On 2022/4/4 19:27, John Garry wrote: > Add support to allow the maximum optimised DMA len be set for an IOMMU > group via sysfs. > > This is much the same with the method to change the default domain type > for a group. > > Signed-off-by: John Garry <john.ga...@huawei.com> > --- > .../ABI/testing/sysfs-kernel-iommu_groups | 16 +++++ > drivers/iommu/iommu.c | 59 ++++++++++++++++++- > include/linux/iommu.h | 6 ++ > 3 files changed, 79 insertions(+), 2 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-kernel-iommu_groups > b/Documentation/ABI/testing/sysfs-kernel-iommu_groups > index b15af6a5bc08..ed6f72794f6c 100644 > --- a/Documentation/ABI/testing/sysfs-kernel-iommu_groups > +++ b/Documentation/ABI/testing/sysfs-kernel-iommu_groups > @@ -63,3 +63,19 @@ Description: /sys/kernel/iommu_groups/<grp_id>/type > shows the type of default > system could lead to catastrophic effects (the users might > need to reboot the machine to get it to normal state). So, it's > expected that the users understand what they're doing. > + > +What: /sys/kernel/iommu_groups/<grp_id>/max_opt_dma_size > +Date: Feb 2022 > +KernelVersion: v5.18 > +Contact: iommu@lists.linux-foundation.org > +Description: /sys/kernel/iommu_groups/<grp_id>/max_opt_dma_size shows the > + max optimised DMA size for the default IOMMU domain associated > + with the group. > + Each IOMMU domain has an IOVA domain. The IOVA domain caches > + IOVAs upto a certain size as a performance optimisation. > + This sysfs file allows the range of the IOVA domain caching be > + set, such that larger than default IOVAs may be cached. > + A value of 0 means that the default caching range is chosen. > + A privileged user could request the kernel the change the range > + by writing to this file. For this to happen, the same rules > + and procedure applies as in changing the default domain type. > diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c > index 10bb10c2a210..7c7258f19bed 100644 > --- a/drivers/iommu/iommu.c > +++ b/drivers/iommu/iommu.c > @@ -48,6 +48,7 @@ struct iommu_group { > struct iommu_domain *default_domain; > struct iommu_domain *domain; > struct list_head entry; > + size_t max_opt_dma_size; > }; > > struct group_device { > @@ -89,6 +90,9 @@ static int iommu_create_device_direct_mappings(struct > iommu_group *group, > static struct iommu_group *iommu_group_get_for_dev(struct device *dev); > static ssize_t iommu_group_store_type(struct iommu_group *group, > const char *buf, size_t count); > +static ssize_t iommu_group_store_max_opt_dma_size(struct iommu_group *group, > + const char *buf, > + size_t count); > > #define IOMMU_GROUP_ATTR(_name, _mode, _show, _store) \ > struct iommu_group_attribute iommu_group_attr_##_name = \ > @@ -571,6 +575,12 @@ static ssize_t iommu_group_show_type(struct iommu_group > *group, > return strlen(type); > } > > +static ssize_t iommu_group_show_max_opt_dma_size(struct iommu_group *group, > + char *buf) > +{ > + return sprintf(buf, "%zu\n", group->max_opt_dma_size); > +} > + > static IOMMU_GROUP_ATTR(name, S_IRUGO, iommu_group_show_name, NULL); > > static IOMMU_GROUP_ATTR(reserved_regions, 0444, > @@ -579,6 +589,9 @@ static IOMMU_GROUP_ATTR(reserved_regions, 0444, > static IOMMU_GROUP_ATTR(type, 0644, iommu_group_show_type, > iommu_group_store_type); > > +static IOMMU_GROUP_ATTR(max_opt_dma_size, 0644, > iommu_group_show_max_opt_dma_size, > + iommu_group_store_max_opt_dma_size); > + > static void iommu_group_release(struct kobject *kobj) > { > struct iommu_group *group = to_iommu_group(kobj); > @@ -665,6 +678,10 @@ struct iommu_group *iommu_group_alloc(void) > if (ret) > return ERR_PTR(ret); > > + ret = iommu_group_create_file(group, > &iommu_group_attr_max_opt_dma_size); > + if (ret) > + return ERR_PTR(ret); > + > pr_debug("Allocated group %d\n", group->id); > > return group; > @@ -2087,6 +2104,11 @@ struct iommu_domain *iommu_get_dma_domain(struct > device *dev) > return dev->iommu_group->default_domain; > } > > +size_t iommu_group_get_max_opt_dma_size(struct iommu_group *group) > +{ > + return group->max_opt_dma_size; > +} > + > /* > * IOMMU groups are really the natural working unit of the IOMMU, but > * the IOMMU API works on domains and devices. Bridge that gap by > @@ -2871,12 +2893,14 @@ EXPORT_SYMBOL_GPL(iommu_sva_get_pasid); > * @prev_dev: The device in the group (this is used to make sure that the > device > * hasn't changed after the caller has called this function) > * @type: The type of the new default domain that gets associated with the > group > + * @max_opt_dma_size: Set the IOMMU