panfrost: Add heap_memory_percent driconf support

This also changes `max_mem_alloc_size` to use 100% instead of the
heuristic, consistent with `video_memory`.

Signed-off-by: Karmjit Mahil <karmjit.mahil@igalia.com>

src/gallium/drivers/panfrost/driinfo_panfrost.h

@@ -22,6 +22,7 @@ DRI_CONF_SECTION_PERFORMANCE
 DRI_CONF_SECTION_END
 
 DRI_CONF_SECTION_MISCELLANEOUS
+   DRI_CONF_HEAP_MEMORY_PERCENT(1.0f)
    DRI_CONF_PAN_COMPUTE_CORE_MASK(~0ull)
    DRI_CONF_PAN_FRAGMENT_CORE_MASK(~0ull)
    DRI_CONF_OPT_B(pan_relax_afbc_yuv_imports, false, "Use relaxed import rules for AFBC(YUV)")

src/gallium/drivers/panfrost/pan_resource.c

@@ -14,6 +14,7 @@
 
 #include "frontend/winsys_handle.h"
 #include "util/format/u_format.h"
+#include "util/os_misc.h"
 #include "util/u_debug_image.h"
 #include "util/u_drm.h"
 #include "util/u_gen_mipmap.h"
@@ -1049,10 +1050,10 @@ panfrost_can_create_resource(struct pipe_screen *screen,
    if (!os_get_total_physical_memory(&system_memory))
       return false;
 
-   /* Limit maximum texture size to a quarter of the system memory, to avoid
-    * allocating huge textures on systems with little memory.
-    */
-   return tmp.plane.layout.data_size_B <= system_memory / 4;
+   uint64_t memory =
+      os_get_gpu_heap_size(screen->heap_memory_percent, NULL);
+
+   return tmp.plane.layout.data_size_B <= memory;
 }
 
 static struct pipe_resource *

src/gallium/drivers/panfrost/pan_screen.c

@@ -12,6 +12,7 @@
 #include "pipe/p_screen.h"
 #include "util/format/u_format.h"
 #include "util/format/u_format_s3tc.h"
+#include "util/os_misc.h"
 #include "util/os_time.h"
 #include "util/u_debug.h"
 #include "util/u_memory.h"
@@ -634,18 +635,8 @@ panfrost_init_compute_caps(struct panfrost_screen *screen)
     */
    caps->max_threads_per_block = dev->arch >= 6 ? 256 : 128;
 
-   uint64_t total_ram;
-   if (!os_get_total_physical_memory(&total_ram))
-      total_ram = 0;
-
-   /* We don't want to burn too much ram with the GPU. If the user has 4GiB
-    * or less, we use at most half. If they have more than 4GiB, we use 3/4.
-    */
-   uint64_t available_ram;
-   if (total_ram <= 4ull * 1024 * 1024 * 1024)
-      available_ram = total_ram / 2;
-   else
-      available_ram = total_ram * 3 / 4;
+   const uint64_t available_ram =
+      os_get_gpu_heap_size(screen->heap_memory_percent, NULL);
 
    /* 48bit address space max, with the lower 32MB reserved. We clamp
     * things so it matches kmod VA range limitations.
@@ -843,9 +834,8 @@ panfrost_init_screen_caps(struct panfrost_screen *screen)
 
    caps->max_texture_gather_offset = 7;
 
-   uint64_t system_memory;
-   caps->video_memory = os_get_total_physical_memory(&system_memory) ?
-      system_memory >> 20 : 0;
+   caps->video_memory =
+      os_get_gpu_heap_size(screen->heap_memory_percent, NULL) >> 20;
 
    caps->shader_stencil_export = true;
    caps->conditional_render = true;
@@ -1063,6 +1053,11 @@ panfrost_create_screen(int fd, const struct pipe_screen_config *config,
    snprintf(screen->renderer_string, sizeof(screen->renderer_string),
             "%s MC%u (Panfrost)", dev->model->name, core_count);
 
+   screen->heap_memory_percent =
+      driQueryOptionf(config->options, "heap_memory_percent");
+   if (screen->heap_memory_percent == OS_GPU_HEAP_SIZE_HEURISTIC)
+      screen->heap_memory_percent = 1.0f;
+
    screen->afbc_tiled = driQueryOptionb(config->options, "pan_afbc_tiled");
 
    screen->force_afbc_packing = dev->debug & PAN_DBG_FORCE_PACK;

src/gallium/drivers/panfrost/pan_screen.h

@@ -106,6 +106,8 @@ struct panfrost_screen {
    struct panfrost_vtable vtbl;
    struct disk_cache *disk_cache;
 
+   float heap_memory_percent;
+
    /* Use AFBC tiled layout whenever possible */
    bool afbc_tiled;