From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752252Ab2KTHU6 (ORCPT ); Tue, 20 Nov 2012 02:20:58 -0500 Received: from gate.crashing.org ([63.228.1.57]:49322 "EHLO gate.crashing.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751946Ab2KTHU4 (ORCPT ); Tue, 20 Nov 2012 02:20:56 -0500 Message-ID: <1353396032.17856.7.camel@pasglop> Subject: Re: [PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc() From: Benjamin Herrenschmidt To: Ben Hutchings Cc: Jesse Barnes , Stephen Rothwell , ppc-dev , LKML , linux-pci , Bjorn Helgaas Date: Tue, 20 Nov 2012 18:20:32 +1100 In-Reply-To: <1279893388.2089.9.camel@achroite.uk.solarflarecom.com> References: <20100723102202.871a3131.sfr@canb.auug.org.au> <1279847985.4883.391.camel@localhost> <1279850740.6381.19.camel@concordia> <1279893388.2089.9.camel@achroite.uk.solarflarecom.com> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 2010-07-23 at 14:56 +0100, Ben Hutchings wrote: > 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. Looks reasonable... Jesse ? Cheers, Ben. > 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 > > Signed-off-by: Ben Hutchings > --- > Compile-tested only. > > Ben. > > arch/ia64/kernel/msi_ia64.c | 2 +- > arch/ia64/sn/kernel/msi_sn.c | 2 +- > arch/x86/kernel/apic/io_apic.c | 2 +- > drivers/pci/msi.c | 47 +++++++++++++++++++++++++++++++++++---- > include/linux/msi.h | 2 + > 5 files changed, 47 insertions(+), 8 deletions(-) > > diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c > index 6c89228..4a746ea 100644 > --- a/arch/ia64/kernel/msi_ia64.c > +++ b/arch/ia64/kernel/msi_ia64.c > @@ -25,7 +25,7 @@ static int ia64_set_msi_irq_affinity(unsigned int irq, > if (irq_prepare_move(irq, cpu)) > return -1; > > - read_msi_msg(irq, &msg); > + get_cached_msi_msg(irq, &msg); > > addr = msg.address_lo; > addr &= MSI_ADDR_DEST_ID_MASK; > diff --git a/arch/ia64/sn/kernel/msi_sn.c b/arch/ia64/sn/kernel/msi_sn.c > index ebfdd6a..0c72dd4 100644 > --- a/arch/ia64/sn/kernel/msi_sn.c > +++ b/arch/ia64/sn/kernel/msi_sn.c > @@ -175,7 +175,7 @@ static int sn_set_msi_irq_affinity(unsigned int irq, > * Release XIO resources for the old MSI PCI address > */ > > - read_msi_msg(irq, &msg); > + get_cached_msi_msg(irq, &msg); > sn_pdev = (struct pcidev_info *)sn_irq_info->irq_pciioinfo; > pdev = sn_pdev->pdi_linux_pcidev; > provider = SN_PCIDEV_BUSPROVIDER(pdev); > diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c > index e41ed24..4dc0084 100644 > --- a/arch/x86/kernel/apic/io_apic.c > +++ b/arch/x86/kernel/apic/io_apic.c > @@ -3397,7 +3397,7 @@ static int set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask) > > cfg = desc->chip_data; > > - read_msi_msg_desc(desc, &msg); > + get_cached_msi_msg_desc(desc, &msg); > > msg.data &= ~MSI_DATA_VECTOR_MASK; > msg.data |= MSI_DATA_VECTOR(cfg->vector); > 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) > diff --git a/include/linux/msi.h b/include/linux/msi.h > index 6991ab5..91b05c1 100644 > --- a/include/linux/msi.h > +++ b/include/linux/msi.h > @@ -14,8 +14,10 @@ struct irq_desc; > extern void mask_msi_irq(unsigned int irq); > extern void unmask_msi_irq(unsigned int irq); > extern void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg); > +extern void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg); > extern void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg); > extern void read_msi_msg(unsigned int irq, struct msi_msg *msg); > +extern void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg); > extern void write_msi_msg(unsigned int irq, struct msi_msg *msg); > > struct msi_desc { > -- > 1.6.2.5 > From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from