From patchwork Mon Mar 4 15:28:08 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Louis Chauvet X-Patchwork-Id: 13580735 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 C52BBC54E4A for ; Mon, 4 Mar 2024 15:29:27 +0000 (UTC) Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 6B2A211227C; Mon, 4 Mar 2024 15:29:26 +0000 (UTC) Authentication-Results: gabe.freedesktop.org; dkim=pass (2048-bit key; unprotected) header.d=bootlin.com header.i=@bootlin.com header.b="A40f85aL"; dkim-atps=neutral Received: from relay5-d.mail.gandi.net (relay5-d.mail.gandi.net [217.70.183.197]) by gabe.freedesktop.org (Postfix) with ESMTPS id F30DA11228A for ; Mon, 4 Mar 2024 15:29:23 +0000 (UTC) Received: by mail.gandi.net (Postfix) with ESMTPSA id AB8EB1C0003; Mon, 4 Mar 2024 15:29:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1709566162; 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=UoEJVitgQdwqzYit9x2fRkuhzwqFW+P/Z98aACWVEW8=; b=A40f85aLh9dvPmu6NQ4HVs515kE5Vo2AFNqoZxD0H8wTrxVzZg1IfGJ24QMKN9cQZCOBSZ 8QdfhBf7wYlU2xvmJkwxGOa/tYr7IVHuhE6aIT5varV4B5PqeOB96jt6ojN9MZLP/etuAY sH0ZA76Fr00Zhu3N+YCTvcY4Yl/4jeJrjv20NvU7Tzia0cyQkcYH/k8SHm4X6UQefUGLSs hn1pzeD2H08eiLA3igrkkM1lvV8npLX+FQr+3l/vDKGSEj60htcQd4YP1MkrVp8397y8/H tDrHvgMEXetGeNVL3i4NK/+LVKc1NS1+8me7N1E3jh3Uk2CntdaPXdTpcUPAGA== From: Louis Chauvet Date: Mon, 04 Mar 2024 16:28:08 +0100 Subject: [PATCH v4 03/14] drm/vkms: write/update the documentation for pixel conversion and pixel write functions MIME-Version: 1.0 Message-Id: <20240304-yuv-v4-3-76beac8e9793@bootlin.com> References: <20240304-yuv-v4-0-76beac8e9793@bootlin.com> In-Reply-To: <20240304-yuv-v4-0-76beac8e9793@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 , pekka.paalanen@haloniitty.fi Cc: dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org, jeremie.dautheribes@bootlin.com, miquel.raynal@bootlin.com, thomas.petazzoni@bootlin.com, seanpaul@google.com, marcheu@google.com, nicolejadeyee@google.com, Louis Chauvet X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=7282; i=louis.chauvet@bootlin.com; h=from:subject:message-id; bh=rAa69AVNvXwStTD/zFUG8N7xq95vym8ycf+nNk+Pqpg=; b=owEBbQKS/ZANAwAIASCtLsZbECziAcsmYgBl5ejLsCb3xgbo3eBxhb/+Zom9MLwlxhoqz5/HCrlI 1rnOZ76JAjMEAAEIAB0WIQRPj7g/vng8MQxQWQQgrS7GWxAs4gUCZeXoywAKCRAgrS7GWxAs4iiMD/ 9ihUJJRxg0jAcIVdcO+M/zG6DiWT7lXk6c4RZ1s2knRRgJlGyx1T3UfZl8PxTIDo+UFkMqDvcCHF9N VgdhgEmzOyQTEWPhPMP/1B4MrX1GPWUuR0KQBVW3fcXVQMtef5jt19v3FOPrN2/TM4fCZo7iw7p1Ed SGseHVUfeBWuc3wXA5xbdNezswG3daF89bhm3mgQ+OjKnopkC9IvHGObxNFKvdNMMSSQIJZlhrpna8 Ic7KeSBmvIspO5vulIkMtKLE/a2jErY4bd1sDMW3knlRp0Hy72XpkjGOLxEvWHkKffM2qXjDr2i9Lt f5N/r8NJpUET2f7dqCwH512eExZB1yjZeVrZvff2UGV3Ivz17ZmUIho621jGi3vYAySRI3QKfz+CKg LWXSKpS0UGHTWKWn5m4ezAr48ImFzGcSFrpSV8izhIg6fsp2ygAZG4rbtCiKJ4kQnfFgTPYgJ7Z8Bt qmlYsSSXfqXCZcfZ+qwbSy1OAExrj845GIqHI3KnZJk1iD8x4NVnbF0Bjwyt/390QewsuqWbZs0yk+ tgtMsah/IribpsJ+g/4NAqtUM+Z9HUuhZNQtzthH2XY90zFA84gVYdM8OK3hSGvabY4tv4JQis87SH lSnlGCOlLzAuO2uLPkZYLYZq08bAEQ+L3C23Dgk3lj+BAyUsxyed7miBHpIg== 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 | 7 ++++ drivers/gpu/drm/vkms/vkms_drv.h | 13 ++++++++ drivers/gpu/drm/vkms/vkms_formats.c | 62 ++++++++++++++++++++++++++++++------ 3 files changed, 73 insertions(+), 9 deletions(-) diff --git a/drivers/gpu/drm/vkms/vkms_composer.c b/drivers/gpu/drm/vkms/vkms_composer.c index c6d9b4a65809..da0651a94c9b 100644 --- a/drivers/gpu/drm/vkms/vkms_composer.c +++ b/drivers/gpu/drm/vkms/vkms_composer.c @@ -189,6 +189,13 @@ 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 to avoid heavy memory usage. It is a necessary + * complexity to avoid poor blending performance. + * + * The function vkms_compose_row is used to read a line, pixel-by-pixel, into the staging + * buffer. + */ 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..6e3dc8682ff9 100644 --- a/drivers/gpu/drm/vkms/vkms_formats.c +++ b/drivers/gpu/drm/vkms/vkms_formats.c @@ -9,6 +9,18 @@ #include "vkms_formats.h" +/** + * pixel_offset() - Get the offset of 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 ensure that the framebuffer associated with this request uses a pixel format + * where block_h == block_w == 1. + * If this requirement is not fulfilled, the resulting offset can point to an other pixel or + * outside of the buffer. + */ static size_t pixel_offset(const struct vkms_frame_info *frame_info, int x, int y) { struct drm_framebuffer *fb = frame_info->fb; @@ -17,18 +29,22 @@ 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. * This function assumes the channels are packed together, i.e. a color channel * comes immediately after another in the memory. And therefore, this function * doesn't work for YUV with chroma subsampling (e.g. YUV420 and NV21). + * + * The caller must ensure that the framebuffer associated with this request uses a pixel format + * where block_h == block_w == 1, otherwise the returned pointer can be outside the buffer. */ static void *packed_pixels_addr(const struct vkms_frame_info *frame_info, int x, int y) @@ -53,6 +69,13 @@ 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 +168,11 @@ 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 +238,14 @@ 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 +259,13 @@ 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: DRM_FORMAT_* value for which to obtain a conversion function (see [drm_fourcc.h]) + */ void *get_pixel_conversion_function(u32 format) { switch (format) { @@ -247,6 +284,13 @@ 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: DRM_FORMAT_* value for which to obtain a conversion function (see [drm_fourcc.h]) + */ void *get_pixel_write_function(u32 format) { switch (format) {