From patchwork Fri Feb 23 11:37:23 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Louis Chauvet X-Patchwork-Id: 13568938 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from gabe.freedesktop.org (gabe.freedesktop.org [131.252.210.177]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 1358FC5478C for ; Fri, 23 Feb 2024 11:38:08 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 7D65310EBCF; Fri, 23 Feb 2024 11:38:06 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.b="CoS7pxYK"; dkim-atps=neutral Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [217.70.183.194]) by gabe.freedesktop.org (Postfix) with ESMTPS id E077E10E0C5 for ; Fri, 23 Feb 2024 11:37:47 +0000 (UTC) Received: by mail.gandi.net (Postfix) with ESMTPSA id 9EEF040009; Fri, 23 Feb 2024 11:37:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1708688266; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=U5UinReH6vUXNxBJ97EG+ZqktERoBQAcu/k8mtlmiaY=; b=CoS7pxYKCeWB23zyjrumCaMa+xAnUMvTeoN/GZkSgbmne85fAH30Jx5iHOZWlHhCATQeTF h/Tmn6TPGETR9cWb5G4b2SZ+wno186d4k1pI/tclFUqQTrdEt4hFd6eHOTjtL7pyZW5b+u sQLOjtmhcYTaj1ZISUYi8Z8Tu9CG2i7caU/CpdlwvCNXKzsnEncnwu6pkSw3pLA3pWwXxW RsLRYLAvCVSyD4NG7xPgE2aODwIDJCwHUnQSRxVURcSJDTdX7Q3pB/JpNqpG+C4XuYG50k 4hfXoQyd6IxPIRc9AcKoqHopR0qxBVkQ0zqxA4sdAzEAYXCWTsI05G+VpyNYLA== From: Louis Chauvet Date: Fri, 23 Feb 2024 12:37:23 +0100 Subject: [PATCH v2 3/9] drm/vkms: write/update the documentation for pixel conversion and pixel write functions MIME-Version: 1.0 Message-Id: <20240223-yuv-v2-3-aa6be2827bb7@bootlin.com> References: <20240223-yuv-v2-0-aa6be2827bb7@bootlin.com> In-Reply-To: <20240223-yuv-v2-0-aa6be2827bb7@bootlin.com> To: Rodrigo Siqueira , Melissa Wen , =?utf-8?q?Ma=C3=ADra_Canal?= , Haneen Mohammed , Daniel Vetter , Maarten Lankhorst , Maxime Ripard , Thomas Zimmermann , David Airlie , arthurgrillo@riseup.net, Jonathan Corbet Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, jeremie.dautheribes@bootlin.com, miquel.raynal@bootlin.com, thomas.petazzoni@bootlin.com, Louis Chauvet X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=6432; i=louis.chauvet@bootlin.com; h=from:subject:message-id; bh=+DsmO8SGjkaXdS5jYLEBNm7wDQTKeBuOh6cIQzNvHU8=; b=owEBbQKS/ZANAwAIASCtLsZbECziAcsmYgBl2IOELQdbsAL3kPoQQMyXC3JqipcWeSAmxUPjPdxL d/KVrGuJAjMEAAEIAB0WIQRPj7g/vng8MQxQWQQgrS7GWxAs4gUCZdiDhAAKCRAgrS7GWxAs4uboEA Cq/5qtV9Y5FvfIqHbu4XA94FvAcUfEnpZKNSgk1MYRGk0lerUT5AToE34MC59pzv48BvCXZpbY/CLE QNwsSBr3kl1p8UOanos2TCOiaACkVZ6WJauMELLu9I2vKbz6+1+ENlH1JXha8cLIA+i+BN/YjvTTX2 guPJwFzyRet8vA+IBwVLp61vWbBrnbXLonIUJlzNMfTJ348RdZzYcmMBU/iNhrxzgu/au4Ruef8ZR6 n7Y9zdfH60Zie93eEVY5qklmwR+KPMjA4YXkAvgP6hJF0uZqzzYoDooA35NRqb8KAj3dV/YWH11mx2 5cU1Ly0/K6M2nTs+SnVkJB7ZSCB+qxXFIUlWyZvMCNU7yYuw+ELmzKeivzNcifq769KuioUDYknwcA b6safCAMTi46oD9vuCJyAyW8d8G2DcKlxciPZQ4f3tJJmdmyC7I4IYnZnAaGL9I/7DauNCjO6JuBQW ZMn0KeltOycRUt8wufbTDhuFvWsIrJsmua8DJ8m/5kzOiB5rIguFhJer5RHN0+WUo7z45oGSZJveLk v+wkCGXgx/bHDm+kXQT3Du3d4J2MENBdx2v5Pd+2t5oa3Qcd0UkEzWZgWbcrCYEJxrrwLqE/BriMOj TqCeK8hrkI4dp2dRWEcTDyzQHXEKldd3KlCTYIWwaKUoEqAPDbqcbbEu7Ocg== X-Developer-Key: i=louis.chauvet@bootlin.com; a=openpgp; fpr=8B7104AE9A272D6693F527F2EC1883F55E0B40A5 X-GND-Sasl: louis.chauvet@bootlin.com X-BeenThere: dri-devel@lists.freedesktop.