Commit a310acd7 authored by Stephan Günther's avatar Stephan Günther Committed by Jens Axboe
Browse files

NVMe: use split lo_hi_{read,write}q 

Some controllers may require ordered split transfers even on 64bit
machines, e.g. Apple's NVMe controller as found in the MacBook8,1 and
MacBookAir7,1 (256/512GB models).

This patch enforces ordered split transfers on 64bit platforms, which
works around that issue for all controllers. As pointed out by Christoph
[1] there should be no performance impact due to that modification.

[1] http://lists.infradead.org/pipermail/linux-nvme/2015-November/002965.html



Signed-off-by: default avatarStephan Guenther <guenther@tum.de>
Signed-off-by: default avatarMaurice Leclaire <leclaire@in.tum.de>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>

Updated by me to explicitly use lo_hi_read/writeq instead of playing
define tricks.

Signed-off-by: default avatarJens Axboe <axboe@fb.com>
parent 1fa8cc52

drivers/nvme/host/pci.c

+6 −6
Original line number Diff line number Diff line
@@ -1725,7 +1725,7 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev) 
{

	int result;

	u32 aqa;

	u64 cap = readq(&dev->bar->cap);

	u64 cap = lo_hi_readq(&dev->bar->cap);

	struct nvme_queue *nvmeq;

	unsigned page_shift = PAGE_SHIFT;

	unsigned dev_page_min = NVME_CAP_MPSMIN(cap) + 12;
@@ -1774,8 +1774,8 @@ static int nvme_configure_admin_queue(struct nvme_dev *dev) 
	dev->ctrl_config |= NVME_CC_IOSQES | NVME_CC_IOCQES;



	writel(aqa, &dev->bar->aqa);

	writeq(nvmeq->sq_dma_addr, &dev->bar->asq);

	writeq(nvmeq->cq_dma_addr, &dev->bar->acq);

	lo_hi_writeq(nvmeq->sq_dma_addr, &dev->bar->asq);

	lo_hi_writeq(nvmeq->cq_dma_addr, &dev->bar->acq);



	result = nvme_enable_ctrl(dev, cap);

	if (result)
@@ -2606,7 +2606,7 @@ static int nvme_dev_add(struct nvme_dev *dev) 
	struct pci_dev *pdev = to_pci_dev(dev->dev);

	int res;

	struct nvme_id_ctrl *ctrl;

	int shift = NVME_CAP_MPSMIN(readq(&dev->bar->cap)) + 12;

	int shift = NVME_CAP_MPSMIN(lo_hi_readq(&dev->bar->cap)) + 12;



	res = nvme_identify_ctrl(dev, &ctrl);

	if (res) {
@@ -2697,7 +2697,7 @@ static int nvme_dev_map(struct nvme_dev *dev) 
			goto unmap;

	}



	cap = readq(&dev->bar->cap);

	cap = lo_hi_readq(&dev->bar->cap);

	dev->q_depth = min_t(int, NVME_CAP_MQES(cap) + 1, NVME_Q_DEPTH);

	dev->db_stride = 1 << NVME_CAP_STRIDE(cap);

	dev->dbs = ((void __iomem *)dev->bar) + 4096;
@@ -2760,7 +2760,7 @@ static void nvme_wait_dq(struct nvme_delq_ctx *dq, struct nvme_dev *dev) 
			 * queues than admin tags.

			 */

			set_current_state(TASK_RUNNING);

			nvme_disable_ctrl(dev, readq(&dev->bar->cap));

			nvme_disable_ctrl(dev, lo_hi_readq(&dev->bar->cap));

			nvme_clear_queue(dev->queues[0]);

			flush_kthread_worker(dq->worker);

			nvme_disable_queue(dev, 0);

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