[PATCH v9 0/4] iommu/smmu-v3: Workaround for hisilicon 161010801 erratum(reserve HW MSI)

[PATCH v9 0/4] 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 and DT 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:
1. Added a generic helper function to IORT code to retrieve the
   associated ITS base address from a device IORT node.
2. Added a generic helper function to of iommu code to retrieve the
   associated msi controller base address from for a PCI RC
   msi-mapping and also platform device msi-parent.
3. Blacklisted HiSilicon PCIe controllers on DT based hip06/hip07
   platforms when SMMUv3 is enabled as there is no DT based solution
   for this as of now.

Changelog:

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.


Shameer Kolothum (4):
  ACPI/IORT: Add msi address regions reservation helper
  iommu/dma: Add a helper function to reserve HW MSI address regions for
    IOMMU drivers
  iommu/arm-smmu-v3:Enable ACPI based HiSilicon erratum 161010801
  PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

 drivers/acpi/arm64/iort.c        | 97 ++++++++++++++++++++++++++++++++++++++--
 drivers/iommu/arm-smmu-v3.c      | 27 ++++++++---
 drivers/iommu/dma-iommu.c        | 20 +++++++++
 drivers/irqchip/irq-gic-v3-its.c |  3 +-
 drivers/pci/dwc/pcie-hisi.c      | 12 +++++
 include/linux/acpi_iort.h        |  7 ++-
 include/linux/dma-iommu.h        |  7 +++
 7 files changed, 163 insertions(+), 10 deletions(-)

-- 
1.9.1

[PATCH v9 1/4] 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.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
[lorenzo.pieralisi at arm.com: updated commit log/added comments]
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
---
 drivers/acpi/arm64/iort.c        | 97 ++++++++++++++++++++++++++++++++++++++--
 drivers/irqchip/irq-gic-v3-its.c |  3 +-
 include/linux/acpi_iort.h        |  7 ++-
 3 files changed, 102 insertions(+), 5 deletions(-)

diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 9565d57..876c0e1 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 __maybe_unused iort_find_its_base(u32 its_id, phys_addr_t *base)
+{
+	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 +661,73 @@ int iort_add_device_replay(const struct iommu_ops *ops, struct device *dev)
 
 	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 reserved regions on success (0 if no associated msi
+ *          regions), appropriate error value otherwise. The ITS interrupt
+ *          translation space(ITS_base + 0x010000) 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 *node, *its_node = NULL;
+	int i, resv = 0;
+
+	node = iort_find_dev_node(dev);
+	if (!node)
+		return -ENODEV;
+
+	/*
+	 * 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.
+	 */
+	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_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)
@@ -646,6 +735,8 @@ 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_msi_get_resv_regions(struct device *dev, struct list_head *head)
+{ return -ENODEV; }
 #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 e8d8934..19d1ff6 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -3197,7 +3197,8 @@ 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 8d3f0bf..182a577 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 @@
 /* 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 -ENODEV; }
 #endif
 
 #endif /* __ACPI_IORT_H__ */
-- 
1.9.1

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Shameer Kolothum]

IOMMU drivers can use this to implement their .get_resv_regions callback
for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region).

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++
 include/linux/dma-iommu.h |  7 +++++++
 2 files changed, 27 insertions(+)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 9d1cebe..bae677e 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>
@@ -27,6 +28,7 @@
 #include <linux/iova.h>
 #include <linux/irq.h>
 #include <linux/mm.h>
+#include <linux/of_iommu.h>
 #include <linux/pci.h>
 #include <linux/scatterlist.h>
 #include <linux/vmalloc.h>
@@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
 }
 EXPORT_SYMBOL(iommu_dma_get_resv_regions);
 
+/**
+ * iommu_dma_get_msi_resv_regions - Reserved region driver helper
+ * @dev: Device from iommu_get_resv_regions()
+ * @list: Reserved region list from iommu_get_resv_regions()
+ *
+ * IOMMU drivers can use this to implement their .get_resv_regions
+ * callback for HW MSI specific reservations. For now, this only
+ * covers ITS MSI region reservation using ACPI IORT helper function.
+ */
+int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list)
+{
+	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode))
+		return iort_iommu_msi_get_resv_regions(dev, list);
+
+	return -ENODEV;
+}
+EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions);
+
 static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
 		phys_addr_t start, phys_addr_t end)
 {
diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
index 92f2083..6062ef0 100644
--- a/include/linux/dma-iommu.h
+++ b/include/linux/dma-iommu.h
@@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
 void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
 void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
 
+int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list);
+
 #else
 
 struct iommu_domain;
@@ -107,6 +109,11 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he
 {
 }
 
+static inline int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list)
+{
+	return -ENODEV;
+}
+
 #endif	/* CONFIG_IOMMU_DMA */
 #endif	/* __KERNEL__ */
 #endif	/* __DMA_IOMMU_H */
-- 
1.9.1

[PATCH v9 3/4] iommu/arm-smmu-v3:Enable ACPI based HiSilicon erratum 161010801

[Shameer Kolothum]

The HiSilicon erratum 161010801 describes the limitation of HiSilicon
platforms Hip06/Hip07 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 a ACPI table 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.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 drivers/iommu/arm-smmu-v3.c | 27 ++++++++++++++++++++++-----
 1 file changed, 22 insertions(+), 5 deletions(-)

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index e67ba6c..dd42ae9 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -608,6 +608,7 @@ struct arm_smmu_device {
 
 #define ARM_SMMU_OPT_SKIP_PREFETCH	(1 << 0)
 #define ARM_SMMU_OPT_PAGE0_REGS_ONLY	(1 << 1)
+#define ARM_SMMU_OPT_RESV_HW_MSI	(1 << 2)
 	u32				options;
 
 	struct arm_smmu_cmdq		cmdq;
@@ -1934,14 +1935,29 @@ static void arm_smmu_get_resv_regions(struct device *dev,
 				      struct list_head *head)
 {
 	struct iommu_resv_region *region;
+	struct arm_smmu_master_data *master = dev->iommu_fwspec->iommu_priv;
+	struct arm_smmu_device *smmu = master->smmu;
 	int prot = IOMMU_WRITE | IOMMU_NOEXEC | IOMMU_MMIO;
+	int resv = 0;
 
-	region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
-					 prot, IOMMU_RESV_SW_MSI);
-	if (!region)
-		return;
+	if ((smmu->options & ARM_SMMU_OPT_RESV_HW_MSI)) {
 
-	list_add_tail(&region->list, head);
+		resv = iommu_dma_get_msi_resv_regions(dev, head);
+
+		if (resv < 0) {
+			dev_warn(dev, "HW MSI region resv failed: %d\n", resv);
+			return;
+		}
+	}
+
+	if (!resv) {
+		region = iommu_alloc_resv_region(MSI_IOVA_BASE, MSI_IOVA_LENGTH,
+						 prot, IOMMU_RESV_SW_MSI);
+		if (!region)
+			return;
+
+		list_add_tail(&region->list, head);
+	}
 
 	iommu_dma_get_resv_regions(dev, head);
 }
@@ -2667,6 +2683,7 @@ static void acpi_smmu_get_options(u32 model, struct arm_smmu_device *smmu)
 		break;
 	case ACPI_IORT_SMMU_HISILICON_HI161X:
 		smmu->options |= ARM_SMMU_OPT_SKIP_PREFETCH;
+		smmu->options |= ARM_SMMU_OPT_RESV_HW_MSI;
 		break;
 	}
 
-- 
1.9.1

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Shameer Kolothum]

The HiSilicon erratum 161010801 describes the limitation of
HiSilicon platforms hip06/hip07 to support the SMMUv3 mappings
for MSI transactions.

PCIe controller on these 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. In order to workaround this, ARM
SMMUv3 driver requires a quirk to treat the MSI regions separately.
Such a quirk is currently missing for DT based systems and therefore
we need to blacklist the hip06/hip07 PCIe controllers.

Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
---
 drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
index a201791..6800747 100644
--- a/drivers/pci/dwc/pcie-hisi.c
+++ b/drivers/pci/dwc/pcie-hisi.c
@@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device *pdev)
 	struct resource *reg;
 	int ret;
 
+	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
+			of_property_read_bool(dev->of_node, "iommu-map")) {
+		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
+		return -ENODEV;
+	}
+
 	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
 	if (!hisi_pcie)
 		return -ENOMEM;
@@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct platform_device *pdev)
 	struct device *dev = &pdev->dev;
 	struct pci_ecam_ops *ops;
 
+	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
+			of_property_read_bool(dev->of_node, "iommu-map")) {
+		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
+		return -ENODEV;
+	}
+
 	ops = (struct pci_ecam_ops *)of_device_get_match_data(dev);
 	return pci_host_common_probe(pdev, ops);
 }
-- 
1.9.1

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Gabriele Paoloni]

Hi Shameer

> -----Original Message-----
> From: Shameerali Kolothum Thodi
> Sent: 06 October 2017 15:05
> To: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> sudeep.holla at arm.com; will.deacon at arm.com; robin.murphy at arm.com;
> joro at 8bytes.org; bhelgaas at google.com; Gabriele Paoloni
> Cc: John Garry; iommu at lists.linux-foundation.org; linux-arm-
> kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> pci at vger.kernel.org; devel at acpica.org; Linuxarm; Wangzhou (B);
> Guohanjun (Hanjun Guo); Shameerali Kolothum Thodi
> Subject: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers
> behind SMMUv3
> 
> The HiSilicon erratum 161010801 describes the limitation of
> HiSilicon platforms hip06/hip07 to support the SMMUv3 mappings
> for MSI transactions.
> 
> PCIe controller on these 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. In order to workaround this, ARM
> SMMUv3 driver requires a quirk to treat the MSI regions separately.
> Such a quirk is currently missing for DT based systems and therefore
> we need to blacklist the hip06/hip07 PCIe controllers.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

For this patch
Acked-by: Gabriele Paoloni <gabriele.paoloni@huawei.com>

> ---
>  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> index a201791..6800747 100644
> --- a/drivers/pci/dwc/pcie-hisi.c
> +++ b/drivers/pci/dwc/pcie-hisi.c
> @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device
> *pdev)
>  	struct resource *reg;
>  	int ret;
> 
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
>  	if (!hisi_pcie)
>  		return -ENOMEM;
> @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct
> platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct pci_ecam_ops *ops;
> 
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	ops = (struct pci_ecam_ops *)of_device_get_match_data(dev);
>  	return pci_host_common_probe(pdev, ops);
>  }
> --
> 1.9.1
> 

