drm/amd/display: resolve correct MALL size for dcn401

[WHY]
Code for dcn401 to calculate available MALL size for display was shared
with dcn32 and did not provide the correct result for all ASICs.

[HOW]
Add dcn401 specific function to properly calculate the available MALL
for display.

Reviewed-by: Chris Park <chris.park@amd.com>
Signed-off-by: Dillon Varone <dillon.varone@amd.com>
Signed-off-by: Roman Li <roman.li@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/display/dc/resource/dcn32/dcn32_resource.c

@@ -1990,6 +1990,10 @@ unsigned int dcn32_calculate_mall_ways_from_bytes(const struct dc *dc, unsigned
 		return 0;
 	}
 
+	if (dc->caps.max_cab_allocation_bytes == 0) {
+		return 0xffffffff;
+	}
+
 	/* add 2 lines for worst case alignment */
 	cache_lines_used = total_size_in_mall_bytes / dc->caps.cache_line_size + 2;
 

drivers/gpu/drm/amd/display/dc/resource/dcn401/dcn401_resource.c

@@ -1704,6 +1704,29 @@ static int dcn401_get_power_profile(const struct dc_state *context)
 	return dpm_level;
 }
 
+static unsigned int dcn401_calc_num_avail_chans_for_mall(struct dc *dc, unsigned int num_chans)
+{
+	unsigned int num_available_chans = 1;
+
+	/* channels for MALL must be a power of 2 */
+	while (num_chans > 1) {
+		num_available_chans = (num_available_chans << 1);
+		num_chans = (num_chans >> 1);
+	}
+
+	/* cannot be odd */
+	num_available_chans &= ~1;
+
+	/* clamp to max available channels for MALL per ASIC */
+	if (ASICREV_IS_GC_12_0_0_A0(dc->ctx->asic_id.hw_internal_rev)) {
+		num_available_chans = num_available_chans > 16 ? 16 : num_available_chans;
+	} else if (ASICREV_IS_GC_12_0_1_A0(dc->ctx->asic_id.hw_internal_rev)) {
+		num_available_chans = num_available_chans > 8 ? 8 : num_available_chans;
+	}
+
+	return num_available_chans;
+}
+
 static struct resource_funcs dcn401_res_pool_funcs = {
 	.destroy = dcn401_destroy_resource_pool,
 	.link_enc_create = dcn401_link_encoder_create,
@@ -1812,14 +1835,12 @@ static bool dcn401_resource_construct(
 	dc->caps.min_horizontal_blanking_period = 80;
 	dc->caps.dmdata_alloc_size = 2048;
 	dc->caps.mall_size_per_mem_channel = 4;
-	/* total size = mall per channel * num channels * 1024 * 1024 */
-	dc->caps.mall_size_total = dc->caps.mall_size_per_mem_channel * dc->ctx->dc_bios->vram_info.num_chans * 1048576;
 	dc->caps.cursor_cache_size = dc->caps.max_cursor_size * dc->caps.max_cursor_size * 8;
 	dc->caps.cache_line_size = 64;
 	dc->caps.cache_num_ways = 16;
 
 	/* Calculate the available MALL space */
-	dc->caps.max_cab_allocation_bytes = dcn32_calc_num_avail_chans_for_mall(
+	dc->caps.max_cab_allocation_bytes = dcn401_calc_num_avail_chans_for_mall(
 		dc, dc->ctx->dc_bios->vram_info.num_chans) *
 		dc->caps.mall_size_per_mem_channel * 1024 * 1024;
 	dc->caps.mall_size_total = dc->caps.max_cab_allocation_bytes;