[PATCH AUTOSEL 5.6 149/149] PCI: Use ioremap(), not phys_to_virt() for platform ROM

Sasha Levin
2020-04-11T23:07:00Z

From: Mikel Rychliski <mikel@mikelr.com>

[ Upstream commit 72e0ef0e5f067fd991f702f0b2635d911d0cf208 ]

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:
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

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.

Link: https://lore.kernel.org/r/20200319021623.5426-1-mikel@mikelr.com
Signed-off-by: Mikel Rychliski <mikel@mikelr.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 31 +++++++++++--------
.../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 50dff69a0f6e3..b1172d93c99c3 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 9b91da09dc5f8..8d9812a51ef63 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 c42f73fad3e31..bb29cf02974d1 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 137bf0cee897c..8fc9a4e911e3a 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 3840a541a9de5..7268dcf1f23e9 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);
--
2.20.1