diff --git a/drivers/gpu/drm/i915/intel_bios.c b/drivers/gpu/drm/i915/intel_bios.c index 6e018ba5303564932d313eccbc98ab63e8fae1ce..198fc3c3291b2ac05540ea36ef853c9826b23efa 100644 --- a/drivers/gpu/drm/i915/intel_bios.c +++ b/drivers/gpu/drm/i915/intel_bios.c @@ -1199,15 +1199,22 @@ static const struct dmi_system_id intel_no_opregion_vbt[] = { { } }; -static const struct bdb_header *validate_vbt(const void *base, size_t size, - const void *_vbt, +static const struct bdb_header *validate_vbt(const void __iomem *_base, + size_t size, + const void __iomem *_vbt, const char *source) { - const struct vbt_header *vbt = _vbt; - size_t offset; + /* + * This is the one place where we explicitly discard the address space + * (__iomem) of the BIOS/VBT. (And this will cause a sparse complaint.) + * From now on everything is based on 'base', and treated as regular + * memory. + */ + const void *base = (const void *) _base; + size_t offset = _vbt - _base; + const struct vbt_header *vbt = base + offset; const struct bdb_header *bdb; - offset = _vbt - base; if (offset + sizeof(struct vbt_header) > size) { DRM_DEBUG_DRIVER("VBT header incomplete\n"); return NULL; @@ -1235,14 +1242,14 @@ static const struct bdb_header *validate_vbt(const void *base, size_t size, return bdb; } -static const struct bdb_header *find_vbt(void *bios, size_t size) +static const struct bdb_header *find_vbt(void __iomem *bios, size_t size) { const struct bdb_header *bdb = NULL; size_t i; /* Scour memory looking for the VBT signature. */ for (i = 0; i + 4 < size; i++) { - if (memcmp(bios + i, "$VBT", 4) == 0) { + if (ioread32(bios + i) == *((const u32 *) "$VBT")) { bdb = validate_vbt(bios, size, bios + i, "PCI ROM"); break; }