anv: fixup assertions on lowered storage formats

With VK_FORMAT_B10G11R11_UFLOAT_PACK32 in particular, we're seeing
applications create image views with swizzle = R,G,B,0

But since the format has no alpha channel, the swizzle value for it
does not matter for the equivalence we're trying to verify.

Signed-off-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Fixes: a9edc268b9 ("anv: validate image view lowered storage formats for storage")
Reviewed-by: José Roberto de Souza <jose.souza@intel.com>
Reviewed-by: Tapani Pälli <tapani.palli@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/18081>

src/intel/isl/isl.h

@@ -2357,6 +2357,22 @@ isl_swizzle_is_identity(struct isl_swizzle swizzle)
           swizzle.a == ISL_CHANNEL_SELECT_ALPHA;
 }
 
+static inline bool
+isl_swizzle_is_identity_for_format(enum isl_format format,
+                                   struct isl_swizzle swizzle)
+{
+   const struct isl_format_layout *layout = isl_format_get_layout(format);
+
+#define channel_id_or_zero(name, ID)                 \
+   (swizzle.name == ISL_CHANNEL_SELECT_##ID ||       \
+    layout->channels.name.bits == 0)
+   return channel_id_or_zero(r, RED) &&
+          channel_id_or_zero(g, GREEN) &&
+          channel_id_or_zero(b, BLUE) &&
+          channel_id_or_zero(a, ALPHA);
+#undef channel_id_or_zero
+}
+
 bool
 isl_swizzle_supports_rendering(const struct intel_device_info *devinfo,
                                struct isl_swizzle swizzle);

src/intel/vulkan/anv_image.c

@@ -2566,7 +2566,7 @@ anv_image_fill_surface_state(struct anv_device *device,
           */
          assert(isl_formats_have_same_bits_per_channel(lower_format,
                                                        view.format) ||
-                isl_swizzle_is_identity(view.swizzle));
+                isl_swizzle_is_identity_for_format(view.format, view.swizzle));
 
          view.format = lower_format;
       }