On Mon, Feb 24, 2020 at 9:46 PM Daniel Vetter daniel.vetter@ffwll.ch wrote:
On Mon, Feb 24, 2020 at 5:31 PM Emil Velikov emil.l.velikov@gmail.com wrote:
On Sat, 22 Feb 2020 at 17:54, Daniel Vetter daniel.vetter@ffwll.ch wrote:
It's the last user, and more importantly, it's the last non-legacy user of anything in drm_pci.c.
The only tricky bit is the agp initialization. But a close look shows that radeon does not use the drm_agp midlayer (the main use of that is drm_bufs for legacy drivers), and instead could use the agp subsystem directly (like nouveau does already). Hence we can just pull this in too.
A further step would be to entirely drop the use of drm_device->agp, but feels like too much churn just for this patch.
Signed-off-by: Daniel Vetter daniel.vetter@intel.com Cc: Alex Deucher alexander.deucher@amd.com Cc: "Christian König" christian.koenig@amd.com Cc: "David (ChunMing) Zhou" David1.Zhou@amd.com Cc: amd-gfx@lists.freedesktop.org
drivers/gpu/drm/radeon/radeon_drv.c | 43 +++++++++++++++++++++++++++-- drivers/gpu/drm/radeon/radeon_kms.c | 6 ++++ 2 files changed, 47 insertions(+), 2 deletions(-)
diff --git a/drivers/gpu/drm/radeon/radeon_drv.c b/drivers/gpu/drm/radeon/radeon_drv.c index 49ce2e7d5f9e..59f8186a2415 100644 --- a/drivers/gpu/drm/radeon/radeon_drv.c +++ b/drivers/gpu/drm/radeon/radeon_drv.c @@ -37,6 +37,7 @@ #include <linux/vga_switcheroo.h> #include <linux/mmu_notifier.h>
+#include <drm/drm_agpsupport.h> #include <drm/drm_crtc_helper.h> #include <drm/drm_drv.h> #include <drm/drm_fb_helper.h> @@ -322,6 +323,7 @@ static int radeon_pci_probe(struct pci_dev *pdev, const struct pci_device_id *ent) { unsigned long flags = 0;
struct drm_device *dev; int ret; if (!ent)@@ -362,7 +364,44 @@ static int radeon_pci_probe(struct pci_dev *pdev, if (ret) return ret;
return drm_get_pci_dev(pdev, ent, &kms_driver);
dev = drm_dev_alloc(&kms_driver, &pdev->dev);if (IS_ERR(dev))return PTR_ERR(dev);ret = pci_enable_device(pdev);if (ret)goto err_free;dev->pdev = pdev;+#ifdef __alpha__
dev->hose = pdev->sysdata;+#endif
pci_set_drvdata(pdev, dev);if (pci_find_capability(dev->pdev, PCI_CAP_ID_AGP))dev->agp = drm_agp_init(dev);if (dev->agp) {dev->agp->agp_mtrr = arch_phys_wc_add(dev->agp->agp_info.aper_base,dev->agp->agp_info.aper_size *1024 * 1024);}IMHO a better solution is kill off the drm_agpsupport.c dependency all together. As-is it's still used, making the legacy vs not line really moot.
Especially, since the AGP ioctl (in the legacy code) can manipulate the underlying state.
Off the top of my head, in radeon_agp_init():
- at the top agp_backend_acquire() + agp_copy_info()
- followed up by existing mode magic
- opencode the enable - agp_enable() + acquired = true;
- mtrr = arch_phys_wc_add() and the rest
In radeon_agp_fini()
- if !acquired { agp_backend_release(); acquired = false }
Something like ^^ should result in a net diffstat of around zero. All thanks to the interesting layer that drm_agp is ;-)
With this in place we can make move drm_device::agp and DRM_IOCTL_AGP_INFO behind CONFIG_DRM_LEGACY.
Yeah could be done, but I was more out to get the drm_pci.c stuff, not the agp stuff. But I did realize that nouveau also just directly accesses the agp bridge stuff, so we could indeed nuke the midlayer here. The legacy agp stuff ioctl stuff should be behind DRIVER_LEGACY checks already, so no way to cause harm that way (I hope at least, if there's a gap we'd need to close it).
Haha, I should read code before hitting send.
It's totally wide open root hole. I guess no one ever bothered to run a fuzzer on a radeon.ko or amdgpu.ko (before the patch to stop using drm_get_pci_dev at least) hw. And I never cared since we've killed the fake agp stuff that i915.ko used a long time ago.
So yeah I think at least sprinkling DRIVER_LEGACY checks over all this, and reviewing old radeon userspace, would be really good. Once we have that we can then do the second step and retire the agp midlayer. But first we need to add the uapi checks/changes. -Daniel