From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1A4962E63B for ; Wed, 20 Sep 2023 12:13:35 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 921FBC433C8; Wed, 20 Sep 2023 12:13:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1695212014; bh=aAZEmJ6SPVopabwHWdQc4DAUFgQYfNNx25RlIZap+RI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=cJhhOw8ragnl/KpOego+BrJ83JMPTg3X74SvJRQSsCK00BXfs2AY/zrYbtBf9kZx4 NHPS1lLfWakfAN0AM9he5tfoT6/HyChhGE+ioe1JNPyBqvmgog2w4YFjPuAS0EKXmE 8AzS1R3FVrH4sZllqAAeW0TNRtyqH+Aa3QWStdQ4= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Lukas Wunner , =?UTF-8?q?Ilpo=20J=C3=A4rvinen?= , Bjorn Helgaas , Alex Deucher , Sasha Levin Subject: [PATCH 4.19 118/273] drm/amdgpu: Use RMW accessors for changing LNKCTL Date: Wed, 20 Sep 2023 13:29:18 +0200 Message-ID: <20230920112850.138128656@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20230920112846.440597133@linuxfoundation.org> References: <20230920112846.440597133@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ilpo Järvinen [ Upstream commit ce7d88110b9ed5f33fe79ea6d4ed049fb0e57bce ] Don't assume that only the driver would be accessing LNKCTL. ASPM policy changes can trigger write to LNKCTL outside of driver's control. And in the case of upstream bridge, the driver does not even own the device it's changing the registers for. Use RMW capability accessors which do proper locking to avoid losing concurrent updates to the register value. Suggested-by: Lukas Wunner Fixes: a2e73f56fa62 ("drm/amdgpu: Add support for CIK parts") Fixes: 62a37553414a ("drm/amdgpu: add si implementation v10") Link: https://lore.kernel.org/r/20230717120503.15276-6-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Acked-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/cik.c | 36 +++++++++----------------------- drivers/gpu/drm/amd/amdgpu/si.c | 36 +++++++++----------------------- 2 files changed, 20 insertions(+), 52 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/cik.c b/drivers/gpu/drm/amd/amdgpu/cik.c index 35f9bcd17b1b2..7ff16edcda266 100644 --- a/drivers/gpu/drm/amd/amdgpu/cik.c +++ b/drivers/gpu/drm/amd/amdgpu/cik.c @@ -1421,17 +1421,8 @@ static void cik_pcie_gen3_enable(struct amdgpu_device *adev) u16 bridge_cfg2, gpu_cfg2; u32 max_lw, current_lw, tmp; - pcie_capability_read_word(root, PCI_EXP_LNKCTL, - &bridge_cfg); - pcie_capability_read_word(adev->pdev, PCI_EXP_LNKCTL, - &gpu_cfg); - - tmp16 = bridge_cfg | PCI_EXP_LNKCTL_HAWD; - pcie_capability_write_word(root, PCI_EXP_LNKCTL, tmp16); - - tmp16 = gpu_cfg | PCI_EXP_LNKCTL_HAWD; - pcie_capability_write_word(adev->pdev, PCI_EXP_LNKCTL, - tmp16); + pcie_capability_set_word(root, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_HAWD); + pcie_capability_set_word(adev->pdev, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_HAWD); tmp = RREG32_PCIE(ixPCIE_LC_STATUS1); max_lw = (tmp & PCIE_LC_STATUS1__LC_DETECTED_LINK_WIDTH_MASK) >> @@ -1484,21 +1475,14 @@ static void cik_pcie_gen3_enable(struct amdgpu_device *adev) msleep(100); /* linkctl */ - pcie_capability_read_word(root, PCI_EXP_LNKCTL, - &tmp16); - tmp16 &= ~PCI_EXP_LNKCTL_HAWD; - tmp16 |= (bridge_cfg & PCI_EXP_LNKCTL_HAWD); - pcie_capability_write_word(root, PCI_EXP_LNKCTL, - tmp16); - - pcie_capability_read_word(adev->pdev, - PCI_EXP_LNKCTL, - &tmp16); - tmp16 &= ~PCI_EXP_LNKCTL_HAWD; - tmp16 |= (gpu_cfg & PCI_EXP_LNKCTL_HAWD); - pcie_capability_write_word(adev->pdev, - PCI_EXP_LNKCTL, - tmp16); + pcie_capability_clear_and_set_word(root, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_HAWD, + bridge_cfg & + PCI_EXP_LNKCTL_HAWD); + pcie_capability_clear_and_set_word(adev->pdev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_HAWD, + gpu_cfg & + PCI_EXP_LNKCTL_HAWD); /* linkctl2 */ pcie_capability_read_word(root, PCI_EXP_LNKCTL2, diff --git a/drivers/gpu/drm/amd/amdgpu/si.c b/drivers/gpu/drm/amd/amdgpu/si.c index c6516f82f29c8..580d74f26b69f 100644 --- a/drivers/gpu/drm/amd/amdgpu/si.c +++ b/drivers/gpu/drm/amd/amdgpu/si.c @@ -1601,17 +1601,8 @@ static void si_pcie_gen3_enable(struct amdgpu_device *adev) u16 bridge_cfg2, gpu_cfg2; u32 max_lw, current_lw, tmp; - pcie_capability_read_word(root, PCI_EXP_LNKCTL, - &bridge_cfg); - pcie_capability_read_word(adev->pdev, PCI_EXP_LNKCTL, - &gpu_cfg); - - tmp16 = bridge_cfg | PCI_EXP_LNKCTL_HAWD; - pcie_capability_write_word(root, PCI_EXP_LNKCTL, tmp16); - - tmp16 = gpu_cfg | PCI_EXP_LNKCTL_HAWD; - pcie_capability_write_word(adev->pdev, PCI_EXP_LNKCTL, - tmp16); + pcie_capability_set_word(root, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_HAWD); + pcie_capability_set_word(adev->pdev, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_HAWD); tmp = RREG32_PCIE(PCIE_LC_STATUS1); max_lw = (tmp & LC_DETECTED_LINK_WIDTH_MASK) >> LC_DETECTED_LINK_WIDTH_SHIFT; @@ -1656,21 +1647,14 @@ static void si_pcie_gen3_enable(struct amdgpu_device *adev) mdelay(100); - pcie_capability_read_word(root, PCI_EXP_LNKCTL, - &tmp16); - tmp16 &= ~PCI_EXP_LNKCTL_HAWD; - tmp16 |= (bridge_cfg & PCI_EXP_LNKCTL_HAWD); - pcie_capability_write_word(root, PCI_EXP_LNKCTL, - tmp16); - - pcie_capability_read_word(adev->pdev, - PCI_EXP_LNKCTL, - &tmp16); - tmp16 &= ~PCI_EXP_LNKCTL_HAWD; - tmp16 |= (gpu_cfg & PCI_EXP_LNKCTL_HAWD); - pcie_capability_write_word(adev->pdev, - PCI_EXP_LNKCTL, - tmp16); + pcie_capability_clear_and_set_word(root, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_HAWD, + bridge_cfg & + PCI_EXP_LNKCTL_HAWD); + pcie_capability_clear_and_set_word(adev->pdev, PCI_EXP_LNKCTL, + PCI_EXP_LNKCTL_HAWD, + gpu_cfg & + PCI_EXP_LNKCTL_HAWD); pcie_capability_read_word(root, PCI_EXP_LNKCTL2, &tmp16); -- 2.40.1