[RFC,5/5] x86/PCI: Remove unused X86_DEV_DMA_OPS

Commit Message

Jon Derrick Dec. 31, 2019, 8:24 p.m. UTC

VMD was the only user of device dma operations. Now that the IOMMU has
been made aware of direct DMA aliases, VMD domain devices can reference
the VMD endpoint directly and the VMD device dma operations has been
made obsolete.

Signed-off-by: Jon Derrick <[e-mail]>
---
 arch/x86/Kconfig              |  3 ---
 arch/x86/include/asm/device.h | 10 ----------
 arch/x86/pci/common.c         | 38 --------------------------------------
 3 files changed, 51 deletions(-)

Comments

Christoph Hellwig Jan. 9, 2020, 2:37 p.m. UTC | #1

On Tue, Dec 31, 2019 at 01:24:23PM -0700, Jon Derrick wrote:
> VMD was the only user of device dma operations. Now that the IOMMU has
> been made aware of direct DMA aliases, VMD domain devices can reference
> the VMD endpoint directly and the VMD device dma operations has been
> made obsolete.
> 
> Signed-off-by: Jon Derrick <[e-mail]>

This seems to be a 1:1 copy of my patch from August?

Jon Derrick Jan. 9, 2020, 3:06 p.m. UTC | #2

On Thu, 2020-01-09 at 15:37 +0100, Christoph Hellwig wrote:
> On Tue, Dec 31, 2019 at 01:24:23PM -0700, Jon Derrick wrote:
> > VMD was the only user of device dma operations. Now that the IOMMU has
> > been made aware of direct DMA aliases, VMD domain devices can reference
> > the VMD endpoint directly and the VMD device dma operations has been
> > made obsolete.
> > 
> > Signed-off-by: Jon Derrick <[e-mail]>
> 
> This seems to be a 1:1 copy of my patch from August?
Sorry I didn't notice that. I'll give you attributions.

Patch

diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 5e89499..77f9426 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -2955,9 +2955,6 @@  config HAVE_ATOMIC_IOMAP
 	def_bool y
 	depends on X86_32
 
-config X86_DEV_DMA_OPS
-	bool
-
 source "drivers/firmware/Kconfig"
 
 source "arch/x86/kvm/Kconfig"
diff --git a/arch/x86/include/asm/device.h b/arch/x86/include/asm/device.h
index 5e12c63..7e31f7f 100644
--- a/arch/x86/include/asm/device.h
+++ b/arch/x86/include/asm/device.h
@@ -8,16 +8,6 @@  struct dev_archdata {
 #endif
 };
 
-#if defined(CONFIG_X86_DEV_DMA_OPS) && defined(CONFIG_PCI_DOMAINS)
-struct dma_domain {
-	struct list_head node;
-	const struct dma_map_ops *dma_ops;
-	int domain_nr;
-};
-void add_dma_domain(struct dma_domain *domain);
-void del_dma_domain(struct dma_domain *domain);
-#endif
-
 struct pdev_archdata {
 };
 
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 4022609..fcf03da 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -625,43 +625,6 @@  unsigned int pcibios_assign_all_busses(void)
 	return (pci_probe & PCI_ASSIGN_ALL_BUSSES) ? 1 : 0;
 }
 
-#if defined(CONFIG_X86_DEV_DMA_OPS) && defined(CONFIG_PCI_DOMAINS)
-static LIST_HEAD(dma_domain_list);
-static DEFINE_SPINLOCK(dma_domain_list_lock);
-
-void add_dma_domain(struct dma_domain *domain)
-{
-	spin_lock(&dma_domain_list_lock);
-	list_add(&domain->node, &dma_domain_list);
-	spin_unlock(&dma_domain_list_lock);
-}
-EXPORT_SYMBOL_GPL(add_dma_domain);
-
-void del_dma_domain(struct dma_domain *domain)
-{
-	spin_lock(&dma_domain_list_lock);
-	list_del(&domain->node);
-	spin_unlock(&dma_domain_list_lock);
-}
-EXPORT_SYMBOL_GPL(del_dma_domain);
-
-static void set_dma_domain_ops(struct pci_dev *pdev)
-{
-	struct dma_domain *domain;
-
-	spin_lock(&dma_domain_list_lock);
-	list_for_each_entry(domain, &dma_domain_list, node) {
-		if (pci_domain_nr(pdev->bus) == domain->domain_nr) {
-			pdev->dev.dma_ops = domain->dma_ops;
-			break;
-		}
-	}
-	spin_unlock(&dma_domain_list_lock);
-}
-#else
-static void set_dma_domain_ops(struct pci_dev *pdev) {}
-#endif
-
 static void set_dev_domain_options(struct pci_dev *pdev)
 {
 	if (is_vmd(pdev->bus)) {
@@ -701,7 +664,6 @@  int pcibios_add_device(struct pci_dev *dev)
 		pa_data = data->next;
 		memunmap(data);
 	}
-	set_dma_domain_ops(dev);
 	set_dev_domain_options(dev);
 	return 0;
 }