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Direct Rendering Infrastructure - Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dri-devel-bounces@lists.freedesktop.org Sender: "dri-devel" Add some documentation on pixel conversion functions. Update of outdated comments for pixel_write functions. Signed-off-by: Louis Chauvet --- drivers/gpu/drm/vkms/vkms_composer.c | 4 +++ drivers/gpu/drm/vkms/vkms_drv.h | 13 ++++++++ drivers/gpu/drm/vkms/vkms_formats.c | 58 ++++++++++++++++++++++++++++++------ 3 files changed, 66 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c index c6d9b4a65809..5b341222d239 100644 --- a/drivers/gpu/drm/vkms/vkms_composer.c +++ b/drivers/gpu/drm/vkms/vkms_composer.c @@ -189,6 +189,10 @@ static void blend(struct vkms_writeback_job *wb, size_t crtc_y_limit = crtc_state->base.crtc->mode.vdisplay; + /* + * The planes are composed line-by-line. It is a necessary complexity to avoid poor + * blending performance. + */ for (size_t y = 0; y < crtc_y_limit; y++) { fill_background(&background_color, output_buffer); diff --git a/drivers/gpu/drm/vkms/vkms_drv.h b/drivers/gpu/drm/vkms/vkms_drv.h index b4b357447292..18086423a3a7 100644 --- a/drivers/gpu/drm/vkms/vkms_drv.h +++ b/drivers/gpu/drm/vkms/vkms_drv.h @@ -25,6 +25,17 @@ #define VKMS_LUT_SIZE 256 +/** + * struct vkms_frame_info - structure to store the state of a frame + * + * @fb: backing drm framebuffer + * @src: source rectangle of this frame in the source framebuffer + * @dst: destination rectangle in the crtc buffer + * @map: see drm_shadow_plane_state@data + * @rotation: rotation applied to the source. + * + * @src and @dst should have the same size modulo the rotation. + */ struct vkms_frame_info { struct drm_framebuffer *fb; struct drm_rect src, dst; @@ -52,6 +63,8 @@ struct vkms_writeback_job { * vkms_plane_state - Driver specific plane state * @base: base plane state * @frame_info: data required for composing computation + * @pixel_read: function to read a pixel in this plane. The creator of a vkms_plane_state must + * ensure that this pointer is valid */ struct vkms_plane_state { struct drm_shadow_plane_state base; diff --git a/drivers/gpu/drm/vkms/vkms_formats.c b/drivers/gpu/drm/vkms/vkms_formats.c index 172830a3936a..cb7a49b7c8e7 100644 --- a/drivers/gpu/drm/vkms/vkms_formats.c +++ b/drivers/gpu/drm/vkms/vkms_formats.c @@ -9,6 +9,17 @@ #include "vkms_formats.h" +/** + * packed_pixels_offset() - Get the offset of the block containing the pixel at coordinates x/y + * in the first plane + * + * @frame_info: Buffer metadata + * @x: The x coordinate of the wanted pixel in the buffer + * @y: The y coordinate of the wanted pixel in the buffer + * + * The caller must be aware that this offset is not always a pointer to a pixel. If individual + * pixel values are needed, they have to be extracted from the resulting block. + */ static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int y) { struct drm_framebuffer *fb = frame_info->fb; @@ -17,12 +28,13 @@ static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int + (x * fb->format->cpp[0]); } -/* - * packed_pixels_addr - Get the pointer to pixel of a given pair of coordinates +/** + * packed_pixels_addr() - Get the pointer to the block containing the pixel at the given + * coordinates * * @frame_info: Buffer metadata - * @x: The x(width) coordinate of the 2D buffer - * @y: The y(Heigth) coordinate of the 2D buffer + * @x: The x(width) coordinate inside the plane + * @y: The y(height) coordinate inside the plane * * Takes the information stored in the frame_info, a pair of coordinates, and * returns the address of the first color channel. @@ -53,6 +65,13 @@ static int get_x_position(const struct vkms_frame_info *frame_info, int limit, i return x; } +/* + * The following functions take pixel data from the buffer and convert them to the format + * ARGB16161616 in out_pixel. + * + * They are used in the `vkms_compose_row` function to handle multiple formats. + */ + static void ARGB8888_to_argb_u16(u8 *src_pixels, struct pixel_argb_u16 *out_pixel) { /* @@ -145,12 +164,11 @@ void vkms_compose_row(struct line_buffer *stage_buffer, struct vkms_plane_state } /* - * The following functions take an line of argb_u16 pixels from the - * src_buffer, convert them to a specific format, and store them in the - * destination. + * The following functions take one argb_u16 pixel and convert it to a specific format. The + * result is stored in @dst_pixels. * - * They are used in the `compose_active_planes` to convert and store a line - * from the src_buffer to the writeback buffer. + * They are used in the `vkms_writeback_row` to convert and store a pixel from the src_buffer to + * the writeback buffer. */ static void argb_u16_to_ARGB8888(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel) { @@ -216,6 +234,14 @@ static void argb_u16_to_RGB565(u8 *dst_pixels, struct pixel_argb_u16 *in_pixel) *pixels = cpu_to_le16(r << 11 | g << 5 | b); } +/** + * Generic loop for all supported writeback format. It is executed just after the blending to + * write a line in the writeback buffer. + * + * @wb: Job where to insert the final image + * @src_buffer: Line to write + * @y: Row to write in the writeback buffer + */ void vkms_writeback_row(struct vkms_writeback_job *wb, const struct line_buffer *src_buffer, int y) { @@ -229,6 +255,13 @@ void vkms_writeback_row(struct vkms_writeback_job *wb, wb->pixel_write(dst_pixels, &in_pixels[x]); } +/** + * Retrieve the correct read_pixel function for a specific format. + * The returned pointer is NULL for unsupported pixel formats. The caller must ensure that the + * pointer is valid before using it in a vkms_plane_state. + * + * @format: 4cc of the format + */ void *get_pixel_conversion_function(u32 format) { switch (format) { @@ -247,6 +280,13 @@ void *get_pixel_conversion_function(u32 format) } } +/** + * Retrieve the correct write_pixel function for a specific format. + * The returned pointer is NULL for unsupported pixel formats. The caller must ensure that the + * pointer is valid before using it in a vkms_writeback_job. + * + * @format: 4cc of the format + */ void *get_pixel_write_function(u32 format) { switch (format) {