On 07/03/17 03:17, Magnus Damm wrote:
> From: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
>
> Introduce an alternative set of iommu_ops suitable for 64-bit ARM
> as well as 32-bit ARM when CONFIG_IOMMU_DMA=y. Also adjust the
> Kconfig to depend on ARM or IOMMU_DMA. Initialize the device
> from ->xlate() when CONFIG_IOMMU_DMA=y.
>
> Signed-off-by: Magnus Damm <damm+renesas@xxxxxxxxxxxxx>
> ---
>
> Changes since V6:
> - Rolled in the following patches from "r8a7795 support V2":
> [PATCH v2 04/11] iommu/ipmmu-vmsa: Reuse iommu groups
> [PATCH v2 06/11] iommu/ipmmu-vmsa: Teach xlate() to skip disabled iommus
> - Moved find_group() implementation to prevent warning on 32-bit ARM
> - Rolled in the following patch from "IPMMU slave device whitelist V2":
> [PATCH/RFC v2 3/4] iommu/ipmmu-vmsa: Check devices in xlate()
>
> drivers/iommu/Kconfig | 1
> drivers/iommu/ipmmu-vmsa.c | 164 +++++++++++++++++++++++++++++++++++++++++---
> 2 files changed, 157 insertions(+), 8 deletions(-)
>
> --- 0001/drivers/iommu/Kconfig
> +++ work/drivers/iommu/Kconfig 2017-03-06 18:42:42.000000000 +0900
> @@ -274,6 +274,7 @@ config EXYNOS_IOMMU_DEBUG
>
> config IPMMU_VMSA
> bool "Renesas VMSA-compatible IPMMU"
> + depends on ARM || IOMMU_DMA
> depends on ARM_LPAE
> depends on ARCH_RENESAS || COMPILE_TEST
> select IOMMU_API
> --- 0009/drivers/iommu/ipmmu-vmsa.c
> +++ work/drivers/iommu/ipmmu-vmsa.c 2017-03-06 19:22:27.700607110 +0900
> @@ -10,6 +10,7 @@
>
> #include <linux/bitmap.h>
> #include <linux/delay.h>
> +#include <linux/dma-iommu.h>
> #include <linux/dma-mapping.h>
> #include <linux/err.h>
> #include <linux/export.h>
> @@ -22,8 +23,10 @@
> #include <linux/sizes.h>
> #include <linux/slab.h>
>
> +#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
> #include <asm/dma-iommu.h>
> #include <asm/pgalloc.h>
> +#endif
>
> #include "io-pgtable.h"
>
> @@ -57,6 +60,8 @@ struct ipmmu_vmsa_archdata {
> struct ipmmu_vmsa_device *mmu;
> unsigned int *utlbs;
> unsigned int num_utlbs;
> + struct device *dev;
> + struct list_head list;
> };
>
> static DEFINE_SPINLOCK(ipmmu_devices_lock);
> @@ -522,14 +527,6 @@ static struct iommu_domain *__ipmmu_doma
> return &domain->io_domain;
> }
>
> -static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
> -{
> - if (type != IOMMU_DOMAIN_UNMANAGED)
> - return NULL;
> -
> - return __ipmmu_domain_alloc(type);
> -}
> -
> static void ipmmu_domain_free(struct iommu_domain *io_domain)
> {
> struct ipmmu_vmsa_domain *domain = to_vmsa_domain(io_domain);
> @@ -572,6 +569,9 @@ static int ipmmu_attach_device(struct io
> dev_err(dev, "Can't attach IPMMU %s to domain on IPMMU %s\n",
> dev_name(mmu->dev), dev_name(domain->mmu->dev));
> ret = -EINVAL;
> + } else {
> + dev_info(dev, "Reusing IPMMU context %u\n",
> + domain->context_id);
Indentation?
> }
>
> spin_unlock_irqrestore(&domain->lock, flags);
> @@ -708,6 +708,7 @@ static int ipmmu_init_platform_device(st
> archdata->mmu = mmu;
> archdata->utlbs = utlbs;
> archdata->num_utlbs = num_utlbs;
> + archdata->dev = dev;
> dev->archdata.iommu = archdata;
> return 0;
>
> @@ -716,6 +717,16 @@ error:
> return ret;
> }
>
> +#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
> +
> +static struct iommu_domain *ipmmu_domain_alloc(unsigned type)
> +{
> + if (type != IOMMU_DOMAIN_UNMANAGED)
> + return NULL;
> +
> + return __ipmmu_domain_alloc(type);
> +}
> +
> static int ipmmu_add_device(struct device *dev)
> {
> struct ipmmu_vmsa_archdata *archdata;
> @@ -823,6 +834,141 @@ static const struct iommu_ops ipmmu_ops
> .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
> };
>
> +#endif /* !CONFIG_ARM && CONFIG_IOMMU_DMA */
> +
> +#ifdef CONFIG_IOMMU_DMA
> +
> +static DEFINE_SPINLOCK(ipmmu_slave_devices_lock);
> +static LIST_HEAD(ipmmu_slave_devices);
> +
> +static struct iommu_domain *ipmmu_domain_alloc_dma(unsigned type)
> +{
> + struct iommu_domain *io_domain = NULL;
> +
> + switch (type) {
> + case IOMMU_DOMAIN_UNMANAGED:
> + io_domain = __ipmmu_domain_alloc(type);
> + break;
> +
> + case IOMMU_DOMAIN_DMA:
> + io_domain = __ipmmu_domain_alloc(type);
> + if (io_domain)
> + iommu_get_dma_cookie(io_domain);
> + break;
> + }
> +
> + return io_domain;
> +}
I still think it would be tidier to put this logic straight into
__ipmmu_domain_alloc(), and use that directly as the callback for this
case. The ipmmu_domain_alloc() wrapper ensures that IOMMU_DOMAIN_DMA
can't be passed through in the legacy 32-bit case, and the cookie calls
are stubbed for !CONFIG_IOMMU_DMA so there are no build concerns.
