[PATCH v3 1/2] genirq/msi: Extract common sysfs populate entries to MSI core from PCI

Barry Song
2021-08-13T03:57:06Z

This patch makes PCI's MSI sysfs code common in MSI so that other busses
such as platform can reuse it.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Bjorn Helgaas <bhelgaas@google.com>
Signed-off-by: Barry Song <song.bao.hua@hisilicon.com>
---
drivers/pci/msi.c | 124 ++++--------------------------------------------
include/linux/msi.h | 4 ++
kernel/irq/msi.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++
3 files changed, 147 insertions(+), 115 deletions(-)

diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c
index 9232255..4b9c0bb 100644
--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -338,9 +338,7 @@ static void free_msi_irqs(struct pci_dev *dev)
{
struct list_head *msi_list = dev_to_msi_list(&dev->dev);
struct msi_desc *entry, *tmp;
- struct attribute **msi_attrs;
- struct device_attribute *dev_attr;
- int i, count = 0;
+ int i;

for_each_pci_msi_entry(entry, dev)
if (entry->irq)
@@ -360,18 +358,7 @@ static void free_msi_irqs(struct pci_dev *dev)
}

if (dev->msi_irq_groups) {
- sysfs_remove_groups(&dev->dev.kobj, dev->msi_irq_groups);
- msi_attrs = dev->msi_irq_groups[0]->attrs;
- while (msi_attrs[count]) {
- dev_attr = container_of(msi_attrs[count],
- struct device_attribute, attr);
- kfree(dev_attr->attr.name);
- kfree(dev_attr);
- ++count;
- }
- kfree(msi_attrs);
- kfree(dev->msi_irq_groups[0]);
- kfree(dev->msi_irq_groups);
+ msi_destroy_sysfs(&dev->dev, dev->msi_irq_groups);
dev->msi_irq_groups = NULL;
}
}
@@ -452,102 +439,6 @@ void pci_restore_msi_state(struct pci_dev *dev)
}
EXPORT_SYMBOL_GPL(pci_restore_msi_state);

-static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
- char *buf)
-{
- struct msi_desc *entry;
- unsigned long irq;
- int retval;
-
- retval = kstrtoul(attr->attr.name, 10, &irq);
- if (retval)
- return retval;
-
- entry = irq_get_msi_desc(irq);
- if (!entry)
- return -ENODEV;
-
- return sysfs_emit(buf, "%s\n",
- entry->msi_attrib.is_msix ? "msix" : "msi");
-}
-
-static int populate_msi_sysfs(struct pci_dev *pdev)
-{
- struct attribute **msi_attrs;
- struct attribute *msi_attr;
- struct device_attribute *msi_dev_attr;
- struct attribute_group *msi_irq_group;
- const struct attribute_group **msi_irq_groups;
- struct msi_desc *entry;
- int ret = -ENOMEM;
- int num_msi = 0;
- int count = 0;
- int i;
-
- /* Determine how many msi entries we have */
- for_each_pci_msi_entry(entry, pdev)
- num_msi += entry->nvec_used;
- if (!num_msi)
- return 0;
-
- /* Dynamically create the MSI attributes for the PCI device */
- msi_attrs = kcalloc(num_msi + 1, sizeof(void *), GFP_KERNEL);
- if (!msi_attrs)
- return -ENOMEM;
- for_each_pci_msi_entry(entry, pdev) {
- for (i = 0; i < entry->nvec_used; i++) {
- msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL);
- if (!msi_dev_attr)
- goto error_attrs;
- msi_attrs[count] = &msi_dev_attr->attr;
-
- sysfs_attr_init(&msi_dev_attr->attr);
- msi_dev_attr->attr.name = kasprintf(GFP_KERNEL, "%d",
- entry->irq + i);
- if (!msi_dev_attr->attr.name)
- goto error_attrs;
- msi_dev_attr->attr.mode = S_IRUGO;
- msi_dev_attr->show = msi_mode_show;
- ++count;
- }
- }
-
- msi_irq_group = kzalloc(sizeof(*msi_irq_group), GFP_KERNEL);
- if (!msi_irq_group)
- goto error_attrs;
- msi_irq_group->name = "msi_irqs";
- msi_irq_group->attrs = msi_attrs;
-
- msi_irq_groups = kcalloc(2, sizeof(void *), GFP_KERNEL);
- if (!msi_irq_groups)
- goto error_irq_group;
- msi_irq_groups[0] = msi_irq_group;
-
- ret = sysfs_create_groups(&pdev->dev.kobj, msi_irq_groups);
- if (ret)
- goto error_irq_groups;
- pdev->msi_irq_groups = msi_irq_groups;
-
- return 0;
-
-error_irq_groups:
- kfree(msi_irq_groups);
-error_irq_group:
- kfree(msi_irq_group);
-error_attrs:
- count = 0;
- msi_attr = msi_attrs[count];
- while (msi_attr) {
- msi_dev_attr = container_of(msi_attr, struct device_attribute, attr);
- kfree(msi_attr->name);
- kfree(msi_dev_attr);
- ++count;
- msi_attr = msi_attrs[count];
- }
- kfree(msi_attrs);
- return ret;
-}
-
static struct msi_desc *
msi_setup_entry(struct pci_dev *dev, int nvec, struct irq_affinity *affd)
{
@@ -648,8 +539,9 @@ static int msi_capability_init(struct pci_dev *dev, int nvec,
return ret;
}

