| Message ID | 1398164568-6048-1-git-send-email-arun.kk@samsung.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
Hi Arun, Thank you for the patch. On Tuesday 22 April 2014 16:32:48 Arun Kumar K wrote: > The patch adds IOMMU support for MFC driver. I've been working on an IOMMU driver lately, which led me to think about how drivers should be interfaced with IOMMUs. Runtime IOMMU handling is performed by the DMA mapping API, but in many cases (including Exynos platforms) the arm_iommu_create_mapping() and arm_iommu_attach_device() functions still need to be called explicitly by drivers, which doesn't seem a very good idea to me. Ideally IOMMU usage should be completely transparent for bus master drivers, without requiring any driver modification to use the IOMMU. What would you think about improving the Exynos IOMMU driver to create the mapping and attach the device instead of having to modify all bus master drivers ? See the ipmmu_add_device() function in http://www.spinics.net/lists/linux-sh/msg30488.html for a possible implementation. > Signed-off-by: Arun Kumar K <arun.kk@samsung.com> > --- > This patch is tested on IOMMU support series [1] posted > by KyonHo Cho. > [1] https://lkml.org/lkml/2014/3/14/9 > --- > drivers/media/platform/s5p-mfc/s5p_mfc.c | 33 +++++++++++++++++++++++++++ > 1 file changed, 33 insertions(+) > > diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c > b/drivers/media/platform/s5p-mfc/s5p_mfc.c index 89356ae..1f248ba 100644 > --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c > +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c > @@ -32,11 +32,18 @@ > #include "s5p_mfc_opr.h" > #include "s5p_mfc_cmd.h" > #include "s5p_mfc_pm.h" > +#ifdef CONFIG_EXYNOS_IOMMU > +#include <asm/dma-iommu.h> > +#endif > > #define S5P_MFC_NAME "s5p-mfc" > #define S5P_MFC_DEC_NAME "s5p-mfc-dec" > #define S5P_MFC_ENC_NAME "s5p-mfc-enc" > > +#ifdef CONFIG_EXYNOS_IOMMU > +static struct dma_iommu_mapping *mapping; > +#endif > + > int debug; > module_param(debug, int, S_IRUGO | S_IWUSR); > MODULE_PARM_DESC(debug, "Debug level - higher value produces more verbose > messages"); @@ -1013,6 +1020,23 @@ static void *mfc_get_drv_data(struct > platform_device *pdev); > > static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev *dev) > { > +#ifdef CONFIG_EXYNOS_IOMMU > + struct device *mdev = &dev->plat_dev->dev; > + > + mapping = arm_iommu_create_mapping(&platform_bus_type, 0x20000000, > + SZ_256M); > + if (mapping == NULL) { > + mfc_err("IOMMU mapping failed\n"); > + return -EFAULT; > + } > + mdev->dma_parms = devm_kzalloc(&dev->plat_dev->dev, > + sizeof(*mdev->dma_parms), GFP_KERNEL); > + dma_set_max_seg_size(mdev, 0xffffffffu); > + arm_iommu_attach_device(mdev, mapping); > + > + dev->mem_dev_l = dev->mem_dev_r = mdev; > + return 0; > +#else > unsigned int mem_info[2] = { }; > > dev->mem_dev_l = devm_kzalloc(&dev->plat_dev->dev, > @@ -1049,6 +1073,7 @@ static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev > *dev) return -ENOMEM; > } > return 0; > +#endif > } > > /* MFC probe function */ > @@ -1228,6 +1253,10 @@ err_mem_init_ctx_1: > vb2_dma_contig_cleanup_ctx(dev->alloc_ctx[0]); > err_res: > s5p_mfc_final_pm(dev); > +#ifdef CONFIG_EXYNOS_IOMMU > + if (mapping) > + arm_iommu_release_mapping(mapping); > +#endif > > pr_debug("%s-- with error\n", __func__); > return ret; > @@ -1256,6 +1285,10 @@ static int s5p_mfc_remove(struct platform_device > *pdev) put_device(dev->mem_dev_r); > } > > +#ifdef CONFIG_EXYNOS_IOMMU > + if (mapping) > + arm_iommu_release_mapping(mapping); > +#endif > s5p_mfc_final_pm(dev); > return 0; > }
