drm/nouveau/bios: fix shadowing of ACPI ROMs larger than 64KiB

Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

1 files changed, 10 insertions, 11 deletions

diff --git a/drivers/gpu/drm/nouveau/core/subdev/bios/base.c b/drivers/gpu/drm/nouveau/core/subdev/bios/base.c
index 2fbb6df697cd..dcb5c2befc92 100644
--- a/drivers/gpu/drm/nouveau/core/subdev/bios/base.c
+++ b/drivers/gpu/drm/nouveau/core/subdev/bios/base.c
@@ -185,23 +185,22 @@ static void
 nouveau_bios_shadow_acpi(struct nouveau_bios *bios)
 {
         struct pci_dev *pdev = nv_device(bios)->pdev;
-        int cnt = 65536 / 4096;
-        int ret;
+        int ret, cnt, i;
+        u8  data[3];
 
         if (!nouveau_acpi_rom_supported(pdev))
                 return;
 
-        bios->data = kmalloc(65536, GFP_KERNEL);
         bios->size = 0;
-        if (!bios->data)
-                return;
-
-        while (cnt--) {
-                ret = nouveau_acpi_get_bios_chunk(bios->data, bios->size, 4096);
-                if (ret != 4096)
-                        return;
+        if (nouveau_acpi_get_bios_chunk(data, 0, 3) == 3)
+                bios->size = data[2] * 512;
 
-                bios->size += 4096;
+        bios->data = kmalloc(bios->size, GFP_KERNEL);
+        for (i = 0; bios->data && i < bios->size; i += cnt) {
+                cnt = min((bios->size - i), (u32)4096);
+                ret = nouveau_acpi_get_bios_chunk(bios->data, i, cnt);
+                if (ret != cnt)
+                        break;
         }
 }