- ret = populate_msi_sysfs(dev);
- if (ret) {
+ dev->msi_irq_groups = msi_populate_sysfs(&dev->dev);
+ if (IS_ERR(dev->msi_irq_groups)) {
+ ret = PTR_ERR(dev->msi_irq_groups);
msi_mask_irq(entry, mask, ~mask);
free_msi_irqs(dev);
return ret;
@@ -804,9 +696,11 @@ static int msix_capability_init(struct pci_dev *dev, struct msix_entry *entries,

msix_program_entries(dev, entries);

- ret = populate_msi_sysfs(dev);
- if (ret)
+ dev->msi_irq_groups = msi_populate_sysfs(&dev->dev);
+ if (IS_ERR(dev->msi_irq_groups)) {
+ ret = PTR_ERR(dev->msi_irq_groups);
goto out_free;
+ }

/* Set MSI-X enabled bits and unmask the function */
pci_intx_for_msi(dev, 0);
diff --git a/include/linux/msi.h b/include/linux/msi.h
index 6aff469..375f1f9 100644
--- a/include/linux/msi.h
+++ b/include/linux/msi.h
@@ -237,6 +237,10 @@ struct msi_desc *alloc_msi_entry(struct device *dev, int nvec,
void pci_msi_mask_irq(struct irq_data *data);
void pci_msi_unmask_irq(struct irq_data *data);

+const struct attribute_group **msi_populate_sysfs(struct device *dev);
+void msi_destroy_sysfs(struct device *dev,
+ const struct attribute_group **msi_irq_groups);
+
/*
* The arch hooks to setup up msi irqs. Default functions are implemented
* as weak symbols so that they /can/ be overriden by architecture specific
diff --git a/kernel/irq/msi.c b/kernel/irq/msi.c
index c41965e..f153bca 100644
--- a/kernel/irq/msi.c
+++ b/kernel/irq/msi.c
@@ -14,6 +14,7 @@
#include <linux/irqdomain.h>
#include <linux/msi.h>
#include <linux/slab.h>
+#include <linux/pci.h>

#include "internals.h"

@@ -69,6 +70,139 @@ void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
}
EXPORT_SYMBOL_GPL(get_cached_msi_msg);

