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>

4 files changed, 28 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/os/linux/module.c b/drivers/gpu/nvgpu/os/linux/module.c
index a81d837b..ebe2e650 100644
--- a/drivers/gpu/nvgpu/os/linux/module.c
+++ b/drivers/gpu/nvgpu/os/linux/module.c
@@ -680,6 +680,16 @@ void __iomem *nvgpu_devm_ioremap(struct device *dev, resource_size_t offset,
         return devm_ioremap(dev, offset, size);
 }
 
+u64 nvgpu_resource_addr(struct platform_device *dev, int i)
+{
+        struct resource *r = platform_get_resource(dev, IORESOURCE_MEM, i);
+
+        if (!r)
+                return 0;
+
+        return r->start;
+}
+
 static irqreturn_t gk20a_intr_isr_stall(int irq, void *dev_id)
 {
         struct gk20a *g = dev_id;
@@ -764,6 +774,14 @@ static int gk20a_init_support(struct platform_device *pdev)
                 goto fail;
         }
 
+        l->regs_bus_addr = nvgpu_resource_addr(pdev,
+                        GK20A_BAR0_IORESOURCE_MEM);
+        if (!l->regs_bus_addr) {
+                nvgpu_err(g, "failed to read register bus offset");
+                err = -ENODEV;
+                goto fail;
+        }
+
         l->bar1 = nvgpu_devm_ioremap_resource(pdev,
                                               GK20A_BAR1_IORESOURCE_MEM,
                                               &l->bar1_mem);
diff --git a/drivers/gpu/nvgpu/os/linux/module.h b/drivers/gpu/nvgpu/os/linux/module.h
index da61425d..76c72748 100644
--- a/drivers/gpu/nvgpu/os/linux/module.h
+++ b/drivers/gpu/nvgpu/os/linux/module.h
@@ -29,6 +29,7 @@ void __iomem *nvgpu_devm_ioremap_resource(struct platform_device *dev, int i,
                 struct resource **out);
 void __iomem *nvgpu_devm_ioremap(struct device *dev, resource_size_t offset,
                 resource_size_t size);
+u64 nvgpu_resource_addr(struct platform_device *dev, int i);
 extern struct class nvgpu_class;
 
 #endif
diff --git a/drivers/gpu/nvgpu/os/linux/os_linux.h b/drivers/gpu/nvgpu/os/linux/os_linux.h
index 5f636f49..d4b5a770 100644
--- a/drivers/gpu/nvgpu/os/linux/os_linux.h
+++ b/drivers/gpu/nvgpu/os/linux/os_linux.h
@@ -128,6 +128,8 @@ struct nvgpu_os_linux {
         void __iomem *usermode_regs;
         void __iomem *usermode_regs_saved;
 
+        u64 regs_bus_addr;
+
         struct nvgpu_os_linux_ops ops;
 
 #ifdef CONFIG_DEBUG_FS
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)) {