MPT3SAS_FMT "CurrentHostPageSize is 0: Setting "
+			"default host page size to 4k\n", ioc->name);
+		ioc->page_size = 1 << MPT3SAS_HOST_PAGE_SIZE_4K;
+	}
+	dinitprintk(ioc, pr_info(MPT3SAS_FMT "CurrentHostPageSize(%d)\n",
+		ioc->name, facts->CurrentHostPageSize));
 
 	dinitprintk(ioc, pr_info(MPT3SAS_FMT
 		"hba queue depth(%d), max chains per io(%d)\n",
@@ -4511,6 +5087,7 @@ _base_send_ioc_init(struct MPT3SAS_ADAPTER *ioc)
 	mpi_request.VP_ID = 0;
 	mpi_request.MsgVersion = cpu_to_le16(ioc->hba_mpi_version_belonged);
 	mpi_request.HeaderVersion = cpu_to_le16(MPI2_HEADER_VERSION);
+	mpi_request.HostPageSize = MPT3SAS_HOST_PAGE_SIZE_4K;
 
 	if (_base_is_controller_msix_enabled(ioc))
 		mpi_request.HostMSIxVectors = ioc->reply_queue_count;
@@ -5379,6 +5956,7 @@ mpt3sas_base_attach(struct MPT3SAS_ADAPTER *ioc)
 		 */
 		ioc->build_sg_scmd = &_base_build_sg_scmd_ieee;
 		ioc->build_sg = &_base_build_sg_ieee;
+		ioc->build_nvme_prp = &_base_build_nvme_prp;
 		ioc->build_zero_len_sge = &_base_build_zero_len_sge_ieee;
 		ioc->sge_size_ieee = sizeof(Mpi2IeeeSgeSimple64_t);
 
diff --git a/drivers/scsi/mpt3sas/mpt3sas_base.h b/drivers/scsi/mpt3sas/mpt3sas_base.h
index c522057..4caa91e 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_base.h
+++ b/drivers/scsi/mpt3sas/mpt3sas_base.h
@@ -54,6 +54,7 @@
 #include "mpi/mpi2_raid.h"
 #include "mpi/mpi2_tool.h"
 #include "mpi/mpi2_sas.h"
+#include "mpi/mpi2_pci.h"
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -113,6 +114,7 @@
 #define MPT3SAS_RAID_QUEUE_DEPTH	128
 
 #define MPT3SAS_RAID_MAX_SECTORS	8192
+#define MPT3SAS_HOST_PAGE_SIZE_4K	12
 
 #define MPT_NAME_LENGTH			32	/* generic length of strings */
 #define MPT_STRING_LENGTH		64
@@ -131,6 +133,15 @@
 #define DEFAULT_NUM_FWCHAIN_ELEMTS	8
 
 /*
+ * NVMe defines
+ */
+#define	NVME_PRP_SIZE			8	/* PRP size */
+#define	NVME_CMD_PRP1_OFFSET		24	/* PRP1 offset in NVMe cmd */
+#define	NVME_CMD_PRP2_OFFSET		32	/* PRP2 offset in NVMe cmd */
+#define	NVME_ERROR_RESPONSE_SIZE	16	/* Max NVME Error Response */
+#define	NVME_PRP_PAGE_SIZE		4096	/* Page size */
+
+/*
  * reset phases
  */
 #define MPT3_IOC_PRE_RESET		1 /* prior to host reset */
@@ -731,6 +742,16 @@ enum reset_type {
 };
 
 /**
+ * struct pcie_sg_list - PCIe SGL buffer (contiguous per I/O)
+ * @pcie_sgl: PCIe native SGL for NVMe devices
+ * @pcie_sgl_dma: physical address
+ */
+struct pcie_sg_list {
+	void            *pcie_sgl;
+	dma_addr_t      pcie_sgl_dma;
+};
+
+/**
  * struct chain_tracker - firmware chain tracker
  * @chain_buffer: chain buffer
  * @chain_buffer_dma: physical address
@@ -756,6 +777,7 @@ struct scsiio_tracker {
 	struct scsi_cmnd *scmd;
 	u8	cb_idx;
 	u8	direct_io;
+	struct pcie_sg_list pcie_sg_list;
 	struct list_head chain_list;
 	struct list_head tracker_list;
 	u16     msix_io;
@@ -829,13 +851,19 @@ typedef void (*MPT_ADD_SGE)(void *paddr, u32 flags_length, dma_addr_t dma_addr);
 
