(pci-msi-remove-unsafe-and-unnecessary-hardware-access.patch, pci-msi-restore-read_msi_msg_desc-add-get_cached_msi_msg_desc.patch)
149 lines
5.1 KiB
Diff
149 lines
5.1 KiB
Diff
From 30da55242818a8ca08583188ebcbaccd283ad4d9 Mon Sep 17 00:00:00 2001
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From: Ben Hutchings <bhutchings@solarflare.com>
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Date: Fri, 23 Jul 2010 14:56:28 +0100
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Subject: PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc()
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From: Ben Hutchings <bhutchings@solarflare.com>
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commit 30da55242818a8ca08583188ebcbaccd283ad4d9 upstream.
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commit 2ca1af9aa3285c6a5f103ed31ad09f7399fc65d7 "PCI: MSI: Remove
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unsafe and unnecessary hardware access" changed read_msi_msg_desc() to
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return the last MSI message written instead of reading it from the
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device, since it may be called while the device is in a reduced
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power state.
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However, the pSeries platform code really does need to read messages
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from the device, since they are initially written by firmware.
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Therefore:
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- Restore the previous behaviour of read_msi_msg_desc()
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- Add new functions get_cached_msi_msg{,_desc}() which return the
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last MSI message written
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- Use the new functions where appropriate
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Acked-by: Michael Ellerman <michael@ellerman.id.au>
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Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
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Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
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Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
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---
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arch/ia64/kernel/msi_ia64.c | 2 -
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arch/ia64/sn/kernel/msi_sn.c | 2 -
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arch/x86/kernel/apic/io_apic.c | 2 -
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drivers/pci/msi.c | 47 ++++++++++++++++++++++++++++++++++++-----
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include/linux/msi.h | 2 +
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5 files changed, 47 insertions(+), 8 deletions(-)
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--- a/arch/ia64/kernel/msi_ia64.c
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+++ b/arch/ia64/kernel/msi_ia64.c
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@@ -25,7 +25,7 @@ static int ia64_set_msi_irq_affinity(uns
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if (irq_prepare_move(irq, cpu))
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return -1;
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- read_msi_msg(irq, &msg);
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+ get_cached_msi_msg(irq, &msg);
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addr = msg.address_lo;
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addr &= MSI_ADDR_DEST_ID_MASK;
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--- a/arch/ia64/sn/kernel/msi_sn.c
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+++ b/arch/ia64/sn/kernel/msi_sn.c
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@@ -174,7 +174,7 @@ static int sn_set_msi_irq_affinity(unsig
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* Release XIO resources for the old MSI PCI address
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*/
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- read_msi_msg(irq, &msg);
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+ get_cached_msi_msg(irq, &msg);
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sn_pdev = (struct pcidev_info *)sn_irq_info->irq_pciioinfo;
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pdev = sn_pdev->pdi_linux_pcidev;
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provider = SN_PCIDEV_BUSPROVIDER(pdev);
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--- a/arch/x86/kernel/apic/io_apic.c
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+++ b/arch/x86/kernel/apic/io_apic.c
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@@ -3338,7 +3338,7 @@ static int set_msi_irq_affinity(unsigned
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cfg = desc->chip_data;
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- read_msi_msg_desc(desc, &msg);
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+ get_cached_msi_msg_desc(desc, &msg);
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msg.data &= ~MSI_DATA_VECTOR_MASK;
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msg.data |= MSI_DATA_VECTOR(cfg->vector);
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--- a/drivers/pci/msi.c
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+++ b/drivers/pci/msi.c
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@@ -196,9 +196,46 @@ void read_msi_msg_desc(struct irq_desc *
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{
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struct msi_desc *entry = get_irq_desc_msi(desc);
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- /* We do not touch the hardware (which may not even be
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- * accessible at the moment) but return the last message
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- * written. Assert that this is valid, assuming that
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+ BUG_ON(entry->dev->current_state != PCI_D0);
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+
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+ if (entry->msi_attrib.is_msix) {
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+ void __iomem *base = entry->mask_base +
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+ entry->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
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+
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+ msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
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+ msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
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+ msg->data = readl(base + PCI_MSIX_ENTRY_DATA);
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+ } else {
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+ struct pci_dev *dev = entry->dev;
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+ int pos = entry->msi_attrib.pos;
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+ u16 data;
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+
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+ pci_read_config_dword(dev, msi_lower_address_reg(pos),
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+ &msg->address_lo);
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+ if (entry->msi_attrib.is_64) {
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+ pci_read_config_dword(dev, msi_upper_address_reg(pos),
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+ &msg->address_hi);
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+ pci_read_config_word(dev, msi_data_reg(pos, 1), &data);
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+ } else {
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+ msg->address_hi = 0;
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+ pci_read_config_word(dev, msi_data_reg(pos, 0), &data);
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+ }
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+ msg->data = data;
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+ }
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+}
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+
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+void read_msi_msg(unsigned int irq, struct msi_msg *msg)
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+{
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+ struct irq_desc *desc = irq_to_desc(irq);
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+
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+ read_msi_msg_desc(desc, msg);
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+}
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+
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+void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg)
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+{
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+ struct msi_desc *entry = get_irq_desc_msi(desc);
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+
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+ /* Assert that the cache is valid, assuming that
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* valid messages are not all-zeroes. */
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BUG_ON(!(entry->msg.address_hi | entry->msg.address_lo |
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entry->msg.data));
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@@ -206,11 +243,11 @@ void read_msi_msg_desc(struct irq_desc *
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*msg = entry->msg;
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}
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-void read_msi_msg(unsigned int irq, struct msi_msg *msg)
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+void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg)
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{
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struct irq_desc *desc = irq_to_desc(irq);
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- read_msi_msg_desc(desc, msg);
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+ get_cached_msi_msg_desc(desc, msg);
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}
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void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg)
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--- a/include/linux/msi.h
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+++ b/include/linux/msi.h
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@@ -14,8 +14,10 @@ struct irq_desc;
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extern void mask_msi_irq(unsigned int irq);
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extern void unmask_msi_irq(unsigned int irq);
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extern void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
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+extern void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
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extern void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg);
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extern void read_msi_msg(unsigned int irq, struct msi_msg *msg);
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+extern void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg);
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extern void write_msi_msg(unsigned int irq, struct msi_msg *msg);
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struct msi_desc {
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