> +static void ipmmu_domain_free_dma(struct iommu_domain *io_domain)
> +{
> + switch (io_domain->type) {
> + case IOMMU_DOMAIN_DMA:
> + iommu_put_dma_cookie(io_domain);
> + /* fall-through */
> + default:
> + ipmmu_domain_free(io_domain);
> + break;
> + }
> +}
And similarly. The day when 32-bit ARM gets cleaned up to use groups and
default domains properly creeps ever closer (the probe deferral series
looks on-track to finally get in this cycle), so the less fragmentation
and #ifdeffery to untangle at that point the better.
> +static int ipmmu_add_device_dma(struct device *dev)
> +{
> + struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
> + struct iommu_group *group;
> +
> + /* The device has been verified in xlate() */
> + if (!archdata)
> + return -ENODEV;
> +
> + group = iommu_group_get_for_dev(dev);
> + if (IS_ERR(group))
> + return PTR_ERR(group);
> +
> + spin_lock(&ipmmu_slave_devices_lock);
> + list_add(&archdata->list, &ipmmu_slave_devices);
> + spin_unlock(&ipmmu_slave_devices_lock);
> + return 0;
> +}
> +
> +static void ipmmu_remove_device_dma(struct device *dev)
> +{
> + struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
> +
> + spin_lock(&ipmmu_slave_devices_lock);
> + list_del(&archdata->list);
> + spin_unlock(&ipmmu_slave_devices_lock);
> +
> + iommu_group_remove_device(dev);
> +}
> +
> +static struct device *ipmmu_find_sibling_device(struct device *dev)
> +{
> + struct ipmmu_vmsa_archdata *archdata = dev->archdata.iommu;
> + struct ipmmu_vmsa_archdata *sibling_archdata = NULL;
> + bool found = false;
> +
> + spin_lock(&ipmmu_slave_devices_lock);
> +
> + list_for_each_entry(sibling_archdata, &ipmmu_slave_devices, list) {
> + if (archdata == sibling_archdata)
> + continue;
> + if (sibling_archdata->mmu == archdata->mmu) {
So every master behind the same IPMMU gets put in the same group? In
that case, you don't need any of this machinery - you can simply keep
track of a group per IPMMU instance directly. See mtk_iommu.c for an
example.
> + found = true;
> + break;
> + }
> + }
> +
> + spin_unlock(&ipmmu_slave_devices_lock);
> +
> + return found ? sibling_archdata->dev : NULL;
> +}
> +
> +static struct iommu_group *ipmmu_find_group_dma(struct device *dev)
> +{
> + struct iommu_group *group;
> + struct device *sibling;
> +
> + sibling = ipmmu_find_sibling_device(dev);
> + if (sibling)
> + group = iommu_group_get(sibling);
> + if (!sibling || IS_ERR(group))
> + group = generic_device_group(dev);
> +
> + return group;
> +}
> +
> +static int ipmmu_of_xlate_dma(struct device *dev,
> + struct of_phandle_args *spec)
> +{
> + /* If the IPMMU device is disabled in DT then return error
> + * to make sure the of_iommu code does not install ops
> + * even though the iommu device is disabled
> + */
If you're only calling iommu_device_register() from ipmmu_probe(), you
should never see that problem in the first place (because a disabled
node won't even get its platform device created, let alone probe a
driver). I guess this a leftover from when the init_fn once called
of_iommu_set_ops()?
Robin.
> + if (!of_device_is_available(spec->np))
> + return -ENODEV;
> +
> + return ipmmu_init_platform_device(dev);
> +}
> +
> +static const struct iommu_ops ipmmu_ops = {
> + .domain_alloc = ipmmu_domain_alloc_dma,
> + .domain_free = ipmmu_domain_free_dma,
> + .attach_dev = ipmmu_attach_device,
> + .detach_dev = ipmmu_detach_device,
> + .map = ipmmu_map,
> + .unmap = ipmmu_unmap,
> + .map_sg = default_iommu_map_sg,
> + .iova_to_phys = ipmmu_iova_to_phys,
> + .add_device = ipmmu_add_device_dma,
> + .remove_device = ipmmu_remove_device_dma,
> + .device_group = ipmmu_find_group_dma,
> + .pgsize_bitmap = SZ_1G | SZ_2M | SZ_4K,
> + .of_xlate = ipmmu_of_xlate_dma,
> +};
> +
> +#endif /* CONFIG_IOMMU_DMA */
> +
> /* -----------------------------------------------------------------------------
> * Probe/remove and init
> */
> @@ -912,7 +1058,9 @@ static int ipmmu_remove(struct platform_
> list_del(&mmu->list);
> spin_unlock(&ipmmu_devices_lock);
>
> +#if defined(CONFIG_ARM) && !defined(CONFIG_IOMMU_DMA)
> arm_iommu_release_mapping(mmu->mapping);
> +#endif
>
> ipmmu_device_reset(mmu);
>
>
