panfrost: add color-attachment and msaa helpers

In order to enable higher MSAA modes, we're going to have to perform
some calculations on how to budget the (sometimes) limited tile-buffer
space.

Due to limited tilebuffer space, we need to prioritize a bit here.
First, we reserve space for 4x MSAA for all formats. Then we try to fit
8 color attachments into the tile-buffer. And then finally, we calculate
how many extra multi-sample buffers we can fit into the rest.

The reason we reserve 4x MSAA first, is that this is required by all
Vulkan versions. It also prevents us from regressing existing features.

Then we try to pick 8 color attachments next, because that's required by
Vulkan 1.4 as well as Vulkan Roadmap 2024 and D3D12. Vulkan Roadmap 2022
requires 7 as well.

This adds helpers that implements this, which can be used by both the
Gallium and the Vulkan driver. It's really benefitial if both of these
drivers prioritize the same way here.

Reviewed-by: Lars-Ivar Hesselberg Simonsen <lars-ivar.simonsen@arm.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/33925>

src/panfrost/lib/pan_props.h

@@ -30,6 +30,8 @@
 #include <stdbool.h>
 #include <stdint.h>
 
+#include "util/macros.h"
+
 struct pan_kmod_dev;
 struct pan_kmod_dev_props;
 
@@ -142,4 +144,49 @@ panfrost_max_effective_tile_size(unsigned arch)
    return 16 * 16;
 }
 
+/* Returns the maximum usable color tilebuffer-size. This is *usually* twice
+ * the optimal tilebuffer-size, but not always.
+ */
+static inline unsigned
+pan_get_max_tib_size(unsigned arch, const struct panfrost_model *model)
+{
+   unsigned tib_size = panfrost_query_optimal_tib_size(model);
+
+   /* On V5, as well as V6 and later, we can disable pipelining to gain some
+    * extra tib memory.
+    */
+   if (arch > 4 && arch != 6)
+      return tib_size * 2;
+
+   return tib_size;
+}
+
+static inline uint32_t
+pan_get_max_cbufs(unsigned arch, unsigned max_tib_size)
+{
+   if (arch < 5)
+      return 1;
+
+   const unsigned min_msaa = 4;            /* Vulkan *requires* at least 4x MSAA support */
+   const unsigned max_cbuf_format = 4 * 4; /* R32G32B32A32 */
+   const unsigned min_tile_size = 4 * 4;
+
+   unsigned max_cbufs =
+      max_tib_size / (min_msaa * max_cbuf_format * min_tile_size);
+
+   return MIN2(max_cbufs, 8);
+}
+
+static inline unsigned
+pan_get_max_msaa(unsigned arch, unsigned max_tib_size, unsigned max_cbuf_atts,
+                 unsigned format_size)
+{
+   assert(max_cbuf_atts > 0);
+   assert(format_size > 0);
+   const unsigned min_tile_size = 4 * 4;
+   unsigned max_msaa = max_tib_size / (max_cbuf_atts * format_size *
+                                       min_tile_size);
+   return MIN2(max_msaa, arch >= 5 ? 16 : 8);
+}
+
 #endif