Le mardi 16 septembre 2014 à 13:54 +0200, Marek Szyprowski a écrit :
The driver doesn't need to do anything important in device add/remove callbacks, because initialization will be done from device-tree specific callbacks added later. IOMMU groups created by current code were never used.
Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com
The exyons iommu init fails if those are removed, that is it never reach init_done: 1. exynos_iommu_setup 2. - exynos_iommu_init 3. ---bus_set_iommu 4. ------ add_iommu_group
that is (4) add_iommu_group returns ENODEV to bus_set_iommu, the latter doing so to exynos_iommu_init. Which thus error out before the init_done is set to true.
Mind restoring device_add/remove is not that easy. Either I did not and modified add_iommu_group to return 0 if add_device was not defined. This works. Otherwise I did revert this patch but had to also move the iommu_init from iommu.c before of_iommu_init in arch/arm/kernel/setup.c (switching iommu_init to global namespace in the process). This to avoid use of not yet initialized mutex iommu_group_mutex and crash that follow suit. This mutex is used in iommu_group_add_device called by exynos_iommu_add_device.
The logs of the first issue, ie exynos_iommo_init and bus_set_iommu returns ENODEV
[ 0.602816] exynos_iommu_init: Failed to register exynos-iommu driver. [ 0.603358] platform 13620000.sysmmu: device is not dma coherent [ 0.603384] platform 13620000.sysmmu: device is not behind an iommu [ 0.605243] exynos-sysmmu 13620000.sysmmu: genpd_dev_pm_attach() failed to find PM domain: -2 [ 0.606399] exynos_iommu_init: Failed to register exynos-iommu driver. [ 0.607263] platform 13630000.sysmmu: device is not dma coherent [ 0.607290] platform 13630000.sysmmu: device is not behind an iommu [ 0.609111] exynos-sysmmu 13620000.sysmmu: genpd_dev_pm_attach() failed to find PM domain: -2 [ 0.609464] exynos-sysmmu 13620000.sysmmu: Unbalanced pm_runtime_enable! [ 0.609868] exynos-sysmmu 13630000.sysmmu: genpd_dev_pm_attach() failed to find PM domain: -2 (...) [ 0.946506] platform 10800000.g2d: device is not dma coherent [ 0.946553] platform 10800000.g2d: device is not behind an iommu (...)
Mind the power domain failure comes from me not finding a way to apply the power domain registration this early yet .
Best regards, Alban Broweys
drivers/iommu/exynos-iommu.c | 28 ---------------------------- 1 file changed, 28 deletions(-)
diff --git a/drivers/iommu/exynos-iommu.c b/drivers/iommu/exynos-iommu.c index b271348a4ec1..1b3f00726cd4 100644 --- a/drivers/iommu/exynos-iommu.c +++ b/drivers/iommu/exynos-iommu.c @@ -1055,32 +1055,6 @@ static phys_addr_t exynos_iommu_iova_to_phys(struct iommu_domain *domain, return phys; } -static int exynos_iommu_add_device(struct device *dev) -{
- struct iommu_group *group;
- int ret;
- group = iommu_group_get(dev);
- if (!group) {
group = iommu_group_alloc();if (IS_ERR(group)) {dev_err(dev, "Failed to allocate IOMMU group\n");return PTR_ERR(group);}- }
- ret = iommu_group_add_device(group, dev);
- iommu_group_put(group);
- return ret;
-}
-static void exynos_iommu_remove_device(struct device *dev) -{
- iommu_group_remove_device(dev);
-}
static const struct iommu_ops exynos_iommu_ops = { .domain_init = exynos_iommu_domain_init, .domain_destroy = exynos_iommu_domain_destroy, @@ -1089,8 +1063,6 @@ static const struct iommu_ops exynos_iommu_ops = { .map = exynos_iommu_map, .unmap = exynos_iommu_unmap, .iova_to_phys = exynos_iommu_iova_to_phys,
- .add_device = exynos_iommu_add_device,
- .remove_device = exynos_iommu_remove_device, .pgsize_bitmap = SECT_SIZE | LPAGE_SIZE | SPAGE_SIZE,
};