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Zhou Wang]

On 2017/10/6 22:04, Shameer Kolothum wrote:
> The HiSilicon erratum 161010801 describes the limitation of
> HiSilicon platforms hip06/hip07 to support the SMMUv3 mappings
> for MSI transactions.
> 
> PCIe controller on these 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. In order to workaround this, ARM
> SMMUv3 driver requires a quirk to treat the MSI regions separately.
> Such a quirk is currently missing for DT based systems and therefore
> we need to blacklist the hip06/hip07 PCIe controllers.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> index a201791..6800747 100644
> --- a/drivers/pci/dwc/pcie-hisi.c
> +++ b/drivers/pci/dwc/pcie-hisi.c
> @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device *pdev)
>  	struct resource *reg;
>  	int ret;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
>  	if (!hisi_pcie)
>  		return -ENOMEM;
> @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct pci_ecam_ops *ops;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	ops = (struct pci_ecam_ops *)of_device_get_match_data(dev);
>  	return pci_host_common_probe(pdev, ops);
>  }
>

Acked-by: Zhou Wang <wangzhou1@hisilicon.com>

Thanks,
Zhou

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Bjorn Helgaas]

Please change subject line:

-  PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3
+  PCI: hisi: Blacklist hip06/hip07 controllers behind SMMUv3

On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> The HiSilicon erratum 161010801 describes the limitation of
> HiSilicon platforms hip06/hip07 to support the SMMUv3 mappings
> for MSI transactions.

I don't suppose there's a URL for this erratum, is there?

> PCIe controller on these 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. In order to workaround this, ARM
> SMMUv3 driver requires a quirk to treat the MSI regions separately.
> Such a quirk is currently missing for DT based systems and therefore
> we need to blacklist the hip06/hip07 PCIe controllers.

I don't understand the DT connection here.  If this is a hardware
erratum, I assume the a quirk would be required whether the system
uses DT, ACPI, etc.

> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

I assume this will go via some non-PCI tree.  If I were applying this,
I would look for an ack from Zhou or Gabriele in addition to mine.

> ---
>  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> index a201791..6800747 100644
> --- a/drivers/pci/dwc/pcie-hisi.c
> +++ b/drivers/pci/dwc/pcie-hisi.c
> @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device *pdev)
>  	struct resource *reg;
>  	int ret;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {

Does the presence of "iommu-map" tell you this is an SMMUv3?  Could it
have a different type of IOMMU?  I can't tell from reading
Documentation/devicetree/bindings/pci/pci-iommu.txt.

Why do you care whether CONFIG_ARM_SMMU_V3 is set?  Does MSI work
correctly if SMMUv3 is present but not used?

Is it really necessary to ignore the PCIe controller completely?
Could you use the devices below it as long as you disable MSI for
them?  I know there are probably devices that require MSI, so maybe
it's easier to just ignore everything than to respond to reports of
"my device doesn't work because it requires MSI."

> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
>  	if (!hisi_pcie)
>  		return -ENOMEM;
> @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct pci_ecam_ops *ops;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	ops = (struct pci_ecam_ops *)of_device_get_match_data(dev);
>  	return pci_host_common_probe(pdev, ops);
>  }
> -- 
> 1.9.1
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Bjorn Helgaas]

On Mon, Oct 09, 2017 at 06:54:52PM -0500, Bjorn Helgaas wrote:
> Please change subject line:
> 
> -  PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3
> +  PCI: hisi: Blacklist hip06/hip07 controllers behind SMMUv3
> 
> On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> > The HiSilicon erratum 161010801 describes the limitation of
> > HiSilicon platforms hip06/hip07 to support the SMMUv3 mappings
> > for MSI transactions.
> 
> I don't suppose there's a URL for this erratum, is there?
> 
> > PCIe controller on these 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. In order to workaround this, ARM
> > SMMUv3 driver requires a quirk to treat the MSI regions separately.
> > Such a quirk is currently missing for DT based systems and therefore
> > we need to blacklist the hip06/hip07 PCIe controllers.
> 
> I don't understand the DT connection here.  If this is a hardware
> erratum, I assume the a quirk would be required whether the system
> uses DT, ACPI, etc.
> 
> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> 
> I assume this will go via some non-PCI tree.  If I were applying this,
> I would look for an ack from Zhou or Gabriele in addition to mine.

Never mind about this part; I see they already have acked it.  I really
need to learn to read the whole thread before responding :)

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Shameerali Kolothum Thodi]

HI Bjorn,

> -----Original Message-----
> From: Bjorn Helgaas [mailto:helgaas at kernel.org]
> Sent: Tuesday, October 10, 2017 12:55 AM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> sudeep.holla at arm.com; will.deacon at arm.com; robin.murphy at arm.com;
> joro at 8bytes.org; bhelgaas at google.com; Gabriele Paoloni
> <gabriele.paoloni@huawei.com>; John Garry <john.garry@huawei.com>;
> iommu at lists.linux-foundation.org; linux-arm-kernel at lists.infradead.org;
> linux-acpi at vger.kernel.org; linux-pci at vger.kernel.org; devel at acpica.org;
> Linuxarm <linuxarm@huawei.com>; Wangzhou (B)
> <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>
> Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind
> SMMUv3
> 
> Please change subject line:
> 
> -  PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3
> +  PCI: hisi: Blacklist hip06/hip07 controllers behind SMMUv3

Ok.

> On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> > The HiSilicon erratum 161010801 describes the limitation of HiSilicon
> > platforms hip06/hip07 to support the SMMUv3 mappings for MSI
> > transactions.
> 
> I don't suppose there's a URL for this erratum, is there?

We don't have anything public at the moment. This is part of the internal
documentation at the moment.

> > PCIe controller on these 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. In order to workaround this, ARM
> > SMMUv3 driver requires a quirk to treat the MSI regions separately.
> > Such a quirk is currently missing for DT based systems and therefore
> > we need to blacklist the hip06/hip07 PCIe controllers.
> 
> I don't understand the DT connection here.  If this is a hardware erratum, I
> assume the a quirk would be required whether the system uses DT, ACPI,
> etc.

Yes, this is a hardware erratum and we are almost there to add the ACPI
quirk into the SMMUv3 driver for this.  But we got the feedback that 
either we have to have the DT support or we should blacklist the affected
devices so that from the SMMUv3 driver point of view it will not run into the
quirk unnecessarily[1].

We attempted to provide a DT solution, but it looks like DT requires more
discussions and a more generic approach than ACPI[2]. Hence we are blacklisting
the PCIe for now so that we can have the ACPI support goes through. (Also we 
don't have the DT binding in the mainline which support SMMU on these 
platforms and also DT is not officially supported for these platforms).

> > Signed-off-by: Shameer Kolothum
> <shameerali.kolothum.thodi@huawei.com>
> 
> I assume this will go via some non-PCI tree.  If I were applying this, I would
> look for an ack from Zhou or Gabriele in addition to mine.
> 
> > ---
> >  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> > index a201791..6800747 100644
> > --- a/drivers/pci/dwc/pcie-hisi.c
> > +++ b/drivers/pci/dwc/pcie-hisi.c
> > @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device
> *pdev)
> >  	struct resource *reg;
> >  	int ret;
> >
> > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > +			of_property_read_bool(dev->of_node, "iommu-
> map")) {
> 
> Does the presence of "iommu-map" tell you this is an SMMUv3?  Could it
> have a different type of IOMMU?  I can't tell from reading
> Documentation/devicetree/bindings/pci/pci-iommu.txt.

Only if the SMMUv3 driver is loaded and iommu-map binding property present,
the pcie devices will use SMMU translated iova for MSI doorbell addresses.

> Why do you care whether CONFIG_ARM_SMMU_V3 is set?  Does MSI work
> correctly if SMMUv3 is present but not used?

Yes. MSI will work if no SMMUv3 is used.

> Is it really necessary to ignore the PCIe controller completely?
> Could you use the devices below it as long as you disable MSI for them?  I
> know there are probably devices that require MSI, so maybe it's easier to
> just ignore everything than to respond to reports of "my device doesn't work
> because it requires MSI."

We are blacklisting MSI for PCIe only if the kernel is using DT and is configured
to use SMMUv3. Otherwise it is fine. And as I said above DT is not officially
supported on these platforms.

Thanks,
Shameer

1. [PATCH v6 3/3] iommu/arm-smmu-v3:Enable ACPI based HiSilicon erratum 161010801
https://www.spinics.net/lists/arm-kernel/msg602873.html
2. [PATCH v8 3/5] iommu/of: Add msi address regions reservation helper
https://www.spinics.net/lists/arm-kernel/msg609431.html

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Lorenzo Pieralisi]

On Tue, Oct 10, 2017 at 09:42:30AM +0000, Shameerali Kolothum Thodi wrote:

[...]

> > > diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> > > index a201791..6800747 100644
> > > --- a/drivers/pci/dwc/pcie-hisi.c
> > > +++ b/drivers/pci/dwc/pcie-hisi.c
> > > @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device
> > *pdev)
> > >  	struct resource *reg;
> > >  	int ret;
> > >
> > > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > > +			of_property_read_bool(dev->of_node, "iommu-
> > map")) {
> > 
> > Does the presence of "iommu-map" tell you this is an SMMUv3?  Could it
> > have a different type of IOMMU?  I can't tell from reading
> > Documentation/devicetree/bindings/pci/pci-iommu.txt.
> 
> Only if the SMMUv3 driver is loaded and iommu-map binding property present,
> the pcie devices will use SMMU translated iova for MSI doorbell addresses.

And the iommu-map property _actually_ points at an OF node with an
SMMUv3 compatible string - the sheer fact that the SMMUv3 driver
is compiled in is not sufficient IIUC.