gate.crashing.org (gate.crashing.org [63.228.1.57]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by ozlabs.org (Postfix) with ESMTPS id CFCF72C008C for ; Tue, 20 Nov 2012 18:20:50 +1100 (EST) Message-ID: <1353396032.17856.7.camel@pasglop> Subject: Re: [PATCH] PCI: MSI: Restore read_msi_msg_desc(); add get_cached_msi_msg_desc() From: Benjamin Herrenschmidt To: Ben Hutchings Date: Tue, 20 Nov 2012 18:20:32 +1100 In-Reply-To: <1279893388.2089.9.camel@achroite.uk.solarflarecom.com> References: <20100723102202.871a3131.sfr@canb.auug.org.au> <1279847985.4883.391.camel@localhost> <1279850740.6381.19.camel@concordia> <1279893388.2089.9.camel@achroite.uk.solarflarecom.com> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Cc: Stephen Rothwell , linux-pci , LKML , Jesse Barnes , Bjorn Helgaas , ppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Fri, 2010-07-23 at 14:56 +0100, Ben Hutchings wrote: > 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. Looks reasonable... Jesse ? Cheers, Ben. > 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 > > Signed-off-by: Ben Hutchings > --- > Compile-tested only. > > Ben. > > arch/ia64/kernel/msi_ia64.c | 2 +- > arch/ia64/sn/kernel/msi_sn.c | 2 +- > arch/x86/kernel/apic/io_apic.c | 2 +- > drivers/pci/msi.c | 47 +++++++++++++++++++++++++++++++++++---- > include/linux/msi.h | 2 + > 5 files changed, 47 insertions(+), 8 deletions(-) > > diff --git a/arch/ia64/kernel/msi_ia64.c b/arch/ia64/kernel/msi_ia64.c > index 6c89228..4a746ea 100644 > --- a/arch/ia64/kernel/msi_ia64.c > +++ b/arch/ia64/kernel/msi_ia64.c > @@ -25,7 +25,7 @@ static int ia64_set_msi_irq_affinity(unsigned int irq, > if (irq_prepare_move(irq, cpu)) > return -1; > > - read_msi_msg(irq, &msg); > + get_cached_msi_msg(irq, &msg); > > addr = msg.address_lo; > addr &= MSI_ADDR_DEST_ID_MASK; > diff --git a/arch/ia64/sn/kernel/msi_sn.c b/arch/ia64/sn/kernel/msi_sn.c > index ebfdd6a..0c72dd4 100644 > --- a/arch/ia64/sn/kernel/msi_sn.c > +++ b/arch/ia64/sn/kernel/msi_sn.c > @@ -175,7 +175,7 @@ static int sn_set_msi_irq_affinity(unsigned int irq, > * Release XIO resources for the old MSI PCI address > */ > > - read_msi_msg(irq, &msg); > + get_cached_msi_msg(irq, &msg); > sn_pdev = (struct pcidev_info *)sn_irq_info->irq_pciioinfo; > pdev = sn_pdev->pdi_linux_pcidev; > provider = SN_PCIDEV_BUSPROVIDER(pdev); > diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c > index e41ed24..4dc0084 100644 > --- a/arch/x86/kernel/apic/io_apic.c > +++ b/arch/x86/kernel/apic/io_apic.c > @@ -3397,7 +3397,7 @@ static int set_msi_irq_affinity(unsigned int irq, const struct cpumask *mask) > > cfg = desc->chip_data; > > - read_msi_msg_desc(desc, &msg); > + get_cached_msi_msg_desc(desc, &msg); > > msg.data &= ~MSI_DATA_VECTOR_MASK; > msg.data |= MSI_DATA_VECTOR(cfg->vector); > 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) > diff --git a/include/linux/msi.h b/include/linux/msi.h > index 6991ab5..91b05c1 100644 > --- a/include/linux/msi.h > +++ b/include/linux/msi.h > @@ -14,8 +14,10 @@ struct irq_desc; > extern void mask_msi_irq(unsigned int irq); > extern void unmask_msi_irq(unsigned int irq); > extern void read_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg); > +extern void get_cached_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg); > extern void write_msi_msg_desc(struct irq_desc *desc, struct msi_msg *msg); > extern void read_msi_msg(unsigned int irq, struct msi_msg *msg); > +extern void get_cached_msi_msg(unsigned int irq, struct msi_msg *msg); > extern void write_msi_msg(unsigned int irq, struct msi_msg *msg); > > struct msi_desc { > -- > 1.6.2.5 >