gpu: nvgpu: Abstract IO aperture accessors

Add abstraction of IO aperture accessors. Add new functions
gk20a_io_exists() and gk20a_io_valid_reg() to remove dependencies to
aperture fields from common code.

Implement Linux version of the abstraction by moving gk20a_readl()
and gk20a_writel() to new Linux specific io.c. Move the fields
defining IO aperture to nvgpu_os_linux.

Add t19x specific IO aperture initialization functions and add t19x
specific section to nvgpu_os_linux.

JIRA NVGPU-259

Change-Id: I09e79cda60d11a20d1099a9aaa6d2375236e94ce
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1569698
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

8 files changed, 209 insertions, 28 deletions

diff --git a/drivers/gpu/nvgpu/common/linux/driver_common.c b/drivers/gpu/nvgpu/common/linux/driver_common.c
index 7c4645a8..734bc1d2 100644
--- a/drivers/gpu/nvgpu/common/linux/driver_common.c
+++ b/drivers/gpu/nvgpu/common/linux/driver_common.c
@@ -54,8 +54,8 @@ static void nvgpu_init_vars(struct gk20a *g)
         nvgpu_mutex_init(&g->poweron_lock);
         nvgpu_mutex_init(&g->poweroff_lock);
 
-        g->regs_saved = g->regs;
-        g->bar1_saved = g->bar1;
+        l->regs_saved = l->regs;
+        l->bar1_saved = l->bar1;
 
         g->emc3d_ratio = EMC3D_DEFAULT_RATIO;
 
diff --git a/drivers/gpu/nvgpu/common/linux/io.c b/drivers/gpu/nvgpu/common/linux/io.c
new file mode 100644
index 00000000..04a9fbe8
--- /dev/null
+++ b/drivers/gpu/nvgpu/common/linux/io.c
@@ -0,0 +1,110 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ */
+
+#include <nvgpu/io.h>
+#include <nvgpu/types.h>
+
+#include "os_linux.h"
+#include "gk20a/gk20a.h"
+
+void nvgpu_writel(struct gk20a *g, u32 r, u32 v)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        if (unlikely(!l->regs)) {
+                __gk20a_warn_on_no_regs();
+                gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x (failed)", r, v);
+        } else {
+                writel_relaxed(v, l->regs + r);
+                nvgpu_smp_wmb();
+                gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x", r, v);
+        }
+}
+
+u32 nvgpu_readl(struct gk20a *g, u32 r)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+        u32 v = 0xffffffff;
+
+        if (unlikely(!l->regs)) {
+                __gk20a_warn_on_no_regs();
+                gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x (failed)", r, v);
+        } else {
+                v = readl(l->regs + r);
+                if (v == 0xffffffff)
+                        __nvgpu_check_gpu_state(g);
+                gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x", r, v);
+        }
+
+        return v;
+}
+
+void nvgpu_writel_check(struct gk20a *g, u32 r, u32 v)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        if (unlikely(!l->regs)) {
+                __gk20a_warn_on_no_regs();
+                gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x (failed)", r, v);
+        } else {
+                nvgpu_smp_wmb();
+                do {
+                        writel_relaxed(v, l->regs + r);
+                } while (readl(l->regs + r) != v);
+                gk20a_dbg(gpu_dbg_reg, "r=0x%x v=0x%x", r, v);
+        }
+}
+
+void nvgpu_bar1_writel(struct gk20a *g, u32 b, u32 v)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        if (unlikely(!l->bar1)) {
+                __gk20a_warn_on_no_regs();
+                gk20a_dbg(gpu_dbg_reg, "b=0x%x v=0x%x (failed)", b, v);
+        } else {
+                nvgpu_smp_wmb();
+                writel_relaxed(v, l->bar1 + b);
+                gk20a_dbg(gpu_dbg_reg, "b=0x%x v=0x%x", b, v);
+        }
+}
+
+u32 nvgpu_bar1_readl(struct gk20a *g, u32 b)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+        u32 v = 0xffffffff;
+
+        if (unlikely(!l->bar1)) {
+                __gk20a_warn_on_no_regs();
+                gk20a_dbg(gpu_dbg_reg, "b=0x%x v=0x%x (failed)", b, v);
+        } else {
+                v = readl(l->bar1 + b);
+                gk20a_dbg(gpu_dbg_reg, "b=0x%x v=0x%x", b, v);
+        }
+
+        return v;
+}
+
+bool nvgpu_io_exists(struct gk20a *g)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        return l->regs != NULL;
+}
+
+bool nvgpu_io_valid_reg(struct gk20a *g, u32 r)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        return r < resource_size(l->regs);
+}
diff --git a/drivers/gpu/nvgpu/common/linux/module.c b/drivers/gpu/nvgpu/common/linux/module.c
index 52f987b2..fe3e4e6f 100644
--- a/drivers/gpu/nvgpu/common/linux/module.c
+++ b/drivers/gpu/nvgpu/common/linux/module.c
@@ -137,6 +137,23 @@ void gk20a_idle(struct gk20a *g)
         }
 }
 