Lorenzo

> > Why do you care whether CONFIG_ARM_SMMU_V3 is set?  Does MSI work
> > correctly if SMMUv3 is present but not used?
> 
> Yes. MSI will work if no SMMUv3 is used.
> 
> > Is it really necessary to ignore the PCIe controller completely?
> > Could you use the devices below it as long as you disable MSI for them?  I
> > know there are probably devices that require MSI, so maybe it's easier to
> > just ignore everything than to respond to reports of "my device doesn't work
> > because it requires MSI."
> 
> We are blacklisting MSI for PCIe only if the kernel is using DT and is configured
> to use SMMUv3. Otherwise it is fine. And as I said above DT is not officially
> supported on these platforms.
> 
> Thanks,
> Shameer
> 
> 1. [PATCH v6 3/3] iommu/arm-smmu-v3:Enable ACPI based HiSilicon erratum 161010801
> https://www.spinics.net/lists/arm-kernel/msg602873.html
> 2. [PATCH v8 3/5] iommu/of: Add msi address regions reservation helper
> https://www.spinics.net/lists/arm-kernel/msg609431.html
> 
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Gabriele Paoloni]

Hi Lorenzo

[...]

> > > Does the presence of "iommu-map" tell you this is an SMMUv3?  Could
> it
> > > have a different type of IOMMU?  I can't tell from reading
> > > Documentation/devicetree/bindings/pci/pci-iommu.txt.
> >
> > Only if the SMMUv3 driver is loaded and iommu-map binding property
> present,
> > the pcie devices will use SMMU translated iova for MSI doorbell
> addresses.
> 
> And the iommu-map property _actually_ points at an OF node with an
> SMMUv3 compatible string - the sheer fact that the SMMUv3 driver
> is compiled in is not sufficient IIUC.

The blacklisted controller can only be present in an SoC that supports
SMMUv3 only.

>From our view checking that SMMUv3 is compiled in and also checking that
the DT contains iommu-map is sufficient to decide to blacklist the controller.

Thanks
Gab 

> 
> Lorenzo
> 

[...]

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Bjorn Helgaas]

On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> The HiSilicon erratum 161010801 describes the limitation of
> HiSilicon platforms hip06/hip07 to support the SMMUv3 mappings
> for MSI transactions.
> 
> PCIe controller on these 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. In order to workaround this, ARM
> SMMUv3 driver requires a quirk to treat the MSI regions separately.
> Such a quirk is currently missing for DT based systems and therefore
> we need to blacklist the hip06/hip07 PCIe controllers.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>

Acked-by: Bjorn Helgaas <bhelgaas@google.com>

> ---
>  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> index a201791..6800747 100644
> --- a/drivers/pci/dwc/pcie-hisi.c
> +++ b/drivers/pci/dwc/pcie-hisi.c
> @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device *pdev)
>  	struct resource *reg;
>  	int ret;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
>  	if (!hisi_pcie)
>  		return -ENOMEM;
> @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct pci_ecam_ops *ops;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	ops = (struct pci_ecam_ops *)of_device_get_match_data(dev);
>  	return pci_host_common_probe(pdev, ops);
>  }
> -- 
> 1.9.1
> 
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-acpi" in
> the body of a message to majordomo at vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

[PATCH v9 0/4] iommu/smmu-v3: Workaround for hisilicon 161010801 erratum(reserve HW MSI)

[Shameerali Kolothum Thodi]

Hi Will,

Any further comments on this series, please? 

We do have the ack from all relevant people for the "[PATCH v9 4/4] PCI: hisi: blacklist
hip06/hip07 controllers behind SMMUv3" now. 

Really appreciate if you can take a look and let us know.

Many thanks,
Shameer

> -----Original Message-----
> From: Shameerali Kolothum Thodi
> Sent: Friday, October 06, 2017 3:05 PM
> To: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> sudeep.holla at arm.com; will.deacon at arm.com; robin.murphy at arm.com;
> joro at 8bytes.org; bhelgaas at google.com; Gabriele Paoloni
> <gabriele.paoloni@huawei.com>
> Cc: John Garry <john.garry@huawei.com>; iommu at lists.linux-
> foundation.org; linux-arm-kernel at lists.infradead.org; linux-
> acpi at vger.kernel.org; linux-pci at vger.kernel.org; devel at acpica.org;
> Linuxarm <linuxarm@huawei.com>; Wangzhou (B)
> <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>; Shameerali Kolothum Thodi
> <shameerali.kolothum.thodi@huawei.com>
> Subject: [PATCH v9 0/4] iommu/smmu-v3: Workaround for hisilicon
> 161010801 erratum(reserve HW MSI)
> 
> 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 and DT 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:
> 1. Added a generic helper function to IORT code to retrieve the
>    associated ITS base address from a device IORT node.
> 2. Added a generic helper function to of iommu code to retrieve the
>    associated msi controller base address from for a PCI RC
>    msi-mapping and also platform device msi-parent.
> 3. Blacklisted HiSilicon PCIe controllers on DT based hip06/hip07
>    platforms when SMMUv3 is enabled as there is no DT based solution
>    for this as of now.
> 
> Changelog:
> 
> 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.
> 
> 
> Shameer Kolothum (4):
>   ACPI/IORT: Add msi address regions reservation helper
>   iommu/dma: Add a helper function to reserve HW MSI address regions for
>     IOMMU drivers
>   iommu/arm-smmu-v3:Enable ACPI based HiSilicon erratum 161010801
>   PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3
> 
>  drivers/acpi/arm64/iort.c        | 97
> ++++++++++++++++++++++++++++++++++++++--
>  drivers/iommu/arm-smmu-v3.c      | 27 ++++++++---
>  drivers/iommu/dma-iommu.c        | 20 +++++++++
>  drivers/irqchip/irq-gic-v3-its.c |  3 +-
>  drivers/pci/dwc/pcie-hisi.c      | 12 +++++
>  include/linux/acpi_iort.h        |  7 ++-
>  include/linux/dma-iommu.h        |  7 +++
>  7 files changed, 163 insertions(+), 10 deletions(-)
> 
> --
> 1.9.1
> 

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Will Deacon]

On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> The HiSilicon erratum 161010801 describes the limitation of
> HiSilicon platforms hip06/hip07 to support the SMMUv3 mappings
> for MSI transactions.
> 
> PCIe controller on these 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. In order to workaround this, ARM
> SMMUv3 driver requires a quirk to treat the MSI regions separately.
> Such a quirk is currently missing for DT based systems and therefore
> we need to blacklist the hip06/hip07 PCIe controllers.
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
>  1 file changed, 12 insertions(+)
> 
> diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> index a201791..6800747 100644
> --- a/drivers/pci/dwc/pcie-hisi.c
> +++ b/drivers/pci/dwc/pcie-hisi.c
> @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device *pdev)
>  	struct resource *reg;
>  	int ret;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}
> +
>  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
>  	if (!hisi_pcie)
>  		return -ENOMEM;
> @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct platform_device *pdev)
>  	struct device *dev = &pdev->dev;
>  	struct pci_ecam_ops *ops;
>  
> +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> +			of_property_read_bool(dev->of_node, "iommu-map")) {
> +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting PCIe controllers behind SMMUv3\n");
> +		return -ENODEV;
> +	}

This isn't the right way to solve this problem. I was really hoping you'd
come up with a solution for DT, and I know you've been trying, so I suppose
for now we'll just have to go with the ACPI workaround you have and leave DT
in the balance. I'm not at all happy with that, but I don't think this patch
really improves things.

What I think you should do is remove the relevant smmu/iommu-map entries
from the .dts files that are available for these platforms (i.e. comment
them out with a description as to why).

Will

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Will Deacon]

On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote:
> IOMMU drivers can use this to implement their .get_resv_regions callback
> for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region).
> 
> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> ---
>  drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++
>  include/linux/dma-iommu.h |  7 +++++++
>  2 files changed, 27 insertions(+)

I'd like to see Robin's Ack on this, because this is his code and he had
ideas on ways to solve this problem properly.

Will

> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 9d1cebe..bae677e 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>
> @@ -27,6 +28,7 @@
>  #include <linux/iova.h>
>  #include <linux/irq.h>
>  #include <linux/mm.h>
> +#include <linux/of_iommu.h>
>  #include <linux/pci.h>
>  #include <linux/scatterlist.h>
>  #include <linux/vmalloc.h>
> @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list)
>  }
>  EXPORT_SYMBOL(iommu_dma_get_resv_regions);
>  
> +/**
> + * iommu_dma_get_msi_resv_regions - Reserved region driver helper
> + * @dev: Device from iommu_get_resv_regions()
> + * @list: Reserved region list from iommu_get_resv_regions()
> + *
> + * IOMMU drivers can use this to implement their .get_resv_regions
> + * callback for HW MSI specific reservations. For now, this only
> + * covers ITS MSI region reservation using ACPI IORT helper function.
> + */
> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list)
> +{
> +	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode))
> +		return iort_iommu_msi_get_resv_regions(dev, list);
> +
> +	return -ENODEV;
> +}
> +EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions);
> +
>  static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
>  		phys_addr_t start, phys_addr_t end)
>  {
> diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
> index 92f2083..6062ef0 100644
> --- a/include/linux/dma-iommu.h
> +++ b/include/linux/dma-iommu.h
> @@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev, dma_addr_t handle,
>  void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
>  void iommu_dma_get_resv_regions(struct device *dev, struct list_head *list);
>  
> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list);
> +
>  #else
>  
>  struct iommu_domain;
> @@ -107,6 +109,11 @@ static inline void iommu_dma_get_resv_regions(struct device *dev, struct list_he
>  {
>  }
>  
> +static inline int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head *list)
> +{
> +	return -ENODEV;
> +}
> +
>  #endif	/* CONFIG_IOMMU_DMA */
>  #endif	/* __KERNEL__ */
>  #endif	/* __DMA_IOMMU_H */
> -- 
> 1.9.1
> 
> 

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Will Deacon [mailto:will.deacon at arm.com]
> Sent: Friday, October 13, 2017 8:22 PM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> pci at vger.kernel.org; devel at acpica.org; Linuxarm <linuxarm@huawei.com>;
> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>
> Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind
> SMMUv3
> 
> On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> > The HiSilicon erratum 161010801 describes the limitation of HiSilicon
> > platforms hip06/hip07 to support the SMMUv3 mappings for MSI
> > transactions.
> >
> > PCIe controller on these 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. In order to workaround this, ARM
> > SMMUv3 driver requires a quirk to treat the MSI regions separately.
> > Such a quirk is currently missing for DT based systems and therefore
> > we need to blacklist the hip06/hip07 PCIe controllers.
> >
> > Signed-off-by: Shameer Kolothum
> <shameerali.kolothum.thodi@huawei.com>
> > ---
> >  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
> >  1 file changed, 12 insertions(+)
> >
> > diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> > index a201791..6800747 100644
> > --- a/drivers/pci/dwc/pcie-hisi.c
> > +++ b/drivers/pci/dwc/pcie-hisi.c
> > @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device
> *pdev)
> >  	struct resource *reg;
> >  	int ret;
> >
> > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > +			of_property_read_bool(dev->of_node, "iommu-
> map")) {
> > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> PCIe controllers behind SMMUv3\n");
> > +		return -ENODEV;
> > +	}
> > +
> >  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
> >  	if (!hisi_pcie)
> >  		return -ENOMEM;
> > @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct
> platform_device *pdev)
> >  	struct device *dev = &pdev->dev;
> >  	struct pci_ecam_ops *ops;
> >
> > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > +			of_property_read_bool(dev->of_node, "iommu-
> map")) {
> > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> PCIe controllers behind SMMUv3\n");
> > +		return -ENODEV;
> > +	}
> 
> This isn't the right way to solve this problem. I was really hoping you'd come
> up with a solution for DT, and I know you've been trying, so I suppose for
> now we'll just have to go with the ACPI workaround you have and leave DT in
> the balance. I'm not at all happy with that, but I don't think this patch really
> improves things.

