[PATCH v13 0/2] iommu/smmu-v3: Workaround for hisilicon 161010801 erratum(reserve HW MSI)

[PATCH v13 0/2] iommu/smmu-v3: Workaround for hisilicon 161010801 erratum(reserve HW MSI)

[Shameer Kolothum]

On certain HiSilicon platforms (hip06/hip07) the GIC ITS and PCIe RC
deviates from the standard implementation and this breaks PCIe MSI
functionality when SMMU is enabled.

The HiSilicon erratum 161010801 describes this limitation of certain
HiSilicon platforms to support the SMMU mappings for MSI transactions.
On these platforms GICv3 ITS translator is presented with the deviceID
by extending the MSI payload data to 64 bits to include the deviceID.
Hence, the PCIe controller on this platforms has to differentiate the MSI
payload against other DMA payload and has to modify the MSI payload.
This basically makes it difficult for this platforms to have a SMMU
translation for MSI.

This patch implements an ACPI based quirk to reserve the hw msi regions
in the smmu-v3 driver which means these address regions will not be
translated and will be excluded from iova allocations.

To implement this quirk, the following changes are incorporated,
  -Added a generic helper function to IORT code to retrieve and reserve
   the associated ITS base address from a device IORT node. The function
   has a check for smmu model to determine whether the platform requires
   the HW MSI reservation or not.

Changelog:

v12 --> v13
- Added Reviewed-by tags for patch #1.
- Dropped the .dts changes (patch #3) from this series. That will be
  send separately. 

v11--> v12
-Thanks to Lorenzo, Fixed !CONFIG_IOMMU_API compile error(patch #1).

v10 --> v11
-Addressed comments from Lorenzo(patch#1)
-Added Robin's Reviewed-by to patch #2

v9 --> v10
Addressed comments:
-Moved smmu model check to iort helper function to selectively apply
 the msi reservation which will make the fn call generic from iommu-dma.
-Removed PCI blacklisting patch, instead added smmu nodes(disabled)
 with comments to hip06/hip07 dts file.

v8 --> v9
-Thanks to Marc, fixed IORT helper function to reserve the ITS
 translater region only.
-Removed the DT support for MSI reservation and blacklisted
 HiSilicon PCIe controllers on DT based systems when SMMUv3 is
 enabled.

v7 --> v8
Addressed comments from Rob and Lorenzo:
 -Modified to use DT compatible string for errata.
 -Changed logic to retrieve the msi-parent for DT case.

v6 --> v7
Addressed request from Will to add DT support for the erratum:
 - added bt binding
 - add of_iommu_msi_get_resv_regions()
New arm64 silicon errata entry
Rename iort_iommu_{its->msi}_get_resv_regions

v5 --> v6
Addressed comments from Robin and Lorenzo:
-No change to patch#1 .
-Reverted v5 patch#2 as this might break the platforms where this quirk
  is not applicable. Provided a generic function in iommu code and added
  back the quirk implementation in SMMU v3 driver(patch#3)

v4 --> v5
Addressed comments from Robin and Lorenzo:
-Added a comment to make it clear that, for now, only straightforward
  HW topologies are handled while reserving ITS regions(patch #1).

v3 --> v4
Rebased on 4.13-rc1.
Addressed comments from Robin, Will and Lorenzo:
-As suggested by Robin, moved the ITS msi reservation into
  iommu_dma_get_resv_regions().
-Added its_count != resv region failure case(patch #1).

v2 --> v3
Addressed comments from Lorenzo and Robin:
-Removed dev_is_pci() check in smmuV3 driver.
-Don't treat device not having an ITS mapping as an error in
  iort helper function.

v1 --> v2
-patch 2/2: Invoke iort helper fn based on fwnode type(acpi).

RFCv2 -->PATCH
-Incorporated Lorenzo's review comments.

RFC v1 --> RFC v2
Based on Robin's review comments,
-Removed  the generic erratum framework.
-Using IORT/MADT tables to retrieve the ITS base addr instead
 of vendor specific CSRT table.