group max_opt_dma_size if non-zero > * > * Returns 0 on success and error code on failure > * > */ > static int iommu_change_dev_def_domain(struct iommu_group *group, > - struct device *prev_dev, int type) > + struct device *prev_dev, int type, > + unsigned long max_opt_dma_size) > { > struct iommu_domain *prev_dom; > struct group_device *grp_dev; > @@ -2977,6 +3001,9 @@ static int iommu_change_dev_def_domain(struct > iommu_group *group, > > group->domain = group->default_domain; > > + if (max_opt_dma_size) > + group->max_opt_dma_size = max_opt_dma_size; Why not add a new function just do this? In this way, we do not need to modify iommu_change_dev_def_domain() and patch 3/5 can be dropped. > + > /* > * Release the mutex here because ops->probe_finalize() call-back of > * some vendor IOMMU drivers calls arm_iommu_attach_device() which > @@ -3003,6 +3030,7 @@ static int iommu_change_dev_def_domain(struct > iommu_group *group, > > enum iommu_group_op { > CHANGE_GROUP_TYPE, > + CHANGE_DMA_OPT_SIZE, > }; > > static int __iommu_group_store_type(const char *buf, struct iommu_group > *group, > @@ -3031,7 +3059,24 @@ static int __iommu_group_store_type(const char *buf, > struct iommu_group *group, > return -EINVAL; > } > > - return iommu_change_dev_def_domain(group, dev, type); > + return iommu_change_dev_def_domain(group, dev, type, 0); > +} > + > +static int __iommu_group_store_max_opt_dma_size(const char *buf, > + struct iommu_group *group, > + struct device *dev) > +{ > + unsigned long val; > + > + if (kstrtoul(buf, 0, &val) || !val) > + return -EINVAL; > + > + if (device_is_bound(dev)) { > + pr_err_ratelimited("Device is still bound to driver\n"); > + return -EINVAL; > + } > + > + return iommu_change_dev_def_domain(group, dev, __IOMMU_DOMAIN_SAME, > val); > } > > /* > @@ -3108,6 +3153,9 @@ static ssize_t iommu_group_store_common(struct > iommu_group *group, > case CHANGE_GROUP_TYPE: > ret = __iommu_group_store_type(buf, group, dev); > break; > + case CHANGE_DMA_OPT_SIZE: > + ret = __iommu_group_store_max_opt_dma_size(buf, group, dev); > + break; > default: > ret = -EINVAL; > } > @@ -3124,3 +3172,10 @@ static ssize_t iommu_group_store_type(struct > iommu_group *group, > { > return iommu_group_store_common(group, CHANGE_GROUP_TYPE, buf, count); > } > + > +static ssize_t iommu_group_store_max_opt_dma_size(struct iommu_group *group, > + const char *buf, > + size_t count) > +{ > + return iommu_group_store_common(group, CHANGE_DMA_OPT_SIZE, buf, count); > +} > diff --git a/include/linux/iommu.h b/include/linux/iommu.h > index b141cf71c7af..6915e68c40b7 100644 > --- a/include/linux/iommu.h > +++ b/include/linux/iommu.h > @@ -430,6 +430,7 @@ extern int iommu_sva_unbind_gpasid(struct iommu_domain > *domain, > struct device *dev, ioasid_t pasid); > extern struct iommu_domain *iommu_get_domain_for_dev(struct device *dev); > extern struct iommu_domain *iommu_get_dma_domain(struct device *dev); > +extern size_t iommu_group_get_max_opt_dma_size(struct iommu_group *group); > extern int iommu_map(struct iommu_domain *domain, unsigned long iova, > phys_addr_t paddr, size_t size, int prot); > extern int iommu_map_atomic(struct iommu_domain *domain, unsigned long iova, > @@ -725,6 +726,11 @@ static inline struct iommu_domain > *iommu_get_domain_for_dev(struct device *dev) > return NULL; > } > > +static inline size_t iommu_group_get_max_opt_dma_size(struct iommu_group > *group) > +{ > + return 0; > +} > + > static inline int iommu_map(struct iommu_domain *domain, unsigned long iova, > phys_addr_t paddr, size_t size, int prot) > { > -- Regards, Zhen Lei _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH RESEND v5 4/5] iommu: Allow max opt DMA len be set for a group via sysfs
Leizhen (ThunderTown) via iommu Thu, 07 Apr 2022 01:21:46 -0700
- [PATCH RESEND v5 0/5] iommu: Allow IOVA rc... John Garry via iommu
- [PATCH RESEND v5 1/5] iommu: Refactor... John Garry via iommu
- Re: [PATCH RESEND v5 1/5] iommu: ... Leizhen (ThunderTown) via iommu
- [PATCH RESEND v5 2/5] iova: Allow rca... John Garry via iommu
- Re: [PATCH RESEND v5 2/5] iova: A... Leizhen (ThunderTown) via iommu
- [PATCH RESEND v5 3/5] iommu: Allow io... John Garry via iommu
- [PATCH RESEND v5 4/5] iommu: Allow ma... John Garry via iommu
- Re: [PATCH RESEND v5 4/5] iommu: ... Leizhen (ThunderTown) via iommu
- Re: [PATCH RESEND v5 4/5] iom... John Garry via iommu
- [PATCH RESEND v5 5/5] iova: Add iova_... John Garry via iommu
- Re: [PATCH RESEND v5 5/5] iova: A... Leizhen (ThunderTown) via iommu
- Re: [PATCH RESEND v5 5/5] iov... John Garry via iommu