From 61451af5a20331f49044bf1a9c695b0eb93de7fb Mon Sep 17 00:00:00 2001
From: Mike Blumenkrantz <michael.blumenkrantz@gmail.com>
Date: Wed, 29 Mar 2023 09:16:18 -0400
Subject: [PATCH] zink: rework choose_pdev (again)

there are two cases to be handled here:
* normal
* software

the latter case requires env vars based on the frontend, and if a sw
device isn't found then init should fail

the former case should (in theory) just yolo the first device and assume
that's what the user wanted based on whatever env vars and layers are
in use

fixes #7508, #7132

maybe also affects #8152

Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/22184>
---
 src/gallium/drivers/zink/zink_screen.c | 95 ++++++++++++++--------------------
 1 file changed, 40 insertions(+), 55 deletions(-)

diff --git a/src/gallium/drivers/zink/zink_screen.c b/src/gallium/drivers/zink/zink_screen.c
index a752862..5ff786c 100644
--- a/src/gallium/drivers/zink/zink_screen.c
+++ b/src/gallium/drivers/zink/zink_screen.c
@@ -1496,71 +1496,58 @@ zink_destroy_screen(struct pipe_screen *pscreen)
    glsl_type_singleton_decref();
 }
 
-static bool
+static void
 choose_pdev(struct zink_screen *screen)
 {
-   uint32_t i, pdev_count;
-   VkPhysicalDevice *pdevs;
-   bool is_cpu = false;
-   VkResult result = VKSCR(EnumeratePhysicalDevices)(screen->instance, &pdev_count, NULL);
-   if (result != VK_SUCCESS) {
-      mesa_loge("ZINK: vkEnumeratePhysicalDevices failed (%s)", vk_Result_to_str(result));
-      return is_cpu;
-   }
+   bool cpu = debug_get_bool_option("LIBGL_ALWAYS_SOFTWARE", false) ||
+              debug_get_bool_option("D3D_ALWAYS_SOFTWARE", false);
+   if (cpu) {
+      uint32_t i, pdev_count;
+      VkPhysicalDevice *pdevs;
+      VkResult result = VKSCR(EnumeratePhysicalDevices)(screen->instance, &pdev_count, NULL);
+      if (result != VK_SUCCESS) {
+         mesa_loge("ZINK: vkEnumeratePhysicalDevices failed (%s)", vk_Result_to_str(result));
+         return;
+      }
 
-   assert(pdev_count > 0);
+      assert(pdev_count > 0);
 
-   pdevs = malloc(sizeof(*pdevs) * pdev_count);
-   result = VKSCR(EnumeratePhysicalDevices)(screen->instance, &pdev_count, pdevs);
-   assert(result == VK_SUCCESS);
-   assert(pdev_count > 0);
+      pdevs = malloc(sizeof(*pdevs) * pdev_count);
+      result = VKSCR(EnumeratePhysicalDevices)(screen->instance, &pdev_count, pdevs);
+      assert(result == VK_SUCCESS);
+      assert(pdev_count > 0);
 
-   VkPhysicalDeviceProperties props;
-   bool cpu = debug_get_bool_option("LIBGL_ALWAYS_SOFTWARE", false) ||
-              debug_get_bool_option("D3D_ALWAYS_SOFTWARE", false);
-   /* priority when multiple drivers are available (highest to lowest):
-      VK_PHYSICAL_DEVICE_TYPE_VIRTUAL_GPU
-      VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU
-      VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU
-      VK_PHYSICAL_DEVICE_TYPE_CPU
-      VK_PHYSICAL_DEVICE_TYPE_OTHER
-
-    * users should specify VK_ICD_FILENAMES since this is a standardized variable
-    * used by all vulkan applications
-    */
-   unsigned prio_map[] = {
-      [VK_PHYSICAL_DEVICE_TYPE_OTHER] = 0,
-      [VK_PHYSICAL_DEVICE_TYPE_CPU] = 1,
-      [VK_PHYSICAL_DEVICE_TYPE_INTEGRATED_GPU] = 2,
-      [VK_PHYSICAL_DEVICE_TYPE_DISCRETE_GPU] = 3,
-      [VK_PHYSICAL_DEVICE_TYPE_VIRTUAL_GPU] = 4,
-   };
-   unsigned idx = 0;
-   int cur_prio = 0;
-   for (i = 0; i < pdev_count; ++i) {
-      VKSCR(GetPhysicalDeviceProperties)(pdevs[i], &props);
+      VkPhysicalDeviceProperties props;
+      int idx = -1;
+      for (i = 0; i < pdev_count; ++i) {
+         VKSCR(GetPhysicalDeviceProperties)(pdevs[i], &props);
 
-      if (cpu) {
          /* if user wants cpu, only give them cpu */
          if (props.deviceType == VK_PHYSICAL_DEVICE_TYPE_CPU) {
             idx = i;
-            cur_prio = prio_map[props.deviceType];
             break;
          }
-      } else {
-         assert(props.deviceType <= VK_PHYSICAL_DEVICE_TYPE_CPU);
-         if (prio_map[props.deviceType] > cur_prio) {
-            idx = i;
-            cur_prio = prio_map[props.deviceType];
-         }
       }
+      if (idx != -1)
+         /* valid cpu device */
+         screen->pdev = pdevs[idx];
+      free(pdevs);
+      if (idx == -1) {
+         mesa_loge("ZINK: CPU device requested but none found!");
+         return;
+      }
+   } else {
+      VkPhysicalDevice pdev;
+      unsigned pdev_count = 1;
+      VkResult result = VKSCR(EnumeratePhysicalDevices)(screen->instance, &pdev_count, &pdev);
+      if (result != VK_SUCCESS && result != VK_INCOMPLETE) {
+         mesa_loge("ZINK: vkEnumeratePhysicalDevices failed (%s)", vk_Result_to_str(result));
+         return;
+      }
+      screen->pdev = pdev;
    }
-   is_cpu = cur_prio == prio_map[VK_PHYSICAL_DEVICE_TYPE_CPU];
-   if (cpu != is_cpu)
-      goto out;
-
-   screen->pdev = pdevs[idx];
    VKSCR(GetPhysicalDeviceProperties)(screen->pdev, &screen->info.props);
+
    screen->info.device_version = screen->info.props.apiVersion;
 
    /* runtime version is the lesser of the instance version and device version */
@@ -1575,9 +1562,6 @@ choose_pdev(struct zink_screen *screen)
       screen->spirv_version = SPIRV_VERSION(1, 3);
    else
       screen->spirv_version = SPIRV_VERSION(1, 0);
-out:
-   free(pdevs);
-   return is_cpu;
 }
 
 static void
@@ -2757,9 +2741,10 @@ zink_internal_create_screen(const struct pipe_screen_config *config)
       (zink_debug & ZINK_DEBUG_VALIDATION) && !create_debug(screen))
       debug_printf("ZINK: failed to setup debug utils\n");
 
-   screen->is_cpu = choose_pdev(screen);
+   choose_pdev(screen);
    if (screen->pdev == VK_NULL_HANDLE)
       goto fail;
+   screen->is_cpu = screen->info.props.deviceType == VK_PHYSICAL_DEVICE_TYPE_CPU;
 
    update_queue_props(screen);
 
-- 
2.7.4