Shameerali Kolothum Thodi (2):
  ACPI/IORT: Add msi address regions reservation helper
  iommu/dma: Add HW MSI(GICv3 ITS) address regions reservation

 drivers/acpi/arm64/iort.c        | 111 +++++++++++++++++++++++++++++++++++++--
 drivers/iommu/dma-iommu.c        |   8 ++-
 drivers/irqchip/irq-gic-v3-its.c |   3 +-
 include/linux/acpi_iort.h        |   7 ++-
 4 files changed, 123 insertions(+), 6 deletions(-)

-- 
2.7.4

[PATCH v13 1/2] ACPI/IORT: Add msi address regions reservation helper

[Shameer Kolothum]

On some platforms msi parent address regions have to be excluded from
normal IOVA allocation in that they are detected and decoded in a HW
specific way by system components and so they cannot be considered normal
IOVA address space.

Add a helper function that retrieves ITS address regions - the msi
parent - 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. The function checks for the smmu model number and
only applies the msi reservation if the platform requires it.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
[For the ITS part]
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
---
 drivers/acpi/arm64/iort.c        | 111 +++++++++++++++++++++++++++++++++++++--
 drivers/irqchip/irq-gic-v3-its.c |   3 +-
 include/linux/acpi_iort.h        |   7 ++-
 3 files changed, 116 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 95255ec..e2f7bdd 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;
 };
 
@@ -161,14 +162,16 @@ static LIST_HEAD(iort_msi_chip_list);
 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;
 
@@ -178,6 +181,7 @@ 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);
@@ -581,6 +585,24 @@ int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id)
 	return -ENODEV;
 }
 
+static int __maybe_unused iort_find_its_base(u32 its_id, phys_addr_t *base)
+{
+	struct iort_its_msi_chip *its_msi_chip;
+	int ret = -ENODEV;
+
+	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;
+			ret = 0;
+			break;
+		}
+	}
+	spin_unlock(&iort_msi_chip_lock);
+
+	return ret;
+}
+
 /**
  * iort_dev_find_its_id() - Find the ITS identifier for a device
  * @dev: The device.
@@ -766,6 +788,24 @@ static inline bool iort_iommu_driver_enabled(u8 type)
 }
 
 #ifdef CONFIG_IOMMU_API
+static struct acpi_iort_node *iort_get_msi_resv_iommu(struct device *dev)
+{
+	struct acpi_iort_node *iommu;
+	struct iommu_fwspec *fwspec = dev->iommu_fwspec;
+
+	iommu = iort_get_iort_node(fwspec->iommu_fwnode);
+
+	if (iommu && (iommu->type == ACPI_IORT_NODE_SMMU_V3)) {
+		struct acpi_iort_smmu_v3 *smmu;
+
+		smmu = (struct acpi_iort_smmu_v3 *)iommu->node_data;
+		if (smmu->model == ACPI_IORT_SMMU_V3_HISILICON_HI161X)
+			return iommu;
+	}
+
+	return NULL;
+}
+
 static inline const struct iommu_ops *iort_fwspec_iommu_ops(
 				struct iommu_fwspec *fwspec)
 {
@@ -782,6 +822,69 @@ static inline int iort_add_device_replay(const struct iommu_ops *ops,
 
