[PATCH RFC 06/15] ims-msi: Enable IMS interrupts

Dave Jiang
2020-04-21T23:34:28Z

From: Megha Dey <megha.dey@linux.intel.com>

To enable IMS interrupts,

1. create an IMS irqdomain (arch_create_ims_irq_domain()) associated
with the interrupt remapping unit.

2. Add 'IMS' to the enum platform_msi_type to differentiate between
specific actions required for different types of platform-msi, currently
generic platform-msi and IMS

Signed-off-by: Megha Dey <megha.dey@linux.intel.com>
---
arch/x86/include/asm/irq_remapping.h | 6 ++++
drivers/base/ims-msi.c | 15 ++++++++++
drivers/base/platform-msi.c | 51 +++++++++++++++++++++++++---------
drivers/iommu/intel-iommu.c | 2 +
drivers/iommu/intel_irq_remapping.c | 31 +++++++++++++++++++--
include/linux/intel-iommu.h | 3 ++
include/linux/msi.h | 9 ++++++
7 files changed, 100 insertions(+), 17 deletions(-)

diff --git a/arch/x86/include/asm/irq_remapping.h b/arch/x86/include/asm/irq_remapping.h
index 4bc985f1e2e4..575e48c31b78 100644
--- a/arch/x86/include/asm/irq_remapping.h
+++ b/arch/x86/include/asm/irq_remapping.h
@@ -53,6 +53,12 @@ irq_remapping_get_irq_domain(struct irq_alloc_info *info);
extern struct irq_domain *
arch_create_remap_msi_irq_domain(struct irq_domain *par, const char *n, int id);

+/* Create IMS irqdomain, use @parent as the parent irqdomain. */
+#ifdef CONFIG_MSI_IMS
+extern struct irq_domain *arch_create_ims_irq_domain(struct irq_domain *parent,
+ const char *name);
+#endif
+
/* Get parent irqdomain for interrupt remapping irqdomain */
static inline struct irq_domain *arch_get_ir_parent_domain(void)
{
diff --git a/drivers/base/ims-msi.c b/drivers/base/ims-msi.c
index 896a5a1b2252..ac21088bcb83 100644
--- a/drivers/base/ims-msi.c
+++ b/drivers/base/ims-msi.c
@@ -14,6 +14,7 @@
#include <linux/mdev.h>
#include <linux/msi.h>
#include <linux/pci.h>
+#include <asm/irq_remapping.h>

static u32 __dev_ims_desc_mask_irq(struct msi_desc *desc, u32 flag)
{
@@ -101,6 +102,20 @@ static void dev_ims_set_desc(msi_alloc_info_t *arg, struct msi_desc *desc)
arg->ims_hwirq = platform_msi_calc_hwirq(desc);
}

+struct irq_domain *dev_get_ims_domain(struct device *dev)
+{
+ struct irq_alloc_info info;
+
+ if (dev_is_mdev(dev))
+ dev = mdev_to_parent(dev);
+
+ init_irq_alloc_info(&info, NULL);
+ info.type = X86_IRQ_ALLOC_TYPE_IMS;
+ info.dev = dev;
+
+ return irq_remapping_get_irq_domain(&info);
+}
+
static struct msi_domain_ops dev_ims_domain_ops = {
.get_hwirq = dev_ims_get_hwirq,
.msi_prepare = dev_ims_prepare,
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c
index 6d8840db4a85..204ce8041c17 100644
--- a/drivers/base/platform-msi.c
+++ b/drivers/base/platform-msi.c
@@ -118,6 +118,8 @@ static void platform_msi_free_descs(struct device *dev, int base, int nvec,
kfree(platform_msi_group);
}
}
+
+ dev->platform_msi_type = 0;
}

static int platform_msi_alloc_descs_with_irq(struct device *dev, int virq,
@@ -205,18 +207,22 @@ platform_msi_alloc_priv_data(struct device *dev, unsigned int nvec,
* accordingly (which would impact the max number of MSI
* capable devices).
*/
- if (!dev->msi_domain || !platform_ops->write_msg || !nvec ||
- nvec > MAX_DEV_MSIS)
+ if (!platform_ops->write_msg || !nvec || nvec > MAX_DEV_MSIS)
return ERR_PTR(-EINVAL);

- if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
- dev_err(dev, "Incompatible msi_domain, giving up\n");
- return ERR_PTR(-EINVAL);
- }
+ if (dev->platform_msi_type == GEN_PLAT_MSI) {
+ if (!dev->msi_domain)
+ return ERR_PTR(-EINVAL);
+
+ if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
+ dev_err(dev, "Incompatible msi_domain, giving up\n");
+ return ERR_PTR(-EINVAL);
+ }

