since enabling MSIs disables the pin-based IRQ and the driver will not
receive interrupts on the old interrupt.
-4.2.2 pci_disable_msi
+4.2.2 pci_enable_msi_block
+
+int pci_enable_msi_block(struct pci_dev *dev, int count)
+
+This variation on the above call allows a device driver to request multiple
+MSIs. The MSI specification only allows interrupts to be allocated in
+powers of two, up to a maximum of 2^5 (32).
+
+If this function returns 0, it has succeeded in allocating at least as many
+interrupts as the driver requested (it may have allocated more in order
+to satisfy the power-of-two requirement). In this case, the function
+enables MSI on this device and updates dev->irq to be the lowest of
+the new interrupts assigned to it. The other interrupts assigned to
+the device are in the range dev->irq to dev->irq + count - 1.
+
+If this function returns a negative number, it indicates an error and
+the driver should not attempt to request any more MSI interrupts for
+this device. If this function returns a positive number, it will be
+less than 'count' and indicate the number of interrupts that could have
+been allocated. In neither case will the irq value have been
+updated, nor will the device have been switched into MSI mode.
+
+The device driver must decide what action to take if
+pci_enable_msi_block() returns a value less than the number asked for.
+Some devices can make use of fewer interrupts than the maximum they
+request; in this case the driver should call pci_enable_msi_block()
+again. Note that it is not guaranteed to succeed, even when the
+'count' has been reduced to the value returned from a previous call to
+pci_enable_msi_block(). This is because there are multiple constraints
+on the number of vectors that can be allocated; pci_enable_msi_block()
+will return as soon as it finds any constraint that doesn't allow the
+call to succeed.
+
+4.2.3 pci_disable_msi
void pci_disable_msi(struct pci_dev *dev)
-This function should be used to undo the effect of pci_enable_msi().
-Calling it restores dev->irq to the pin-based interrupt number and frees
-the previously allocated message signaled interrupt(s). The interrupt
-may subsequently be assigned to another device, so drivers should not
-cache the value of dev->irq.
+This function should be used to undo the effect of pci_enable_msi() or
+pci_enable_msi_block(). Calling it restores dev->irq to the pin-based
+interrupt number and frees the previously allocated message signaled
+interrupt(s). The interrupt may subsequently be assigned to another
+device, so drivers should not cache the value of dev->irq.
A device driver must always call free_irq() on the interrupt(s)
for which it has called request_irq() before calling this function.
struct msi_desc *entry;
int ret;
+ /*
+ * If an architecture wants to support multiple MSI, it needs to
+ * override arch_setup_msi_irqs()
+ */
+ if (type == PCI_CAP_ID_MSI && nvec > 1)
+ return 1;
+
list_for_each_entry(entry, &dev->msi_list, list) {
ret = arch_setup_msi_irq(dev, entry);
if (ret < 0)
struct msi_desc *entry;
list_for_each_entry(entry, &dev->msi_list, list) {
- if (entry->irq != 0)
- arch_teardown_msi_irq(entry->irq);
+ int i, nvec;
+ if (entry->irq == 0)
+ continue;
+ nvec = 1 << entry->msi_attrib.multiple;
+ for (i = 0; i < nvec; i++)
+ arch_teardown_msi_irq(entry->irq + i);
}
}
#endif
msix_mask_irq(desc, flag);
readl(desc->mask_base); /* Flush write to device */
} else {
- msi_mask_irq(desc, 1, flag);
+ unsigned offset = irq - desc->dev->irq;
+ msi_mask_irq(desc, 1 << offset, flag << offset);
}
}
} else {
struct pci_dev *dev = entry->dev;
int pos = entry->msi_attrib.pos;
+ u16 msgctl;
+
+ pci_read_config_word(dev, msi_control_reg(pos), &msgctl);
+ msgctl &= ~PCI_MSI_FLAGS_QSIZE;
+ msgctl |= entry->msi_attrib.multiple << 4;
+ pci_write_config_word(dev, msi_control_reg(pos), msgctl);
pci_write_config_dword(dev, msi_lower_address_reg(pos),
msg->address_lo);
pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &control);
msi_mask_irq(entry, msi_capable_mask(control), entry->masked);
control &= ~PCI_MSI_FLAGS_QSIZE;
- control |= PCI_MSI_FLAGS_ENABLE;
+ control |= (entry->msi_attrib.multiple << 4) | PCI_MSI_FLAGS_ENABLE;
pci_write_config_word(dev, pos + PCI_MSI_FLAGS, control);
}
/**
* msi_capability_init - configure device's MSI capability structure
* @dev: pointer to the pci_dev data structure of MSI device function
+ * @nvec: number of interrupts to allocate
*
- * Setup the MSI capability structure of device function with a single
- * MSI irq, regardless of device function is capable of handling
- * multiple messages. A return of zero indicates the successful setup
- * of an entry zero with the new MSI irq or non-zero for otherwise.