Yes Will, this is to get the ACPI support enabled for now. 

> What I think you should do is remove the relevant smmu/iommu-map
> entries from the .dts files that are available for these platforms (i.e.
> comment them out with a description as to why).

We don't have any smmu/iommu-map entries for these platforms in the 
.dts files [1][2]. We are not aiming for any official DT support for these platforms.
This patch is to enforce the non-support.

Thanks,
Shameer

1. http://elixir.free-electrons.com/linux/v4.14-rc4/source/arch/arm64/boot/dts/hisilicon/hip07.dtsi
2. http://elixir.free-electrons.com/linux/v4.14-rc4/source/arch/arm64/boot/dts/hisilicon/hip06.dtsi

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Shameerali Kolothum Thodi]

Hi Robin,

> -----Original Message-----
> From: Will Deacon [mailto:will.deacon at arm.com]
> Sent: Friday, October 13, 2017 8:24 PM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> pci at vger.kernel.org; devel at acpica.org; Linuxarm <linuxarm@huawei.com>;
> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>
> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW
> MSI address regions for IOMMU drivers
> 
> On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote:
> > IOMMU drivers can use this to implement their .get_resv_regions callback
> > for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region).
> >
> > Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
> > ---
> >  drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++
> >  include/linux/dma-iommu.h |  7 +++++++
> >  2 files changed, 27 insertions(+)
> 
> I'd like to see Robin's Ack on this, because this is his code and he had
> ideas on ways to solve this problem properly.

Please let us know if it is ok to go ahead with ACPI support for now.
It will help our customers to start using pass-through for PCIe.

Thanks,
Shameer

> 
> Will
> 
> > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > index 9d1cebe..bae677e 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>
> > @@ -27,6 +28,7 @@
> >  #include <linux/iova.h>
> >  #include <linux/irq.h>
> >  #include <linux/mm.h>
> > +#include <linux/of_iommu.h>
> >  #include <linux/pci.h>
> >  #include <linux/scatterlist.h>
> >  #include <linux/vmalloc.h>
> > @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device
> *dev, struct list_head *list)
> >  }
> >  EXPORT_SYMBOL(iommu_dma_get_resv_regions);
> >
> > +/**
> > + * iommu_dma_get_msi_resv_regions - Reserved region driver helper
> > + * @dev: Device from iommu_get_resv_regions()
> > + * @list: Reserved region list from iommu_get_resv_regions()
> > + *
> > + * IOMMU drivers can use this to implement their .get_resv_regions
> > + * callback for HW MSI specific reservations. For now, this only
> > + * covers ITS MSI region reservation using ACPI IORT helper function.
> > + */
> > +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head
> *list)
> > +{
> > +	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode))
> > +		return iort_iommu_msi_get_resv_regions(dev, list);
> > +
> > +	return -ENODEV;
> > +}
> > +EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions);
> > +
> >  static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
> >  		phys_addr_t start, phys_addr_t end)
> >  {
> > diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
> > index 92f2083..6062ef0 100644
> > --- a/include/linux/dma-iommu.h
> > +++ b/include/linux/dma-iommu.h
> > @@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev,
> dma_addr_t handle,
> >  void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
> >  void iommu_dma_get_resv_regions(struct device *dev, struct list_head
> *list);
> >
> > +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head
> *list);
> > +
> >  #else
> >
> >  struct iommu_domain;
> > @@ -107,6 +109,11 @@ static inline void
> iommu_dma_get_resv_regions(struct device *dev, struct list_he
> >  {
> >  }
> >
> > +static inline int iommu_dma_get_msi_resv_regions(struct device *dev,
> struct list_head *list)
> > +{
> > +	return -ENODEV;
> > +}
> > +
> >  #endif	/* CONFIG_IOMMU_DMA */
> >  #endif	/* __KERNEL__ */
> >  #endif	/* __DMA_IOMMU_H */
> > --
> > 1.9.1
> >
> >

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Will Deacon]

On Sun, Oct 15, 2017 at 07:46:34AM +0000, Shameerali Kolothum Thodi wrote:
> 
> 
> > -----Original Message-----
> > From: Will Deacon [mailto:will.deacon at arm.com]
> > Sent: Friday, October 13, 2017 8:22 PM
> > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> > Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> > sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> > bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> > John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> > linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> > pci at vger.kernel.org; devel at acpica.org; Linuxarm <linuxarm@huawei.com>;
> > Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> > <guohanjun@huawei.com>
> > Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind
> > SMMUv3
> > 
> > On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> > > The HiSilicon erratum 161010801 describes the limitation of HiSilicon
> > > platforms hip06/hip07 to support the SMMUv3 mappings for MSI
> > > transactions.
> > >
> > > PCIe controller on these 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. In order to workaround this, ARM
> > > SMMUv3 driver requires a quirk to treat the MSI regions separately.
> > > Such a quirk is currently missing for DT based systems and therefore
> > > we need to blacklist the hip06/hip07 PCIe controllers.
> > >
> > > Signed-off-by: Shameer Kolothum
> > <shameerali.kolothum.thodi@huawei.com>
> > > ---
> > >  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
> > >  1 file changed, 12 insertions(+)
> > >
> > > diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> > > index a201791..6800747 100644
> > > --- a/drivers/pci/dwc/pcie-hisi.c
> > > +++ b/drivers/pci/dwc/pcie-hisi.c
> > > @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device
> > *pdev)
> > >  	struct resource *reg;
> > >  	int ret;
> > >
> > > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > > +			of_property_read_bool(dev->of_node, "iommu-
> > map")) {
> > > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> > PCIe controllers behind SMMUv3\n");
> > > +		return -ENODEV;
> > > +	}
> > > +
> > >  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
> > >  	if (!hisi_pcie)
> > >  		return -ENOMEM;
> > > @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct
> > platform_device *pdev)
> > >  	struct device *dev = &pdev->dev;
> > >  	struct pci_ecam_ops *ops;
> > >
> > > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > > +			of_property_read_bool(dev->of_node, "iommu-
> > map")) {
> > > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> > PCIe controllers behind SMMUv3\n");
> > > +		return -ENODEV;
> > > +	}
> > 
> > This isn't the right way to solve this problem. I was really hoping you'd come
> > up with a solution for DT, and I know you've been trying, so I suppose for
> > now we'll just have to go with the ACPI workaround you have and leave DT in
> > the balance. I'm not at all happy with that, but I don't think this patch really
> > improves things.
> 
> Yes Will, this is to get the ACPI support enabled for now. 
> 
> > What I think you should do is remove the relevant smmu/iommu-map
> > entries from the .dts files that are available for these platforms (i.e.
> > comment them out with a description as to why).
> 
> We don't have any smmu/iommu-map entries for these platforms in the 
> .dts files [1][2]. We are not aiming for any official DT support for these platforms.
> This patch is to enforce the non-support.

Understood, but this has dragged on for a while and I don't think this patch
is the right way to enforce things. The best approach might actually be to
add the SMMU to the DTs, but commented out with a comment explaining why
it's not a good idea to enable it.

Will

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Shameerali Kolothum Thodi]

Hi Will,

> -----Original Message-----
> From: Will Deacon [mailto:will.deacon at arm.com]
> Sent: Wednesday, October 18, 2017 11:52 AM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> pci at vger.kernel.org; devel at acpica.org; Linuxarm <linuxarm@huawei.com>;
> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>
> Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind
> SMMUv3
> 
> On Sun, Oct 15, 2017 at 07:46:34AM +0000, Shameerali Kolothum Thodi wrote:
> >
> >
> > > -----Original Message-----
> > > From: Will Deacon [mailto:will.deacon at arm.com]
> > > Sent: Friday, October 13, 2017 8:22 PM
> > > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> > > Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> > > sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> > > bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> > > John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> > > linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> > > pci at vger.kernel.org; devel at acpica.org; Linuxarm
> <linuxarm@huawei.com>;
> > > Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> > > <guohanjun@huawei.com>
> > > Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers
> behind
> > > SMMUv3
> > >
> > > On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> > > > The HiSilicon erratum 161010801 describes the limitation of HiSilicon
> > > > platforms hip06/hip07 to support the SMMUv3 mappings for MSI
> > > > transactions.
> > > >
> > > > PCIe controller on these 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. In order to workaround this, ARM
> > > > SMMUv3 driver requires a quirk to treat the MSI regions separately.
> > > > Such a quirk is currently missing for DT based systems and therefore
> > > > we need to blacklist the hip06/hip07 PCIe controllers.
> > > >
> > > > Signed-off-by: Shameer Kolothum
> > > <shameerali.kolothum.thodi@huawei.com>
> > > > ---
> > > >  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
> > > >  1 file changed, 12 insertions(+)
> > > >
> > > > diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> > > > index a201791..6800747 100644
> > > > --- a/drivers/pci/dwc/pcie-hisi.c
> > > > +++ b/drivers/pci/dwc/pcie-hisi.c
> > > > @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device
> > > *pdev)
> > > >  	struct resource *reg;
> > > >  	int ret;
> > > >
> > > > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > > > +			of_property_read_bool(dev->of_node, "iommu-
> > > map")) {
> > > > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> > > PCIe controllers behind SMMUv3\n");
> > > > +		return -ENODEV;
> > > > +	}
> > > > +
> > > >  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
> > > >  	if (!hisi_pcie)
> > > >  		return -ENOMEM;
> > > > @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct
> > > platform_device *pdev)
> > > >  	struct device *dev = &pdev->dev;
> > > >  	struct pci_ecam_ops *ops;
> > > >
> > > > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > > > +			of_property_read_bool(dev->of_node, "iommu-
> > > map")) {
> > > > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> > > PCIe controllers behind SMMUv3\n");
> > > > +		return -ENODEV;
> > > > +	}
> > >
> > > This isn't the right way to solve this problem. I was really hoping you'd
> come
> > > up with a solution for DT, and I know you've been trying, so I suppose for
> > > now we'll just have to go with the ACPI workaround you have and leave DT
> in
> > > the balance. I'm not at all happy with that, but I don't think this patch really
> > > improves things.
> >
> > Yes Will, this is to get the ACPI support enabled for now.
> >
> > > What I think you should do is remove the relevant smmu/iommu-map
> > > entries from the .dts files that are available for these platforms (i.e.
> > > comment them out with a description as to why).
> >
> > We don't have any smmu/iommu-map entries for these platforms in the
> > .dts files [1][2]. We are not aiming for any official DT support for these
> platforms.
> > This patch is to enforce the non-support.
> 
> Understood, but this has dragged on for a while and I don't think this patch
> is the right way to enforce things. The best approach might actually be to
> add the SMMU to the DTs, but commented out with a comment explaining why
> it's not a good idea to enable it.

