Re: [PATCH 4/4] media: venus: add PIL support

From: Vikash Garodia
Date: Fri Jun 01 2018 - 02:53:34 EST

Hi Stan,

On 2018-05-22 18:32, Stanimir Varbanov wrote:
Hi Vikash,

On 05/17/2018 02:32 PM, Vikash Garodia wrote:
This adds support to load the video firmware
and bring ARM9 out of reset. This is useful
for platforms which does not have trustzone
to reset the ARM9.

Signed-off-by: Vikash Garodia <vgarodia@xxxxxxxxxxxxxx>
---
.../devicetree/bindings/media/qcom,venus.txt | 8 +-
drivers/media/platform/qcom/venus/core.c | 67 +++++++--
drivers/media/platform/qcom/venus/core.h | 6 +
drivers/media/platform/qcom/venus/firmware.c | 163 +++++++++++++++++----
drivers/media/platform/qcom/venus/firmware.h | 10 +-
5 files changed, 217 insertions(+), 37 deletions(-)

diff --git a/Documentation/devicetree/bindings/media/qcom,venus.txt b/Documentation/devicetree/bindings/media/qcom,venus.txt
index 00d0d1b..0ff0f2d 100644
--- a/Documentation/devicetree/bindings/media/qcom,venus.txt
+++ b/Documentation/devicetree/bindings/media/qcom,venus.txt

for this change in DT binding you have to cc devicetree ML. And probably
it could be separate patch.

Will keep it as a separate patch and add the DT reviewers.

@@ -53,7 +53,7 @@

* Subnodes
The Venus video-codec node must contain two subnodes representing
-video-decoder and video-encoder.
+video-decoder and video-encoder, one optional firmware subnode.

Every of video-encoder or video-decoder subnode should have:

@@ -79,6 +79,8 @@ Every of video-encoder or video-decoder subnode should have:
power domain which is responsible for collapsing
and restoring power to the subcore.

+The firmware sub node must contain the iommus specifiers for ARM9.
+
* An Example
video-codec@1d00000 {
compatible = "qcom,msm8916-venus";
@@ -105,4 +107,8 @@ Every of video-encoder or video-decoder subnode should have:
clock-names = "core";
power-domains = <&mmcc VENUS_CORE1_GDSC>;
};
+ firmware {

venus-firmware
Ok.

+ compatible = "qcom,venus-pil-no-tz";

this should be following the other subnodes compatible names:

compatible = "venus-firmware";

Probably "venus-firmware-no-tz". Want to keep "-no-tz" explicitly as this node
is not needed for TZ based PIL.

+ iommus = <&apps_smmu 0x10b2 0x0>;
+ }
};
diff --git a/drivers/media/platform/qcom/venus/core.c b/drivers/media/platform/qcom/venus/core.c
index 1308488..16910558 100644
--- a/drivers/media/platform/qcom/venus/core.c
+++ b/drivers/media/platform/qcom/venus/core.c
@@ -22,6 +22,7 @@
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/pm_runtime.h>
+#include <linux/iommu.h>
#include <media/videobuf2-v4l2.h>
#include <media/v4l2-mem2mem.h>
#include <media/v4l2-ioctl.h>
@@ -30,6 +31,7 @@
#include "vdec.h"
#include "venc.h"
#include "firmware.h"
+#include "hfi_venus.h"

static void venus_event_notify(struct venus_core *core, u32 event)
{
@@ -76,7 +78,7 @@ static void venus_sys_error_handler(struct work_struct *work)
hfi_core_deinit(core, true);
hfi_destroy(core);
mutex_lock(&core->lock);
- venus_shutdown(core->dev);
+ venus_shutdown(core);

pm_runtime_put_sync(core->dev);

@@ -84,7 +86,7 @@ static void venus_sys_error_handler(struct work_struct *work)

pm_runtime_get_sync(core->dev);

- ret |= venus_boot(core->dev, core->res->fwname);
+ ret |= venus_boot(core);

ret |= hfi_core_resume(core, true);

