From: Sam Bobroff sbobroff@linux.ibm.com
[ Upstream commit 62d91dd2851e8ae2ca552f1b090a3575a4edf759 ]
The INTERRUPT_CNTL2 register expects a valid DMA address, but is currently set with a GPU MC address. This can cause problems on systems that detect the resulting DMA read from an invalid address (found on a Power8 guest).
Instead, use the DMA address of the dummy page because it will always be safe.
Fixes: d8f60cfc9345 ("drm/radeon/kms: Add support for interrupts on r6xx/r7xx chips (v3)") Fixes: 25a857fbe973 ("drm/radeon/kms: add support for interrupts on SI") Fixes: a59781bbe528 ("drm/radeon: add support for interrupts on CIK (v5)") Signed-off-by: Sam Bobroff sbobroff@linux.ibm.com Signed-off-by: Alex Deucher alexander.deucher@amd.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/radeon/cik.c | 4 ++-- drivers/gpu/drm/radeon/r600.c | 4 ++-- drivers/gpu/drm/radeon/si.c | 4 ++-- 3 files changed, 6 insertions(+), 6 deletions(-)
diff --git a/drivers/gpu/drm/radeon/cik.c b/drivers/gpu/drm/radeon/cik.c index b99f3e59011c..5fcb5869a489 100644 --- a/drivers/gpu/drm/radeon/cik.c +++ b/drivers/gpu/drm/radeon/cik.c @@ -7026,8 +7026,8 @@ static int cik_irq_init(struct radeon_device *rdev) }
/* setup interrupt control */ - /* XXX this should actually be a bus address, not an MC address. same on older asics */ - WREG32(INTERRUPT_CNTL2, rdev->ih.gpu_addr >> 8); + /* set dummy read address to dummy page address */ + WREG32(INTERRUPT_CNTL2, rdev->dummy_page.addr >> 8); interrupt_cntl = RREG32(INTERRUPT_CNTL); /* IH_DUMMY_RD_OVERRIDE=0 - dummy read disabled with msi, enabled without msi * IH_DUMMY_RD_OVERRIDE=1 - dummy read controlled by IH_DUMMY_RD_EN diff --git a/drivers/gpu/drm/radeon/r600.c b/drivers/gpu/drm/radeon/r600.c index f2eac6b6c46a..9569c35f8766 100644 --- a/drivers/gpu/drm/radeon/r600.c +++ b/drivers/gpu/drm/radeon/r600.c @@ -3697,8 +3697,8 @@ int r600_irq_init(struct radeon_device *rdev) }
/* setup interrupt control */ - /* set dummy read address to ring address */ - WREG32(INTERRUPT_CNTL2, rdev->ih.gpu_addr >> 8); + /* set dummy read address to dummy page address */ + WREG32(INTERRUPT_CNTL2, rdev->dummy_page.addr >> 8); interrupt_cntl = RREG32(INTERRUPT_CNTL); /* IH_DUMMY_RD_OVERRIDE=0 - dummy read disabled with msi, enabled without msi * IH_DUMMY_RD_OVERRIDE=1 - dummy read controlled by IH_DUMMY_RD_EN diff --git a/drivers/gpu/drm/radeon/si.c b/drivers/gpu/drm/radeon/si.c index b75d809c292e..919d389869ce 100644 --- a/drivers/gpu/drm/radeon/si.c +++ b/drivers/gpu/drm/radeon/si.c @@ -6018,8 +6018,8 @@ static int si_irq_init(struct radeon_device *rdev) }
/* setup interrupt control */ - /* set dummy read address to ring address */ - WREG32(INTERRUPT_CNTL2, rdev->ih.gpu_addr >> 8); + /* set dummy read address to dummy page address */ + WREG32(INTERRUPT_CNTL2, rdev->dummy_page.addr >> 8); interrupt_cntl = RREG32(INTERRUPT_CNTL); /* IH_DUMMY_RD_OVERRIDE=0 - dummy read disabled with msi, enabled without msi * IH_DUMMY_RD_OVERRIDE=1 - dummy read controlled by IH_DUMMY_RD_EN