Ok. Just to clarify, you would like to replace this patch with another 
one with smmu entries in dts and commenting/disabling them with explanation.
Or you would like to have that in addition to this one?

Please take a look at below snippet where I have added the smmu dts nodes
and disabled them with comments.

If this looks ok, I can sent it out soon. Please let me know.

Many Thanks,
Shameer

-- >8 --
diff --git a/arch/arm64/boot/dts/hisilicon/hip06.dtsi b/arch/arm64/boot/dts/hisilicon/hip06.dtsi
index a049b64..b561ac6 100644
--- a/arch/arm64/boot/dts/hisilicon/hip06.dtsi
+++ b/arch/arm64/boot/dts/hisilicon/hip06.dtsi
@@ -291,6 +291,20 @@
 			#interrupt-cells = <2>;
 			num-pins = <128>;
 		};
+
+		mbigen_pcie0: intc_pcie0 {
+			msi-parent = <&its_dsa 0x40085>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+			num-pins = <10>;
+		};
+
+		mbigen_smmu_pcie_intc: intc_smmu_pcie {
+			msi-parent = <&its_dsa 0x40b0c>;
+			interrupt-controller;
+			#interrupt-cells = <2>;
+			num-pins = <3>;
+		};
 	};
 
 	mbigen_dsa at c0080000 {
@@ -312,6 +326,27 @@
 		};
 	};
 
+	/** HiSilicon erratum 161010801: Please make sure that
+	 *  the smmu (pcie) node on hip06 is disabled as this will
+	 *  break the PCIe functionality when iommu-map entry
+	 *  is used along with the PCIe node.
+	 */
+	smmu0: smmu_pcie {
+		compatible = "arm,smmu-v3";
+		reg = <0x0 0xa0040000 0x0 0x20000>;
+		interrupt-parent  = <&mbigen_smmu_pcie_intc>;
+		interrupts = <871 1>,
+			<872 1>,
+			<873 1>;
+
+		interrupt-names = "eventq", "gerror", "cmdq-sync";
+		#iommu-cells = <1>;
+		dma-coherent;
+		smmu-cb-memtype = <0x0 0x1>;
+		hisilicon,broken-prefetch-cmd;
+		status = "disabled";
+	};
+
 	soc {
 		compatible = "simple-bus";
 		#address-cells = <2>;
@@ -676,6 +711,29 @@
 				     <637 1>,<638 1>,<639 1>;
 			status = "disabled";
 		};
+
+		pcie0: pcie at a0090000 {
+			compatible = "hisilicon,pcie-almost-ecam";
+			reg = <0 0xb0000000 0 0x2000000>, <0 0xa0090000 0 0x10000>;
+			bus-range = <0  31>;
+			msi-map = <0x0000 &its_dsa 0x0000 0x2000>;
+			msi-map-mask = <0xffff>;
+			#address-cells = <3>;
+			#size-cells = <2>;
+			device_type = "pci";
+			dma-coherent;
+			/*iommu-map = <0x0 &smmu0 0x0 0x10000>;*/
+			ranges = <0x02000000 0 0xb2000000 0x0 0xb2000000 0 0x5ff0000
+				  0x01000000 0 0 0 0xb7ff0000 0 0x10000>;
+			#interrupt-cells = <1>;
+                        interrupt-map-mask = <0xf800 0 0 7>;
+                        interrupt-map = <0x0 0 0 1 &mbigen_pcie0 650 4
+                                         0x0 0 0 2 &mbigen_pcie0 650 4
+                                         0x0 0 0 3 &mbigen_pcie0 650 4
+                                         0x0 0 0 4 &mbigen_pcie0 650 4>;
+			status = "disabled";
+		};
+
 	};
 
 };
diff --git a/arch/arm64/boot/dts/hisilicon/hip07.dtsi b/arch/arm64/boot/dts/hisilicon/hip07.dtsi
index 2c01a21..a483325 100644
--- a/arch/arm64/boot/dts/hisilicon/hip07.dtsi
+++ b/arch/arm64/boot/dts/hisilicon/hip07.dtsi
@@ -1083,6 +1083,26 @@
 		};
 	};
 
+	/** HiSilicon erratum 161010801: Please make sure that
+	 *  the smmu (pcie) node on hip07 is disabled as this will
+	 *  break the PCIe functionality when iommu-map entry
+	 *  is used along with the PCIe node.
+	 */
+	smmu0: smmu_pcie {
+		compatible = "arm,smmu-v3";
+		reg = <0x0 0xa0040000 0x0 0x20000>;
+		interrupt-parent  = <&mbigen_smmu_pcie>;
+		interrupts = <871 1>,
+			<872 1>,
+			<873 1>;
+		interrupt-names = "eventq", "gerror", "cmdq-sync";
+		#iommu-cells = <1>;
+		dma-coherent;
+		smmu-cb-memtype = <0x0 0x1>;
+		hisilicon,broken-prefetch-cmd;
+		status = "disabled";
+	};
+
 	soc {
 		compatible = "simple-bus";
 		#address-cells = <2>;
@@ -1546,6 +1566,7 @@
 			#size-cells = <2>;
 			device_type = "pci";
 			dma-coherent;
+			/*iommu-map = <0x0 &smmu0 0x20000 0x10000>;*/
 			ranges = <0x02000000 0 0xa8000000 0 0xa8000000 0 0x77f0000
 				  0x01000000 0 0 0 0xaf7f0000 0 0x10000>;
 			#interrupt-cells = <1>;
-- >8 --

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Robin Murphy]

On 16/10/17 17:09, Shameerali Kolothum Thodi wrote:
> Hi Robin,
> 
>> -----Original Message-----
>> From: Will Deacon [mailto:will.deacon at arm.com]
>> Sent: Friday, October 13, 2017 8:24 PM
>> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
>> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
>> sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
>> bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
>> John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
>> linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
>> pci at vger.kernel.org; devel at acpica.org; Linuxarm <linuxarm@huawei.com>;
>> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
>> <guohanjun@huawei.com>
>> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW
>> MSI address regions for IOMMU drivers
>>
>> On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote:
>>> IOMMU drivers can use this to implement their .get_resv_regions callback
>>> for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region).
>>>
>>> Signed-off-by: Shameer Kolothum <shameerali.kolothum.thodi@huawei.com>
>>> ---
>>>  drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++
>>>  include/linux/dma-iommu.h |  7 +++++++
>>>  2 files changed, 27 insertions(+)
>>
>> I'd like to see Robin's Ack on this, because this is his code and he had
>> ideas on ways to solve this problem properly.
> 
> Please let us know if it is ok to go ahead with ACPI support for now.
> It will help our customers to start using pass-through for PCIe.
> 
> Thanks,
> Shameer
> 
>>
>> Will
>>
>>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
>>> index 9d1cebe..bae677e 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>
>>> @@ -27,6 +28,7 @@
>>>  #include <linux/iova.h>
>>>  #include <linux/irq.h>
>>>  #include <linux/mm.h>
>>> +#include <linux/of_iommu.h>
>>>  #include <linux/pci.h>
>>>  #include <linux/scatterlist.h>
>>>  #include <linux/vmalloc.h>
>>> @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device
>> *dev, struct list_head *list)
>>>  }
>>>  EXPORT_SYMBOL(iommu_dma_get_resv_regions);
>>>
>>> +/**
>>> + * iommu_dma_get_msi_resv_regions - Reserved region driver helper
>>> + * @dev: Device from iommu_get_resv_regions()
>>> + * @list: Reserved region list from iommu_get_resv_regions()
>>> + *
>>> + * IOMMU drivers can use this to implement their .get_resv_regions
>>> + * callback for HW MSI specific reservations. For now, this only

This doesn't make an awful lot of sense - there's only one reserved
region callback, so iommu-dma shouldn't be offering two separate and
non-overlapping implementations.

>>> + * covers ITS MSI region reservation using ACPI IORT helper function.
>>> + */
>>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head
>> *list)
>>> +{
>>> +	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode))
>>> +		return iort_iommu_msi_get_resv_regions(dev, list);

Either this call knows how to do the right thing for any platform and
should be made from iommu_dma_get_reserved_regions() directly, or it's
tightly coupled to the HiSilicon quirk in the SMMUv3 driver and
iommu-dma doesn't need to know - the middle ground presented here is
surely the worst of both worlds.

Robin.

