drm/radeon: split ATRM support out from the ATPX handler (v3)

There are systems that use ATRM, but not ATPX.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=41265

V2: fix #ifdefs as per Greg's comments
V3: fix it harder

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org

1 files changed, 76 insertions, 4 deletions

diff --git a/drivers/gpu/drm/radeon/radeon_bios.c b/drivers/gpu/drm/radeon/radeon_bios.c
index ab0b2f7292ae..d306cc8fdeaa 100644
--- a/drivers/gpu/drm/radeon/radeon_bios.c
+++ b/drivers/gpu/drm/radeon/radeon_bios.c
@@ -99,16 +99,81 @@ static bool radeon_read_bios(struct radeon_device *rdev)
 	return true;
 }
 
+#ifdef CONFIG_ACPI
 /* ATRM is used to get the BIOS on the discrete cards in
  * dual-gpu systems.
  */
+/* retrieve the ROM in 4k blocks */
+#define ATRM_BIOS_PAGE 4096
+/**
+ * radeon_atrm_call - fetch a chunk of the vbios
+ *
+ * @atrm_handle: acpi ATRM handle
+ * @bios: vbios image pointer
+ * @offset: offset of vbios image data to fetch
+ * @len: length of vbios image data to fetch
+ *
+ * Executes ATRM to fetch a chunk of the discrete
+ * vbios image on PX systems (all asics).
+ * Returns the length of the buffer fetched.
+ */
+static int radeon_atrm_call(acpi_handle atrm_handle, uint8_t *bios,
+			    int offset, int len)
+{
+	acpi_status status;
+	union acpi_object atrm_arg_elements[2], *obj;
+	struct acpi_object_list atrm_arg;
+	struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL};
+
+	atrm_arg.count = 2;
+	atrm_arg.pointer = &atrm_arg_elements[0];
+
+	atrm_arg_elements[0].type = ACPI_TYPE_INTEGER;
+	atrm_arg_elements[0].integer.value = offset;
+
+	atrm_arg_elements[1].type = ACPI_TYPE_INTEGER;
+	atrm_arg_elements[1].integer.value = len;
+
+	status = acpi_evaluate_object(atrm_handle, NULL, &atrm_arg, &buffer);
+	if (ACPI_FAILURE(status)) {
+		printk("failed to evaluate ATRM got %s\n", acpi_format_exception(status));
+		return -ENODEV;
+	}
+
+	obj = (union acpi_object *)buffer.pointer;
+	memcpy(bios+offset, obj->buffer.pointer, obj->buffer.length);
+	len = obj->buffer.length;
+	kfree(buffer.pointer);
+	return len;
+}
+
 static bool radeon_atrm_get_bios(struct radeon_device *rdev)
 {
 	int ret;
 	int size = 256 * 1024;
 	int i;
+	struct pci_dev *pdev = NULL;
+	acpi_handle dhandle, atrm_handle;
+	acpi_status status;
+	bool found = false;
 
-	if (!radeon_atrm_supported(rdev->pdev))
+	/* ATRM is for the discrete card only */
+	if (rdev->flags & RADEON_IS_IGP)
+		return false;
+
+	while ((pdev = pci_get_class(PCI_CLASS_DISPLAY_VGA << 8, pdev)) != NULL) {
+		dhandle = DEVICE_ACPI_HANDLE(&pdev->dev);
+		if (!dhandle)
+			continue;
+
+		status = acpi_get_handle(dhandle, "ATRM", &atrm_handle);
+		if (!ACPI_FAILURE(status)) {
+			found = true;
+			break;
+		}
+	}
+
+	if (!found)
 		return false;
 
 	rdev->bios = kmalloc(size, GFP_KERNEL);
@@ -118,9 +183,10 @@ static bool radeon_atrm_get_bios(struct radeon_device *rdev)
 	}
 
 	for (i = 0; i < size / ATRM_BIOS_PAGE; i++) {
-		ret = radeon_atrm_get_bios_chunk(rdev->bios,
-						 (i * ATRM_BIOS_PAGE),
-						 ATRM_BIOS_PAGE);
+		ret = radeon_atrm_call(atrm_handle,
+				       rdev->bios,
+				       (i * ATRM_BIOS_PAGE),
+				       ATRM_BIOS_PAGE);
 		if (ret < ATRM_BIOS_PAGE)
 			break;
 	}
@@ -131,6 +197,12 @@ static bool radeon_atrm_get_bios(struct radeon_device *rdev)
 	}
 	return true;
 }
+#else
+static inline bool radeon_atrm_get_bios(struct radeon_device *rdev)
+{
+	return false;
+}
+#endif
 
 static bool ni_read_disabled_bios(struct radeon_device *rdev)
 {