iommu: Add "iommu.strict" command line option

Add a generic command line option to enable lazy unmapping via IOVA
flush queues, which will initally be suuported by iommu-dma. This echoes
the semantics of "intel_iommu=strict" (albeit with the opposite default
value), but in the driver-agnostic fashion of "iommu.passthrough".

Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
[rm: move handling out of SMMUv3 driver, clean up documentation]
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
[will: dropped broken printk when parsing command-line option]
Signed-off-by: Will Deacon <will.deacon@arm.com>
This commit is contained in:
Zhen Lei
2018-09-20 17:10:23 +01:00
committed by Will Deacon
parent 2da274cdf9
commit 68a6efe86f
2 changed files with 26 additions and 0 deletions

View File

@@ -41,6 +41,7 @@ static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_IDENTITY;
#else
static unsigned int iommu_def_domain_type = IOMMU_DOMAIN_DMA;
#endif
static bool iommu_dma_strict __read_mostly = true;
struct iommu_callback_data {
const struct iommu_ops *ops;
@@ -131,6 +132,12 @@ static int __init iommu_set_def_domain_type(char *str)
}
early_param("iommu.passthrough", iommu_set_def_domain_type);
static int __init iommu_dma_setup(char *str)
{
return kstrtobool(str, &iommu_dma_strict);
}
early_param("iommu.strict", iommu_dma_setup);
static ssize_t iommu_group_attr_show(struct kobject *kobj,
struct attribute *__attr, char *buf)
{
@@ -1072,6 +1079,13 @@ struct iommu_group *iommu_group_get_for_dev(struct device *dev)
group->default_domain = dom;
if (!group->domain)
group->domain = dom;
if (dom && !iommu_dma_strict) {
int attr = 1;
iommu_domain_set_attr(dom,
DOMAIN_ATTR_DMA_USE_FLUSH_QUEUE,
&attr);
}
}
ret = iommu_group_add_device(group, dev);