>>> +
>>> +	return -ENODEV;
>>> +}
>>> +EXPORT_SYMBOL(iommu_dma_get_msi_resv_regions);
>>> +
>>>  static int cookie_init_hw_msi_region(struct iommu_dma_cookie *cookie,
>>>  		phys_addr_t start, phys_addr_t end)
>>>  {
>>> diff --git a/include/linux/dma-iommu.h b/include/linux/dma-iommu.h
>>> index 92f2083..6062ef0 100644
>>> --- a/include/linux/dma-iommu.h
>>> +++ b/include/linux/dma-iommu.h
>>> @@ -74,6 +74,8 @@ void iommu_dma_unmap_resource(struct device *dev,
>> dma_addr_t handle,
>>>  void iommu_dma_map_msi_msg(int irq, struct msi_msg *msg);
>>>  void iommu_dma_get_resv_regions(struct device *dev, struct list_head
>> *list);
>>>
>>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct list_head
>> *list);
>>> +
>>>  #else
>>>
>>>  struct iommu_domain;
>>> @@ -107,6 +109,11 @@ static inline void
>> iommu_dma_get_resv_regions(struct device *dev, struct list_he
>>>  {
>>>  }
>>>
>>> +static inline int iommu_dma_get_msi_resv_regions(struct device *dev,
>> struct list_head *list)
>>> +{
>>> +	return -ENODEV;
>>> +}
>>> +
>>>  #endif	/* CONFIG_IOMMU_DMA */
>>>  #endif	/* __KERNEL__ */
>>>  #endif	/* __DMA_IOMMU_H */
>>> --
>>> 1.9.1
>>>
>>>
> 
> _______________________________________________
> linux-arm-kernel mailing list
> linux-arm-kernel at lists.infradead.org
> http://lists.infradead.org/mailman/listinfo/linux-arm-kernel
> 

[PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind SMMUv3

[Will Deacon]

On Wed, Oct 18, 2017 at 12:25:09PM +0000, Shameerali Kolothum Thodi wrote:
> Hi Will,
> 
> > -----Original Message-----
> > From: Will Deacon [mailto:will.deacon at arm.com]
> > Sent: Wednesday, October 18, 2017 11:52 AM
> > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> > Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> > sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> > bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> > John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> > linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> > pci at vger.kernel.org; devel at acpica.org; Linuxarm <linuxarm@huawei.com>;
> > Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> > <guohanjun@huawei.com>
> > Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers behind
> > SMMUv3
> > 
> > On Sun, Oct 15, 2017 at 07:46:34AM +0000, Shameerali Kolothum Thodi wrote:
> > >
> > >
> > > > -----Original Message-----
> > > > From: Will Deacon [mailto:will.deacon at arm.com]
> > > > Sent: Friday, October 13, 2017 8:22 PM
> > > > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> > > > Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> > > > sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> > > > bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> > > > John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> > > > linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> > > > pci at vger.kernel.org; devel at acpica.org; Linuxarm
> > <linuxarm@huawei.com>;
> > > > Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> > > > <guohanjun@huawei.com>
> > > > Subject: Re: [PATCH v9 4/4] PCI: hisi: blacklist hip06/hip07 controllers
> > behind
> > > > SMMUv3
> > > >
> > > > On Fri, Oct 06, 2017 at 03:04:50PM +0100, Shameer Kolothum wrote:
> > > > > The HiSilicon erratum 161010801 describes the limitation of HiSilicon
> > > > > platforms hip06/hip07 to support the SMMUv3 mappings for MSI
> > > > > transactions.
> > > > >
> > > > > PCIe controller on these 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. In order to workaround this, ARM
> > > > > SMMUv3 driver requires a quirk to treat the MSI regions separately.
> > > > > Such a quirk is currently missing for DT based systems and therefore
> > > > > we need to blacklist the hip06/hip07 PCIe controllers.
> > > > >
> > > > > Signed-off-by: Shameer Kolothum
> > > > <shameerali.kolothum.thodi@huawei.com>
> > > > > ---
> > > > >  drivers/pci/dwc/pcie-hisi.c | 12 ++++++++++++
> > > > >  1 file changed, 12 insertions(+)
> > > > >
> > > > > diff --git a/drivers/pci/dwc/pcie-hisi.c b/drivers/pci/dwc/pcie-hisi.c
> > > > > index a201791..6800747 100644
> > > > > --- a/drivers/pci/dwc/pcie-hisi.c
> > > > > +++ b/drivers/pci/dwc/pcie-hisi.c
> > > > > @@ -270,6 +270,12 @@ static int hisi_pcie_probe(struct platform_device
> > > > *pdev)
> > > > >  	struct resource *reg;
> > > > >  	int ret;
> > > > >
> > > > > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > > > > +			of_property_read_bool(dev->of_node, "iommu-
> > > > map")) {
> > > > > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> > > > PCIe controllers behind SMMUv3\n");
> > > > > +		return -ENODEV;
> > > > > +	}
> > > > > +
> > > > >  	hisi_pcie = devm_kzalloc(dev, sizeof(*hisi_pcie), GFP_KERNEL);
> > > > >  	if (!hisi_pcie)
> > > > >  		return -ENOMEM;
> > > > > @@ -340,6 +346,12 @@ static int hisi_pcie_almost_ecam_probe(struct
> > > > platform_device *pdev)
> > > > >  	struct device *dev = &pdev->dev;
> > > > >  	struct pci_ecam_ops *ops;
> > > > >
> > > > > +	if ((IS_BUILTIN(CONFIG_ARM_SMMU_V3)) &&
> > > > > +			of_property_read_bool(dev->of_node, "iommu-
> > > > map")) {
> > > > > +		dev_warn(dev, "HiSilicon erratum 161010801: blacklisting
> > > > PCIe controllers behind SMMUv3\n");
> > > > > +		return -ENODEV;
> > > > > +	}
> > > >
> > > > This isn't the right way to solve this problem. I was really hoping you'd
> > come
> > > > up with a solution for DT, and I know you've been trying, so I suppose for
> > > > now we'll just have to go with the ACPI workaround you have and leave DT
> > in
> > > > the balance. I'm not at all happy with that, but I don't think this patch really
> > > > improves things.
> > >
> > > Yes Will, this is to get the ACPI support enabled for now.
> > >
> > > > What I think you should do is remove the relevant smmu/iommu-map
> > > > entries from the .dts files that are available for these platforms (i.e.
> > > > comment them out with a description as to why).
> > >
> > > We don't have any smmu/iommu-map entries for these platforms in the
> > > .dts files [1][2]. We are not aiming for any official DT support for these
> > platforms.
> > > This patch is to enforce the non-support.
> > 
> > Understood, but this has dragged on for a while and I don't think this patch
> > is the right way to enforce things. The best approach might actually be to
> > add the SMMU to the DTs, but commented out with a comment explaining why
> > it's not a good idea to enable it.
> 
> Ok. Just to clarify, you would like to replace this patch with another 
> one with smmu entries in dts and commenting/disabling them with explanation.
> Or you would like to have that in addition to this one?

Yes, I'm saying let's do that instead. My preference is still that we would
have all of this working for DT, but it's clear that isn't going to happen
and so I'm trying to unblock the ACPI bits whilst not having subtle breakage
with DT.

> +	/** HiSilicon erratum 161010801: Please make sure that
> +	 *  the smmu (pcie) node on hip06 is disabled as this will
> +	 *  break the PCIe functionality when iommu-map entry
> +	 *  is used along with the PCIe node.

It would be good to have a better description of what is broken and why,
along with a link to the mailing link discussion.

Will

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Robin Murphy [mailto:robin.murphy at arm.com]
> Sent: Wednesday, October 18, 2017 1:34 PM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;
> Will Deacon <will.deacon@arm.com>
> Cc: lorenzo.pieralisi at arm.com; Gabriele Paoloni
> <gabriele.paoloni@huawei.com>; marc.zyngier at arm.com; linux-
> pci at vger.kernel.org; joro at 8bytes.org; John Garry <john.garry@huawei.com>;
> Guohanjun (Hanjun Guo) <guohanjun@huawei.com>; Linuxarm
> <linuxarm@huawei.com>; linux-acpi at vger.kernel.org; iommu at lists.linux-
> foundation.org; Wangzhou (B) <wangzhou1@hisilicon.com>;
> sudeep.holla at arm.com; bhelgaas at google.com; linux-arm-
> kernel at lists.infradead.org; devel at acpica.org
> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW
> MSI address regions for IOMMU drivers
> 
> On 16/10/17 17:09, Shameerali Kolothum Thodi wrote:
> > Hi Robin,
> >
> >> -----Original Message-----
> >> From: Will Deacon [mailto:will.deacon at arm.com]
> >> Sent: Friday, October 13, 2017 8:24 PM
> >> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> >> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> >> sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> >> bhelgaas at google.com; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> >> John Garry <john.garry@huawei.com>; iommu at lists.linux-foundation.org;
> >> linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org; linux-
> >> pci at vger.kernel.org; devel at acpica.org; Linuxarm
> <linuxarm@huawei.com>;
> >> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> >> <guohanjun@huawei.com>
> >> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve
> HW
> >> MSI address regions for IOMMU drivers
> >>
> >> On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote:
> >>> IOMMU drivers can use this to implement their .get_resv_regions callback
> >>> for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI region).
> >>>
> >>> Signed-off-by: Shameer Kolothum
> <shameerali.kolothum.thodi@huawei.com>
> >>> ---
> >>>  drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++
> >>>  include/linux/dma-iommu.h |  7 +++++++
> >>>  2 files changed, 27 insertions(+)
> >>
> >> I'd like to see Robin's Ack on this, because this is his code and he had
> >> ideas on ways to solve this problem properly.
> >
> > Please let us know if it is ok to go ahead with ACPI support for now.
> > It will help our customers to start using pass-through for PCIe.
> >
> > Thanks,
> > Shameer
> >
> >>
> >> Will
> >>
> >>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> >>> index 9d1cebe..bae677e 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>
> >>> @@ -27,6 +28,7 @@
> >>>  #include <linux/iova.h>
> >>>  #include <linux/irq.h>
> >>>  #include <linux/mm.h>
> >>> +#include <linux/of_iommu.h>
> >>>  #include <linux/pci.h>
> >>>  #include <linux/scatterlist.h>
> >>>  #include <linux/vmalloc.h>
> >>> @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct device
> >> *dev, struct list_head *list)
> >>>  }
> >>>  EXPORT_SYMBOL(iommu_dma_get_resv_regions);
> >>>
> >>> +/**
> >>> + * iommu_dma_get_msi_resv_regions - Reserved region driver helper
> >>> + * @dev: Device from iommu_get_resv_regions()
> >>> + * @list: Reserved region list from iommu_get_resv_regions()
> >>> + *
> >>> + * IOMMU drivers can use this to implement their .get_resv_regions
> >>> + * callback for HW MSI specific reservations. For now, this only
> 
> This doesn't make an awful lot of sense - there's only one reserved
> region callback, so iommu-dma shouldn't be offering two separate and
> non-overlapping implementations.
> 
> >>> + * covers ITS MSI region reservation using ACPI IORT helper function.
> >>> + */
> >>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct
> list_head
> >> *list)
> >>> +{
> >>> +	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode))
> >>> +		return iort_iommu_msi_get_resv_regions(dev, list);
> 
> Either this call knows how to do the right thing for any platform and
> should be made from iommu_dma_get_reserved_regions() directly, or it's
> tightly coupled to the HiSilicon quirk in the SMMUv3 driver and
> iommu-dma doesn't need to know - the middle ground presented here is
> surely the worst of both worlds.