Hi Laurent, Thank you for the review. On Tue, Apr 22, 2014 at 5:23 PM, Laurent Pinchart <laurent.pinchart@ideasonboard.com> wrote: > Hi Arun, > > Thank you for the patch. > > On Tuesday 22 April 2014 16:32:48 Arun Kumar K wrote: >> The patch adds IOMMU support for MFC driver. > > I've been working on an IOMMU driver lately, which led me to think about how > drivers should be interfaced with IOMMUs. Runtime IOMMU handling is performed > by the DMA mapping API, but in many cases (including Exynos platforms) the > arm_iommu_create_mapping() and arm_iommu_attach_device() functions still need > to be called explicitly by drivers, which doesn't seem a very good idea to me. > Ideally IOMMU usage should be completely transparent for bus master drivers, > without requiring any driver modification to use the IOMMU. > > What would you think about improving the Exynos IOMMU driver to create the > mapping and attach the device instead of having to modify all bus master > drivers ? See the ipmmu_add_device() function in > http://www.spinics.net/lists/linux-sh/msg30488.html for a possible > implementation. > Yes that would be a better solution. But as far as I know, exynos platforms has few more complications where multiple IOMMUs are present for single IP. The exynos iommu work is still under progress and KyonHo Cho will have some inputs / comments on this. This seems to me a valid usecase which can be considered for exynos iommu also. Regards Arun >> Signed-off-by: Arun Kumar K <arun.kk@samsung.com> >> --- >> This patch is tested on IOMMU support series [1] posted >> by KyonHo Cho. >> [1] https://lkml.org/lkml/2014/3/14/9 >> --- >> drivers/media/platform/s5p-mfc/s5p_mfc.c | 33 +++++++++++++++++++++++++++ >> 1 file changed, 33 insertions(+) >> >> diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c >> b/drivers/media/platform/s5p-mfc/s5p_mfc.c index 89356ae..1f248ba 100644 >> --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c >> +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c >> @@ -32,11 +32,18 @@ >> #include "s5p_mfc_opr.h" >> #include "s5p_mfc_cmd.h" >> #include "s5p_mfc_pm.h" >> +#ifdef CONFIG_EXYNOS_IOMMU >> +#include <asm/dma-iommu.h> >> +#endif >> >> #define S5P_MFC_NAME "s5p-mfc" >> #define S5P_MFC_DEC_NAME "s5p-mfc-dec" >> #define S5P_MFC_ENC_NAME "s5p-mfc-enc" >> >> +#ifdef CONFIG_EXYNOS_IOMMU >> +static struct dma_iommu_mapping *mapping; >> +#endif >> + >> int debug; >> module_param(debug, int, S_IRUGO | S_IWUSR); >> MODULE_PARM_DESC(debug, "Debug level - higher value produces more verbose >> messages"); @@ -1013,6 +1020,23 @@ static void *mfc_get_drv_data(struct >> platform_device *pdev); >> >> static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev *dev) >> { >> +#ifdef CONFIG_EXYNOS_IOMMU >> + struct device *mdev = &dev->plat_dev->dev; >> + >> + mapping = arm_iommu_create_mapping(&platform_bus_type, 0x20000000, >> + SZ_256M); >> + if (mapping == NULL) { >> + mfc_err("IOMMU mapping failed\n"); >> + return -EFAULT; >> + } >> + mdev->dma_parms = devm_kzalloc(&dev->plat_dev->dev, >> + sizeof(*mdev->dma_parms), GFP_KERNEL); >> + dma_set_max_seg_size(mdev, 0xffffffffu); >> + arm_iommu_attach_device(mdev, mapping); >> + >> + dev->mem_dev_l = dev->mem_dev_r = mdev; >> + return 0; >> +#else >> unsigned int mem_info[2] = { }; >> >> dev->mem_dev_l = devm_kzalloc(&dev->plat_dev->dev, >> @@ -1049,6 +1073,7 @@ static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev >> *dev) return -ENOMEM; >> } >> return 0; >> +#endif >> } >> >> /* MFC probe function */ >> @@ -1228,6 +1253,10 @@ err_mem_init_ctx_1: >> vb2_dma_contig_cleanup_ctx(dev->alloc_ctx[0]); >> err_res: >> s5p_mfc_final_pm(dev); >> +#ifdef CONFIG_EXYNOS_IOMMU >> + if (mapping) >> + arm_iommu_release_mapping(mapping); >> +#endif >> >> pr_debug("%s-- with error\n", __func__); >> return ret; >> @@ -1256,6 +1285,10 @@ static int s5p_mfc_remove(struct platform_device >> *pdev) put_device(dev->mem_dev_r); >> } >> >> +#ifdef CONFIG_EXYNOS_IOMMU >> + if (mapping) >> + arm_iommu_release_mapping(mapping); >> +#endif >> s5p_mfc_final_pm(dev); >> return 0; >> } > > -- > Regards, > > Laurent Pinchart > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Hi