Re: [PATCH v2 4/7] media: iris: add context bank devices using iommu-map
From: Dmitry Baryshkov
Date: Tue Mar 03 2026 - 17:25:27 EST
On Wed, Mar 04, 2026 at 12:16:50AM +0530, Vikash Garodia wrote:
>
> On 2/28/2026 1:50 AM, Dmitry Baryshkov wrote:
> > On Fri, Feb 27, 2026 at 07:41:20PM +0530, Vikash Garodia wrote:
> > > Introduce different context banks(CB) and the associated buffer region.
> > > Different stream IDs from VPU would be associated to one of these CB.
> > > Multiple CBs are needed to increase the IOVA for the video usecases like
> > > higher concurrent sessions.
> > >
> > > Co-developed-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
> > > Signed-off-by: Vishnu Reddy <busanna.reddy@xxxxxxxxxxxxxxxx>
> > > Signed-off-by: Vikash Garodia <vikash.garodia@xxxxxxxxxxxxxxxx>
> > > ---
> > > .../platform/qcom/iris/iris_platform_common.h | 18 +++++++
> > > drivers/media/platform/qcom/iris/iris_probe.c | 60 ++++++++++++++++++++--
> > > drivers/media/platform/qcom/iris/iris_resources.c | 36 +++++++++++++
> > > drivers/media/platform/qcom/iris/iris_resources.h | 1 +
> > > 4 files changed, 111 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/drivers/media/platform/qcom/iris/iris_platform_common.h b/drivers/media/platform/qcom/iris/iris_platform_common.h
> > > index 5a489917580eb10022fdcb52f7321a915e8b239d..03c50d6e54853fca34d7d32f65d09eb80945fcdd 100644
> > > --- a/drivers/media/platform/qcom/iris/iris_platform_common.h
> > > +++ b/drivers/media/platform/qcom/iris/iris_platform_common.h
> > > @@ -204,6 +204,22 @@ struct icc_vote_data {
> > > u32 fps;
> > > };
> > > +enum iris_buffer_region {
> > > + IRIS_BITSTREAM_REGION = BIT(0),
> > > + IRIS_NON_PIXEL_REGION = BIT(1),
> > > + IRIS_PIXEL_REGION = BIT(2),
> > > + IRIS_SECURE_BITSTREAM_REGION = BIT(3),
> > > + IRIS_SECURE_NON_PIXEL_REGION = BIT(4),
> > > + IRIS_SECURE_PIXEL_REGION = BIT(5),
> >
> > Can a context bank belong to multiple regions at the same time?
>
> yes, they would.
How? Each set of CBs is defined by a separate function in the DT. How
can CB belong to multiple regions? Could you please provide an example?
>
> >
> > > +};
> > > +
> > > +struct iris_context_bank {
> > > + struct device *dev;
> >
> > Separate data and the actual device. Define a wrapper around struct
> > device for the actual runtime usage.
>
> we still have to store the list of dynamically created device. Name can be
> used to fetch the device from the list, i think the existing approach is
> simpler ?
You don't need a list. You have an array of the size, which is known and
fixed. You have at most 9 functions, which means less than 9 devices.
>
> >
> > > + const char *name;
> > > + const u32 f_id;
> > > + const enum iris_buffer_region region;
> > > +};
> > > +
> > > enum platform_pm_domain_type {
> > > IRIS_CTRL_POWER_DOMAIN,
> > > IRIS_HW_POWER_DOMAIN,
> > > @@ -246,6 +262,8 @@ struct iris_platform_data {
> > > u32 inst_fw_caps_enc_size;
> > > const struct tz_cp_config *tz_cp_config_data;
> > > u32 tz_cp_config_data_size;
> > > + struct iris_context_bank *cb_data;
> > > + u32 cb_data_size;
> >
> > Do they differ from platform to platform?
> Yes
>
> > Mark them as const, it should be data only.
>
> cb_data_size can be marked as const
Why is cb_data non-const?
>
> >
> > > u32 core_arch;
> > > u32 hw_response_timeout;
> > > struct ubwc_config_data *ubwc_config;
> > > diff --git a/drivers/media/platform/qcom/iris/iris_probe.c b/drivers/media/platform/qcom/iris/iris_probe.c
> > > index ddaacda523ecb9990af0dd0640196223fbcc2cab..557adb038328a75510591d91569819abc0b7b1c9 100644
> > > --- a/drivers/media/platform/qcom/iris/iris_probe.c
> > > +++ b/drivers/media/platform/qcom/iris/iris_probe.c
> > > @@ -123,6 +123,49 @@ static int iris_init_resets(struct iris_core *core)
> > > core->iris_platform_data->controller_rst_tbl_size);
> > > }
> > > +static void iris_destroy_child_device(struct iris_context_bank *cb)
> > > +{
> > > + struct device *dev = cb->dev;
> > > +
> > > + if (dev)
> > > + device_unregister(dev);
> > > +
> > > + cb->dev = NULL;
> > > +}
> > > +
> > > +static void iris_deinit_context_bank_devices(struct iris_core *core)
> > > +{
> > > + struct iris_context_bank *cb;
> > > + int i;
> > > +
> > > + for (i = 0; i < core->iris_platform_data->cb_data_size; i++) {
> > > + cb = &core->iris_platform_data->cb_data[i];
> > > + iris_destroy_child_device(cb);
> > > + }
> > > +}
> > > +
> > > +static int iris_init_context_bank_devices(struct iris_core *core)
> > > +{