Right. I think we have discussed this earlier[1] and had a v4 based on invoking
the iort_iommu_its_get_resv_regions() within the iommu_dma_get_resv_regions().
But later as you rightly pointed out, we were not checking for platforms which
requires this quirk inside the iort code and that will break the platforms which are 
happy with MSI translations. Hence moved to the current implementation in v6
after this discussion here[2]
 
And earlier I think in the v3 version we had the function called from smmu driver
directly and the feedback was that it should be abstracted from the driver.

May be it is still possible to move the function call inside the 
iommu_dma_get_resv_regions() and do the smmu model check inside
 the iort helper function and selectively apply the HW MSI reservations.

But I think it is much neater if we can invoke the iort_get_msi_regions() directly
from SMMUv3 based on the model.

Thoughts?

Thanks,
Shameer
1. https://patches.linaro.org/patch/106268/
2. https://www.spinics.net/lists/arm-kernel/msg599162.html

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Shameerali Kolothum Thodi]

Hi Lorenzo/Will,

> -----Original Message-----
> From: Shameerali Kolothum Thodi
> Sent: Wednesday, October 18, 2017 3:24 PM
> To: 'Robin Murphy' <robin.murphy@arm.com>; Will Deacon
> <will.deacon@arm.com>
> Cc: lorenzo.pieralisi at arm.com; Gabriele Paoloni
> <gabriele.paoloni@huawei.com>; marc.zyngier at arm.com; linux-
> pci at vger.kernel.org; joro at 8bytes.org; John Garry <john.garry@huawei.com>;
> Guohanjun (Hanjun Guo) <guohanjun@huawei.com>; Linuxarm
> <linuxarm@huawei.com>; linux-acpi at vger.kernel.org; iommu at lists.linux-
> foundation.org; Wangzhou (B) <wangzhou1@hisilicon.com>;
> sudeep.holla at arm.com; bhelgaas at google.com; linux-arm-
> kernel at lists.infradead.org; devel at acpica.org
> Subject: RE: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW
> MSI address regions for IOMMU drivers
> 
> 
> 
> > -----Original Message-----
> > From: Robin Murphy [mailto:robin.murphy at arm.com]
> > Sent: Wednesday, October 18, 2017 1:34 PM
> > To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>;
> > Will Deacon <will.deacon@arm.com>
> > Cc: lorenzo.pieralisi at arm.com; Gabriele Paoloni
> > <gabriele.paoloni@huawei.com>; marc.zyngier at arm.com; linux-
> > pci at vger.kernel.org; joro at 8bytes.org; John Garry
> > <john.garry@huawei.com>; Guohanjun (Hanjun Guo)
> > <guohanjun@huawei.com>; Linuxarm <linuxarm@huawei.com>;
> > linux-acpi at vger.kernel.org; iommu at lists.linux- foundation.org;
> > Wangzhou (B) <wangzhou1@hisilicon.com>; sudeep.holla at arm.com;
> > bhelgaas at google.com; linux-arm- kernel at lists.infradead.org;
> > devel at acpica.org
> > Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to
> > reserve HW MSI address regions for IOMMU drivers
> >
> > On 16/10/17 17:09, Shameerali Kolothum Thodi wrote:
> > > Hi Robin,
> > >
> > >> -----Original Message-----
> > >> From: Will Deacon [mailto:will.deacon at arm.com]
> > >> Sent: Friday, October 13, 2017 8:24 PM
> > >> To: Shameerali Kolothum Thodi
> > >> <shameerali.kolothum.thodi@huawei.com>
> > >> Cc: lorenzo.pieralisi at arm.com; marc.zyngier at arm.com;
> > >> sudeep.holla at arm.com; robin.murphy at arm.com; joro at 8bytes.org;
> > >> bhelgaas at google.com; Gabriele Paoloni
> > >> <gabriele.paoloni@huawei.com>; John Garry <john.garry@huawei.com>;
> > >> iommu at lists.linux-foundation.org;
> > >> linux-arm-kernel at lists.infradead.org; linux-acpi at vger.kernel.org;
> > >> linux- pci at vger.kernel.org; devel at acpica.org; Linuxarm
> > <linuxarm@huawei.com>;
> > >> Wangzhou (B) <wangzhou1@hisilicon.com>; Guohanjun (Hanjun Guo)
> > >> <guohanjun@huawei.com>
> > >> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to
> > >> reserve
> > HW
> > >> MSI address regions for IOMMU drivers
> > >>
> > >> On Fri, Oct 06, 2017 at 03:04:48PM +0100, Shameer Kolothum wrote:
> > >>> IOMMU drivers can use this to implement their .get_resv_regions
> > >>> callback for HW MSI specific reservations(e.g. ARM GICv3 ITS MSI
> region).
> > >>>
> > >>> Signed-off-by: Shameer Kolothum
> > <shameerali.kolothum.thodi@huawei.com>
> > >>> ---
> > >>>  drivers/iommu/dma-iommu.c | 20 ++++++++++++++++++++
> > >>> include/linux/dma-iommu.h |  7 +++++++
> > >>>  2 files changed, 27 insertions(+)
> > >>
> > >> I'd like to see Robin's Ack on this, because this is his code and
> > >> he had ideas on ways to solve this problem properly.
> > >
> > > Please let us know if it is ok to go ahead with ACPI support for now.
> > > It will help our customers to start using pass-through for PCIe.
> > >
> > > Thanks,
> > > Shameer
> > >
> > >>
> > >> Will
> > >>
> > >>> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > >>> index 9d1cebe..bae677e 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>
> > >>> @@ -27,6 +28,7 @@
> > >>>  #include <linux/iova.h>
> > >>>  #include <linux/irq.h>
> > >>>  #include <linux/mm.h>
> > >>> +#include <linux/of_iommu.h>
> > >>>  #include <linux/pci.h>
> > >>>  #include <linux/scatterlist.h>
> > >>>  #include <linux/vmalloc.h>
> > >>> @@ -198,6 +200,24 @@ void iommu_dma_get_resv_regions(struct
> device
> > >> *dev, struct list_head *list)
> > >>>  }
> > >>>  EXPORT_SYMBOL(iommu_dma_get_resv_regions);
> > >>>
> > >>> +/**
> > >>> + * iommu_dma_get_msi_resv_regions - Reserved region driver helper
> > >>> + * @dev: Device from iommu_get_resv_regions()
> > >>> + * @list: Reserved region list from iommu_get_resv_regions()
> > >>> + *
> > >>> + * IOMMU drivers can use this to implement their
> > >>> +.get_resv_regions
> > >>> + * callback for HW MSI specific reservations. For now, this only
> >
> > This doesn't make an awful lot of sense - there's only one reserved
> > region callback, so iommu-dma shouldn't be offering two separate and
> > non-overlapping implementations.
> >
> > >>> + * covers ITS MSI region reservation using ACPI IORT helper function.
> > >>> + */
> > >>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct
> > list_head
> > >> *list)
> > >>> +{
> > >>> +	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode))
> > >>> +		return iort_iommu_msi_get_resv_regions(dev, list);
> >
> > Either this call knows how to do the right thing for any platform and
> > should be made from iommu_dma_get_reserved_regions() directly, or it's
> > tightly coupled to the HiSilicon quirk in the SMMUv3 driver and
> > iommu-dma doesn't need to know - the middle ground presented here is
> > surely the worst of both worlds.
> 
> Right. I think we have discussed this earlier[1] and had a v4 based on invoking
> the iort_iommu_its_get_resv_regions() within the
> iommu_dma_get_resv_regions().
> But later as you rightly pointed out, we were not checking for platforms which
> requires this quirk inside the iort code and that will break the platforms which
> are happy with MSI translations. Hence moved to the current implementation
> in v6 after this discussion here[2]
> 
> And earlier I think in the v3 version we had the function called from smmu
> driver directly and the feedback was that it should be abstracted from the
> driver.
> 
> May be it is still possible to move the function call inside the
> iommu_dma_get_resv_regions() and do the smmu model check inside  the iort
> helper function and selectively apply the HW MSI reservations.
> 
> But I think it is much neater if we can invoke the iort_get_msi_regions()
> directly from SMMUv3 based on the model.
> 
> Thoughts?

As we still don?t have a clear resolution on how to invoke the 
iort_iommu_msi_get_resv_regions(), I have gone back and attempted to move the
smmu model check inside the iort code. This means the function will selectively
apply HW MSI reservation based on the platform and also the function can be 
invoked from the iommu_dma_get_resv_regions() directly.

Could you please take a look at the below snippet and let me know your feedback.
Hope we can make some progress on this series.

