[PATCH v2 2/2] PCI: Use ioremap(), not phys_to_virt() for platform ROM
Mikel Rychliski
mikel at mikelr.com
Thu Mar 5 03:41:26 UTC 2020
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 using ioremap() instead of phys_to_virt() in
pci_platform_rom().
Now that pci_platform_rom() creates a new mapping to access the ROM
image, update all callers to remove this mapping after extracting the
BIOS.
Signed-off-by: Mikel Rychliski <mikel at mikelr.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c | 1 +
drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c | 11 ++++++++++-
drivers/gpu/drm/radeon/radeon_bios.c | 1 +
drivers/pci/rom.c | 9 ++++++---
4 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
index 50dff69a0f6e..ea6a1fa98ad9 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_bios.c
@@ -207,6 +207,7 @@ static bool amdgpu_read_platform_bios(struct amdgpu_device *adev)
return false;
memcpy_fromio(adev->bios, bios, size);
+ iounmap(bios);
if (!check_atom_bios(adev->bios, size)) {
kfree(adev->bios);
diff --git a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c
index 9b91da09dc5f..8a60a0db7b14 100644
--- a/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c
+++ b/drivers/gpu/drm/nouveau/nvkm/subdev/bios/shadowpci.c
@@ -111,11 +111,20 @@ 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 c3ae4c92a115..712b88d88957 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -123,6 +123,7 @@ static bool radeon_read_platform_bios(struct radeon_device *rdev)
return false;
memcpy_fromio(rdev->bios, bios, size);
+ iounmap(bios);
if (size == 0 || rdev->bios[0] != 0x55 || rdev->bios[1] != 0xaa) {
kfree(rdev->bios);
diff --git a/drivers/pci/rom.c b/drivers/pci/rom.c
index 137bf0cee897..b38257d23e6e 100644
--- a/drivers/pci/rom.c
+++ b/drivers/pci/rom.c
@@ -197,16 +197,19 @@ void pci_unmap_rom(struct pci_dev *pdev, void __iomem *rom)
EXPORT_SYMBOL(pci_unmap_rom);
/**
- * pci_platform_rom - provides a pointer to any ROM image provided by the
- * platform
+ * pci_platform_rom - ioremap() the ROM image provided by the platform
* @pdev: pointer to pci device struct
* @size: pointer to receive size of pci window over ROM
+ *
+ * Return: kernel virtual pointer to image of ROM
+ *
+ * The caller is responsible for removing the mapping with iounmap()
*/
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 ioremap(pdev->rom, pdev->romlen);
}
return NULL;
--
2.13.7
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