From 78013eaadf696d2105982abb4018fbae394ca08f Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Mon, 14 Feb 2022 14:11:44 +0100
Subject: x86: remove the IOMMU table infrastructure

The IOMMU table tries to separate the different IOMMUs into different
backends, but actually requires various cross calls.

Rewrite the code to do the generic swiotlb/swiotlb-xen setup directly
in pci-dma.c and then just call into the IOMMU drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
---
 arch/x86/xen/Makefile          |  2 -
 arch/x86/xen/pci-swiotlb-xen.c | 96 ------------------------------------------
 2 files changed, 98 deletions(-)
 delete mode 100644 arch/x86/xen/pci-swiotlb-xen.c

(limited to 'arch/x86/xen')

diff --git a/arch/x86/xen/Makefile b/arch/x86/xen/Makefile
index 4953260e281c..3c5b52fbe4a7 100644
--- a/arch/x86/xen/Makefile
+++ b/arch/x86/xen/Makefile
@@ -47,6 +47,4 @@ obj-$(CONFIG_XEN_DEBUG_FS)	+= debugfs.o
 
 obj-$(CONFIG_XEN_PV_DOM0)	+= vga.o
 
-obj-$(CONFIG_SWIOTLB_XEN)	+= pci-swiotlb-xen.o
-
 obj-$(CONFIG_XEN_EFI)		+= efi.o
diff --git a/arch/x86/xen/pci-swiotlb-xen.c b/arch/x86/xen/pci-swiotlb-xen.c
deleted file mode 100644
index 46df59aeaa06..000000000000
--- a/arch/x86/xen/pci-swiotlb-xen.c
+++ /dev/null
@@ -1,96 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-
-/* Glue code to lib/swiotlb-xen.c */
-
-#include <linux/dma-map-ops.h>
-#include <linux/pci.h>
-#include <xen/swiotlb-xen.h>
-
-#include <asm/xen/hypervisor.h>
-#include <xen/xen.h>
-#include <asm/iommu_table.h>
-
-
-#include <asm/xen/swiotlb-xen.h>
-#ifdef CONFIG_X86_64
-#include <asm/iommu.h>
-#include <asm/dma.h>
-#endif
-#include <linux/export.h>
-
-static int xen_swiotlb __read_mostly;
-
-/*
- * pci_xen_swiotlb_detect - set xen_swiotlb to 1 if necessary
- *
- * This returns non-zero if we are forced to use xen_swiotlb (by the boot
- * option).
- */
-int __init pci_xen_swiotlb_detect(void)
-{
-
-	if (!xen_pv_domain())
-		return 0;
-
-	/* If running as PV guest, either iommu=soft, or swiotlb=force will
-	 * activate this IOMMU. If running as PV privileged, activate it
-	 * irregardless.
-	 */
-	if (xen_initial_domain() || swiotlb || swiotlb_force == SWIOTLB_FORCE)
-		xen_swiotlb = 1;
-
-	/* If we are running under Xen, we MUST disable the native SWIOTLB.
-	 * Don't worry about swiotlb_force flag activating the native, as
-	 * the 'swiotlb' flag is the only one turning it on. */
-	swiotlb = 0;
-
-#ifdef CONFIG_X86_64
-	/* pci_swiotlb_detect_4gb turns on native SWIOTLB if no_iommu == 0
-	 * (so no iommu=X command line over-writes).
-	 * Considering that PV guests do not want the *native SWIOTLB* but
-	 * only Xen SWIOTLB it is not useful to us so set no_iommu=1 here.
-	 */
-	if (max_pfn > MAX_DMA32_PFN)
-		no_iommu = 1;
-#endif
-	return xen_swiotlb;
-}
-
-static void __init pci_xen_swiotlb_init(void)
-{
-	if (xen_swiotlb) {
-		xen_swiotlb_init_early();
-		dma_ops = &xen_swiotlb_dma_ops;
-
-#ifdef CONFIG_PCI
-		/* Make sure ACS will be enabled */
-		pci_request_acs();
-#endif
-	}
-}
-
-int pci_xen_swiotlb_init_late(void)
-{
-	int rc;
-
-	if (xen_swiotlb)
-		return 0;
-
-	rc = xen_swiotlb_init();
-	if (rc)
-		return rc;
-
-	dma_ops = &xen_swiotlb_dma_ops;
-#ifdef CONFIG_PCI
-	/* Make sure ACS will be enabled */
-	pci_request_acs();
-#endif
-
-	return 0;
-}
-EXPORT_SYMBOL_GPL(pci_xen_swiotlb_init_late);
-
-IOMMU_INIT_FINISH(pci_xen_swiotlb_detect,
-		  NULL,
-		  pci_xen_swiotlb_init,
-		  NULL);
-- 
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