[PATCH v3] PCI: Use ioremap(), not phys_to_virt() for platform ROM
Deucher, Alexander
Alexander.Deucher at amd.com
Mon Mar 30 13:54:33 UTC 2020
[AMD Public Use]
> -----Original Message-----
> From: Bjorn Helgaas <helgaas at kernel.org>
> Sent: Saturday, March 28, 2020 4:19 PM
> To: Mikel Rychliski <mikel at mikelr.com>
> Cc: amd-gfx at lists.freedesktop.org; linux-pci at vger.kernel.org;
> nouveau at lists.freedesktop.org; Deucher, Alexander
> <Alexander.Deucher at amd.com>; Koenig, Christian
> <Christian.Koenig at amd.com>; Zhou, David(ChunMing)
> <David1.Zhou at amd.com>; Matthew Garrett
> <matthewgarrett at google.com>; Ben Skeggs <bskeggs at redhat.com>;
> Christoph Hellwig <hch at lst.de>
> Subject: Re: [PATCH v3] PCI: Use ioremap(), not phys_to_virt() for platform
> ROM
>
> On Wed, Mar 18, 2020 at 10:16:23PM -0400, Mikel Rychliski wrote:
> > On some EFI systems, the video BIOS is provided by the EFI firmware.
> > The boot stub code stores the physical address of the ROM image in pdev-
> >rom.
> > Currently we attempt to access this pointer using phys_to_virt(),
> > which doesn't work with CONFIG_HIGHMEM.
> >
> > On these systems, attempting to load the radeon module on a x86_32
> > kernel can result in the following:
> >
> > BUG: unable to handle page fault for address: 3e8ed03c
> > #PF: supervisor read access in kernel mode
> > #PF: error_code(0x0000) - not-present page
> > *pde = 00000000
> > Oops: 0000 [#1] PREEMPT SMP
> > CPU: 0 PID: 317 Comm: systemd-udevd Not tainted 5.6.0-rc3-next-
> 20200228 #2
> > Hardware name: Apple Computer, Inc. MacPro1,1/Mac-F4208DC8, BIOS
> MP11.88Z.005C.B08.0707021221 07/02/07
> > EIP: radeon_get_bios+0x5ed/0xe50 [radeon]
> > Code: 00 00 84 c0 0f 85 12 fd ff ff c7 87 64 01 00 00 00 00 00 00 8b 47 08 8b
> 55 b0 e8 1e 83 e1 d6 85 c0 74 1a 8b 55 c0 85 d2 74 13 <80> 38 55 75 0e 80 78 01
> aa 0f 84 a4 03 00 00 8d 74 26 00 68 dc 06
> > EAX: 3e8ed03c EBX: 00000000 ECX: 3e8ed03c EDX: 00010000
> > ESI: 00040000 EDI: eec04000 EBP: eef3fc60 ESP: eef3fbe0
> > DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068 EFLAGS: 00010206
> > CR0: 80050033 CR2: 3e8ed03c CR3: 2ec77000 CR4: 000006d0
> > Call Trace:
> > ? register_client+0x34/0xe0
> > ? register_client+0xab/0xe0
> > r520_init+0x26/0x240 [radeon]
> > radeon_device_init+0x533/0xa50 [radeon]
> > radeon_driver_load_kms+0x80/0x220 [radeon]
> > drm_dev_register+0xa7/0x180 [drm]
> > radeon_pci_probe+0x10f/0x1a0 [radeon]
> > pci_device_probe+0xd4/0x140
> > really_probe+0x13d/0x3b0
> > driver_probe_device+0x56/0xd0
> > device_driver_attach+0x49/0x50
> > __driver_attach+0x79/0x130
> > ? device_driver_attach+0x50/0x50
> > bus_for_each_dev+0x5b/0xa0
> > driver_attach+0x19/0x20
> > ? device_driver_attach+0x50/0x50
> > bus_add_driver+0x117/0x1d0
> > ? pci_bus_num_vf+0x20/0x20
> > driver_register+0x66/0xb0
> > ? 0xf80f4000
> > __pci_register_driver+0x3d/0x40
> > radeon_init+0x82/0x1000 [radeon]
> > do_one_initcall+0x42/0x200
> > ? kvfree+0x25/0x30
> > ? __vunmap+0x206/0x230
> > ? kmem_cache_alloc_trace+0x16f/0x220
> > ? do_init_module+0x21/0x220
> > do_init_module+0x50/0x220
> > load_module+0x1f26/0x2200
> > sys_init_module+0x12d/0x160
> > do_fast_syscall_32+0x82/0x250
> > entry_SYSENTER_32+0xa5/0xf8
> >
> > Fix the issue by updating all drivers which can access a platform
> > provided ROM. Instead of calling the helper function
> > pci_platform_rom() which uses phys_to_virt(), call ioremap() directly on
> the pdev->rom.
