[PATCH v4 1/2] acpi:iort: Add an IORT helper function to reserve HW ITS address regions for IOMMU drivers
Robin Murphy
robin.murphy at arm.com
Tue Jul 25 10:32:40 PDT 2017
On 25/07/17 18:11, Lorenzo Pieralisi wrote:
> On Tue, Jul 25, 2017 at 12:17:31PM +0100, Shameer Kolothum wrote:
>> The helper function retrieves ITS address regions through IORT
>> device <-> ITS mappings and reserves it so that these regions
>> will not be translated by IOMMU and will be excluded from IOVA
>> allocations. IOMMU drivers can use this to implement their
>> .get_resv_regions callback.
>>
>> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi at huawei.com>
>> ---
>> drivers/acpi/arm64/iort.c | 91 ++++++++++++++++++++++++++++++++++++++--
>> drivers/irqchip/irq-gic-v3-its.c | 3 +-
>> include/linux/acpi_iort.h | 8 +++-
>> 3 files changed, 97 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
>> index a3215ee..e28f30c 100644
>> --- a/drivers/acpi/arm64/iort.c
>> +++ b/drivers/acpi/arm64/iort.c
>> @@ -39,6 +39,7 @@
>> struct iort_its_msi_chip {
>> struct list_head list;
>> struct fwnode_handle *fw_node;
>> + phys_addr_t base_addr;
>> u32 translation_id;
>> };
>>
>> @@ -136,14 +137,16 @@ typedef acpi_status (*iort_find_node_callback)
>> static DEFINE_SPINLOCK(iort_msi_chip_lock);
>>
>> /**
>> - * iort_register_domain_token() - register domain token and related ITS ID
>> - * to the list from where we can get it back later on.
>> + * iort_register_domain_token() - register domain token along with related
>> + * ITS ID and base address to the list from where we can get it back later on.
>> * @trans_id: ITS ID.
>> + * @base: ITS base address.
>> * @fw_node: Domain token.
>> *
>> * Returns: 0 on success, -ENOMEM if no memory when allocating list element
>> */
>> -int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node)
>> +int iort_register_domain_token(int trans_id, phys_addr_t base,
>> + struct fwnode_handle *fw_node)
>> {
>> struct iort_its_msi_chip *its_msi_chip;
>>
>> @@ -153,6 +156,7 @@ int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node)
>>
>> its_msi_chip->fw_node = fw_node;
>> its_msi_chip->translation_id = trans_id;
>> + its_msi_chip->base_addr = base;
>>
>> spin_lock(&iort_msi_chip_lock);
>> list_add(&its_msi_chip->list, &iort_msi_chip_list);
>> @@ -481,6 +485,24 @@ int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
>> return -ENODEV;
>> }
>>
>> +static int iort_find_its_base(u32 its_id, phys_addr_t *base)
>
> You have to tag it as __maybe_unused for the !IOMMU_API case.
>
>> +{
>> + struct iort_its_msi_chip *its_msi_chip;
>> + bool match = false;
>> +
>> + spin_lock(&iort_msi_chip_lock);
>> + list_for_each_entry(its_msi_chip, &iort_msi_chip_list, list) {
>> + if (its_msi_chip->translation_id == its_id) {
>> + *base = its_msi_chip->base_addr;
>> + match = true;
>> + break;
>> + }
>> + }
>> + spin_unlock(&iort_msi_chip_lock);
>> +
>> + return match ? 0 : -ENODEV;
>> +}
>> +
>> /**
>> * iort_dev_find_its_id() - Find the ITS identifier for a device
>> * @dev: The device.
>> @@ -639,6 +661,67 @@ int iort_add_device_replay(const struct iommu_ops *ops, struct device *dev)
>>
>> return err;
>> }
>> +
>> +/**
>> + * iort_iommu_its_get_resv_regions - Reserved region driver helper
>> + * @dev: Device from iommu_get_resv_regions()
>> + * @list: Reserved region list from iommu_get_resv_regions()
>> + *
>> + * Returns: Number of reserved regions on success(0 if no associated ITS),
>> + * appropriate error value otherwise.
>> + *
>> + * IOMMU drivers can use this to implement their .get_resv_regions callback
>> + * for reserving the HW ITS address regions.
>
> Stale comment.
>
>> + */
>> +int iort_iommu_its_get_resv_regions(struct device *dev, struct list_head *head)
>> +{
>> + int i;
>> + struct acpi_iort_its_group *its;
>> + struct acpi_iort_node *node, *its_node = NULL;
>> + int resv = 0;
>
> Nit: int i, resv = 0;
>
> I can make these changes but I suspect this series will go via IOMMU
> tree, let me know how you want to handle it.
