From 30da55242818a8ca08583188ebcbaccd283ad4d9 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Fri, 23 Jul 2010 14:56:28 +0100 Subject: PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc() commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 "PCI: MSI: Remove unsafe and unnecessary hardware access" changed read_msi_msg_desc() to return the last MSI message written instead of reading it from the device, since it may be called while the device is in a reduced power state. However, the pSeries platform code really does need to read messages from the device, since they are initially written by firmware. Therefore: - Restore the previous behaviour of read_msi_msg_desc() - Add new functions get_cached_msi_msg{,_desc}() which return the last MSI message written - Use the new functions where appropriate Acked-by: Michael Ellerman Signed-off-by: Ben Hutchings Signed-off-by: Jesse Barnes --- drivers/pci/msi.c | 47 ++++++++++++++++++++++++++++++++++++++++++----- 1 file changed, 42 insertions(+), 5 deletions(-) (limited to 'drivers/pci/msi.c') diff --git a/drivers/pci/msi.c b/drivers/pci/msi.c index 4c14f31..69b7be3 100644 --- a/drivers/pci/msi.c +++ b/drivers/pci/msi.c @@ -197,9 +197,46 @@ void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) { struct msi_desc *entry = get_irq_desc_msi(desc); - /* We do not touch the hardware (which may not even be - * accessible at the moment) but return the last message - * written. Assert that this is valid, assuming that + BUG_ON(entry->dev->current_state != PCI_D0); + + if (entry->msi_attrib.is_msix) { + void __iomem *base = entry->mask_base + + entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE; + + msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR); + msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR); + msg->data = readl(base + PCI_MSIX_ENTRY_DATA); + } else { + struct pci_dev *dev = entry->dev; + int pos = entry->msi_attrib.pos; + u16 data; + + pci_read_config_dword(dev, msi_lower_address_reg(pos), + &msg->address_lo); + if (entry->msi_attrib.is_64) { + pci_read_config_dword(dev, msi_upper_address_reg(pos), + &msg->address_hi); + pci_read_config_word(dev, msi_data_reg(pos, 1), &data); + } else { + msg->address_hi = 0; + pci_read_config_word(dev, msi_data_reg(pos, 0), &data); + } + msg->data = data; + } +} + +void read_msi_msg(unsigned int irq, struct msi_msg *msg) +{ + struct irq_desc *desc = irq_to_desc(irq); + + read_msi_msg_desc(desc, msg); +} + +void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) +{ + struct msi_desc *entry = get_irq_desc_msi(desc); + + /* Assert that the cache is valid, assuming that * valid messages are not all-zeroes. */ BUG_ON(!(entry->msg.address_hi | entry->msg.address_lo | entry->msg.data)); @@ -207,11 +244,11 @@ void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) *msg = entry->msg; } -void read_msi_msg(unsigned int irq, struct msi_msg *msg) +void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg) { struct irq_desc *desc = irq_to_desc(irq); - read_msi_msg_desc(desc, msg); + get_cached_msi_msg_desc(desc, msg); } void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg) -- cgit v1.1