> >
> > radeon_read_platform_bios() previously directly accessed an __iomem
> > pointer. Avoid this by calling memcpy_fromio() instead of kmemdup().
> >
> > pci_platform_rom() now has no remaining callers, so remove it.
> >
> > Signed-off-by: Mikel Rychliski <mikel at mikelr.com>
>
> I applied this to pci/resource for v5.7. I would feel better if some of the
> graphics guys chimed in, or even applied it via the DRM tree since most of the
> changes are actually in drivers/gpu.
Feel free to take it through the PCI tree. These areas of radeon and amdgpu don't really change much at all so, I'm not too concerned about a conflict.
Acked-by: Alex Deucher <alexander.deucher at amd.com>
>
> Feel free to add my
>
> Acked-by: Bjorn Helgaas <bhelgaas at google.com>
>
> and let me know if you do that.
>
> > ---
> >
> > Tested on a MacPro 1,1 with a Radeon X1900 XT card and 32-bit kernel.
> >
> > Changes in v3:
> > - Inline pci_platform_rom()
> >
> > Changes in v2:
> > - Add iounmap() call in nouveau
> > - Update function comment for pci_platform_rom()
> > - Minor changes to commit messages
> >
> > drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 31
> +++++++++++++---------
> > .../gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c | 17 ++++++++++-
> -
> > drivers/gpu/drm/radeon/radeon_bios.c | 30 +++++++++++++-------
> -
> > drivers/pci/rom.c | 17 ------------
> > include/linux/pci.h | 1 -
> > 5 files changed, 52 insertions(+), 44 deletions(-)
> >
> > diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
> > b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
> > index 50dff69a0f6e..b1172d93c99c 100644
> > --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
> > +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
> > @@ -192,30 +192,35 @@ static bool amdgpu_read_bios_from_rom(struct
> > amdgpu_device *adev)
> >
> > static bool amdgpu_read_platform_bios(struct amdgpu_device *adev) {
> > - uint8_t __iomem *bios;
> > - size_t size;
> > + phys_addr_t rom = adev->pdev->rom;
> > + size_t romlen = adev->pdev->romlen;
> > + void __iomem *bios;
> >
> > adev->bios = NULL;
> >
> > - bios = pci_platform_rom(adev->pdev, &size);
> > - if (!bios) {
> > + if (!rom || romlen == 0)
> > return false;
> > - }
> >
> > - adev->bios = kzalloc(size, GFP_KERNEL);
> > - if (adev->bios == NULL)
> > + adev->bios = kzalloc(romlen, GFP_KERNEL);
> > + if (!adev->bios)
> > return false;
> >
> > - memcpy_fromio(adev->bios, bios, size);
> > + bios = ioremap(rom, romlen);
> > + if (!bios)
> > + goto free_bios;
> >
> > - if (!check_atom_bios(adev->bios, size)) {
> > - kfree(adev->bios);
> > - return false;
> > - }
> > + memcpy_fromio(adev->bios, bios, romlen);
> > + iounmap(bios);
> >
> > - adev->bios_size = size;
> > + if (!check_atom_bios(adev->bios, romlen))
> > + goto free_bios;
> > +
> > + adev->bios_size = romlen;
> >
> > return true;
> > +free_bios:
> > + kfree(adev->bios);
> > + return false;
> > }
> >
> > #ifdef CONFIG_ACPI
> > diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c
> > b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c
> > index 9b91da09dc5f..8d9812a51ef6 100644
> > --- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c
> > +++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c
> > @@ -101,9 +101,13 @@ platform_init(struct nvkm_bios *bios, const char
> *name)
> > else
> > return ERR_PTR(-ENODEV);
> >
> > + if (!pdev->rom || pdev->romlen == 0)
> > + return ERR_PTR(-ENODEV);
> > +
> > if ((priv = kmalloc(sizeof(*priv), GFP_KERNEL))) {
> > + priv->size = pdev->romlen;