+static ssize_t msi_mode_show(struct device *dev, struct device_attribute *attr,
+ char *buf)
+{
+ struct msi_desc *entry;
+ unsigned long irq;
+ int retval;
+ bool is_msix = false;
+
+ retval = kstrtoul(attr->attr.name, 10, &irq);
+ if (retval)
+ return retval;
+
+ entry = irq_get_msi_desc(irq);
+ if (!entry)
+ return -ENODEV;
+
+ if (dev_is_pci(dev))
+ is_msix = entry->msi_attrib.is_msix;
+
+ return sysfs_emit(buf, "%s\n", is_msix ? "msix" : "msi");
+}
+
+/**
+ * msi_populate_sysfs - Populate msi_irqs sysfs entries for devices
+ * @dev: The device(PCI, platform etc) who will get sysfs entries
+ *
+ * Return attribute_group ** so that specific bus MSI can save it to
+ * somewhere during initilizing msi irqs. If devices has no MSI irq,
+ * return NULL; if it fails to populate sysfs, return ERR_PTR
+ */
+const struct attribute_group **msi_populate_sysfs(struct device *dev)
+{
+ struct attribute **msi_attrs;
+ struct attribute *msi_attr;
+ struct device_attribute *msi_dev_attr;
+ struct attribute_group *msi_irq_group;
+ const struct attribute_group **msi_irq_groups;
+ struct msi_desc *entry;
+ int ret = -ENOMEM;
+ int num_msi = 0;
+ int count = 0;
+ int i;
+
+ /* Determine how many msi entries we have */
+ for_each_msi_entry(entry, dev)
+ num_msi += entry->nvec_used;
+ if (!num_msi)
+ return NULL;
+
+ /* Dynamically create the MSI attributes for the device */
+ msi_attrs = kcalloc(num_msi + 1, sizeof(void *), GFP_KERNEL);
+ if (!msi_attrs)
+ return ERR_PTR(-ENOMEM);
+ for_each_msi_entry(entry, dev) {
+ for (i = 0; i < entry->nvec_used; i++) {
+ msi_dev_attr = kzalloc(sizeof(*msi_dev_attr), GFP_KERNEL);
+ if (!msi_dev_attr)
+ goto error_attrs;
+ msi_attrs[count] = &msi_dev_attr->attr;
+
+ sysfs_attr_init(&msi_dev_attr->attr);
+ msi_dev_attr->attr.name = kasprintf(GFP_KERNEL, "%d",
+ entry->irq + i);
+ if (!msi_dev_attr->attr.name)
+ goto error_attrs;
+ msi_dev_attr->attr.mode = 0444;
+ msi_dev_attr->show = msi_mode_show;
+ ++count;
+ }
+ }
+
+ msi_irq_group = kzalloc(sizeof(*msi_irq_group), GFP_KERNEL);
+ if (!msi_irq_group)
+ goto error_attrs;
+ msi_irq_group->name = "msi_irqs";
+ msi_irq_group->attrs = msi_attrs;
+
+ msi_irq_groups = kcalloc(2, sizeof(void *), GFP_KERNEL);
+ if (!msi_irq_groups)
+ goto error_irq_group;
+ msi_irq_groups[0] = msi_irq_group;
+
+ ret = sysfs_create_groups(&dev->kobj, msi_irq_groups);
+ if (ret)
+ goto error_irq_groups;
+
+ return msi_irq_groups;
+
+error_irq_groups:
+ kfree(msi_irq_groups);
+error_irq_group:
+ kfree(msi_irq_group);
+error_attrs:
+ count = 0;
+ msi_attr = msi_attrs[count];
+ while (msi_attr) {
+ msi_dev_attr = container_of(msi_attr, struct device_attribute, attr);
+ kfree(msi_attr->name);
+ kfree(msi_dev_attr);
+ ++count;
+ msi_attr = msi_attrs[count];
+ }
+ kfree(msi_attrs);
+ return ERR_PTR(ret);
+}
+
+/**
+ * msi_destroy_sysfs - Destroy msi_irqs sysfs entries for devices
+ * @dev: The device(PCI, platform etc) who will remove sysfs entries
+ * @msi_irq_groups: attribute_group for device msi_irqs entries
+ */
+void msi_destroy_sysfs(struct device *dev, const struct attribute_group **msi_irq_groups)
+{
+ struct attribute **msi_attrs;
+ struct device_attribute *dev_attr;
+ int count = 0;
+
+ if (msi_irq_groups) {
+ sysfs_remove_groups(&dev->kobj, msi_irq_groups);
+ msi_attrs = msi_irq_groups[0]->attrs;
+ while (msi_attrs[count]) {
+ dev_attr = container_of(msi_attrs[count],
+ struct device_attribute, attr);
+ kfree(dev_attr->attr.name);
+ kfree(dev_attr);
+ ++count;
+ }
+ kfree(msi_attrs);
+ kfree(msi_irq_groups[0]);
+ kfree(msi_irq_groups);
+ }
+}
+
#ifdef CONFIG_GENERIC_MSI_IRQ_DOMAIN
static inline void irq_chip_write_msi_msg(struct irq_data *data,
struct msi_msg *msg)
--
1.8.3.1