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From: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
To: linux-pci@vger.kernel.org, "Bjorn Helgaas" <bhelgaas@google.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Emmanuel Grumbach" <emmanuel.grumbach@intel.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	"Heiner Kallweit" <hkallweit1@gmail.com>,
	"Lukas Wunner" <lukas@wunner.de>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"Pan, Xinhui" <Xinhui.Pan@amd.com>,
	"David Airlie" <airlied@gmail.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Jammy Zhou" <Jammy.Zhou@amd.com>,
	"Ken Wang" <Qingqing.Wang@amd.com>,
	amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Cc: "Dean Luick" <dean.luick@cornelisnetworks.com>,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
	stable@vger.kernel.org
Subject: [PATCH v2 4/9] drm/amdgpu: Use RMW accessors for changing LNKCTL
Date: Wed, 17 May 2023 13:52:30 +0300	[thread overview]
Message-ID: <20230517105235.29176-5-ilpo.jarvinen@linux.intel.com> (raw)
In-Reply-To: <20230517105235.29176-1-ilpo.jarvinen@linux.intel.com>

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.

Fixes: a2e73f56fa62 ("drm/amdgpu: Add support for CIK parts")
Fixes: 62a37553414a ("drm/amdgpu: add si implementation v10")
Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: stable@vger.kernel.org
---
 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 de6d10390ab2..9be6da37032a 100644
--- a/drivers/gpu/drm/amd/amdgpu/cik.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik.c
@@ -1574,17 +1574,8 @@ 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) >>
@@ -1637,21 +1628,14 @@ 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 7f99e130acd0..fd34c2100bd9 100644
--- a/drivers/gpu/drm/amd/amdgpu/si.c
+++ b/drivers/gpu/drm/amd/amdgpu/si.c
@@ -2276,17 +2276,8 @@ 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;
@@ -2331,21 +2322,14 @@ 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);
-- 
2.30.2


WARNING: multiple messages have this Message-ID (diff)
From: "Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>
To: linux-pci@vger.kernel.org, "Bjorn Helgaas" <bhelgaas@google.com>,
	"Lorenzo Pieralisi" <lorenzo.pieralisi@arm.com>,
	"Rob Herring" <robh@kernel.org>,
	"Krzysztof Wilczyński" <kw@linux.com>,
	"Emmanuel Grumbach" <emmanuel.grumbach@intel.com>,
	"Rafael J . Wysocki" <rafael@kernel.org>,
	"Heiner Kallweit" <hkallweit1@gmail.com>,
	"Lukas Wunner" <lukas@wunner.de>,
	"Alex Deucher" <alexander.deucher@amd.com>,
	"Christian König" <christian.koenig@amd.com>,
	"Pan, Xinhui" <Xinhui.Pan@amd.com>,
	"David Airlie" <airlied@gmail.com>,
	"Daniel Vetter" <daniel@ffwll.ch>,
	"Jammy Zhou" <Jammy.Zhou@amd.com>,
	"Ken Wang" <Qingqing.Wang@amd.com>,
	amd-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org,
	linux-kernel@vger.kernel.org
Cc: "Dean Luick" <dean.luick@cornelisnetworks.com>,
	"Ilpo Järvinen" <ilpo.jarvinen@linux.intel.com>,
	"Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
	stable@vger.kernel.org
Subject: [PATCH v2 4/9] drm/amdgpu: Use RMW accessors for changing LNKCTL
Date: Wed, 17 May 2023 13:52:30 +0300	[thread overview]
Message-ID: <20230517105235.29176-5-ilpo.jarvinen@linux.intel.com> (raw)
In-Reply-To: <20230517105235.29176-1-ilpo.jarvinen@linux.intel.com>

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.

Fixes: a2e73f56fa62 ("drm/amdgpu: Add support for CIK parts")
Fixes: 62a37553414a ("drm/amdgpu: add si implementation v10")
Suggested-by: Lukas Wunner <lukas@wunner.de>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Cc: stable@vger.kernel.org
---
 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 de6d10390ab2..9be6da37032a 100644
--- a/drivers/gpu/drm/amd/amdgpu/cik.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik.c
@@ -1574,17 +1574,8 @@ 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) >>
@@ -1637,21 +1628,14 @@ 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 7f99e130acd0..fd34c2100bd9 100644
--- a/drivers/gpu/drm/amd/amdgpu/si.c
+++ b/drivers/gpu/drm/amd/amdgpu/si.c
@@ -2276,17 +2276,8 @@ 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;
@@ -2331,21 +2322,14 @@ 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);
-- 
2.30.2


  parent reply	other threads:[~2023-05-17 10:56 UTC|newest]

Thread overview: 39+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-05-17 10:52 [PATCH v2 0/9] PCI: Improve PCIe Capability RMW concurrency control Ilpo Järvinen
2023-05-17 10:52 ` [PATCH v2 1/9] PCI: Add locking to RMW PCI Express Capability Register accessors Ilpo Järvinen
2023-05-17 11:32   ` Rafael J. Wysocki
2023-05-17 10:52 ` [PATCH v2 2/9] PCI: pciehp: Use RMW accessors for changing LNKCTL Ilpo Järvinen
2023-05-17 11:32   ` Rafael J. Wysocki
2023-05-17 10:52 ` [PATCH v2 3/9] PCI/ASPM: " Ilpo Järvinen
2023-05-17 11:33   ` Rafael J. Wysocki
2023-06-16 19:10   ` Lukas Wunner
2023-06-19 14:45     ` Ilpo Järvinen
2023-06-19 15:09       ` Bjorn Helgaas
2023-06-19 16:06         ` Ilpo Järvinen
2023-05-17 10:52 ` Ilpo Järvinen [this message]
2023-05-17 10:52   ` [PATCH v2 4/9] drm/amdgpu: " Ilpo Järvinen
2023-05-17 10:52 ` [PATCH v2 5/9] drm/radeon: " Ilpo Järvinen
2023-05-17 10:52   ` Ilpo Järvinen
2023-05-17 10:52 ` [PATCH v2 6/9] net/mlx5: " Ilpo Järvinen
2023-05-17 11:18   ` Moshe Shemesh
2023-05-17 10:52 ` [PATCH v2 7/9] wifi: ath11k: " Ilpo Järvinen
2023-05-17 10:52   ` Ilpo Järvinen
2023-05-17 11:04   ` Kalle Valo
2023-05-17 11:04     ` Kalle Valo
2023-05-17 10:52 ` [PATCH v2 8/9] wifi: ath12k: " Ilpo Järvinen
2023-05-17 10:52   ` Ilpo Järvinen
2023-05-17 11:03   ` Kalle Valo
2023-05-17 11:03     ` Kalle Valo
2023-05-17 10:52 ` [PATCH v2 9/9] wifi: ath10k: " Ilpo Järvinen
2023-05-17 10:52   ` Ilpo Järvinen
2023-05-17 11:05   ` Kalle Valo
2023-05-17 11:05     ` Kalle Valo
2023-05-24 15:10   ` Bjorn Helgaas
2023-05-24 15:10     ` Bjorn Helgaas
2023-05-25 10:11     ` Ilpo Järvinen
2023-05-25 10:11       ` Ilpo Järvinen
2023-05-26 11:48       ` Ilpo Järvinen
2023-05-26 11:48         ` Ilpo Järvinen
2023-05-26 22:26         ` Bjorn Helgaas
2023-05-26 22:26           ` Bjorn Helgaas
2023-05-26 22:20       ` Bjorn Helgaas
2023-05-26 22:20         ` Bjorn Helgaas

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