> > if (ret = -ENODEV,
> > - (priv->rom = pci_platform_rom(pdev, &priv->size)))
> > + (priv->rom = ioremap(pdev->rom, pdev->romlen)))
> > return priv;
> > kfree(priv);
> > }
> > @@ -111,11 +115,20 @@ platform_init(struct nvkm_bios *bios, const char
> *name)
> > return ERR_PTR(ret);
> > }
> >
> > +static void
> > +platform_fini(void *data)
> > +{
> > + struct priv *priv = data;
> > +
> > + iounmap(priv->rom);
> > + kfree(priv);
> > +}
> > +
> > const struct nvbios_source
> > nvbios_platform = {
> > .name = "PLATFORM",
> > .init = platform_init,
> > - .fini = (void(*)(void *))kfree,
> > + .fini = platform_fini,
> > .read = pcirom_read,
> > .rw = true,
> > };
> > diff --git a/drivers/gpu/drm/radeon/radeon_bios.c
> > b/drivers/gpu/drm/radeon/radeon_bios.c
> > index c42f73fad3e3..bb29cf02974d 100644
> > --- a/drivers/gpu/drm/radeon/radeon_bios.c
> > +++ b/drivers/gpu/drm/radeon/radeon_bios.c
> > @@ -108,25 +108,33 @@ static bool radeon_read_bios(struct
> > radeon_device *rdev)
> >
> > static bool radeon_read_platform_bios(struct radeon_device *rdev) {
> > - uint8_t __iomem *bios;
> > - size_t size;
> > + phys_addr_t rom = rdev->pdev->rom;
> > + size_t romlen = rdev->pdev->romlen;
> > + void __iomem *bios;
> >
> > rdev->bios = NULL;
> >
> > - bios = pci_platform_rom(rdev->pdev, &size);
> > - if (!bios) {
> > + if (!rom || romlen == 0)
> > return false;
> > - }
> >
> > - if (size == 0 || bios[0] != 0x55 || bios[1] != 0xaa) {
> > + rdev->bios = kzalloc(romlen, GFP_KERNEL);
> > + if (!rdev->bios)
> > return false;
> > - }
> > - rdev->bios = kmemdup(bios, size, GFP_KERNEL);
> > - if (rdev->bios == NULL) {
> > - return false;
> > - }
> > +
> > + bios = ioremap(rom, romlen);
> > + if (!bios)
> > + goto free_bios;
> > +
> > + memcpy_fromio(rdev->bios, bios, romlen);
> > + iounmap(bios);
> > +
> > + if (rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa)
> > + goto free_bios;
> >
> > return true;
> > +free_bios:
> > + kfree(rdev->bios);
> > + return false;
> > }
> >
> > #ifdef CONFIG_ACPI
> > diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c index
> > 137bf0cee897..8fc9a4e911e3 100644
> > --- a/drivers/pci/rom.c
> > +++ b/drivers/pci/rom.c
> > @@ -195,20 +195,3 @@ void pci_unmap_rom(struct pci_dev *pdev, void
> __iomem *rom)
> > pci_disable_rom(pdev);
> > }
> > EXPORT_SYMBOL(pci_unmap_rom);
> > -
> > -/**
> > - * pci_platform_rom - provides a pointer to any ROM image provided by
> > the
> > - * platform
> > - * @pdev: pointer to pci device struct
> > - * @size: pointer to receive size of pci window over ROM
> > - */
> > -void __iomem *pci_platform_rom(struct pci_dev *pdev, size_t *size) -{
> > - if (pdev->rom && pdev->romlen) {
> > - *size = pdev->romlen;
> > - return phys_to_virt((phys_addr_t)pdev->rom);
> > - }
> > -
> > - return NULL;
> > -}
> > -EXPORT_SYMBOL(pci_platform_rom);
> > diff --git a/include/linux/pci.h b/include/linux/pci.h index
> > 3840a541a9de..7268dcf1f23e 100644
> > --- a/include/linux/pci.h
> > +++ b/include/linux/pci.h
> > @@ -1214,7 +1214,6 @@ int pci_enable_rom(struct pci_dev *pdev); void
> > pci_disable_rom(struct pci_dev *pdev); void __iomem __must_check
> > *pci_map_rom(struct pci_dev *pdev, size_t *size); void
> > pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom); -void
> __iomem
> > __must_check *pci_platform_rom(struct pci_dev *pdev, size_t *size);
> >
> > /* Power management related routines */ int pci_save_state(struct
> > pci_dev *dev);
> > --
> > 2.13.7
> >
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