 /* SAS3.0 support */
 typedef int (*MPT_BUILD_SG_SCMD)(struct MPT3SAS_ADAPTER *ioc,
-		struct scsi_cmnd *scmd, u16 smid);
+	struct scsi_cmnd *scmd, u16 smid, struct _pcie_device *pcie_device);
 typedef void (*MPT_BUILD_SG)(struct MPT3SAS_ADAPTER *ioc, void *psge,
 		dma_addr_t data_out_dma, size_t data_out_sz,
 		dma_addr_t data_in_dma, size_t data_in_sz);
 typedef void (*MPT_BUILD_ZERO_LEN_SGE)(struct MPT3SAS_ADAPTER *ioc,
 		void *paddr);
 
+/* SAS3.5 support */
+typedef void (*NVME_BUILD_PRP)(struct MPT3SAS_ADAPTER *ioc, u16 smid,
+	Mpi26NVMeEncapsulatedRequest_t *nvme_encap_request,
+	dma_addr_t data_out_dma, size_t data_out_sz, dma_addr_t data_in_dma,
+	size_t data_in_sz);
+
 /* To support atomic and non atomic descriptors*/
 typedef void (*PUT_SMID_IO_FP_HIP) (struct MPT3SAS_ADAPTER *ioc, u16 smid,
 	u16 funcdep);
@@ -878,6 +906,7 @@ struct mpt3sas_facts {
 	u16			MaxDevHandle;
 	u16			MaxPersistentEntries;
 	u16			MinDevHandle;
+	u8			CurrentHostPageSize;
 };
 
 struct mpt3sas_port_facts {
@@ -1149,6 +1178,9 @@ struct MPT3SAS_ADAPTER {
 	MPT_BUILD_SG    build_sg_mpi;
 	MPT_BUILD_ZERO_LEN_SGE build_zero_len_sge_mpi;
 
+	/* function ptr for NVMe PRP elements only */
+	NVME_BUILD_PRP  build_nvme_prp;
+
 	/* event log */
 	u32		event_type[MPI2_EVENT_NOTIFY_EVENTMASK_WORDS];
 	u32		event_context;
@@ -1217,6 +1249,11 @@ struct MPT3SAS_ADAPTER {
 	int		pending_io_count;
 	wait_queue_head_t reset_wq;
 
+	/* PCIe SGL */
+	struct dma_pool *pcie_sgl_dma_pool;
+	/* Host Page Size */
+	u32		page_size;
+
 	/* chain */
 	struct chain_tracker *chain_lookup;
 	struct list_head free_chain_list;
@@ -1350,7 +1387,8 @@ void *mpt3sas_base_get_msg_frame(struct MPT3SAS_ADAPTER *ioc, u16 smid);
 void *mpt3sas_base_get_sense_buffer(struct MPT3SAS_ADAPTER *ioc, u16 smid);
 __le32 mpt3sas_base_get_sense_buffer_dma(struct MPT3SAS_ADAPTER *ioc,
 	u16 smid);
-
+void *mpt3sas_base_get_pcie_sgl(struct MPT3SAS_ADAPTER *ioc, u16 smid);
+void *mpt3sas_base_get_pcie_sgl_dma(struct MPT3SAS_ADAPTER *ioc, u16 smid);
 void mpt3sas_base_sync_reply_irqs(struct MPT3SAS_ADAPTER *ioc);
 
 /* hi-priority queue */
@@ -1564,7 +1602,7 @@ void
 mpt3sas_scsi_direct_io_set(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 direct_io);
 void
 mpt3sas_setup_direct_io(struct MPT3SAS_ADAPTER *ioc, struct scsi_cmnd *scmd,
-	struct _raid_device *raid_device, Mpi2SCSIIORequest_t *mpi_request,
+	struct _raid_device *raid_device, Mpi25SCSIIORequest_t *mpi_request,
 	u16 smid);
 
