Commit 1a4e90f2 authored by Marc Zyngier's avatar Marc Zyngier Committed by Joerg Roedel

iommu/rockchip: Perform a reset on shutdown

Trying to do a kexec whilst the iommus are still on is proving to be
a challenging exercise. It is terribly unsafe, as we're reusing the
memory allocated for the page tables, leading to a likely crash.

Let's implement a shutdown method that will at least try to stop
DMA from going crazy behind our back. Note that we need to be
extra cautious when doing so, as the IOMMU may not be clocked
if controlled by a another master, as typical on Rockchip system.
Suggested-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Signed-off-by: default avatarJoerg Roedel <jroedel@suse.de>
parent 0c8efd61
...@@ -1209,6 +1209,23 @@ static int rk_iommu_remove(struct platform_device *pdev) ...@@ -1209,6 +1209,23 @@ static int rk_iommu_remove(struct platform_device *pdev)
return 0; return 0;
} }
static void rk_iommu_shutdown(struct platform_device *pdev)
{
struct rk_iommu *iommu = platform_get_drvdata(pdev);
/*
* Be careful not to try to shutdown an otherwise unused
* IOMMU, as it is likely not to be clocked, and accessing it
* would just block. An IOMMU without a domain is likely to be
* unused, so let's use this as a (weak) guard.
*/
if (iommu && iommu->domain) {
rk_iommu_enable_stall(iommu);
rk_iommu_disable_paging(iommu);
rk_iommu_force_reset(iommu);
}
}
static const struct of_device_id rk_iommu_dt_ids[] = { static const struct of_device_id rk_iommu_dt_ids[] = {
{ .compatible = "rockchip,iommu" }, { .compatible = "rockchip,iommu" },
{ /* sentinel */ } { /* sentinel */ }
...@@ -1218,6 +1235,7 @@ MODULE_DEVICE_TABLE(of, rk_iommu_dt_ids); ...@@ -1218,6 +1235,7 @@ MODULE_DEVICE_TABLE(of, rk_iommu_dt_ids);
static struct platform_driver rk_iommu_driver = { static struct platform_driver rk_iommu_driver = {
.probe = rk_iommu_probe, .probe = rk_iommu_probe,
.remove = rk_iommu_remove, .remove = rk_iommu_remove,
.shutdown = rk_iommu_shutdown,
.driver = { .driver = {
.name = "rk_iommu", .name = "rk_iommu",
.of_match_table = rk_iommu_dt_ids, .of_match_table = rk_iommu_dt_ids,
......
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