@@ -179,6 +181,20 @@ static u32 to_v4l2_codec_type(u32 codec)
}
}

+static int store_firmware_dev(struct device *dev, void *data)
+{
+ struct venus_core *core;
+
+ core = (struct venus_core *)data;
+ if (!core)
+ return -EINVAL;
+
+ if (of_device_is_compatible(dev->of_node, "qcom,venus-pil-no-tz"))
+ core->fw.dev = dev;
+
+ return 0;
+}
+
static int venus_enumerate_codecs(struct venus_core *core, u32 type)
{
const struct hfi_inst_ops dummy_ops = {};
@@ -229,6 +245,7 @@ static int venus_probe(struct platform_device *pdev)
struct device *dev = &pdev->dev;
struct venus_core *core;
struct resource *r;
+ struct iommu_domain *iommu_domain;
int ret;

core = devm_kzalloc(dev, sizeof(*core), GFP_KERNEL);
@@ -279,7 +296,14 @@ static int venus_probe(struct platform_device *pdev)
if (ret < 0)
goto err_runtime_disable;

- ret = venus_boot(dev, core->res->fwname);
+ ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+ if (ret)
+ goto err_runtime_disable;
+
+ /* Attempt to register child devices */

This comment is wrong, the child devices are created by
of_platform_populate above.

Good catch. Intend was to mention something like "Attempt to store firmware
device". Will correct it.

+ ret = device_for_each_child(dev, core, store_firmware_dev);

Why we need these complex gymnastics to get struct device pointer when
that could be done in venus_firmware .probe method?

I think the answer is because you want to avoid having venus-firmware.ko
(because you have to have separate struct device for iommu SID). In that
case it would be better to make venus-firmware.ko.

I can have the venus firmware .probe method without venus-firmware.ko. I had
the probe method initially, but since it was just storing the device pointer,
i am doing it while iterating over the child nodes.

+
+ ret = venus_boot(core);
if (ret)
goto err_runtime_disable;

@@ -303,14 +327,17 @@ static int venus_probe(struct platform_device *pdev)
if (ret)
goto err_core_deinit;

- ret = of_platform_populate(dev->of_node, NULL, NULL, dev);
+ ret = pm_runtime_put_sync(dev);
if (ret)
goto err_dev_unregister;

- ret = pm_runtime_put_sync(dev);
- if (ret)
+ iommu_domain = iommu_get_domain_for_dev(dev);
+ if (!iommu_domain)
goto err_dev_unregister;

+ iommu_domain->geometry.aperture_start = VENUS_FW_MEM_SIZE;
+ iommu_domain->geometry.aperture_end = VENUS_MAX_MEM_REGION;

I don't think that is needed for this struct device (Venus DT node
struct device). And also why aperture_start is on 6th MB? I think that
this iommu domain is for venus_non_secure iommu context_bank.

ARM9 cannot accept iova as 0x0 for data buffers. The range is from firmware
end address(VENUS_FW_MEM_SIZE) till 3.5 GB. When the driver programs the
register for firmware start and end address, and provides a buffer having
iova in the firmware range, it would end up generating a different SID and
would lead to issues.

Those geometry parameters are checked/used only from dma-iommu.c. They
are checked before entering on venus_probe and only when
geometry.force_aperture is true. So updating those params here doesn't
make any sense to iommu?

I am not very sure on this part. We can stay with dma_set_mask_and_coherent
to keep the upper limit check. For lower limit, we can keep it as a TODO
for future.

+
return 0;

err_dev_unregister:
@@ -318,7 +345,7 @@ static int venus_probe(struct platform_device *pdev)
err_core_deinit:
hfi_core_deinit(core, false);
err_venus_shutdown:
- venus_shutdown(dev);
+ venus_shutdown(core);
err_runtime_disable:
pm_runtime_set_suspended(dev);
pm_runtime_disable(dev);
@@ -339,7 +366,7 @@ static int venus_remove(struct platform_device *pdev)
WARN_ON(ret);

hfi_destroy(core);
- venus_shutdown(dev);
+ venus_shutdown(core);
of_platform_depopulate(dev);

pm_runtime_put_sync(dev);
@@ -483,7 +510,29 @@ static __maybe_unused int venus_runtime_resume(struct device *dev)
.pm = &venus_pm_ops,
},
};
-module_platform_driver(qcom_venus_driver);
+
+static int __init venus_init(void)
+{
+ int ret;
+
+ ret = platform_driver_register(&qcom_video_firmware_driver);
+ if (ret)
+ return ret;

I think that this shouldn't be here, it is clear that firmware loader
code should be on separate device/driver (even outside of venus DT node).

