From patchwork Sat Oct 2 15:45:27 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Sean Paul X-Patchwork-Id: 12532203 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2AD93C433F5 for ; Sat, 2 Oct 2021 15:45:49 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id C632461B1C for ; Sat, 2 Oct 2021 15:45:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org C632461B1C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=poorly.run Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=lists.freedesktop.org Received: from gabe.freedesktop.org (localhost [127.0.0.1]) by gabe.freedesktop.org (Postfix) with ESMTP id 404D189338; Sat, 2 Oct 2021 15:45:47 +0000 (UTC) Received: from mail-qt1-x82b.google.com (mail-qt1-x82b.google.com [IPv6:2607:f8b0:4864:20::82b]) by gabe.freedesktop.org (Postfix) with ESMTPS id C13EC89338 for ; Sat, 2 Oct 2021 15:45:45 +0000 (UTC) Received: by mail-qt1-x82b.google.com with SMTP id f15so11929191qtv.9 for ; Sat, 02 Oct 2021 08:45:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=poorly.run; s=google; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=N7nCMGTCgys5hRW4WhI1DxCYZ01ugVhghWDldMJPqiw=; b=ZeyVB3Ww5+MndgRRuyKNgtxr4Xg4kU888pfduDgU4Da9wYrVcs0RSOBDqA7sjnLbWF ntkU1BR9LIebqEuq3E1U4V6xFqsjmRBILGZTDWbHeIN1WaTIO6/dXDxrHhDoxUi4RVVw LUXKPw6ajDT4ZS9d34nTBdp6Xdp3U29OPq8Qj7fGhKE2/88OyYLs2xJzxLhrVMlysO3z DeMhm2a70aUOvJxZWZ9lr3QeewUwi630gffYiCOxs5ziujd7Jn5ROzdNl1lfUyz048lH OcZ1pqrskrkbuHq/b5f3VQIM2qb2WFeVbZ+pwoMf568DgTS4CZ7Ar7/+RKXIxGZQ4teS DxjQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=N7nCMGTCgys5hRW4WhI1DxCYZ01ugVhghWDldMJPqiw=; b=zqnMcD9tiaggwaoNIJZ1ThCajHMDCiM2HF1J8q8nVSzF9I6Qm3HFmBMYA5wJkcLw3o pPUSq1XgccvJBzNOGAZK5qFyxzqGJGJV/n+cyip80Lu2YRqSgx7y90yiL4dS4/t0CGub HS9OMtPGArnZHjrTKsA5ZSwSrauxiOw/9aYOA8CCeHjhC8D5i8+SksjJc7XiHgzgZoDq x7HhsQ9e59scQGiHJoG/ccefIzSg74Ps3Qgn0g3HwZekZ5cP84auQxpt8pXAqb3cobE+ WcpctEZjbeJoHEBTzo2LEI9RsB5uDkZmAoc1d5glVFYE6rEAwFwKS2M4gcB8RBtn2819 EwVA== X-Gm-Message-State: AOAM533m3ORaLiRcPhcDKuCO1Dj+GdiE/i5EKM6iuHJO9foyMCTq75DX RmySO4/OjPPANiIxW1nuqzY12mJW+iM3DA== X-Google-Smtp-Source: ABdhPJz4Tta3xzWqk6v8cvex6TIIE1hil6jjUKR8RLxF+R9pJLP3Q6jwhOKiCY2c+h7VKis5wS51xg== X-Received: by 2002:aed:27c1:: with SMTP id m1mr4214009qtg.241.1633189544259; Sat, 02 Oct 2021 08:45:44 -0700 (PDT) Received: from localhost ([167.100.64.199]) by smtp.gmail.com with ESMTPSA id p9sm4682358qkm.23.2021.10.02.08.45.43 (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Sat, 02 Oct 2021 08:45:43 -0700 (PDT) From: Sean Paul To: dri-devel@lists.freedesktop.org Cc: Sean Paul , =?utf-8?b?VmlsbGUgU3lyasOkbMOk?= , Fernando Ramos Subject: [PATCH 01/16] Revert "drm: cleanup: remove drm_modeset_(un)lock_all()" Date: Sat, 2 Oct 2021 11:45:27 -0400 Message-Id: <20211002154542.15800-1-sean@poorly.run> X-Mailer: git-send-email 2.31.0 MIME-Version: 1.0 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" From: Sean Paul This reverts commit 8d813d1a535c8c7503a5f4061654a73026be8c5e. This patchset breaks on intel platforms and was previously NACK'd by Ville. Cc: Ville Syrjälä Cc: Fernando Ramos Signed-off-by: Sean Paul --- drivers/gpu/drm/drm_modeset_lock.c | 94 +++++++++++++++++++++++++++++- include/drm/drm_modeset_lock.h | 2 + 2 files changed, 93 insertions(+), 3 deletions(-) diff --git a/drivers/gpu/drm/drm_modeset_lock.c b/drivers/gpu/drm/drm_modeset_lock.c index afd1351749a5..fcfe1a03c4a1 100644 --- a/drivers/gpu/drm/drm_modeset_lock.c +++ b/drivers/gpu/drm/drm_modeset_lock.c @@ -77,6 +77,93 @@ static DEFINE_WW_CLASS(crtc_ww_class); +/** + * drm_modeset_lock_all - take all modeset locks + * @dev: DRM device + * + * This function takes all modeset locks, suitable where a more fine-grained + * scheme isn't (yet) implemented. Locks