 	return err;
 }
+
+/**
+ * iort_iommu_msi_get_resv_regions - Reserved region driver helper
+ * @dev: Device from iommu_get_resv_regions()
+ * @head: Reserved region list from iommu_get_resv_regions()
+ *
+ * Returns: Number of msi reserved regions on success (0 if platform
+ *          doesn't require the reservation or no associated msi regions),
+ *          appropriate error value otherwise. The ITS interrupt translation
+ *          spaces (ITS_base + SZ_64K, SZ_64K) associated with the device
+ *          are the msi reserved regions.
+ */
+int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
+{
+	struct acpi_iort_its_group *its;
+	struct acpi_iort_node *iommu_node, *its_node = NULL;
+	int i, resv = 0;
+
+	iommu_node = iort_get_msi_resv_iommu(dev);
+	if (!iommu_node)
+		return 0;
+
+	/*
+	 * Current logic to reserve ITS regions relies on HW topologies
+	 * where a given PCI or named component maps its IDs to only one
+	 * ITS group; if a PCI or named component can map its IDs to
+	 * different ITS groups through IORT mappings this function has
+	 * to be reworked to ensure we reserve regions for all ITS groups
+	 * a given PCI or named component may map IDs to.
+	 */
+
+	for (i = 0; i < dev->iommu_fwspec->num_ids; i++) {
+		its_node = iort_node_map_id(iommu_node,
+					dev->iommu_fwspec->ids[i],
+					NULL, IORT_MSI_TYPE);
+		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_64K, SZ_64K,
+							 prot, IOMMU_RESV_MSI);
+			if (region) {
+				list_add_tail(&region->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)
@@ -789,6 +892,8 @@ static inline const struct iommu_ops *iort_fwspec_iommu_ops(
 static inline int iort_add_device_replay(const struct iommu_ops *ops,
 					 struct device *dev)
 { return 0; }
+int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
+{ return 0; }
 #endif
 
 static int iort_iommu_xlate(struct device *dev, struct acpi_iort_node *node,
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 06f025f..ab99d1b 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3450,7 +3450,8 @@ 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 2f7a292..38cd77b 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
@@ -38,6 +39,7 @@ int iort_pmsi_get_dev_id(struct device *dev, u32 *dev_id);
 /* IOMMU interface */
 void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *size);
 const struct iommu_ops *iort_iommu_configure(struct device *dev);
+int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head);
 #else
 static inline void acpi_iort_init(void) { }
 static inline u32 iort_msi_map_rid(struct device *dev, u32 req_id)
@@ -52,6 +54,9 @@ static inline void iort_dma_setup(struct device *dev, u64 *dma_addr,
 static inline const struct iommu_ops *iort_iommu_configure(
 				      struct device *dev)
 { return NULL; }
+static inline
+int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
+{ return 0; }
 #endif
 
 #endif /* __ACPI_IORT_H__ */
-- 
2.7.4

[PATCH v13 2/2] iommu/dma: Add HW MSI(GICv3 ITS) address regions reservation

[Shameer Kolothum]

Modified iommu_dma_get_resv_regions() to include GICv3 ITS
region on ACPI based ARM platfiorms which may require HW MSI
reservations.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
---
 drivers/iommu/dma-iommu.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 25914d3..f05f3cf 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -19,6 +19,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <linux/acpi_iort.h>
 #include <linux/device.h>
 #include <linux/dma-iommu.h>
 #include <linux/gfp.h>
@@ -167,13 +168,18 @@ EXPORT_SYMBOL(iommu_put_dma_cookie);
  *
  * IOMMU drivers can use this to implement their .get_resv_regions callback
  * for general non-IOMMU-specific reservations. Currently, this covers host
- * bridge windows for PCI devices.
+ * bridge windows for PCI devices and GICv3 ITS region reservation on ACPI
+ * based ARM platforms that may require HW MSI reservation.
  */
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 {
 	struct pci_host_bridge *bridge;
 	struct resource_entry *window;
 
+	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode) &&
+		iort_iommu_msi_get_resv_regions(dev, list) < 0)
+		return;
+
 	if (!dev_is_pci(dev))
 		return;
 
-- 
2.7.4

[PATCH v13 0/2] iommu/smmu-v3: Workaround for hisilicon 161010801 erratum(reserve HW MSI)

[Joerg Roedel]

On Tue, Feb 13, 2018 at 03:20:49PM +0000, Shameer Kolothum wrote:
> Shameerali Kolothum Thodi (2):
>   ACPI/IORT: Add msi address regions reservation helper
>   iommu/dma: Add HW MSI(GICv3 ITS) address regions reservation

Okay, the patches look good to me. I plan to queue them into the IOMMU
tree for v4.17. If anyone has objections, please speak up now.


	Joerg