This is needed to register the driver with platform bus. Otherwise iommu group
for firmware device will not be created and iommu_domain_alloc would fail.

+
+ ret = platform_driver_register(&qcom_venus_driver);
+ if (ret)
+ platform_driver_unregister(&qcom_video_firmware_driver);
+
+ return ret;
+}
+module_init(venus_init);
+
+static void __exit venus_exit(void)
+{
+ platform_driver_unregister(&qcom_venus_driver);
+ platform_driver_unregister(&qcom_video_firmware_driver);
+}
+module_exit(venus_exit);

MODULE_ALIAS("platform:qcom-venus");
MODULE_DESCRIPTION("Qualcomm Venus video encoder and decoder driver");
diff --git a/drivers/media/platform/qcom/venus/core.h b/drivers/media/platform/qcom/venus/core.h
index 85e66e2..68fc8af 100644
--- a/drivers/media/platform/qcom/venus/core.h
+++ b/drivers/media/platform/qcom/venus/core.h
@@ -80,6 +80,11 @@ struct venus_caps {
bool valid;
};

+struct video_firmware {
+ struct device *dev;
+ dma_addr_t iova;
+ struct iommu_domain *iommu_domain;
+};
/**
* struct venus_core - holds core parameters valid for all instances
*
@@ -124,6 +129,7 @@ struct venus_core {
struct device *dev;
struct device *dev_dec;
struct device *dev_enc;
+ struct video_firmware fw;
struct mutex lock;
struct list_head instances;
atomic_t insts_count;
diff --git a/drivers/media/platform/qcom/venus/firmware.c b/drivers/media/platform/qcom/venus/firmware.c
index 8f25375..614c805 100644
--- a/drivers/media/platform/qcom/venus/firmware.c
+++ b/drivers/media/platform/qcom/venus/firmware.c
@@ -12,8 +12,12 @@
*
*/

+#include <linux/module.h>
+#include <linux/of_device.h>
+#include <linux/platform_device.h>
#include <linux/device.h>
#include <linux/firmware.h>
+#include <linux/iommu.h>
#include <linux/delay.h>
#include <linux/kernel.h>
#include <linux/io.h>
@@ -27,8 +31,10 @@
#include "firmware.h"
#include "hfi_venus_io.h"

-#define VENUS_PAS_ID 9
-#define VENUS_FW_MEM_SIZE (6 * SZ_1M)
+static const struct of_device_id firmware_dt_match[] = {
+ { .compatible = "qcom,venus-pil-no-tz" },
+ { }
+};

void venus_reset_hw(struct venus_core *core)
{
@@ -53,40 +59,37 @@ void venus_reset_hw(struct venus_core *core)
/* Bring Arm9 out of reset */
writel_relaxed(0, reg_base + WRAPPER_A9SS_SW_RESET);
}
-int venus_boot(struct device *dev, const char *fwname)
+EXPORT_SYMBOL_GPL(venus_reset_hw);
+
+int venus_load_fw(struct device *dev, const char *fwname,
+ phys_addr_t *mem_phys, size_t *mem_size)
{
const struct firmware *mdt;
struct device_node *node;
- phys_addr_t mem_phys;
struct resource r;
ssize_t fw_size;
- size_t mem_size;
void *mem_va;
int ret;

- if (!IS_ENABLED(CONFIG_QCOM_MDT_LOADER) || !qcom_scm_is_available())
- return -EPROBE_DEFER;
-
node = of_parse_phandle(dev->of_node, "memory-region", 0);
if (!node) {
dev_err(dev, "no memory-region specified\n");
return -EINVAL;
}
-
ret = of_address_to_resource(node, 0, &r);
if (ret)
return ret;

