gpu: nvgpu: Userspace POSIX support

Add support for compiling nvgpu in a POSIX compliant userspace.
This code adds all of the necessary abstraction interfaces (mostly
stubbed) to enabled extremely limited and basic functionality in
nvgpu.

The goal of this code is to facilitate unit testing of the nvgpu
common core. By doing this in userspace it is much easier to write
tests that rely on very particular states within nvgpu since a user
can very precisely control the state of nvgpu.

JIRA NVGPU-525

Change-Id: I30e95016df14997d951075777e0585f912dc5960
Signed-off-by: Alex Waterman <alexw@nvidia.com>
Reviewed-on: https://git-master.nvidia.com/r/1683914
GVS: Gerrit_Virtual_Submit
Reviewed-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

1 files changed, 169 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/common/posix/timers.c b/drivers/gpu/nvgpu/common/posix/timers.c
new file mode 100644
index 00000000..c84b0de5
--- /dev/null
+++ b/drivers/gpu/nvgpu/common/posix/timers.c
@@ -0,0 +1,169 @@
+/*
+ * Copyright (c) 2018, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include <sys/time.h>
+
+#include <nvgpu/bug.h>
+#include <nvgpu/log.h>
+#include <nvgpu/timers.h>
+
+static s64 now(void)
+{
+        return nvgpu_current_time_ms();
+}
+
+/*
+ * Returns true if a > b;
+ */
+static bool time_after(s64 a, s64 b)
+{
+        return a - b > 0;
+}
+
+int nvgpu_timeout_init(struct gk20a *g, struct nvgpu_timeout *timeout,
+                       u32 duration, unsigned long flags)
+{
+        if (flags & ~NVGPU_TIMER_FLAG_MASK)
+                return -EINVAL;
+
+        memset(timeout, 0, sizeof(*timeout));
+
+        timeout->g = g;
+        timeout->flags = flags;
+
+        if (flags & NVGPU_TIMER_RETRY_TIMER)
+                timeout->retries.max = duration;
+        else
+                timeout->time = nvgpu_current_time_ms() + (s64)duration;
+
+        return 0;
+}
+
+static int __nvgpu_timeout_expired_msg_cpu(struct nvgpu_timeout *timeout,
+                                         void *caller,
+                                         const char *fmt, va_list args)
+{
+        struct gk20a *g = timeout->g;
+
+        if (time_after(now(), timeout->time)) {
+                if (!(timeout->flags & NVGPU_TIMER_SILENT_TIMEOUT)) {
+                        char buf[128];
+
+                        vsnprintf(buf, sizeof(buf), fmt, args);
+
+                        nvgpu_err(g, "Timeout detected @ %p %s", caller, buf);
+                }
+
+                return -ETIMEDOUT;
+        }
+
+        return 0;
+}
+
+static int __nvgpu_timeout_expired_msg_retry(struct nvgpu_timeout *timeout,
+                                           void *caller,
+                                           const char *fmt, va_list args)
+{
+        struct gk20a *g = timeout->g;
+
+        if (timeout->retries.attempted >= timeout->retries.max) {
+                if (!(timeout->flags & NVGPU_TIMER_SILENT_TIMEOUT)) {
+                        char buf[128];
+
+                        vsnprintf(buf, sizeof(buf), fmt, args);
+
+                        nvgpu_err(g, "No more retries @ %p %s", caller, buf);
+                }
+
+                return -ETIMEDOUT;
+        }
+
+        timeout->retries.attempted++;
+
+        return 0;
+}
+
+int __nvgpu_timeout_expired_msg(struct nvgpu_timeout *timeout,
+                              void *caller, const char *fmt, ...)
+{
+        int ret;
+        va_list args;
+
+        va_start(args, fmt);
+        if (timeout->flags & NVGPU_TIMER_RETRY_TIMER)
+                ret = __nvgpu_timeout_expired_msg_retry(timeout, caller, fmt,
+                                                      args);
+        else
+                ret = __nvgpu_timeout_expired_msg_cpu(timeout, caller, fmt,
+                                                    args);
+        va_end(args);
+
+        return ret;
+}
+
+int nvgpu_timeout_peek_expired(struct nvgpu_timeout *timeout)
+{
+        if (timeout->flags & NVGPU_TIMER_RETRY_TIMER)
+                return timeout->retries.attempted >= timeout->retries.max;
+        else
+                return time_after(now(), timeout->time);
+}
+
+void nvgpu_udelay(unsigned int usecs)
+{
+        BUG();
+}
+
+void nvgpu_usleep_range(unsigned int min_us, unsigned int max_us)
+{
+        BUG();
+}
+
+void nvgpu_msleep(unsigned int msecs)
+{
+        BUG();
+}
+
+static inline s64 __nvgpu_current_time_us(void)
+{
+        struct timeval now;
+        s64 time_now;
+        int ret;
+
+        ret = gettimeofday(&now, NULL);
+        if (ret != 0)
+                BUG();
+
+        time_now = ((s64)now.tv_sec * (s64)1000000) + (s64)now.tv_usec;
+
+        return time_now;
+}
+
+s64 nvgpu_current_time_ms(void)
+{
+        return __nvgpu_current_time_us() / (s64)1000;
+}
+
+u64 nvgpu_hr_timestamp(void)
+{
+        return __nvgpu_current_time_us();
+}