 /* NCQ Prio Handling Check */
diff --git a/drivers/scsi/mpt3sas/mpt3sas_ctl.c b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
index bdffb69..0c18831 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_ctl.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_ctl.c
@@ -299,6 +299,7 @@ mpt3sas_ctl_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index,
 			}
 		}
 	}
+
 	_ctl_display_some_debug(ioc, smid, "ctl_done", mpi_reply);
 	ioc->ctl_cmds.status &= ~MPT3_CMD_PENDING;
 	complete(&ioc->ctl_cmds.done);
diff --git a/drivers/scsi/mpt3sas/mpt3sas_scsih.c b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
index 4b6b0fa..3e6dd4b 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_scsih.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_scsih.c
@@ -4244,7 +4244,7 @@ _scsih_flush_running_cmds(struct MPT3SAS_ADAPTER *ioc)
  */
 static void
 _scsih_setup_eedp(struct MPT3SAS_ADAPTER *ioc, struct scsi_cmnd *scmd,
-	Mpi2SCSIIORequest_t *mpi_request)
+	Mpi25SCSIIORequest_t *mpi_request)
 {
 	u16 eedp_flags;
 	unsigned char prot_op = scsi_get_prot_op(scmd);
@@ -4347,7 +4347,8 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
 	struct _raid_device *raid_device;
 	struct request *rq = scmd->request;
 	int class;
-	Mpi2SCSIIORequest_t *mpi_request;
+	Mpi25SCSIIORequest_t *mpi_request;
+	struct _pcie_device *pcie_device = NULL;
 	u32 mpi_control;
 	u16 smid;
 	u16 handle;
@@ -4435,7 +4436,7 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
 		goto out;
 	}
 	mpi_request = mpt3sas_base_get_msg_frame(ioc, smid);
-	memset(mpi_request, 0, sizeof(Mpi2SCSIIORequest_t));
+	memset(mpi_request, 0, ioc->request_sz);
 	_scsih_setup_eedp(ioc, scmd, mpi_request);
 
 	if (scmd->cmd_len == 32)
@@ -4454,13 +4455,14 @@ scsih_qcmd(struct Scsi_Host *shost, struct scsi_cmnd *scmd)
 	mpi_request->SenseBufferLength = SCSI_SENSE_BUFFERSIZE;
 	mpi_request->SenseBufferLowAddress =
 	    mpt3sas_base_get_sense_buffer_dma(ioc, smid);
-	mpi_request->SGLOffset0 = offsetof(Mpi2SCSIIORequest_t, SGL) / 4;
+	mpi_request->SGLOffset0 = offsetof(Mpi25SCSIIORequest_t, SGL) / 4;
 	int_to_scsilun(sas_device_priv_data->lun, (struct scsi_lun *)
 	    mpi_request->LUN);
 	memcpy(mpi_request->CDB.CDB32, scmd->cmnd, scmd->cmd_len);
 
 	if (mpi_request->DataLength) {
-		if (ioc->build_sg_scmd(ioc, scmd, smid)) {
+		pcie_device = sas_target_priv_data->pcie_dev;
+		if (ioc->build_sg_scmd(ioc, scmd, smid, pcie_device)) {
 			mpt3sas_base_free_smid(ioc, smid);
 			goto out;
 		}
@@ -4931,7 +4933,7 @@ out_unlock:
 static u8
 _scsih_io_done(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 msix_index, u32 reply)
 {
-	Mpi2SCSIIORequest_t *mpi_request;
+	Mpi25SCSIIORequest_t *mpi_request;
 	Mpi2SCSIIOReply_t *mpi_reply;
 	struct scsi_cmnd *scmd;
 	u16 ioc_status;
diff --git a/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c b/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c
index 540bd50..ced7d9f 100644
--- a/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c
+++ b/drivers/scsi/mpt3sas/mpt3sas_warpdrive.c
@@ -299,7 +299,7 @@ mpt3sas_scsi_direct_io_set(struct MPT3SAS_ADAPTER *ioc, u16 smid, u8 direct_io)
  */
 void
 mpt3sas_setup_direct_io(struct MPT3SAS_ADAPTER *ioc, struct scsi_cmnd *scmd,
-	struct _raid_device *raid_device, Mpi2SCSIIORequest_t *mpi_request,
+	struct _raid_device *raid_device, Mpi25SCSIIORequest_t *mpi_request,
 	u16 smid)
 {
 	sector_t v_lba, p_lba, stripe_off, column, io_size;
-- 
2.5.5




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