- mem_phys = r.start;
- mem_size = resource_size(&r);
+ *mem_phys = r.start;
+ *mem_size = resource_size(&r);

- if (mem_size < VENUS_FW_MEM_SIZE)
+ if (*mem_size < VENUS_FW_MEM_SIZE)
return -EINVAL;

- mem_va = memremap(r.start, mem_size, MEMREMAP_WC);
+ mem_va = memremap(r.start, *mem_size, MEMREMAP_WC);
if (!mem_va) {
dev_err(dev, "unable to map memory region: %pa+%zx\n",
- &r.start, mem_size);
+ &r.start, *mem_size);
return -ENOMEM;
}

@@ -101,24 +104,134 @@ int venus_boot(struct device *dev, const char *fwname)
goto err_unmap;
}

- ret = qcom_mdt_load(dev, mdt, fwname, VENUS_PAS_ID, mem_va, mem_phys,
- mem_size, NULL);
+ ret = qcom_mdt_load(dev, mdt, fwname, VENUS_PAS_ID, mem_va, *mem_phys,
+ *mem_size, NULL);

release_firmware(mdt);

- if (ret)
- goto err_unmap;
-
- ret = qcom_scm_pas_auth_and_reset(VENUS_PAS_ID);
- if (ret)
- goto err_unmap;
-
err_unmap:
memunmap(mem_va);
return ret;
}

-int venus_shutdown(struct device *dev)
+int venus_boot_noTZ(struct venus_core *core, phys_addr_t mem_phys,
+ size_t mem_size)
{
- return qcom_scm_pas_shutdown(VENUS_PAS_ID);
+ struct iommu_domain *iommu;
+ struct device *dev;
+ int ret;
+
+ if (!core->fw.dev)
+ return -EPROBE_DEFER;
+
+ dev = core->fw.dev;
+
+ iommu = iommu_domain_alloc(&platform_bus_type);
+ if (!iommu) {
+ dev_err(dev, "Failed to allocate iommu domain\n");
+ return -ENOMEM;
+ }
+
+ iommu->geometry.aperture_start = 0x0;
+ iommu->geometry.aperture_end = VENUS_FW_MEM_SIZE;

The same comment for geometry params as for venus_probe is valid here.
As this is used only for firmware context bank, i can remove these
explicit iommu configuration.

+
+ ret = iommu_attach_device(iommu, dev);
+ if (ret) {
+ dev_err(dev, "could not attach device\n");
+ goto err_attach;
+ }
+
+ ret = iommu_map(iommu, core->fw.iova, mem_phys, mem_size,
+ IOMMU_READ|IOMMU_WRITE|IOMMU_PRIV);

iova is not initialized and is zero, maybe we don't need that variable
in the venus_firmware structure?

As the iova will be always zero here, i can hard-code as well.

+ if (ret) {
+ dev_err(dev, "could not map video firmware region\n");
+ goto err_map;
+ }
+ core->fw.iommu_domain = iommu;
+ venus_reset_hw(core);
+
+ return 0;
+
+err_map:
+ iommu_detach_device(iommu, dev);
+err_attach:
+ iommu_domain_free(iommu);
+ return ret;
}
+
+int venus_shutdown_noTZ(struct venus_core *core)
+{
+ struct iommu_domain *iommu;
+ u32 reg;
+ struct device *dev = core->fw.dev;
+ void __iomem *reg_base = core->base;
+
+ /* Assert the reset to ARM9 */
+ reg = readl_relaxed(reg_base + WRAPPER_A9SS_SW_RESET);
+ reg |= BIT(4);
+ writel_relaxed(reg, reg_base + WRAPPER_A9SS_SW_RESET);
+
+ /* Make sure reset is asserted before the mapping is removed */
+ mb();
+
+ iommu = core->fw.iommu_domain;
+
+ iommu_unmap(iommu, core->fw.iova, VENUS_FW_MEM_SIZE);
+ iommu_detach_device(iommu, dev);
+ iommu_domain_free(iommu);

check iommu APIs for errors.
Ok.