- **/
-static int msi_capability_init(struct pci_dev *dev)
+ * Setup the MSI capability structure of the device with the requested
+ * number of interrupts. A return value of zero indicates the successful
+ * setup of an entry with the new MSI irq. A negative return value indicates
+ * an error, and a positive return value indicates the number of interrupts
+ * which could have been allocated.
+ */
+static int msi_capability_init(struct pci_dev *dev, int nvec)
{
struct msi_desc *entry;
int pos, ret;
list_add_tail(&entry->list, &dev->msi_list);
/* Configure MSI capability structure */
- ret = arch_setup_msi_irqs(dev, 1, PCI_CAP_ID_MSI);
+ ret = arch_setup_msi_irqs(dev, nvec, PCI_CAP_ID_MSI);
if (ret) {
msi_free_irqs(dev);
return ret;
}
/**
- * pci_enable_msi - configure device's MSI capability structure
- * @dev: pointer to the pci_dev data structure of MSI device function
+ * pci_enable_msi_block - configure device's MSI capability structure
+ * @dev: device to configure
+ * @nvec: number of interrupts to configure
*
- * Setup the MSI capability structure of device function with
- * a single MSI irq upon its software driver call to request for
- * MSI mode enabled on its hardware device function. A return of zero
- * indicates the successful setup of an entry zero with the new MSI
- * irq or non-zero for otherwise.
- **/
-int pci_enable_msi(struct pci_dev* dev)
+ * Allocate IRQs for a device with the MSI capability.
+ * This function returns a negative errno if an error occurs. If it
+ * is unable to allocate the number of interrupts requested, it returns
+ * the number of interrupts it might be able to allocate. If it successfully
+ * allocates at least the number of interrupts requested, it returns 0 and
+ * updates the @dev's irq member to the lowest new interrupt number; the
+ * other interrupt numbers allocated to this device are consecutive.
+ */
+int pci_enable_msi_block(struct pci_dev *dev, unsigned int nvec)
{
- int status;
+ int status, pos, maxvec;
+ u16 msgctl;
+
+ pos = pci_find_capability(dev, PCI_CAP_ID_MSI);
+ if (!pos)
+ return -EINVAL;
+ pci_read_config_word(dev, pos + PCI_MSI_FLAGS, &msgctl);
+ maxvec = 1 << ((msgctl & PCI_MSI_FLAGS_QMASK) >> 1);
+ if (nvec > maxvec)
+ return maxvec;
- status = pci_msi_check_device(dev, 1, PCI_CAP_ID_MSI);
+ status = pci_msi_check_device(dev, nvec, PCI_CAP_ID_MSI);
if (status)
return status;
WARN_ON(!!dev->msi_enabled);
- /* Check whether driver already requested for MSI-X irqs */
+ /* Check whether driver already requested MSI-X irqs */
if (dev->msix_enabled) {
dev_info(&dev->dev, "can't enable MSI "
"(MSI-X already enabled)\n");
return -EINVAL;
}
- status = msi_capability_init(dev);
+
+ status = msi_capability_init(dev, nvec);
return status;
}
-EXPORT_SYMBOL(pci_enable_msi);
+EXPORT_SYMBOL(pci_enable_msi_block);
void pci_msi_shutdown(struct pci_dev *dev)
{
struct msi_desc *entry, *tmp;
list_for_each_entry(entry, &dev->msi_list, list) {
- if (entry->irq)
- BUG_ON(irq_has_action(entry->irq));
+ int i, nvec;
+ if (!entry->irq)
+ continue;
+ nvec = 1 << entry->msi_attrib.multiple;
+ for (i = 0; i < nvec; i++)
+ BUG_ON(irq_has_action(entry->irq + i));
}
arch_teardown_msi_irqs(dev);
projects / GitHub / LineageOS / G12 / android_kernel_amlogic_linux-4.9.git / commitdiff