From 7189576e8a829130192b33c5b64e8a475369c776 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ilpo=20J=C3=A4rvinen?= Date: Mon, 17 Jul 2023 15:04:58 +0300 Subject: [PATCH] drm/radeon: Use RMW accessors for changing LNKCTL MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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: 8a7cd27679d0 ("drm/radeon/cik: add support for pcie gen1/2/3 switching") Fixes: b9d305dfb66c ("drm/radeon: implement pcie gen2/3 support for SI") Link: https://lore.kernel.org/r/20230717120503.15276-7-ilpo.jarvinen@linux.intel.com Signed-off-by: Ilpo Järvinen Signed-off-by: Bjorn Helgaas Acked-by: Alex Deucher --- 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 5819737c..a6f3c81 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 8d5e4b2..a910124 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, -- 2.7.4