>
> Lorenzo
>
>> + node = iort_find_dev_node(dev);
>> + if (!node)
>> + return -ENODEV;
>> +
I'd suggest we also want a comment here to clarify that we're currently
assuming straightforward topologies where all mappings for a given root
complex/named component target the same ITS group. Otherwise we're going
to need somewhat more logic to iterate the its_node processing over
every mapping (or every alias in the PCI case), but avoid creating
duplicate entries.
Robin.
>> + if (dev_is_pci(dev)) {
>> + u32 rid;
>> +
>> + pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, &rid);
>> + its_node = iort_node_map_id(node, rid, NULL, IORT_MSI_TYPE);
>> + } else {
>> + for (i = 0; i < node->mapping_count; i++) {
>> + its_node = iort_node_map_platform_id(node, NULL,
>> + IORT_MSI_TYPE, i);
>> + if (its_node)
>> + break;
>> + }
>> + }
>> +
>> + if (!its_node)
>> + return 0;
>> +
>> + /* Move to ITS specific data */
>> + its = (struct acpi_iort_its_group *)its_node->node_data;
>> +
>> + for (i = 0; i < its->its_count; i++) {
>> + phys_addr_t base;
>> +
>> + if (!iort_find_its_base(its->identifiers[i], &base)) {
>> + int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
>> + struct iommu_resv_region *region;
>> +
>> + region = iommu_alloc_resv_region(base, SZ_128K, prot,
>> + IOMMU_RESV_MSI);
>> + if (region) {
>> + list_add_tail(®ion->list, head);
>> + resv++;
>> + }
>> + }
>> + }
>> +
>> + return (resv == its->its_count) ? resv : -ENODEV;
>> +}
>> #else
>> static inline
>> const struct iommu_ops *iort_fwspec_iommu_ops(struct iommu_fwspec *fwspec)
>> @@ -646,6 +729,8 @@ const struct iommu_ops *iort_fwspec_iommu_ops(struct iommu_fwspec *fwspec)
>> static inline
>> int iort_add_device_replay(const struct iommu_ops *ops, struct device *dev)
>> { return 0; }
>> +int iort_iommu_its_get_resv_regions(struct device *dev, struct list_head *head)
>> +{ return -ENODEV; }
>> #endif
>>
>> static const struct iommu_ops *iort_iommu_xlate(struct device *dev,
>> diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
>> index 6893287..77322b3 100644
>> --- a/drivers/irqchip/irq-gic-v3-its.c
>> +++ b/drivers/irqchip/irq-gic-v3-its.c
>> @@ -1928,7 +1928,8 @@ static int __init gic_acpi_parse_madt_its(struct acpi_subtable_header *header,
>> return -ENOMEM;
>> }
>>
>> - err = iort_register_domain_token(its_entry->translation_id, dom_handle);
>> + err = iort_register_domain_token(its_entry->translation_id, res.start,
>> + dom_handle);
>> if (err) {
>> pr_err("ITS@%pa: Unable to register GICv3 ITS domain token (ITS ID %d) to IORT\n",
>> &res.start, its_entry->translation_id);
>> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
>> index 8379d40..56bb6c7 100644
>> --- a/include/linux/acpi_iort.h
>> +++ b/include/linux/acpi_iort.h
>> @@ -26,7 +26,8 @@
>> #define IORT_IRQ_MASK(irq) (irq & 0xffffffffULL)
>> #define IORT_IRQ_TRIGGER_MASK(irq) ((irq >> 32) & 0xffffffffULL)
>>
>> -int iort_register_domain_token(int trans_id, struct fwnode_handle *fw_node);
>> +int iort_register_domain_token(int trans_id, phys_addr_t base,
>> + struct fwnode_handle *fw_node);
>> void iort_deregister_domain_token(int trans_id);
>> struct fwnode_handle *iort_find_domain_token(int trans_id);
>> #ifdef CONFIG_ACPI_IORT
>> @@ -38,8 +39,10 @@
>> /* IOMMU interface */
>> void iort_set_dma_mask(struct device *dev);
>> const struct iommu_ops *iort_iommu_configure(struct device *dev);
>> +int iort_iommu_its_get_resv_regions(struct device *dev, struct list_head *head);
>> #else
>> static inline void acpi_iort_init(void) { }
>> +static inline bool iort_node_match(u8 type) { return false; }
>> static inline u32 iort_msi_map_rid(struct device *dev, u32 req_id)
>> { return req_id; }
>> static inline struct irq_domain *iort_get_device_domain(struct device *dev,
>> @@ -51,6 +54,9 @@ static inline void iort_set_dma_mask(struct device *dev) { }
>> static inline
>> const struct iommu_ops *iort_iommu_configure(struct device *dev)
>> { return NULL; }
>> +static inline
>> +int iort_iommu_its_get_resv_regions(struct device *dev, struct list_head *head)
>> +{ return -ENODEV; }
>> #endif
>>
>> #endif /* __ACPI_IORT_H__ */
>> --
>> 1.9.1
>>
>>
>> --
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