[PATCH v5 11/19] irqchip: gicv3-its: Split PCI/MSI code from the core ITS driver

Marc Zyngier
2015-07-23T09:30:19Z

It is becoming obvious that having the PCI/MSI code in the same
file as the the core ITS code is giving people implementing non-PCI
MSI support the wrong kind of idea.

In order to make things a bit clearer, let's move the PCI/MSI code
out to its own file. Hopefully it will make it clear that whoever
thinks of hooking into the core ITS better have a very strong point.

We use a temporary entry point that will get removed in a subsequent
patch, once the proper infrastructure is added.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
drivers/irqchip/Makefile | 2 +-
drivers/irqchip/irq-gic-v3-its-pci-msi.c | 105 +++++++++++++++++++++++++++++++
drivers/irqchip/irq-gic-v3-its.c | 93 ++++-----------------------
include/linux/irqchip/arm-gic-v3.h | 6 ++
4 files changed, 123 insertions(+), 83 deletions(-)
create mode 100644 drivers/irqchip/irq-gic-v3-its-pci-msi.c

diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
index b8d4e96..0d5f2a9 100644
--- a/drivers/irqchip/Makefile
+++ b/drivers/irqchip/Makefile
@@ -22,7 +22,7 @@ obj-$(CONFIG_ARCH_SPEAR3XX) += spear-shirq.o
obj-$(CONFIG_ARM_GIC) += irq-gic.o irq-gic-common.o
obj-$(CONFIG_ARM_GIC_V2M) += irq-gic-v2m.o
obj-$(CONFIG_ARM_GIC_V3) += irq-gic-v3.o irq-gic-common.o
-obj-$(CONFIG_ARM_GIC_V3_ITS) += irq-gic-v3-its.o
+obj-$(CONFIG_ARM_GIC_V3_ITS) += irq-gic-v3-its.o irq-gic-v3-its-pci-msi.o
obj-$(CONFIG_ARM_NVIC) += irq-nvic.o
obj-$(CONFIG_ARM_VIC) += irq-vic.o
obj-$(CONFIG_ATMEL_AIC_IRQ) += irq-atmel-aic-common.o irq-atmel-aic.o
diff --git a/drivers/irqchip/irq-gic-v3-its-pci-msi.c b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
new file mode 100644
index 0000000..7614721
--- /dev/null
+++ b/drivers/irqchip/irq-gic-v3-its-pci-msi.c
@@ -0,0 +1,105 @@
+/*
+ * Copyright (C) 2013-2015 ARM Limited, All Rights Reserved.
+ * Author: Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/msi.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_pci.h>
+
+#include <linux/irqchip/arm-gic-v3.h>
+
+static void its_mask_msi_irq(struct irq_data *d)
+{
+ pci_msi_mask_irq(d);
+ irq_chip_mask_parent(d);
+}
+
+static void its_unmask_msi_irq(struct irq_data *d)
+{
+ pci_msi_unmask_irq(d);
+ irq_chip_unmask_parent(d);
+}
+
+static struct irq_chip its_msi_irq_chip = {
+ .name = "ITS-MSI",
+ .irq_unmask = its_unmask_msi_irq,
+ .irq_mask = its_mask_msi_irq,
+ .irq_eoi = irq_chip_eoi_parent,
+ .irq_write_msi_msg = pci_msi_domain_write_msg,
+};
+
+struct its_pci_alias {
+ struct pci_dev *pdev;
+ u32 dev_id;
+ u32 count;
+};
+
+static int its_pci_msi_vec_count(struct pci_dev *pdev)
+{
+ int msi, msix;
+
+ msi = max(pci_msi_vec_count(pdev), 0);
+ msix = max(pci_msix_vec_count(pdev), 0);
+
+ return max(msi, msix);
+}
+
+static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
+{
+ struct its_pci_alias *dev_alias = data;
+
+ dev_alias->dev_id = alias;
+ if (pdev != dev_alias->pdev)
+ dev_alias->count += its_pci_msi_vec_count(dev_alias->pdev);
+
+ return 0;
+}
+
+static int its_pci_msi_prepare(struct irq_domain *domain, struct device *dev,
+ int nvec, msi_alloc_info_t *info)
+{
+ struct pci_dev *pdev;
+ struct its_pci_alias dev_alias;
+
+ if (!dev_is_pci(dev))
+ return -EINVAL;
+
+ pdev = to_pci_dev(dev);
+ dev_alias.pdev = pdev;
+ dev_alias.count = nvec;
+
+ pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias);
+
+ return its_msi_prepare(domain, dev_alias.dev_id, dev_alias.count, info);
+}
+
+static struct msi_domain_ops its_pci_msi_ops = {
+ .msi_prepare = its_pci_msi_prepare,
+};
+
+static struct msi_domain_info its_pci_msi_domain_info = {
+ .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
+ MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
+ .ops = &its_pci_msi_ops,
+ .chip = &its_msi_irq_chip,
+};
+
+struct irq_domain *its_pci_msi_alloc_domain(struct device_node *np,
+ struct irq_domain *parent)
+{
+ return pci_msi_create_irq_domain(np, &its_pci_msi_domain_info, parent);
+}
diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c
index 1b7e155..7c01fe4 100644
--- a/drivers/irqchip/irq-gic-v3-its.c
+++ b/drivers/irqchip/irq-gic-v3-its.c
@@ -611,26 +611,6 @@ static struct irq_chip its_irq_chip = {
.irq_compose_msi_msg = its_irq_compose_msi_msg,
};

