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Code Issues Releases Wiki Activity

drm/amdgpu: Use RMW accessors for changing LNKCTL

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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 <lukas@wunner.de>
Fixes: a2e73f56fa ("drm/amdgpu: Add support for CIK parts")
Fixes: 62a3755341 ("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 <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
This commit is contained in:
Ilpo Järvinen 2023-07-17 15:04:57 +03:00 committed by Bjorn Helgaas
parent e09060b3b6
commit ce7d88110b
2 changed files with 20 additions and 52 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

36
drivers/gpu/drm/amd/amdgpu/cik.c
View File

@ -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,

36
drivers/gpu/drm/amd/amdgpu/si.c
View File

@ -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);