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>,
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 v3 06/10] drm/radeon: Use RMW accessors for changing LNKCTL
Date: Tue, 20 Jun 2023 16:46:20 +0300 [thread overview]
Message-ID: <20230620134624.99688-7-ilpo.jarvinen@linux.intel.com> (raw)
In-Reply-To: <20230620134624.99688-1-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: 8a7cd27679d0 ("drm/radeon/cik: add support for pcie gen1/2/3 switching")
Fixes: b9d305dfb66c ("drm/radeon: implement pcie gen2/3 support for SI")
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/radeon/cik.c | 36 ++++++++++-------------------------
drivers/gpu/drm/radeon/si.c | 37 ++++++++++--------------------------
2 files changed, 20 insertions(+), 53 deletions(-)
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c
index 5819737c21c6..a6f3c811ceb8 100644
--- a/drivers/gpu/drm/radeon/cik.c
+++ b/drivers/gpu/drm/radeon/cik.c
@@ -9534,17 +9534,8 @@ static void cik_pcie_gen3_enable(struct radeon_device *rdev)
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(rdev->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(rdev->pdev, PCI_EXP_LNKCTL,
- tmp16);
+ pcie_capability_set_word(root, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_HAWD);
+ pcie_capability_set_word(rdev->pdev, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_HAWD);
tmp = RREG32_PCIE_PORT(PCIE_LC_STATUS1);
max_lw = (tmp & LC_DETECTED_LINK_WIDTH_MASK) >> LC_DETECTED_LINK_WIDTH_SHIFT;
@@ -9591,21 +9582,14 @@ static void cik_pcie_gen3_enable(struct radeon_device *rdev)
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(rdev->pdev,
- PCI_EXP_LNKCTL,
- &tmp16);
- tmp16 &= ~PCI_EXP_LNKCTL_HAWD;
- tmp16 |= (gpu_cfg & PCI_EXP_LNKCTL_HAWD);
- pcie_capability_write_word(rdev->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(rdev->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/radeon/si.c b/drivers/gpu/drm/radeon/si.c
index 8d5e4b25609d..a91012447b56 100644
--- a/drivers/gpu/drm/radeon/si.c
+++ b/drivers/gpu/drm/radeon/si.c
@@ -7131,17 +7131,8 @@ static void si_pcie_gen3_enable(struct radeon_device *rdev)
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(rdev->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(rdev->pdev, PCI_EXP_LNKCTL,
- tmp16);
+ pcie_capability_set_word(root, PCI_EXP_LNKCTL, PCI_EXP_LNKCTL_HAWD);
+ pcie_capability_set_word(rdev->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;
@@ -7188,22 +7179,14 @@ static void si_pcie_gen3_enable(struct radeon_device *rdev)
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(rdev->pdev,
- PCI_EXP_LNKCTL,
- &tmp16);
- tmp16 &= ~PCI_EXP_LNKCTL_HAWD;
- tmp16 |= (gpu_cfg & PCI_EXP_LNKCTL_HAWD);
- pcie_capability_write_word(rdev->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(rdev->pdev, PCI_EXP_LNKCTL,
+ PCI_EXP_LNKCTL_HAWD,
+ gpu_cfg &
+ PCI_EXP_LNKCTL_HAWD);
/* linkctl2 */
pcie_capability_read_word(root, PCI_EXP_LNKCTL2,
--
2.30.2
next prev parent reply other threads:[~2023-06-20 13:48 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-06-20 13:46 [PATCH v3 00/10] PCI: Improve PCIe Capability RMW concurrency control Ilpo Järvinen
2023-06-20 13:46 ` [PATCH v3 01/10] PCI: Add locking to RMW PCI Express Capability Register accessors Ilpo Järvinen
2023-06-20 13:46 ` [PATCH v3 02/10] PCI: Make link retraining use RMW accessors for changing LNKCTL Ilpo Järvinen
2023-06-20 13:46 ` [PATCH v3 03/10] PCI: pciehp: Use " Ilpo Järvinen
2023-06-20 13:46 ` [PATCH v3 04/10] PCI/ASPM: " Ilpo Järvinen
2023-06-20 13:46 ` [PATCH v3 05/10] drm/amdgpu: " Ilpo Järvinen
2023-06-20 13:46 ` Ilpo Järvinen [this message]
2023-06-20 13:46 ` [PATCH v3 07/10] net/mlx5: " Ilpo Järvinen
2023-06-21 14:46 ` Simon Horman
2023-06-20 13:46 ` [PATCH v3 08/10] wifi: ath11k: " Ilpo Järvinen
2023-06-21 14:47 ` Simon Horman
2023-06-20 13:46 ` [PATCH v3 09/10] wifi: ath12k: " Ilpo Järvinen
2023-06-21 14:47 ` Simon Horman
2023-06-20 13:46 ` [PATCH v3 10/10] wifi: ath10k: " Ilpo Järvinen
2023-06-21 14:46 ` Simon Horman
2023-06-20 14:11 ` [PATCH v3 00/10] PCI: Improve PCIe Capability RMW concurrency control Andy Shevchenko
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