[PATCH 5.10 162/199] nvme-pci: refactor nvme_unmap_data

Greg Kroah-Hartman
2021-01-26T10:07:30Z

From: Christoph Hellwig <hch@lst.de>

commit 9275c206f88e5c49cb3e71932c81c8561083db9e upstream.

Split out three helpers from nvme_unmap_data that will allow finer grained
unwinding from nvme_map_data.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Reviewed-by: Marc Orr <marcorr@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/nvme/host/pci.c | 77 ++++++++++++++++++++++++++++++------------------
1 file changed, 49 insertions(+), 28 deletions(-)

--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -542,50 +542,71 @@ static inline bool nvme_pci_use_sgls(str
return true;
}

-static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
+static void nvme_free_prps(struct nvme_dev *dev, struct request *req)
{
- struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
const int last_prp = NVME_CTRL_PAGE_SIZE / sizeof(__le64) - 1;
- dma_addr_t dma_addr = iod->first_dma, next_dma_addr;
+ struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+ dma_addr_t dma_addr = iod->first_dma;
int i;

- if (iod->dma_len) {
- dma_unmap_page(dev->dev, dma_addr, iod->dma_len,
- rq_dma_dir(req));
- return;
+ for (i = 0; i < iod->npages; i++) {
+ __le64 *prp_list = nvme_pci_iod_list(req)[i];
+ dma_addr_t next_dma_addr = le64_to_cpu(prp_list[last_prp]);
+
+ dma_pool_free(dev->prp_page_pool, prp_list, dma_addr);
+ dma_addr = next_dma_addr;
}

- WARN_ON_ONCE(!iod->nents);
+}

- if (is_pci_p2pdma_page(sg_page(iod->sg)))
- pci_p2pdma_unmap_sg(dev->dev, iod->sg, iod->nents,
- rq_dma_dir(req));
- else
- dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req));
+static void nvme_free_sgls(struct nvme_dev *dev, struct request *req)
+{
+ const int last_sg = SGES_PER_PAGE - 1;
+ struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
+ dma_addr_t dma_addr = iod->first_dma;
+ int i;

+ for (i = 0; i < iod->npages; i++) {
+ struct nvme_sgl_desc *sg_list = nvme_pci_iod_list(req)[i];
+ dma_addr_t next_dma_addr = le64_to_cpu((sg_list[last_sg]).addr);

- if (iod->npages == 0)
- dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
- dma_addr);
+ dma_pool_free(dev->prp_page_pool, sg_list, dma_addr);
+ dma_addr = next_dma_addr;
+ }

- for (i = 0; i < iod->npages; i++) {
- void *addr = nvme_pci_iod_list(req)[i];
+}

- if (iod->use_sgl) {
- struct nvme_sgl_desc *sg_list = addr;
+static void nvme_unmap_sg(struct nvme_dev *dev, struct request *req)
+{
+ struct nvme_iod *iod = blk_mq_rq_to_pdu(req);

- next_dma_addr =
- le64_to_cpu((sg_list[SGES_PER_PAGE - 1]).addr);
- } else {
- __le64 *prp_list = addr;
+ if (is_pci_p2pdma_page(sg_page(iod->sg)))
+ pci_p2pdma_unmap_sg(dev->dev, iod->sg, iod->nents,
+ rq_dma_dir(req));
+ else
+ dma_unmap_sg(dev->dev, iod->sg, iod->nents, rq_dma_dir(req));
+}

- next_dma_addr = le64_to_cpu(prp_list[last_prp]);
- }
+static void nvme_unmap_data(struct nvme_dev *dev, struct request *req)
+{
+ struct nvme_iod *iod = blk_mq_rq_to_pdu(req);

- dma_pool_free(dev->prp_page_pool, addr, dma_addr);
- dma_addr = next_dma_addr;
+ if (iod->dma_len) {
+ dma_unmap_page(dev->dev, iod->first_dma, iod->dma_len,
+ rq_dma_dir(req));
+ return;
}

+ WARN_ON_ONCE(!iod->nents);
+
+ nvme_unmap_sg(dev, req);
+ if (iod->npages == 0)
+ dma_pool_free(dev->prp_small_pool, nvme_pci_iod_list(req)[0],
+ iod->first_dma);
+ else if (iod->use_sgl)
+ nvme_free_sgls(dev, req);
+ else
+ nvme_free_prps(dev, req);
mempool_free(iod->sg, dev->iod_mempool);
}