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From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Alex Williamson <alex.williamson@redhat.com>,
	"Raj, Ashok" <ashok.raj@intel.com>,
	"David S. Miller" <davem@davemloft.net>,
	Bjorn Helgaas <bhelgaas@google.com>,
	linux-pci@vger.kernel.org, Kevin Tian <kevin.tian@intel.com>,
	Marc Zyngier <maz@kernel.org>, Ingo Molnar <mingo@kernel.org>,
	x86@kernel.org, linux-s390@vger.kernel.org,
	Niklas Schnelle <schnelle@linux.ibm.com>,
	Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
	Heiko Carstens <hca@linux.ibm.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>
Subject: [patch V2 16/19] PCI/MSI: Deobfuscate virtual MSI-X
Date: Thu, 29 Jul 2021 23:51:55 +0200	[thread overview]
Message-ID: <20210729222543.151522318@linutronix.de> (raw)
In-Reply-To: <20210729215139.889204656@linutronix.de>

Handling of virtual MSI-X is obfuscated by letting pci_msix_desc_addr()
return NULL and checking the pointer.

Just use msi_desc::msi_attrib.is_virtual at the call sites and get rid of
that pointer check.

No functional change.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
---
V2: New patch
---
 drivers/pci/msi.c |   25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

--- a/drivers/pci/msi.c
+++ b/drivers/pci/msi.c
@@ -166,11 +166,7 @@ static void msi_mask_irq(struct msi_desc
 
 static void __iomem *pci_msix_desc_addr(struct msi_desc *desc)
 {
-	if (desc->msi_attrib.is_virtual)
-		return NULL;
-
-	return desc->mask_base +
-		desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
+	return desc->mask_base + desc->msi_attrib.entry_nr * PCI_MSIX_ENTRY_SIZE;
 }
 
 /*
@@ -182,14 +178,10 @@ static void __iomem *pci_msix_desc_addr(
  */
 static u32 __pci_msix_desc_mask_irq(struct msi_desc *desc, u32 flag)
 {
+	void __iomem *desc_addr = pci_msix_desc_addr(desc);
 	u32 ctrl = desc->msix_ctrl;
-	void __iomem *desc_addr;
-
-	if (pci_msi_ignore_mask)
-		return 0;
 
-	desc_addr = pci_msix_desc_addr(desc);
-	if (!desc_addr)
+	if (pci_msi_ignore_mask || desc->msi_attrib.is_virtual)
 		return 0;
 
 	ctrl &= ~PCI_MSIX_ENTRY_CTRL_MASKBIT;
@@ -256,10 +248,8 @@ void __pci_read_msi_msg(struct msi_desc
 	if (entry->msi_attrib.is_msix) {
 		void __iomem *base = pci_msix_desc_addr(entry);
 
-		if (!base) {
-			WARN_ON(1);
+		if (WARN_ON_ONCE(entry->msi_attrib.is_virtual))
 			return;
-		}
 
 		msg->address_lo = readl(base + PCI_MSIX_ENTRY_LOWER_ADDR);
 		msg->address_hi = readl(base + PCI_MSIX_ENTRY_UPPER_ADDR);
@@ -292,7 +282,7 @@ void __pci_write_msi_msg(struct msi_desc
 		void __iomem *base = pci_msix_desc_addr(entry);
 		bool unmasked = !(entry->msix_ctrl & PCI_MSIX_ENTRY_CTRL_MASKBIT);
 
-		if (!base)
+		if (entry->msi_attrib.is_virtual)
 			goto skip;
 
 		/*
@@ -744,9 +734,10 @@ static int msix_setup_entries(struct pci
 		entry->msi_attrib.default_irq	= dev->irq;
 		entry->mask_base		= base;
 
-		addr = pci_msix_desc_addr(entry);
-		if (addr)
+		if (!entry->msi_attrib.is_virtual) {
+			addr = pci_msix_desc_addr(entry);
 			entry->msix_ctrl = readl(addr + PCI_MSIX_ENTRY_VECTOR_CTRL);
+		}
 
 		list_add_tail(&entry->list, dev_to_msi_list(&dev->dev));
 		if (masks)


  parent reply	other threads:[~2021-07-29 22:35 UTC|newest]

Thread overview: 43+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-07-29 21:51 [patch V2 00/19] PCI/MSI, x86: Cure a couple of inconsistencies Thomas Gleixner
2021-07-29 21:51 ` [patch V2 01/19] PCI/MSI: Enable and mask MSI-X early Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 02/19] PCI/MSI: Mask all unused MSI-X entries Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 03/19] PCI/MSI: Enforce that MSI-X table entry is masked for update Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 04/19] PCI/MSI: Enforce MSI[X] entry updates to be visible Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 05/19] PCI/MSI: Do not set invalid bits in MSI mask Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 06/19] PCI/MSI: Correct misleading comments Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 07/19] PCI/MSI: Use msi_mask_irq() in pci_msi_shutdown() Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 08/19] PCI/MSI: Protect msi_desc::masked for multi-MSI Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 09/19] genirq: Provide IRQCHIP_AFFINITY_PRE_STARTUP Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 10/19] x86/ioapic: Force affinity setup before startup Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 11/19] x86/msi: " Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 12/19] s390/pci: Do not mask MSI[-X] entries on teardown Thomas Gleixner
2021-08-03 12:48   ` Niklas Schnelle
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 13/19] PCI/MSI: Simplify msi_verify_entries() Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 14/19] PCI/MSI: Rename msi_desc::masked Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 15/19] PCI/MSI: Consolidate error handling in msi_capability_init() Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` Thomas Gleixner [this message]
2021-08-10  9:07   ` [tip: irq/core] PCI/MSI: Deobfuscate virtual MSI-X tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 17/19] PCI/MSI: Cleanup msi_mask() Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 18/19] PCI/MSI: Provide a new set of mask and unmask functions Thomas Gleixner
     [not found]   ` <87r1f6bpt7.wl-maz@kernel.org>
2021-08-09 18:56     ` Thomas Gleixner
2021-08-09 19:08       ` [patch V3 " Thomas Gleixner
2021-08-10  9:07         ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-07-29 21:51 ` [patch V2 19/19] PCI/MSI: Use new mask/unmask functions Thomas Gleixner
2021-08-10  9:07   ` [tip: irq/core] " tip-bot2 for Thomas Gleixner
2021-08-10  7:49 ` [patch V2 00/19] PCI/MSI, x86: Cure a couple of inconsistencies Marc Zyngier

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