+/*
+ * Undoes gk20a_lockout_registers().
+ */
+static int gk20a_restore_registers(struct gk20a *g)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        l->regs = l->regs_saved;
+        l->bar1 = l->bar1_saved;
+
+#ifdef CONFIG_TEGRA_19x_GPU
+        t19x_restore_registers(g);
+#endif
+
+        return 0;
+}
+
 int gk20a_pm_finalize_poweron(struct device *dev)
 {
         struct gk20a *g = get_gk20a(dev);
@@ -198,6 +215,27 @@ done:
         return err;
 }
 
+/*
+ * Locks out the driver from accessing GPU registers. This prevents access to
+ * thse registers after the GPU has been clock or power gated. This should help
+ * find annoying bugs where register reads and writes are silently dropped
+ * after the GPU has been turned off. On older chips these reads and writes can
+ * also lock the entire CPU up.
+ */
+static int gk20a_lockout_registers(struct gk20a *g)
+{
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
+        l->regs = NULL;
+        l->bar1 = NULL;
+
+#ifdef CONFIG_TEGRA_19x_GPU
+        t19x_lockout_registers(g);
+#endif
+
+        return 0;
+}
+
 static int gk20a_pm_prepare_poweroff(struct device *dev)
 {
         struct gk20a *g = get_gk20a(dev);
@@ -511,6 +549,8 @@ static irqreturn_t gk20a_intr_thread_stall(int irq, void *dev_id)
 
 void gk20a_remove_support(struct gk20a *g)
 {
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
+
         tegra_unregister_idle_unidle(gk20a_do_idle);
 
         nvgpu_kfree(g, g->dbg_regops_tmp_buf);
@@ -535,36 +575,41 @@ void gk20a_remove_support(struct gk20a *g)
 
         /* free mappings to registers, etc */
 
-        if (g->regs) {
-                iounmap(g->regs);
-                g->regs = NULL;
+        if (l->regs) {
+                iounmap(l->regs);
+                l->regs = NULL;
         }
-        if (g->bar1) {
-                iounmap(g->bar1);
-                g->bar1 = NULL;
+        if (l->bar1) {
+                iounmap(l->bar1);
+                l->bar1 = NULL;
         }
+
+#ifdef CONFIG_TEGRA_19x_GPU
+        t19x_remove_support(g);
+#endif
 }
 
 static int gk20a_init_support(struct platform_device *dev)
 {
         int err = 0;
         struct gk20a *g = get_gk20a(&dev->dev);
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
 
         tegra_register_idle_unidle(gk20a_do_idle, gk20a_do_unidle, g);
 
-        g->regs = gk20a_ioremap_resource(dev, GK20A_BAR0_IORESOURCE_MEM,
-                                         &g->reg_mem);
-        if (IS_ERR(g->regs)) {
+        l->regs = gk20a_ioremap_resource(dev, GK20A_BAR0_IORESOURCE_MEM,
+                                         &l->reg_mem);
+        if (IS_ERR(l->regs)) {
                 nvgpu_err(g, "failed to remap gk20a registers");
-                err = PTR_ERR(g->regs);
+                err = PTR_ERR(l->regs);
                 goto fail;
         }
 
-        g->bar1 = gk20a_ioremap_resource(dev, GK20A_BAR1_IORESOURCE_MEM,
-                                         &g->bar1_mem);
-        if (IS_ERR(g->bar1)) {
+        l->bar1 = gk20a_ioremap_resource(dev, GK20A_BAR1_IORESOURCE_MEM,
+                                         &l->bar1_mem);
+        if (IS_ERR(l->bar1)) {
                 nvgpu_err(g, "failed to remap gk20a bar1");
-                err = PTR_ERR(g->bar1);
+                err = PTR_ERR(l->bar1);
                 goto fail;
         }
 
@@ -584,6 +629,10 @@ static int gk20a_init_support(struct platform_device *dev)
                         goto fail;
         }
 
+#ifdef CONFIG_TEGRA_19x_GPU
+        t19x_init_support(g);
+#endif
+
         return 0;
 
 fail:
diff --git a/drivers/gpu/nvgpu/common/linux/module.h b/drivers/gpu/nvgpu/common/linux/module.h
index 55a3b692..5814d63a 100644
--- a/drivers/gpu/nvgpu/common/linux/module.h
+++ b/drivers/gpu/nvgpu/common/linux/module.h
@@ -13,6 +13,10 @@
 #ifndef __NVGPU_COMMON_LINUX_MODULE_H__
 #define __NVGPU_COMMON_LINUX_MODULE_H__
 
+#ifdef CONFIG_TEGRA_19x_GPU
+#include <nvgpu/linux/module_t19x.h>
+#endif
+
 struct gk20a;
 struct device;
 
diff --git a/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c b/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c
index 8740ac3d..1dbbd1a0 100644
--- a/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c
+++ b/drivers/gpu/nvgpu/common/linux/nvgpu_mem.c
@@ -105,9 +105,10 @@ void nvgpu_mem_end(struct gk20a *g, struct nvgpu_mem *mem)
 
 static void pramin_access_batch_rd_n(struct gk20a *g, u32 start, u32 words, u32 **arg)
 {
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
         u32 r = start, *dest_u32 = *arg;
 