Arun, On Tuesday 22 April 2014 17:52:08 Arun Kumar K wrote: > On Tue, Apr 22, 2014 at 5:23 PM, Laurent Pinchart wrote: > > On Tuesday 22 April 2014 16:32:48 Arun Kumar K wrote: > >> The patch adds IOMMU support for MFC driver. > > > > I've been working on an IOMMU driver lately, which led me to think about > > how drivers should be interfaced with IOMMUs. Runtime IOMMU handling is > > performed by the DMA mapping API, but in many cases (including Exynos > > platforms) the arm_iommu_create_mapping() and arm_iommu_attach_device() > > functions still need to be called explicitly by drivers, which doesn't > > seem a very good idea to me. Ideally IOMMU usage should be completely > > transparent for bus master drivers, without requiring any driver > > modification to use the IOMMU. > > > > What would you think about improving the Exynos IOMMU driver to create the > > mapping and attach the device instead of having to modify all bus master > > drivers ? See the ipmmu_add_device() function in > > http://www.spinics.net/lists/linux-sh/msg30488.html for a possible > > implementation. > > Yes that would be a better solution. But as far as I know, exynos platforms > has few more complications where multiple IOMMUs are present for single IP. > The exynos iommu work is still under progress and KyonHo Cho will have some > inputs / comments on this. This seems to me a valid usecase which can be > considered for exynos iommu also. Thank you. Just to be clear, I don't see a reason to delay this patch until the Exynos IOMMU driver gets support for creating mappings and attaching devices, but it would be nice to see that happen as a cleanup in the not too distant future. > >> Signed-off-by: Arun Kumar K <arun.kk@samsung.com> > >> --- > >> This patch is tested on IOMMU support series [1] posted > >> by KyonHo Cho. > >> [1] https://lkml.org/lkml/2014/3/14/9 > >> --- > >> > >> drivers/media/platform/s5p-mfc/s5p_mfc.c | 33 > >> +++++++++++++++++++++++++++ > >> 1 file changed, 33 insertions(+) > >> > >> diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c > >> b/drivers/media/platform/s5p-mfc/s5p_mfc.c index 89356ae..1f248ba 100644 > >> --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c > >> +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c > >> @@ -32,11 +32,18 @@ > >> > >> #include "s5p_mfc_opr.h" > >> #include "s5p_mfc_cmd.h" > >> #include "s5p_mfc_pm.h" > >> > >> +#ifdef CONFIG_EXYNOS_IOMMU > >> +#include <asm/dma-iommu.h> > >> +#endif > >> > >> #define S5P_MFC_NAME "s5p-mfc" > >> #define S5P_MFC_DEC_NAME "s5p-mfc-dec" > >> #define S5P_MFC_ENC_NAME "s5p-mfc-enc" > >> > >> +#ifdef CONFIG_EXYNOS_IOMMU > >> +static struct dma_iommu_mapping *mapping; > >> +#endif > >> + > >> > >> int debug; > >> module_param(debug, int, S_IRUGO | S_IWUSR); > >> MODULE_PARM_DESC(debug, "Debug level - higher value produces more > >> verbose > >> > >> messages"); @@ -1013,6 +1020,23 @@ static void *mfc_get_drv_data(struct > >> platform_device *pdev); > >> > >> static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev *dev) > >> { > >> > >> +#ifdef CONFIG_EXYNOS_IOMMU > >> + struct device *mdev = &dev->plat_dev->dev; > >> + > >> + mapping = arm_iommu_create_mapping(&platform_bus_type, 0x20000000, > >> + SZ_256M); > >> + if (mapping == NULL) { > >> + mfc_err("IOMMU mapping failed\n"); > >> + return -EFAULT; > >> + } > >> + mdev->dma_parms = devm_kzalloc(&dev->plat_dev->dev, > >> + sizeof(*mdev->dma_parms), GFP_KERNEL); > >> + dma_set_max_seg_size(mdev, 0xffffffffu); > >> + arm_iommu_attach_device(mdev, mapping); > >> + > >> + dev->mem_dev_l = dev->mem_dev_r = mdev; > >> + return 0; > >> +#else > >> > >> unsigned int mem_info[2] = { }; > >> > >> dev->mem_dev_l = devm_kzalloc(&dev->plat_dev->dev, > >> > >> @@ -1049,6 +1073,7 @@ static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev > >> *dev) return -ENOMEM; > >> > >> } > >> return 0; > >> > >> +#endif > >> > >> } > >> > >> /* MFC probe function */ > >> > >> @@ -1228,6 +1253,10 @@ err_mem_init_ctx_1: > >> vb2_dma_contig_cleanup_ctx(dev->alloc_ctx[0]); > >> > >> err_res: > >> s5p_mfc_final_pm(dev); > >> > >> +#ifdef CONFIG_EXYNOS_IOMMU > >> + if (mapping) > >> + arm_iommu_release_mapping(mapping); > >> +#endif > >> > >> pr_debug("%s-- with error\n", __func__); > >> return ret; > >> > >> @@ -1256,6 +1285,10 @@ static int s5p_mfc_remove(struct platform_device > >> *pdev) put_device(dev->mem_dev_r); > >> > >> } > >> > >> +#ifdef CONFIG_EXYNOS_IOMMU > >> + if (mapping) > >> + arm_iommu_release_mapping(mapping); > >> +#endif > >> > >> s5p_mfc_final_pm(dev); > >> return 0; > >> > >> }
Hi Arun, > From: Arun Kumar K [mailto:arunkk.samsung@gmail.com] > Sent: Tuesday, April 22, 2014 2:22 PM > > Hi Laurent, > > Thank you for the review. > > On Tue, Apr 22, 2014 at 5:23 PM, Laurent Pinchart > <laurent.pinchart@ideasonboard.com> wrote: > > Hi Arun, > > > > Thank you for the patch. > > > > On Tuesday 22 April 2014 16:32:48 Arun Kumar K wrote: > >> The patch adds IOMMU support for MFC driver. > > > > I've been working on an IOMMU driver lately, which led me to think > > about how drivers should be interfaced with IOMMUs. Runtime IOMMU > > handling is performed by the DMA mapping API, but in many cases > > (including Exynos platforms) the > > arm_iommu_create_mapping() and arm_iommu_attach_device() functions > > still need to be called explicitly by drivers, which doesn't seem a > very good idea to me. > > Ideally IOMMU usage should be completely transparent for bus master > > drivers, without requiring any driver modification to use the IOMMU. > > > > What would you think about improving the Exynos IOMMU driver to > create > > the mapping and attach the device instead of having to modify all bus > > master drivers ? See the ipmmu_add_device() function in > > http://www.spinics.net/lists/linux-sh/msg30488.html for a possible > > implementation. > > > > Yes that would be a better solution. But as far as I know, exynos > platforms has few more complications where multiple IOMMUs are present > for single IP. > The exynos iommu work is still under progress and KyonHo Cho will have > some inputs / comments on this. This seems to me a valid usecase which > can be considered for exynos iommu also. Arun, could you tell me how did you test this? I think that the MFC driver should not be modified to use iommu. Dma_mapping should be used. On Tizenorg there is a 3.10 kernel with an iommu driver that works with MFC without any patches to the MFC drvier. I disagree to merging this patch, sorry. This should be done the correct way. NACK. Best wishes,
Hi Kamil, On 05/08/14 21:54, Kamil Debski wrote: > Hi Arun, > >> From: Arun Kumar K [mailto:arunkk.samsung@gmail.com] >> Sent: Tuesday, April 22, 2014 2:22 PM >> >> Hi Laurent, >> >> Thank you for the review. >> >> On Tue, Apr 22, 2014 at 5:23 PM, Laurent Pinchart >> <laurent.pinchart@ideasonboard.com> wrote: >>> Hi Arun, >>> >>> Thank you for the patch. >>> >>> On Tuesday 22 April 2014 16:32:48 Arun Kumar K wrote: >>>> The patch adds IOMMU support for MFC driver. >>> >>> I've been working on an IOMMU driver lately, which led me to think >>> about how drivers should be interfaced with IOMMUs. Runtime IOMMU >>> handling is performed by the DMA mapping API, but in many cases >>> (including Exynos platforms) the >>> arm_iommu_create_mapping() and arm_iommu_attach_device() functions >>> still need to be called explicitly by drivers, which doesn't seem a >> very good idea to me. >>> Ideally IOMMU usage should be completely transparent for bus master >>> drivers, without requiring any driver modification to use the IOMMU. >>> >>> What would you think about improving the Exynos IOMMU driver to >> create >>> the mapping and attach the device instead of having to modify all bus >>> master drivers ? See the ipmmu_add_device() function