- /* Already had a helping of MSI? Greed... */
- if (!list_empty(platform_msi_current_group_entry_list(dev)))
- return ERR_PTR(-EBUSY);
+ /* Already had a helping of MSI? Greed... */
+ if (!list_empty(platform_msi_current_group_entry_list(dev)))
+ return ERR_PTR(-EBUSY);
+ }

datap = kzalloc(sizeof(*datap), GFP_KERNEL);
if (!datap)
@@ -254,6 +260,7 @@ static void platform_msi_free_priv_data(struct platform_msi_priv_data *data)
int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec,
const struct platform_msi_ops *platform_ops)
{
+ dev->platform_msi_type = GEN_PLAT_MSI;
return platform_msi_domain_alloc_irqs_group(dev, nvec, platform_ops,
NULL);
}
@@ -265,12 +272,18 @@ int platform_msi_domain_alloc_irqs_group(struct device *dev, unsigned int nvec,
{
struct platform_msi_group_entry *platform_msi_group;
struct platform_msi_priv_data *priv_data;
+ struct irq_domain *domain;
int err;

- dev->platform_msi_type = GEN_PLAT_MSI;
-
- if (group_id)
+ if (!dev->platform_msi_type) {
*group_id = ++dev->group_id;
+ dev->platform_msi_type = IMS;
+ domain = dev_get_ims_domain(dev);
+ if (!domain)
+ return -ENOSYS;
+ } else {
+ domain = dev->msi_domain;
+ }

platform_msi_group = kzalloc(sizeof(*platform_msi_group), GFP_KERNEL);
if (!platform_msi_group) {
@@ -292,10 +305,11 @@ int platform_msi_domain_alloc_irqs_group(struct device *dev, unsigned int nvec,
if (err)
goto out_free_priv_data;

- err = msi_domain_alloc_irqs(dev->msi_domain, dev, nvec);
+ err = msi_domain_alloc_irqs(domain, dev, nvec);
if (err)
goto out_free_desc;

+ dev->platform_msi_type = 0;
return 0;

out_free_desc:
@@ -314,6 +328,7 @@ EXPORT_SYMBOL_GPL(platform_msi_domain_alloc_irqs_group);
*/
void platform_msi_domain_free_irqs(struct device *dev)
{
+ dev->platform_msi_type = GEN_PLAT_MSI;
platform_msi_domain_free_irqs_group(dev, 0);
}
EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs);
@@ -321,6 +336,14 @@ EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs);
void platform_msi_domain_free_irqs_group(struct device *dev, unsigned int group)
{
struct platform_msi_group_entry *platform_msi_group;
+ struct irq_domain *domain;
+
+ if (!dev->platform_msi_type) {
+ dev->platform_msi_type = IMS;
+ domain = dev_get_ims_domain(dev);
+ } else {
+ domain = dev->msi_domain;
+ }

list_for_each_entry(platform_msi_group,
dev_to_platform_msi_group_list((dev)), group_list) {
@@ -334,7 +357,7 @@ void platform_msi_domain_free_irqs_group(struct device *dev, unsigned int group)
}
}
}
- msi_domain_free_irqs_group(dev->msi_domain, dev, group);
+ msi_domain_free_irqs_group(domain, dev, group);
platform_msi_free_descs(dev, 0, MAX_DEV_MSIS, group);
}
EXPORT_SYMBOL_GPL(platform_msi_domain_free_irqs_group);
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index ef0a5246700e..99bb238caea6 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -794,7 +794,7 @@ is_downstream_to_pci_bridge(struct device *dev, struct device *bridge)
return false;
}

-static struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)
+struct intel_iommu *device_to_iommu(struct device *dev, u8 *bus, u8 *devfn)
{
struct dmar_drhd_unit *drhd = NULL;
struct intel_iommu *iommu;
diff --git a/drivers/iommu/intel_irq_remapping.c b/drivers/iommu/intel_irq_remapping.c
index 81e43c1df7ec..1e470c9c3e7d 100644
--- a/drivers/iommu/intel_irq_remapping.c
+++ b/drivers/iommu/intel_irq_remapping.c
@@ -234,6 +234,18 @@ static struct intel_iommu *map_dev_to_ir(struct pci_dev *dev)
return drhd->iommu;
}