-        if (!g->regs) {
+        if (!l->regs) {
                 __gk20a_warn_on_no_regs();
                 return;
         }
@@ -182,15 +183,16 @@ void nvgpu_mem_rd_n(struct gk20a *g, struct nvgpu_mem *mem,
 
 static void pramin_access_batch_wr_n(struct gk20a *g, u32 start, u32 words, u32 **arg)
 {
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
         u32 r = start, *src_u32 = *arg;
 
-        if (!g->regs) {
+        if (!l->regs) {
                 __gk20a_warn_on_no_regs();
                 return;
         }
 
         while (words--) {
-                writel_relaxed(*src_u32++, g->regs + r);
+                writel_relaxed(*src_u32++, l->regs + r);
                 r += sizeof(u32);
         }
 
@@ -256,15 +258,16 @@ void nvgpu_mem_wr_n(struct gk20a *g, struct nvgpu_mem *mem, u32 offset,
 
 static void pramin_access_batch_set(struct gk20a *g, u32 start, u32 words, u32 **arg)
 {
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
         u32 r = start, repeat = **arg;
 
-        if (!g->regs) {
+        if (!l->regs) {
                 __gk20a_warn_on_no_regs();
                 return;
         }
 
         while (words--) {
-                writel_relaxed(repeat, g->regs + r);
+                writel_relaxed(repeat, l->regs + r);
                 r += sizeof(u32);
         }
 }
diff --git a/drivers/gpu/nvgpu/common/linux/os_linux.h b/drivers/gpu/nvgpu/common/linux/os_linux.h
index 48479843..4a3128c3 100644
--- a/drivers/gpu/nvgpu/common/linux/os_linux.h
+++ b/drivers/gpu/nvgpu/common/linux/os_linux.h
@@ -18,6 +18,9 @@
 
 #include <linux/cdev.h>
 
+#ifdef CONFIG_TEGRA_19x_GPU
+#include <nvgpu/linux/os_linux_t19x.h>
+#endif
 #include "gk20a/gk20a.h"
 #include "cde.h"
 
@@ -85,6 +88,17 @@ struct nvgpu_os_linux {
         struct work_struct nonstall_fn_work;
         struct workqueue_struct *nonstall_work_queue;
 
+        struct resource *reg_mem;
+        void __iomem *regs;
+        void __iomem *regs_saved;
+
+        struct resource *bar1_mem;
+        void __iomem *bar1;
+        void __iomem *bar1_saved;
+
+#ifdef CONFIG_TEGRA_19x_GPU
+        struct nvgpu_os_linux_t19x t19x;
+#endif
 #ifdef CONFIG_DEBUG_FS
         struct dentry *debugfs;
         struct dentry *debugfs_alias;
diff --git a/drivers/gpu/nvgpu/common/linux/pci.c b/drivers/gpu/nvgpu/common/linux/pci.c
index 401080ed..50d079bb 100644
--- a/drivers/gpu/nvgpu/common/linux/pci.c
+++ b/drivers/gpu/nvgpu/common/linux/pci.c
@@ -348,20 +348,21 @@ static int nvgpu_pci_init_support(struct pci_dev *pdev)
 {
         int err = 0;
         struct gk20a *g = get_gk20a(&pdev->dev);
+        struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
 
-        g->regs = ioremap(pci_resource_start(pdev, 0),
+        l->regs = ioremap(pci_resource_start(pdev, 0),
                           pci_resource_len(pdev, 0));
-        if (IS_ERR(g->regs)) {
+        if (IS_ERR(l->regs)) {
                 nvgpu_err(g, "failed to remap gk20a registers");
-                err = PTR_ERR(g->regs);
+                err = PTR_ERR(l->regs);
                 goto fail;
         }
 
-        g->bar1 = ioremap(pci_resource_start(pdev, 1),
+        l->bar1 = ioremap(pci_resource_start(pdev, 1),
                           pci_resource_len(pdev, 1));
-        if (IS_ERR(g->bar1)) {
+        if (IS_ERR(l->bar1)) {
                 nvgpu_err(g, "failed to remap gk20a bar1");
-                err = PTR_ERR(g->bar1);
+                err = PTR_ERR(l->bar1);
                 goto fail;
         }
 
diff --git a/drivers/gpu/nvgpu/common/pramin.c b/drivers/gpu/nvgpu/common/pramin.c
index b6166f51..9b04d5a3 100644
--- a/drivers/gpu/nvgpu/common/pramin.c
+++ b/drivers/gpu/nvgpu/common/pramin.c
@@ -51,7 +51,7 @@ void nvgpu_pramin_access_batched(struct gk20a *g, struct nvgpu_mem *mem,
          * driver should be refactored to prevent this from happening, but for
          * now it is ok just to ignore the writes
          */
-        if (!g->regs && nvgpu_is_enabled(g, NVGPU_DRIVER_IS_DYING))
+        if (!gk20a_io_exists(g) && nvgpu_is_enabled(g, NVGPU_DRIVER_IS_DYING))
                 return;
 
         alloc = mem->vidmem_alloc;