in >>> http://www.spinics.net/lists/linux-sh/msg30488.html for a possible >>> implementation. >>> >> >> Yes that would be a better solution. But as far as I know, exynos >> platforms has few more complications where multiple IOMMUs are present >> for single IP. >> The exynos iommu work is still under progress and KyonHo Cho will have >> some inputs / comments on this. This seems to me a valid usecase which >> can be considered for exynos iommu also. > > Arun, could you tell me how did you test this? It is tested on the IOMMU patches sent by KyongHo Cho (v11 series) https://lkml.org/lkml/2014/3/14/9 I found it to work well with v12 too. > I think that the MFC driver should not be modified to use iommu. Dma_mapping > should be used. On Tizenorg there is a 3.10 kernel with an iommu driver that > works with MFC without any patches to the MFC drvier. This is as per the mainline IOMMU driver patches which are being reviewed now. I could see the exynos DRM also using this kind of approach and is already in mainline. Thats why I thought of sending this. > > I disagree to merging this patch, sorry. This should be done the correct way. > Ok. I agree we can wait till the merging of Samsung IOMMU. If it takes care of making the mapping and attaching the device without the master driver intervention, then we can skip this patch. But till now it is not taken care in the patches which are under review for samsung IOMMU. Regards Arun > NACK. > > Best wishes, > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/media/platform/s5p-mfc/s5p_mfc.c b/drivers/media/platform/s5p-mfc/s5p_mfc.c index 89356ae..1f248ba 100644 --- a/drivers/media/platform/s5p-mfc/s5p_mfc.c +++ b/drivers/media/platform/s5p-mfc/s5p_mfc.c @@ -32,11 +32,18 @@ #include "s5p_mfc_opr.h" #include "s5p_mfc_cmd.h" #include "s5p_mfc_pm.h" +#ifdef CONFIG_EXYNOS_IOMMU +#include <asm/dma-iommu.h> +#endif #define S5P_MFC_NAME "s5p-mfc" #define S5P_MFC_DEC_NAME "s5p-mfc-dec" #define S5P_MFC_ENC_NAME "s5p-mfc-enc" +#ifdef CONFIG_EXYNOS_IOMMU +static struct dma_iommu_mapping *mapping; +#endif + int debug; module_param(debug, int, S_IRUGO | S_IWUSR); MODULE_PARM_DESC(debug, "Debug level - higher value produces more verbose messages"); @@ -1013,6 +1020,23 @@ static void *mfc_get_drv_data(struct platform_device *pdev); static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev *dev) { +#ifdef CONFIG_EXYNOS_IOMMU + struct device *mdev = &dev->plat_dev->dev; + + mapping = arm_iommu_create_mapping(&platform_bus_type, 0x20000000, + SZ_256M); + if (mapping == NULL) { + mfc_err("IOMMU mapping failed\n"); + return -EFAULT; + } + mdev->dma_parms = devm_kzalloc(&dev->plat_dev->dev, + sizeof(*mdev->dma_parms), GFP_KERNEL); + dma_set_max_seg_size(mdev, 0xffffffffu); + arm_iommu_attach_device(mdev, mapping); + + dev->mem_dev_l = dev->mem_dev_r = mdev; + return 0; +#else unsigned int mem_info[2] = { }; dev->mem_dev_l = devm_kzalloc(&dev->plat_dev->dev, @@ -1049,6 +1073,7 @@ static int s5p_mfc_alloc_memdevs(struct s5p_mfc_dev *dev) return -ENOMEM; } return 0; +#endif } /* MFC probe function */ @@ -1228,6 +1253,10 @@ err_mem_init_ctx_1: vb2_dma_contig_cleanup_ctx(dev->alloc_ctx[0]); err_res: s5p_mfc_final_pm(dev); +#ifdef CONFIG_EXYNOS_IOMMU + if (mapping) + arm_iommu_release_mapping(mapping); +#endif pr_debug("%s-- with error\n", __func__); return ret; @@ -1256,6 +1285,10 @@ static int s5p_mfc_remove(struct platform_device *pdev) put_device(dev->mem_dev_r); } +#ifdef CONFIG_EXYNOS_IOMMU + if (mapping) + arm_iommu_release_mapping(mapping); +#endif s5p_mfc_final_pm(dev); return 0; }
The patch adds IOMMU support for MFC driver. Signed-off-by: Arun Kumar K <arun.kk@samsung.com> --- This patch is tested on IOMMU support series [1] posted by KyonHo Cho. [1] https://lkml.org/lkml/2014/3/14/9 --- drivers/media/platform/s5p-mfc/s5p_mfc.c | 33 ++++++++++++++++++++++++++++++ 1 file changed, 33 insertions(+)