1 files changed, 111 insertions, 0 deletions
diff --git a/drivers/gpu/drm/nouveau/core/subdev/bios/shadowacpi.c b/drivers/gpu/drm/nouveau/core/subdev/bios/shadowacpi.c
new file mode 100644
index 000000000000..bc130c12ec06
--- /dev/null
+++ b/drivers/gpu/drm/nouveau/core/subdev/bios/shadowacpi.c
@@ -0,0 +1,111 @@
+/*
+ * Copyright 2012 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ */
+
+#include "priv.h"
+
+#if defined(CONFIG_ACPI) && defined(CONFIG_X86)
+int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len);
+bool nouveau_acpi_rom_supported(struct pci_dev *pdev);
+#else
+static inline bool
+nouveau_acpi_rom_supported(struct pci_dev *pdev)
+{
+	return false;
+}
+
+static inline int
+nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len)
+{
+	return -EINVAL;
+}
+#endif
+
+/* This version of the shadow function disobeys the ACPI spec and tries
+ * to fetch in units of more than 4KiB at a time.  This is a LOT faster
+ * on some systems, such as Lenovo W530.
+ */
+static u32
+acpi_read_fast(void *data, u32 offset, u32 length, struct nouveau_bios *bios)
+{
+	u32 limit = (offset + length + 0xfff) & ~0xfff;
+	u32 start = offset & ~0x00000fff;
+	u32 fetch = limit - start;
+
+	if (nvbios_extend(bios, limit) > 0) {
+		int ret = nouveau_acpi_get_bios_chunk(bios->data, start, fetch);
+		if (ret == fetch)
+			return fetch;
+	}
+
+	return 0;
+}
+
+/* Other systems, such as the one in fdo#55948, will report a success
+ * but only return 4KiB of data.  The common bios fetching logic will
+ * detect an invalid image, and fall back to this version of the read
+ * function.
+ */
+static u32
+acpi_read_slow(void *data, u32 offset, u32 length, struct nouveau_bios *bios)
+{
+	u32 limit = (offset + length + 0xfff) & ~0xfff;
+	u32 start = offset & ~0xfff;
+	u32 fetch = 0;
+
+	if (nvbios_extend(bios, limit) > 0) {
+		while (start + fetch < limit) {
+			int ret = nouveau_acpi_get_bios_chunk(bios->data,
+							      start + fetch,
+							      0x1000);
+			if (ret != 0x1000)
+				break;
+			fetch += 0x1000;
+		}
+	}
+
+	return fetch;
+}
+
+static void *
+acpi_init(struct nouveau_bios *bios, const char *name)
+{
+	if (!nouveau_acpi_rom_supported(nv_device(bios)->pdev))
+		return ERR_PTR(-ENODEV);
+	return NULL;
+}
+
+const struct nvbios_source
+nvbios_acpi_fast = {
+	.name = "ACPI",
+	.init = acpi_init,
+	.read = acpi_read_fast,
+	.rw = false,
+};
+
+const struct nvbios_source
+nvbios_acpi_slow = {
+	.name = "ACPI",
+	.init = acpi_init,
+	.read = acpi_read_slow,
+	.rw = false,
+};