linux-kernel - [PATCH 1/3] drm/msm: support firmware-name for zap fw

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Message-Id: <20200108013847.899170-2-robdclark@gmail.com>
Date:   Tue,  7 Jan 2020 17:38:42 -0800
From:   Rob Clark <robdclark@...il.com>
To:     dri-devel@...ts.freedesktop.org
Cc:     devicetree@...r.kernel.org, freedreno@...ts.freedesktop.org,
        linux-arm-msm@...r.kernel.org,
        Bjorn Andersson <bjorn.andersson@...aro.org>,
        Jordan Crouse <jcrouse@...eaurora.org>,
        Sharat Masetty <smasetty@...eaurora.org>,
        Rob Clark <robdclark@...omium.org>,
        Rob Clark <robdclark@...il.com>, Sean Paul <sean@...rly.run>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
        Douglas Anderson <dianders@...omium.org>,
        Brian Masney <masneyb@...tation.org>,
        Fabio Estevam <festevam@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>,
        linux-kernel@...r.kernel.org (open list)
Subject: [PATCH 1/3] drm/msm: support firmware-name for zap fw

From: Rob Clark <robdclark@...omium.org>

Since zap firmware can be device specific, allow for a firmware-name
property in the zap node to specify which firmware to load, similarly to
the scheme used for dsp/wifi/etc.

Signed-off-by: Rob Clark <robdclark@...omium.org>
---
 drivers/gpu/drm/msm/adreno/adreno_gpu.c | 32 ++++++++++++++++++++++---
 1 file changed, 29 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
index 112e8b8a261e..aa8737bd58db 100644
--- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
@@ -26,6 +26,7 @@ static int zap_shader_load_mdt(struct msm_gpu *gpu, const char *fwname,
 {
 	struct device *dev = &gpu->pdev->dev;
 	const struct firmware *fw;
+	const char *signed_fwname = NULL;
 	struct device_node *np, *mem_np;
 	struct resource r;
 	phys_addr_t mem_phys;
@@ -58,8 +59,33 @@ static int zap_shader_load_mdt(struct msm_gpu *gpu, const char *fwname,
 
 	mem_phys = r.start;
 
-	/* Request the MDT file for the firmware */
-	fw = adreno_request_fw(to_adreno_gpu(gpu), fwname);
+	/*
+	 * Check for a firmware-name property.  This is the new scheme
+	 * to handle firmware that may be signed with device specific
+	 * keys, allowing us to have a different zap fw path for different
+	 * devices.
+	 *
+	 * If the firmware-name property is found, we bypass the
+	 * adreno_request_fw() mechanism, because we don't need to handle
+	 * the /lib/firmware/qcom/* vs /lib/firmware/* case.
+	 *
+	 * If the firmware-name property is not found, for backwards
+	 * compatibility we fall back to the fwname from the gpulist
+	 * table.
+	 */
+	of_property_read_string_index(np, "firmware-name", 0, &signed_fwname);
+	if (signed_fwname) {
+		fwname = signed_fwname;
+		ret = request_firmware_direct(&fw, signed_fwname, gpu->dev->dev);
+		if (ret) {
+			DRM_DEV_ERROR(dev, "could not load signed zap firmware: %d\n", ret);
+			fw = ERR_PTR(ret);
+		}
+	} else {
+		/* Request the MDT file for the firmware */
+		fw = adreno_request_fw(to_adreno_gpu(gpu), fwname);
+	}
+
 	if (IS_ERR(fw)) {
 		DRM_DEV_ERROR(dev, "Unable to load %s\n", fwname);
 		return PTR_ERR(fw);
@@ -95,7 +121,7 @@ static int zap_shader_load_mdt(struct msm_gpu *gpu, const char *fwname,
 	 * not.  But since we've already gotten through adreno_request_fw()
 	 * we know which of the two cases it is:
 	 */
-	if (to_adreno_gpu(gpu)->fwloc == FW_LOCATION_LEGACY) {
+	if (signed_fwname || (to_adreno_gpu(gpu)->fwloc == FW_LOCATION_LEGACY)) {
 		ret = qcom_mdt_load(dev, fw, fwname, pasid,
 				mem_region, mem_phys, mem_size, NULL);
 	} else {
-- 
2.24.1