Commit 044a9df1 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

nvme-pci: implement the HMB entry number and size limitations 



Adds support for the new Host Memory Buffer Minimum Descriptor Entry Size
and Host Memory Maximum Descriptors Entries field that were added in
TP 4002 HMB Enhancements.  These allow the controller to advertise
limits for the usual number of segments in the host memory buffer, as
well as a minimum usable per-segment size.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKeith Busch <keith.busch@intel.com>
parent 9620cfba

drivers/nvme/host/core.c

+2 −0
Original line number Diff line number Diff line
@@ -1897,6 +1897,8 @@ int nvme_init_identify(struct nvme_ctrl *ctrl) 
		ctrl->cntlid = le16_to_cpu(id->cntlid);

		ctrl->hmpre = le32_to_cpu(id->hmpre);

		ctrl->hmmin = le32_to_cpu(id->hmmin);

		ctrl->hmminds = le32_to_cpu(id->hmminds);

		ctrl->hmmaxd = le16_to_cpu(id->hmmaxd);

	}



	kfree(id);

drivers/nvme/host/nvme.h

+3 −0
Original line number Diff line number Diff line
@@ -181,8 +181,11 @@ struct nvme_ctrl { 
	u64 ps_max_latency_us;

	bool apst_enabled;



	/* PCIe only: */

	u32 hmpre;

	u32 hmmin;

	u32 hmminds;

	u16 hmmaxd;



	/* Fabrics only */

	u16 sqsize;

drivers/nvme/host/pci.c

+5 −1
Original line number Diff line number Diff line
@@ -1625,6 +1625,10 @@ static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred, 
	tmp = (preferred + chunk_size - 1);

	do_div(tmp, chunk_size);

	max_entries = tmp;



	if (dev->ctrl.hmmaxd && dev->ctrl.hmmaxd < max_entries)

		max_entries = dev->ctrl.hmmaxd;



	descs = dma_zalloc_coherent(dev->dev, max_entries * sizeof(*descs),

			&descs_dma, GFP_KERNEL);

	if (!descs)
@@ -1681,7 +1685,7 @@ static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred) 


	/* start big and work our way down */

	for (chunk_size = min_t(u64, preferred, PAGE_SIZE * MAX_ORDER_NR_PAGES);

	     chunk_size >= PAGE_SIZE * 2;

	     chunk_size >= max_t(u32, dev->ctrl.hmminds * 4096, PAGE_SIZE * 2);

	     chunk_size /= 2) {

		if (!__nvme_alloc_host_mem(dev, preferred, chunk_size)) {

			if (!min || dev->host_mem_size >= min)

include/linux/nvme.h

+3 −1
Original line number Diff line number Diff line
@@ -226,7 +226,9 @@ struct nvme_id_ctrl { 
	__le16			mntmt;

	__le16			mxtmt;

	__le32			sanicap;

	__u8			rsvd332[180];

	__le32			hmminds;

	__le16			hmmaxd;

	__u8			rsvd338[174];

	__u8			sqes;

	__u8			cqes;

	__le16			maxcmd;

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