Hi,
On 2016å¹´06æ10æ¥ 16:03, Tomasz Figa wrote:
> Hi,
>
> On Wed, Jun 8, 2016 at 10:26 PM, Shunqian Zheng <zhengsq at rock-chips.com>
> wrote:
>> Rockchip DRM used the arm special API, arm_iommu_*(), to attach
>> iommu for ARM32 SoCs. This patch convert to common iommu API
>> so it would support ARM64 like RK3399.
>>
>> The general idea is domain_alloc(), attach_device() and
>> arch_setup_dma_ops() to set dma_ops manually for DRM at the last.
>>
>> Signed-off-by: Shunqian Zheng <zhengsq at rock-chips.com>
>> ---
>> drivers/gpu/drm/rockchip/rockchip_drm_drv.c | 130
>> +++++++++++++++++++---------
>> drivers/gpu/drm/rockchip/rockchip_drm_drv.h | 1 +
>> 2 files changed, 89 insertions(+), 42 deletions(-)
>>
> Please see my comments inline.
>
>> diff --git a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
>> b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
>> index f5a68fc..7965a66 100644
>> --- a/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
>> +++ b/drivers/gpu/drm/rockchip/rockchip_drm_drv.c
>> @@ -14,8 +14,6 @@
>> * GNU General Public License for more details.
>> */
>>
>> -#include <asm/dma-iommu.h>
>> -
>> #include <drm/drmP.h>
>> #include <drm/drm_crtc_helper.h>
>> #include <drm/drm_fb_helper.h>
>> @@ -24,6 +22,8 @@
>> #include <linux/module.h>
>> #include <linux/of_graph.h>
>> #include <linux/component.h>
>> +#include <linux/dma-iommu.h>
>> +#include <linux/iommu.h>
>>
>> #include "rockchip_drm_drv.h"
>> #include "rockchip_drm_fb.h"
>> @@ -46,7 +46,8 @@ static bool is_support_iommu = true;
>> int rockchip_drm_dma_attach_device(struct drm_device *drm_dev,
>> struct device *dev)
>> {
>> - struct dma_iommu_mapping *mapping = drm_dev->dev->archdata.mapping;
>> + struct rockchip_drm_private *private = drm_dev->dev_private;
>> + struct iommu_domain *domain = private->domain;
>> int ret;
>>
>> if (!is_support_iommu)
>> @@ -58,16 +59,25 @@ int rockchip_drm_dma_attach_device(struct drm_device
>> *drm_dev,
>>
>> dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
>>
>> - return arm_iommu_attach_device(dev, mapping);
>> + ret = iommu_attach_device(domain, dev);
>> +
> nit: Unnecessary blank line.
Will fix it in v3.
>
>> + if (ret) {
>> + dev_err(dev, "Failed to attach iommu device\n");
>> + return ret;
>> + }
> nit: On the other hand, a blank line here would improve readability.
Will fix it in v3.
>
>> + arch_setup_dma_ops(dev, 0x00000000, SZ_2G,
>> + (struct iommu_ops *)dev->bus->iommu_ops, false);
> This is casting a const pointer to a non-const pointer. which isn't
> really a good idea. I can see that arch_setup_dma_ops() requires a
> writable pointer, though. Looking at the implementations of
> arch_setup_dma_ops() around the platforms (namely arm and arm64...),
> it makes me wonder if the prototype shouldn't be changed to const
> instead.
Actually, kernel-next changed iommu_ops to const by:
53c92d7 iommu: of: enforce const-ness of struct iommu_ops
Will remove casting in the v3.
>
>> + return 0;
>> }
>>
>> void rockchip_drm_dma_detach_device(struct drm_device *drm_dev,
>> struct device *dev)
>> {
>> - if (!is_support_iommu)
>> - return;
>> + struct rockchip_drm_private *private = drm_dev->dev_private;
>> + struct iommu_domain *domain = private->domain;
>>
>> - arm_iommu_detach_device(dev);
>> + if (is_support_iommu)
>> + iommu_detach_device(domain, dev);
>> }
>>
>> int rockchip_register_crtc_funcs(struct drm_crtc *crtc,
>> @@ -132,10 +142,70 @@ static void rockchip_drm_crtc_disable_vblank(struct
>> drm_device *dev,
>> priv->crtc_funcs[pipe]->disable_vblank(crtc);
>> }
>>
>> +static int rockchip_drm_init_iommu(struct drm_device *drm_dev)
>> +{
>> + struct rockchip_drm_private *private = drm_dev->dev_private;
>> + struct device *dev = drm_dev->dev;
>> + int ret;
>> +
>> + dev->dma_parms = devm_kzalloc(dev, sizeof(*dev->dma_parms),
>> + GFP_KERNEL);
>> + if (!dev->dma_parms) {
>> + ret = -ENOMEM;
>> + return ret;
> nit: return -ENOMEM;
Will fix it in v3.
>
>> + }
>> +
>> + ret = dma_set_coherent_mask(dev, DMA_BIT_MASK(32));
>> + if (ret) {
>> + dev_err(dev, "Failed to set coherent mask\n");
>> + return ret;
>> + }
>> +
>> + dma_set_max_seg_size(dev, DMA_BIT_MASK(32));
>> +
>> + private->domain = iommu_domain_alloc(&platform_bus_type);
>> + if (!private->domain)
>> + return -ENOMEM;
>> +
>> + ret = iommu_get_dma_cookie(private->domain);
>> + if (ret) {
>> + dev_err(dev, "Failed to get dma cookie\n");
>> + goto err_free_domain;
>> + }
>> +
>> + ret = iommu_dma_init_domain(private->domain, 0x00000000, SZ_2G);
> I guess djkurtz's TODO comment could be preserved here.
Agree.
Thank you very much.
Shunqian
>
> Best regards,
> Tomasz
>
>
>