+static struct intel_iommu *map_gen_dev_to_ir(struct device *dev)
+{
+ struct intel_iommu *iommu;
+ u8 bus, devfn;
+
+ iommu = device_to_iommu(dev, &bus, &devfn);
+ if (!iommu)
+ return NULL;
+
+ return iommu;
+}
+
static int clear_entries(struct irq_2_iommu *irq_iommu)
{
struct irte *start, *entry, *end;
@@ -572,6 +584,10 @@ static int intel_setup_irq_remapping(struct intel_iommu *iommu)
arch_create_remap_msi_irq_domain(iommu->ir_domain,
"INTEL-IR-MSI",
iommu->seq_id);
+#if IS_ENABLED(CONFIG_MSI_IMS)
+ iommu->ir_ims_domain = arch_create_ims_irq_domain(iommu->ir_domain,
+ "INTEL-IR-IMS");
+#endif

ir_table->base = page_address(pages);
ir_table->bitmap = bitmap;
@@ -637,6 +653,10 @@ static void intel_teardown_irq_remapping(struct intel_iommu *iommu)
irq_domain_remove(iommu->ir_domain);
iommu->ir_domain = NULL;
}
+ if (iommu->ir_ims_domain) {
+ irq_domain_remove(iommu->ir_ims_domain);
+ iommu->ir_ims_domain = NULL;
+ }
free_pages((unsigned long)iommu->ir_table->base,
INTR_REMAP_PAGE_ORDER);
bitmap_free(iommu->ir_table->bitmap);
@@ -1132,6 +1152,11 @@ static struct irq_domain *intel_get_irq_domain(struct irq_alloc_info *info)
if (iommu)
return iommu->ir_msi_domain;
break;
+ case X86_IRQ_ALLOC_TYPE_IMS:
+ iommu = map_gen_dev_to_ir(info->dev);
+ if (iommu)
+ return iommu->ir_ims_domain;
+ break;
default:
break;
}
@@ -1299,9 +1324,10 @@ static void intel_irq_remapping_prepare_irte(struct intel_ir_data *data,
case X86_IRQ_ALLOC_TYPE_HPET:
case X86_IRQ_ALLOC_TYPE_MSI:
case X86_IRQ_ALLOC_TYPE_MSIX:
+ case X86_IRQ_ALLOC_TYPE_IMS:
if (info->type == X86_IRQ_ALLOC_TYPE_HPET)
set_hpet_sid(irte, info->hpet_id);
- else
+ else if (info->type != X86_IRQ_ALLOC_TYPE_IMS)
set_msi_sid(irte, info->msi_dev);

msg->address_hi = MSI_ADDR_BASE_HI;
@@ -1354,7 +1380,8 @@ static int intel_irq_remapping_alloc(struct irq_domain *domain,
if (!info || !iommu)
return -EINVAL;
if (nr_irqs > 1 && info->type != X86_IRQ_ALLOC_TYPE_MSI &&
- info->type != X86_IRQ_ALLOC_TYPE_MSIX)
+ info->type != X86_IRQ_ALLOC_TYPE_MSIX &&
+ info->type != X86_IRQ_ALLOC_TYPE_IMS)
return -EINVAL;

/*
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index 980234ae0312..cdaab83001da 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -557,6 +557,7 @@ struct intel_iommu {
struct ir_table *ir_table; /* Interrupt remapping info */
struct irq_domain *ir_domain;
struct irq_domain *ir_msi_domain;
+ struct irq_domain *ir_ims_domain;
#endif
struct iommu_device iommu; /* IOMMU core code handle */
int node;
@@ -701,6 +702,8 @@ extern struct intel_iommu *intel_svm_device_to_iommu(struct device *dev);
static inline void intel_svm_check(struct intel_iommu *iommu) {}
#endif

+extern struct intel_iommu *device_to_iommu(struct device *dev,
+ u8 *bus, u8 *devfn);
#ifdef CONFIG_INTEL_IOMMU_DEBUGFS
void intel_iommu_debugfs_init(void);
#else
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 8b5f24bf3c47..2f8fa1391333 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -135,6 +135,7 @@ struct msi_desc {
enum platform_msi_type {
NOT_PLAT_MSI = 0,
GEN_PLAT_MSI = 1,
+ IMS = 2,
};

struct platform_msi_group_entry {
@@ -454,4 +455,12 @@ static inline struct irq_domain *pci_msi_get_device_domain(struct pci_dev *pdev)
}
#endif /* CONFIG_PCI_MSI_IRQ_DOMAIN */

+#ifdef CONFIG_MSI_IMS
+struct irq_domain *dev_get_ims_domain(struct device *dev);
+#else
+static inline struct irq_domain *dev_get_ims_domain(struct device *dev)
+{
+ return NULL;
+}
+#endif
#endif /* LINUX_MSI_H */