Thanks,
Shameer

-->8--
diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
index 876c0e1..a27233d 100644
--- a/drivers/acpi/arm64/iort.c
+++ b/drivers/acpi/arm64/iort.c
@@ -619,6 +619,39 @@ static int __maybe_unused __get_pci_rid(struct pci_dev *pdev, u16 alias,
 	return 0;
 }
 
+static bool __maybe_unused iort_hw_msi_resv_enable(struct device *dev,
+					struct acpi_iort_node *node)
+{
+	struct acpi_iort_node *iommu = NULL;
+	int i;
+
+	if (dev_is_pci(dev)) {
+		u32 rid;
+
+		pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, &rid);
+		iommu = iort_node_map_id(node, rid, NULL, IORT_IOMMU_TYPE);
+	} else {
+		for (i = 0; i < node->mapping_count; i++) {
+			iommu = iort_node_map_platform_id(node, NULL,
+							IORT_IOMMU_TYPE, i);
+			if (iommu)
+				break;
+		}
+	}
+
+	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) {
+			dev_notice(dev, "Enabling HiSilicon erratum 161010801\n");
+			return true;
+		}
+	}
+
+	return false;
+}
+
 static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
 			       struct fwnode_handle *fwnode,
 			       const struct iommu_ops *ops)
@@ -682,6 +715,9 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
 	if (!node)
 		return -ENODEV;
 
+	if (!iort_hw_msi_resv_enable(dev, 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
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 9d1cebe..67c6e30 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>
@@ -174,6 +175,10 @@ 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;
 
diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
index 182a577..88f17c9 100644
--- a/include/linux/acpi_iort.h
+++ b/include/linux/acpi_iort.h
@@ -56,7 +56,7 @@ 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 -ENODEV; }
+{ return 0; }
 #endif
 
 #endif /* __ACPI_IORT_H__ */

-->8--

 

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Lorenzo Pieralisi]

On Thu, Oct 26, 2017 at 10:11:58AM +0000, Shameerali Kolothum Thodi wrote:

[...]

> > > >>> +int iommu_dma_get_msi_resv_regions(struct device *dev, struct
> > > list_head
> > > >> *list)
> > > >>> +{
> > > >>> +	if (!is_of_node(dev->iommu_fwspec->iommu_fwnode))
> > > >>> +		return iort_iommu_msi_get_resv_regions(dev, list);
> > >
> > > Either this call knows how to do the right thing for any platform and
> > > should be made from iommu_dma_get_reserved_regions() directly, or it's
> > > tightly coupled to the HiSilicon quirk in the SMMUv3 driver and
> > > iommu-dma doesn't need to know - the middle ground presented here is
> > > surely the worst of both worlds.
> > 
> > Right. I think we have discussed this earlier[1] and had a v4 based on invoking
> > the iort_iommu_its_get_resv_regions() within the
> > iommu_dma_get_resv_regions().
> > But later as you rightly pointed out, we were not checking for platforms which
> > requires this quirk inside the iort code and that will break the platforms which
> > are happy with MSI translations. Hence moved to the current implementation
> > in v6 after this discussion here[2]
> > 
> > And earlier I think in the v3 version we had the function called from smmu
> > driver directly and the feedback was that it should be abstracted from the
> > driver.
> > 
> > May be it is still possible to move the function call inside the
> > iommu_dma_get_resv_regions() and do the smmu model check inside  the iort
> > helper function and selectively apply the HW MSI reservations.
> > 
> > But I think it is much neater if we can invoke the iort_get_msi_regions()
> > directly from SMMUv3 based on the model.
> > 
> > Thoughts?
> 
> As we still don?t have a clear resolution on how to invoke the 
> iort_iommu_msi_get_resv_regions(), I have gone back and attempted to move the
> smmu model check inside the iort code. This means the function will selectively
> apply HW MSI reservation based on the platform and also the function can be 
> invoked from the iommu_dma_get_resv_regions() directly.
> 
> Could you please take a look at the below snippet and let me know your feedback.
> Hope we can make some progress on this series.
> 
> Thanks,
> Shameer
> 
> -->8--
> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index 876c0e1..a27233d 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -619,6 +619,39 @@ static int __maybe_unused __get_pci_rid(struct pci_dev *pdev, u16 alias,
>  	return 0;
>  }
>  
> +static bool __maybe_unused iort_hw_msi_resv_enable(struct device *dev,
> +					struct acpi_iort_node *node)
> +{
> +	struct acpi_iort_node *iommu = NULL;
> +	int i;
> +
> +	if (dev_is_pci(dev)) {
> +		u32 rid;
> +
> +		pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, &rid);
> +		iommu = iort_node_map_id(node, rid, NULL, IORT_IOMMU_TYPE);
> +	} else {
> +		for (i = 0; i < node->mapping_count; i++) {
> +			iommu = iort_node_map_platform_id(node, NULL,
> +							IORT_IOMMU_TYPE, i);
> +			if (iommu)
> +				break;
> +		}
> +	}

You do not need (and I do not want this code) to do the mapping again.

You have the fwnode (ie dev->iommu_fwspec) corresponding to the IOMMU,
you can retrieve the SMMU IORT node by a simple look-up and carry out the
check below.

It would be simpler to set an option in the SMMUv3 driver but then
you go back to square one with DT/ACPI SMMUv3 driver awareness so, if,
with the change above this can make the generic approach work (ie Robin
is happy with it) I am fine with this IORT update as well.

Lorenzo

> +
> +	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) {
> +			dev_notice(dev, "Enabling HiSilicon erratum 161010801\n");
> +			return true;
> +		}
> +	}
> +
> +	return false;
> +}
> +
>  static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
>  			       struct fwnode_handle *fwnode,
>  			       const struct iommu_ops *ops)
> @@ -682,6 +715,9 @@ int iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head *head)
>  	if (!node)
>  		return -ENODEV;
>  
> +	if (!iort_hw_msi_resv_enable(dev, 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
> diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> index 9d1cebe..67c6e30 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>
> @@ -174,6 +175,10 @@ 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;
>  
> diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> index 182a577..88f17c9 100644
> --- a/include/linux/acpi_iort.h
> +++ b/include/linux/acpi_iort.h
> @@ -56,7 +56,7 @@ 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 -ENODEV; }
> +{ return 0; }
>  #endif
>  
>  #endif /* __ACPI_IORT_H__ */
> 
> -->8--
> 
>  
> 

[PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW MSI address regions for IOMMU drivers

[Shameerali Kolothum Thodi]

> -----Original Message-----
> From: Lorenzo Pieralisi [mailto:lorenzo.pieralisi at arm.com]
> Sent: Friday, November 03, 2017 11:35 AM
> To: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
> Cc: Robin Murphy <robin.murphy@arm.com>; Will Deacon
> <will.deacon@arm.com>; Gabriele Paoloni <gabriele.paoloni@huawei.com>;
> marc.zyngier at arm.com; linux-pci at vger.kernel.org; joro at 8bytes.org; John
> Garry <john.garry@huawei.com>; Guohanjun (Hanjun Guo)
> <guohanjun@huawei.com>; Linuxarm <linuxarm@huawei.com>; linux-
> acpi at vger.kernel.org; iommu at lists.linux-foundation.org; Wangzhou (B)
> <wangzhou1@hisilicon.com>; sudeep.holla at arm.com; bhelgaas at google.com;
> linux-arm-kernel at lists.infradead.org; devel at acpica.org
> Subject: Re: [PATCH v9 2/4] iommu/dma: Add a helper function to reserve HW
> MSI address regions for IOMMU drivers
> 
> On Thu, Oct 26, 2017 at 10:11:58AM +0000, Shameerali Kolothum Thodi wrote:
> 
[..]

> >
> > As we still don?t have a clear resolution on how to invoke the
> > iort_iommu_msi_get_resv_regions(), I have gone back and attempted to
> > move the smmu model check inside the iort code. This means the
> > function will selectively apply HW MSI reservation based on the
> > platform and also the function can be invoked from the
> iommu_dma_get_resv_regions() directly.
> >
> > Could you please take a look at the below snippet and let me know your
> feedback.
> > Hope we can make some progress on this series.
> >
> > Thanks,
> > Shameer
> >
> > -->8--
> > diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> > index 876c0e1..a27233d 100644
> > --- a/drivers/acpi/arm64/iort.c
> > +++ b/drivers/acpi/arm64/iort.c
> > @@ -619,6 +619,39 @@ static int __maybe_unused __get_pci_rid(struct
> pci_dev *pdev, u16 alias,
> >  	return 0;
> >  }
> >
> > +static bool __maybe_unused iort_hw_msi_resv_enable(struct device *dev,
> > +					struct acpi_iort_node *node)
> > +{
> > +	struct acpi_iort_node *iommu = NULL;
> > +	int i;
> > +
> > +	if (dev_is_pci(dev)) {
> > +		u32 rid;
> > +
> > +		pci_for_each_dma_alias(to_pci_dev(dev), __get_pci_rid, &rid);
> > +		iommu = iort_node_map_id(node, rid, NULL,
> IORT_IOMMU_TYPE);
> > +	} else {
> > +		for (i = 0; i < node->mapping_count; i++) {
> > +			iommu = iort_node_map_platform_id(node, NULL,
> > +							IORT_IOMMU_TYPE,
> i);
> > +			if (iommu)
> > +				break;
> > +		}
> > +	}
> 
> You do not need (and I do not want this code) to do the mapping again.
> 
> You have the fwnode (ie dev->iommu_fwspec) corresponding to the IOMMU,
> you can retrieve the SMMU IORT node by a simple look-up and carry out the
> check below.

Ok. Understood. I will rework this part then.

> It would be simpler to set an option in the SMMUv3 driver but then you go back
> to square one with DT/ACPI SMMUv3 driver awareness so, if, with the change
> above this can make the generic approach work (ie Robin is happy with it) I am
> fine with this IORT update as well.

Thanks Lorenzo. I will rebase on top of rc1 and prepare v10 with these changes
and sent it out.

Shameer 

> > +
> > +	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) {
> > +			dev_notice(dev, "Enabling HiSilicon erratum
> 161010801\n");
> > +			return true;
> > +		}
> > +	}
> > +
> > +	return false;
> > +}
> > +
> >  static int arm_smmu_iort_xlate(struct device *dev, u32 streamid,
> >  			       struct fwnode_handle *fwnode,
> >  			       const struct iommu_ops *ops) @@ -682,6 +715,9
> @@ int
> > iort_iommu_msi_get_resv_regions(struct device *dev, struct list_head
> *head)
> >  	if (!node)
> >  		return -ENODEV;
> >
> > +	if (!iort_hw_msi_resv_enable(dev, 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
> > diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
> > index 9d1cebe..67c6e30 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>
> > @@ -174,6 +175,10 @@ 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;
> >
> > diff --git a/include/linux/acpi_iort.h b/include/linux/acpi_iort.h
> > index 182a577..88f17c9 100644
> > --- a/include/linux/acpi_iort.h
> > +++ b/include/linux/acpi_iort.h
> > @@ -56,7 +56,7 @@ 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 -ENODEV; }
> > +{ return 0; }
> >  #endif
> >
> >  #endif /* __ACPI_IORT_H__ */
> >
> > -->8--
> >
> >
> >