On 4/8/21 10:01 AM, Logan Gunthorpe wrote:
Introduce a supports_pci_p2pdma() operation in nvme_ctrl_ops to
replace the fixed NVME_F_PCI_P2PDMA flag such that the dma_map_ops
flags can be checked for PCI P2PDMA support.
Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
---
drivers/nvme/host/core.c | 3 ++-
drivers/nvme/host/nvme.h | 2 +-
drivers/nvme/host/pci.c | 11 +++++++++--
3 files changed, 12 insertions(+), 4 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 0896e21642be..223419454516 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3907,7 +3907,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, ns->queue);
blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue);
- if (ctrl->ops->flags & NVME_F_PCI_P2PDMA)
+ if (ctrl->ops->supports_pci_p2pdma &&
+ ctrl->ops->supports_pci_p2pdma(ctrl))
This is a little excessive, as I suspected. How about providing a
default .supports_pci_p2pdma routine that returns false, so that
the op is always available (non-null)? By "default", maybe that
means either requiring an init_the_ops_struct() routine to be
used, and/or checking all the users of struct nvme_ctrl_ops.
Another idea: maybe you don't really need a bool .supports_pci_p2pdma()
routine at all, because the existing .flags really is about right.
You just need the flags to be filled in dynamically. So, do that
during nvme_pci setup/init time: that's when this module would call
dma_pci_p2pdma_supported().
Actually, I think that second idea simplifies things quite a
bit, but only if it's possible. I haven't worked through the
startup order of calls in nvme_pci.
thanks,
--
John Hubbard
NVIDIA
blk_queue_flag_set(QUEUE_FLAG_PCI_P2PDMA, ns->queue);
ns->queue->queuedata = ns;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 07b34175c6ce..9c04df982d2c 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -473,7 +473,6 @@ struct nvme_ctrl_ops {
unsigned int flags;
#define NVME_F_FABRICS (1 << 0)
#define NVME_F_METADATA_SUPPORTED (1 << 1)
-#define NVME_F_PCI_P2PDMA (1 << 2)
int (*reg_read32)(struct nvme_ctrl *ctrl, u32 off, u32 *val);
int (*reg_write32)(struct nvme_ctrl *ctrl, u32 off, u32 val);
int (*reg_read64)(struct nvme_ctrl *ctrl, u32 off, u64 *val);
@@ -481,6 +480,7 @@ struct nvme_ctrl_ops {
void (*submit_async_event)(struct nvme_ctrl *ctrl);
void (*delete_ctrl)(struct nvme_ctrl *ctrl);
int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size);
+ bool (*supports_pci_p2pdma)(struct nvme_ctrl *ctrl);
};
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 7249ae74f71f..14f092973792 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2759,17 +2759,24 @@ static int nvme_pci_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
return snprintf(buf, size, "%s\n", dev_name(&pdev->dev));
}
+static bool nvme_pci_supports_pci_p2pdma(struct nvme_ctrl *ctrl)
+{
+ struct nvme_dev *dev = to_nvme_dev(ctrl);
+
+ return dma_pci_p2pdma_supported(dev->dev);
+}
+
static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
.name = "pcie",
.module = THIS_MODULE,
- .flags = NVME_F_METADATA_SUPPORTED |
- NVME_F_PCI_P2PDMA,
+ .flags = NVME_F_METADATA_SUPPORTED,
.reg_read32 = nvme_pci_reg_read32,
.reg_write32 = nvme_pci_reg_write32,
.reg_read64 = nvme_pci_reg_read64,
.free_ctrl = nvme_pci_free_ctrl,
.submit_async_event = nvme_pci_submit_async_event,
.get_address = nvme_pci_get_address,
+ .supports_pci_p2pdma = nvme_pci_supports_pci_p2pdma,
};
static int nvme_dev_map(struct nvme_dev *dev)