-static void its_mask_msi_irq(struct irq_data *d)
-{
- pci_msi_mask_irq(d);
- irq_chip_mask_parent(d);
-}
-
-static void its_unmask_msi_irq(struct irq_data *d)
-{
- pci_msi_unmask_irq(d);
- irq_chip_unmask_parent(d);
-}
-
-static struct irq_chip its_msi_irq_chip = {
- .name = "ITS-MSI",
- .irq_unmask = its_unmask_msi_irq,
- .irq_mask = its_mask_msi_irq,
- .irq_eoi = irq_chip_eoi_parent,
- .irq_write_msi_msg = pci_msi_domain_write_msg,
-};
-
/*
* How we allocate LPIs:
*
@@ -1173,85 +1153,34 @@ static int its_alloc_device_irq(struct its_device *dev, irq_hw_number_t *hwirq)
return 0;
}

-struct its_pci_alias {
- struct pci_dev *pdev;
- u32 dev_id;
- u32 count;
-};
-
-static int its_pci_msi_vec_count(struct pci_dev *pdev)
-{
- int msi, msix;
-
- msi = max(pci_msi_vec_count(pdev), 0);
- msix = max(pci_msix_vec_count(pdev), 0);
-
- return max(msi, msix);
-}
-
-static int its_get_pci_alias(struct pci_dev *pdev, u16 alias, void *data)
+int its_msi_prepare(struct irq_domain *domain, u32 dev_id,
+ int nvec, msi_alloc_info_t *info)
{
- struct its_pci_alias *dev_alias = data;
-
- dev_alias->dev_id = alias;
- if (pdev != dev_alias->pdev)
- dev_alias->count += its_pci_msi_vec_count(dev_alias->pdev);
-
- return 0;
-}
-
-static int its_msi_prepare(struct irq_domain *domain, struct device *dev,
- int nvec, msi_alloc_info_t *info)
-{
- struct pci_dev *pdev;
struct its_node *its;
struct its_device *its_dev;
- struct its_pci_alias dev_alias;
-
- if (!dev_is_pci(dev))
- return -EINVAL;
-
- pdev = to_pci_dev(dev);
- dev_alias.pdev = pdev;
- dev_alias.count = nvec;

- pci_for_each_dma_alias(pdev, its_get_pci_alias, &dev_alias);
its = domain->parent->host_data;
-
- its_dev = its_find_device(its, dev_alias.dev_id);
+ its_dev = its_find_device(its, dev_id);
if (its_dev) {
/*
* We already have seen this ID, probably through
* another alias (PCI bridge of some sort). No need to
* create the device.
*/
- dev_dbg(dev, "Reusing ITT for devID %x\n", dev_alias.dev_id);
+ pr_debug("Reusing ITT for devID %x\n", dev_id);
goto out;
}

- its_dev = its_create_device(its, dev_alias.dev_id, dev_alias.count);
+ its_dev = its_create_device(its, dev_id, nvec);
if (!its_dev)
return -ENOMEM;

- dev_dbg(&pdev->dev, "ITT %d entries, %d bits\n",
- dev_alias.count, ilog2(dev_alias.count));
+ pr_debug("ITT %d entries, %d bits\n", nvec, ilog2(nvec));
out:
info->scratchpad[0].ptr = its_dev;
- info->scratchpad[1].ptr = dev;
return 0;
}

-static struct msi_domain_ops its_pci_msi_ops = {
- .msi_prepare = its_msi_prepare,
-};
-
-static struct msi_domain_info its_pci_msi_domain_info = {
- .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS |
- MSI_FLAG_MULTI_PCI_MSI | MSI_FLAG_PCI_MSIX),
- .ops = &its_pci_msi_ops,
- .chip = &its_msi_irq_chip,
-};
-
static int its_irq_gic_domain_alloc(struct irq_domain *domain,
unsigned int virq,
irq_hw_number_t hwirq)
@@ -1287,8 +1216,9 @@ static int its_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,

irq_domain_set_hwirq_and_chip(domain, virq + i,
hwirq, &its_irq_chip, its_dev);
- dev_dbg(info->scratchpad[1].ptr, "ID:%d pID:%d vID:%d\n",
- (int)(hwirq - its_dev->lpi_base), (int)hwirq, virq + i);
+ pr_debug("ID:%d pID:%d vID:%d\n",
+ (int)(hwirq - its_dev->lpi_base),
+ (int)hwirq, virq + i);
}

return 0;
@@ -1485,9 +1415,8 @@ static int its_probe(struct device_node *node, struct irq_domain *parent)

its->domain->parent = parent;

- its->msi_chip.domain = pci_msi_create_irq_domain(node,
- &its_pci_msi_domain_info,
- its->domain);
+ its->msi_chip.domain = its_pci_msi_alloc_domain(node,
+ its->domain);
if (!its->msi_chip.domain) {
err = -ENOMEM;
goto out_free_domains;
diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index ffbc034..d6149ba 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -360,6 +360,7 @@
#ifndef __ASSEMBLY__

#include <linux/stringify.h>
+#include <asm/msi.h>

/*
* We need a value to serve as a irq-type for LPIs. Choose one that will
@@ -388,6 +389,11 @@ struct irq_domain;
int its_cpu_init(void);
int its_init(struct device_node *node, struct rdists *rdists,
struct irq_domain *domain);
+int its_msi_prepare(struct irq_domain *domain, u32 dev_id,
+ int nvec, msi_alloc_info_t *info);
+
+struct irq_domain *its_pci_msi_alloc_domain(struct device_node *node,
+ struct irq_domain *parent);

#endif

--
2.1.4