> > > + struct iris_context_bank *cb;
> > > + int ret, i;
> > > +
> > > + for (i = 0; i < core->iris_platform_data->cb_data_size; i++) {
> > > + cb = &core->iris_platform_data->cb_data[i];
> > > +
> > > + ret = iris_create_child_device_and_map(core, cb);
> > > + if (ret)
> > > + goto err_deinit_cb;
> > > + }
> > > +
> > > + return 0;
> > > +
> > > +err_deinit_cb:
> > > + while (i-- > 0)
> > > + iris_destroy_child_device(&core->iris_platform_data->cb_data[i]);
> > > +
> > > + return ret;
> > > +}
> > > +
> > > static int iris_init_resources(struct iris_core *core)
> > > {
> > > int ret;
> > > @@ -193,6 +236,7 @@ static void iris_remove(struct platform_device *pdev)
> > > return;
> > > iris_core_deinit(core);
> > > + iris_deinit_context_bank_devices(core);
> > > video_unregister_device(core->vdev_dec);
> > > video_unregister_device(core->vdev_enc);
> > > @@ -275,12 +319,18 @@ static int iris_probe(struct platform_device *pdev)
> > > platform_set_drvdata(pdev, core);
> > > - dma_mask = core->iris_platform_data->dma_mask;
> > > -
> > > - ret = dma_set_mask_and_coherent(dev, dma_mask);
> > > + ret = iris_init_context_bank_devices(core);
> > > if (ret)
> > > goto err_vdev_unreg_enc;
> > > + dma_mask = core->iris_platform_data->dma_mask;
> > > +
> > > + if (device_iommu_mapped(core->dev)) {
> > > + ret = dma_set_mask_and_coherent(core->dev, dma_mask);
> > > + if (ret)
> > > + goto err_deinit_cb;
> > > + }
> > > +
> > > dma_set_max_seg_size(&pdev->dev, DMA_BIT_MASK(32));
> > > dma_set_seg_boundary(&pdev->dev, DMA_BIT_MASK(32));
> > > @@ -288,10 +338,12 @@ static int iris_probe(struct platform_device *pdev)
> > > pm_runtime_use_autosuspend(core->dev);
> > > ret = devm_pm_runtime_enable(core->dev);
> > > if (ret)
> > > - goto err_vdev_unreg_enc;
> > > + goto err_deinit_cb;
> > > return 0;
> > > +err_deinit_cb:
> > > + iris_deinit_context_bank_devices(core);
> > > err_vdev_unreg_enc:
> > > video_unregister_device(core->vdev_enc);
> > > err_vdev_unreg_dec:
> > > diff --git a/drivers/media/platform/qcom/iris/iris_resources.c b/drivers/media/platform/qcom/iris/iris_resources.c
> > > index 773f6548370a257b8ae7332242544266cbbd61a9..be58e8620086d0f82c2c2bda29247483f5c56d79 100644
> > > --- a/drivers/media/platform/qcom/iris/iris_resources.c
> > > +++ b/drivers/media/platform/qcom/iris/iris_resources.c
> > > @@ -6,6 +6,7 @@
> > > #include <linux/clk.h>
> > > #include <linux/devfreq.h>
> > > #include <linux/interconnect.h>
> > > +#include <linux/iris_vpu_bus.h>
> > > #include <linux/pm_domain.h>
> > > #include <linux/pm_opp.h>
> > > #include <linux/pm_runtime.h>
> > > @@ -141,3 +142,38 @@ int iris_disable_unprepare_clock(struct iris_core *core, enum platform_clk_type
> > > return 0;
> > > }
> > > +
> > > +static void iris_device_release(struct device *dev)
> > > +{
> > > + dev_set_drvdata(dev, NULL);
> > > + kfree(dev);
> > > +}
> > > +
> > > +int iris_create_child_device_and_map(struct iris_core *core, struct iris_context_bank *cb)
> > > +{
> > > + struct device *dev;
> > > + int ret;
> > > +
> > > + dev = kzalloc_obj(*dev);
> > > + if (!dev)
> > > + return -ENOMEM;
> > > +
> > > + dev->release = iris_device_release;
> > > + dev->bus = &iris_vpu_bus_type;
> > > + dev->parent = core->dev;
> > > + dev->coherent_dma_mask = core->iris_platform_data->dma_mask;
> > > + dev->dma_mask = &dev->coherent_dma_mask;
> > > +
> > > + dev_set_name(dev, "%s", cb->name);
> > > + dev_set_drvdata(dev, cb);
> > > +
> > > + ret = device_register(dev);
> > > + if (ret) {
> > > + put_device(dev);
> > > + return ret;
> > > + }
> > > +
> > > + cb->dev = dev;
> > > +
> > > + return 0;
> > > +}
> > > diff --git a/drivers/media/platform/qcom/iris/iris_resources.h b/drivers/media/platform/qcom/iris/iris_resources.h
> > > index 6bfbd2dc6db095ec05e53c894e048285f82446c6..b7efe15facb203eea9ae13d5f0abdcc2ea718b4d 100644
> > > --- a/drivers/media/platform/qcom/iris/iris_resources.h
> > > +++ b/drivers/media/platform/qcom/iris/iris_resources.h
> > > @@ -15,5 +15,6 @@ int iris_unset_icc_bw(struct iris_core *core);
> > > int iris_set_icc_bw(struct iris_core *core, unsigned long icc_bw);
> > > int iris_disable_unprepare_clock(struct iris_core *core, enum platform_clk_type clk_type);
> > > int iris_prepare_enable_clock(struct iris_core *core, enum platform_clk_type clk_type);
> > > +int iris_create_child_device_and_map(struct iris_core *core, struct iris_context_bank *cb);
> > > #endif
> > >
> > > --
> > > 2.34.1
> > >
> >
>
--
With best wishes
Dmitry