must be dropped by calling the + * drm_modeset_unlock_all() function. + * + * This function is deprecated. It allocates a lock acquisition context and + * stores it in &drm_device.mode_config. This facilitate conversion of + * existing code because it removes the need to manually deal with the + * acquisition context, but it is also brittle because the context is global + * and care must be taken not to nest calls. New code should use the + * drm_modeset_lock_all_ctx() function and pass in the context explicitly. + */ +void drm_modeset_lock_all(struct drm_device *dev) +{ + struct drm_mode_config *config = &dev->mode_config; + struct drm_modeset_acquire_ctx *ctx; + int ret; + + ctx = kzalloc(sizeof(*ctx), GFP_KERNEL | __GFP_NOFAIL); + if (WARN_ON(!ctx)) + return; + + mutex_lock(&config->mutex); + + drm_modeset_acquire_init(ctx, 0); + +retry: + ret = drm_modeset_lock_all_ctx(dev, ctx); + if (ret < 0) { + if (ret == -EDEADLK) { + drm_modeset_backoff(ctx); + goto retry; + } + + drm_modeset_acquire_fini(ctx); + kfree(ctx); + return; + } + ww_acquire_done(&ctx->ww_ctx); + + WARN_ON(config->acquire_ctx); + + /* + * We hold the locks now, so it is safe to stash the acquisition + * context for drm_modeset_unlock_all(). + */ + config->acquire_ctx = ctx; + + drm_warn_on_modeset_not_all_locked(dev); +} +EXPORT_SYMBOL(drm_modeset_lock_all); + +/** + * drm_modeset_unlock_all - drop all modeset locks + * @dev: DRM device + * + * This function drops all modeset locks taken by a previous call to the + * drm_modeset_lock_all() function. + * + * This function is deprecated. It uses the lock acquisition context stored + * in &drm_device.mode_config. This facilitates conversion of existing + * code because it removes the need to manually deal with the acquisition + * context, but it is also brittle because the context is global and care must + * be taken not to nest calls. New code should pass the acquisition context + * directly to the drm_modeset_drop_locks() function. + */ +void drm_modeset_unlock_all(struct drm_device *dev) +{ + struct drm_mode_config *config = &dev->mode_config; + struct drm_modeset_acquire_ctx *ctx = config->acquire_ctx; + + if (WARN_ON(!ctx)) + return; + + config->acquire_ctx = NULL; + drm_modeset_drop_locks(ctx); + drm_modeset_acquire_fini(ctx); + + kfree(ctx); + + mutex_unlock(&dev->mode_config.mutex); +} +EXPORT_SYMBOL(drm_modeset_unlock_all); + /** * drm_warn_on_modeset_not_all_locked - check that all modeset locks are locked * @dev: device @@ -293,9 +380,10 @@ EXPORT_SYMBOL(drm_modeset_unlock); * This function takes all modeset locks, suitable where a more fine-grained * scheme isn't (yet) implemented. * - * It doesn't take the &drm_mode_config.mutex since that lock isn't required for - * modeset state changes. Callers which need to grab that lock too need to do so - * outside of the acquire context @ctx. + * Unlike drm_modeset_lock_all(), it doesn't take the &drm_mode_config.mutex + * since that lock isn't required for modeset state changes. Callers which + * need to grab that lock too need to do so outside of the acquire context + * @ctx. * * Locks acquired with this function should be released by calling the * drm_modeset_drop_locks() function on @ctx. diff --git a/include/drm/drm_modeset_lock.h b/include/drm/drm_modeset_lock.h index 865e64bcc4cb..aafd07388eb7 100644 --- a/include/drm/drm_modeset_lock.h +++ b/include/drm/drm_modeset_lock.h @@ -132,6 +132,8 @@ struct drm_device; struct drm_crtc; struct drm_plane; +void drm_modeset_lock_all(struct drm_device *dev); +void drm_modeset_unlock_all(struct drm_device *dev); void drm_warn_on_modeset_not_all_locked(struct drm_device *dev); int drm_modeset_lock_all_ctx(struct drm_device *dev,