[PATCH v6 4/6] vfio/nvgrace-gpu: split the code to wait for GPU ready

ankita
2025-11-25T17:31:01Z

From: Ankit Agrawal <ankita@nvidia.com>

Split the function that check for the GPU device being ready on
the probe.

Move the code to wait for the GPU to be ready through BAR0 register
reads to a separate function. This would help reuse the code.

Reviewed-by: Shameer Kolothum <skolothumtho@nvidia.com>
Signed-off-by: Ankit Agrawal <ankita@nvidia.com>
---
drivers/vfio/pci/nvgrace-gpu/main.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/vfio/pci/nvgrace-gpu/main.c b/drivers/vfio/pci/nvgrace-gpu/main.c
index 8a982310b188..2b736cb82f38 100644
--- a/drivers/vfio/pci/nvgrace-gpu/main.c
+++ b/drivers/vfio/pci/nvgrace-gpu/main.c
@@ -130,6 +130,20 @@ static void nvgrace_gpu_close_device(struct vfio_device *core_vdev)
vfio_pci_core_close_device(core_vdev);
}

+static int nvgrace_gpu_wait_device_ready(void __iomem *io)
+{
+ unsigned long timeout = jiffies + msecs_to_jiffies(POLL_TIMEOUT_MS);
+
+ do {
+ if ((ioread32(io + C2C_LINK_BAR0_OFFSET) == STATUS_READY) &&
+ (ioread32(io + HBM_TRAINING_BAR0_OFFSET) == STATUS_READY))
+ return 0;
+ msleep(POLL_QUANTUM_MS);
+ } while (!time_after(jiffies, timeout));
+
+ return -ETIME;
+}
+
static unsigned long addr_to_pgoff(struct vm_area_struct *vma,
unsigned long addr)
{
@@ -933,9 +947,8 @@ static bool nvgrace_gpu_has_mig_hw_bug(struct pci_dev *pdev)
* Ensure that the BAR0 region is enabled before accessing the
* registers.
*/
-static int nvgrace_gpu_wait_device_ready(struct pci_dev *pdev)
+static int nvgrace_gpu_probe_check_device_ready(struct pci_dev *pdev)
{
- unsigned long timeout = jiffies + msecs_to_jiffies(POLL_TIMEOUT_MS);
void __iomem *io;
int ret = -ETIME;

@@ -953,16 +966,8 @@ static int nvgrace_gpu_wait_device_ready(struct pci_dev *pdev)
goto iomap_exit;
}

- do {
- if ((ioread32(io + C2C_LINK_BAR0_OFFSET) == STATUS_READY) &&
- (ioread32(io + HBM_TRAINING_BAR0_OFFSET) == STATUS_READY)) {
- ret = 0;
- goto reg_check_exit;
- }
- msleep(POLL_QUANTUM_MS);
- } while (!time_after(jiffies, timeout));
+ ret = nvgrace_gpu_wait_device_ready(io);

-reg_check_exit:
pci_iounmap(pdev, io);
iomap_exit:
pci_release_selected_regions(pdev, 1 << 0);
@@ -979,7 +984,7 @@ static int nvgrace_gpu_probe(struct pci_dev *pdev,
u64 memphys, memlength;
int ret;

- ret = nvgrace_gpu_wait_device_ready(pdev);
+ ret = nvgrace_gpu_probe_check_device_ready(pdev);
if (ret)
return ret;

--
2.34.1