gpu: nvgpu: store bus addr of gpu regs

Usermode submit needs to access the usermode region of registers from
userspace. Store the start address of register resource in struct
nvgpu_os_linux to be used in remap to userspace.

Bug 200145225
Bug 200541476

Change-Id: I3796b6bf67942af0cc16c86accb82a013032bfc8
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1811838
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Signed-off-by: Debarshi Dutta <ddutta@nvidia.com>
(cherry picked from commit 38c11db264f776fa495a3ba74caadf4262062b78
in dev-main)
Reviewed-on: https://git-master.nvidia.com/r/2169921
GVS: Gerrit_Virtual_Submit
Reviewed-by: Bibek Basu <bbasu@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 7 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/pci.c b/drivers/gpu/nvgpu/os/linux/pci.c
index 2e456abc..61e412f2 100644
--- a/drivers/gpu/nvgpu/os/linux/pci.c
+++ b/drivers/gpu/nvgpu/os/linux/pci.c
@@ -536,6 +536,13 @@ static int nvgpu_pci_init_support(struct pci_dev *pdev)
                 goto fail;
         }
 
+        l->regs_bus_addr = pci_resource_start(pdev, 0);
+        if (!l->regs_bus_addr) {
+                nvgpu_err(g, "failed to read register bus offset");
+                err = -ENODEV;
+                goto fail;
+        }
+
         l->bar1 = nvgpu_devm_ioremap(dev, pci_resource_start(pdev, 1),
                                      pci_resource_len(pdev, 1));
         if (IS_ERR(l->bar1)) {