ia64: rework iommu probing

ia64 currently organizes the iommu probing along machves, which isn't
very helpful.  Instead just try to probe for Intel IOMMUs in mem_init
as they are properly described in ACPI and if none was found initialize
the swiotlb buffer.  The HP SBA handling is then only done delayed when
the actual hardware is probed. Only in the case that we actually found
usable IOMMUs we then set up the DMA ops and free the not needed
swiotlb buffer.  This scheme gets rid of the need for the dma_init
machvec operation, and the dig_vtd machvec.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://lkml.kernel.org/r/20190813072514.23299-24-hch@lst.de
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 28 insertions, 54 deletions

diff --git a/arch/ia64/hp/common/sba_iommu.c b/arch/ia64/hp/common/sba_iommu.c
index 215fa688b729..a7eff5e6d260 100644
--- a/arch/ia64/hp/common/sba_iommu.c
+++ b/arch/ia64/hp/common/sba_iommu.c
@@ -35,6 +35,7 @@
 #include <linux/iommu-helper.h>
 #include <linux/dma-mapping.h>
 #include <linux/prefetch.h>
+#include <linux/swiotlb.h>
 
 #include <asm/delay.h>		/* ia64_get_itc() */
 #include <asm/io.h>
@@ -43,8 +44,6 @@
 
 #include <asm/acpi-ext.h>
 
-extern int swiotlb_late_init_with_default_size (size_t size);
-
 #define PFX "IOC: "
 
 /*
@@ -2056,27 +2055,33 @@ static int __init acpi_sba_ioc_init_acpi(void)
 /* This has to run before acpi_scan_init(). */
 arch_initcall(acpi_sba_ioc_init_acpi);
 
+static int sba_dma_supported (struct device *dev, u64 mask)
+{
+	/* make sure it's at least 32bit capable */
+	return ((mask & 0xFFFFFFFFUL) == 0xFFFFFFFFUL);
+}
+
+static const struct dma_map_ops sba_dma_ops = {
+	.alloc			= sba_alloc_coherent,
+	.free			= sba_free_coherent,
+	.map_page		= sba_map_page,
+	.unmap_page		= sba_unmap_page,
+	.map_sg			= sba_map_sg_attrs,
+	.unmap_sg		= sba_unmap_sg_attrs,
+	.dma_supported		= sba_dma_supported,
+};
+
 static int __init
 sba_init(void)
 {
-	if (!ia64_platform_is("hpzx1"))
-		return 0;
-
-#if defined(CONFIG_IA64_GENERIC)
-	/* If we are booting a kdump kernel, the sba_iommu will
-	 * cause devices that were not shutdown properly to MCA
-	 * as soon as they are turned back on.  Our only option for
-	 * a successful kdump kernel boot is to use the swiotlb.
+	/*
+	 * If we are booting a kdump kernel, the sba_iommu will cause devices
+	 * that were not shutdown properly to MCA as soon as they are turned
+	 * back on.  Our only option for a successful kdump kernel boot is to
+	 * use swiotlb.
 	 */
-	if (is_kdump_kernel()) {
-		dma_ops = NULL;
-		if (swiotlb_late_init_with_default_size(64 * (1<<20)) != 0)
-			panic("Unable to initialize software I/O TLB:"
-				  " Try machvec=dig boot option");
-		machvec_init("dig");
+	if (is_kdump_kernel())
 		return 0;
-	}
-#endif
 
 	/*
 	 * ioc_found should be populated by the acpi_sba_ioc_handler's .attach()
@@ -2085,22 +2090,8 @@ sba_init(void)
 	while (ioc_found)
 		acpi_sba_ioc_add(ioc_found);
 
-	if (!ioc_list) {
-#ifdef CONFIG_IA64_GENERIC
-		/*
-		 * If we didn't find something sba_iommu can claim, we
-		 * need to setup the swiotlb and switch to the dig machvec.
-		 */
-		dma_ops = NULL;
-		if (swiotlb_late_init_with_default_size(64 * (1<<20)) != 0)
-			panic("Unable to find SBA IOMMU or initialize "
-			      "software I/O TLB: Try machvec=dig boot option");
-		machvec_init("dig");
-#else
-		panic("Unable to find SBA IOMMU: Try a generic or DIG kernel");
-#endif
+	if (!ioc_list)
 		return 0;
-	}
 
 	{
 		struct pci_bus *b = NULL;
@@ -2108,6 +2099,10 @@ sba_init(void)
 			sba_connect_bus(b);
 	}
 
+	/* no need for swiotlb with the iommu */
+	swiotlb_exit();
+	dma_ops = &sba_dma_ops;
+
 #ifdef CONFIG_PROC_FS
 	ioc_proc_init();
 #endif
@@ -2123,12 +2118,6 @@ nosbagart(char *str)
 	return 1;
 }
 
-static int sba_dma_supported (struct device *dev, u64 mask)
-{
-	/* make sure it's at least 32bit capable */
-	return ((mask & 0xFFFFFFFFUL) == 0xFFFFFFFFUL);
-}
-
 __setup("nosbagart", nosbagart);
 
 static int __init
@@ -2153,18 +2142,3 @@ sba_page_override(char *str)
 }
 
 __setup("sbapagesize=",sba_page_override);
-
-const struct dma_map_ops sba_dma_ops = {
-	.alloc			= sba_alloc_coherent,
-	.free			= sba_free_coherent,
-	.map_page		= sba_map_page,
-	.unmap_page		= sba_unmap_page,
-	.map_sg			= sba_map_sg_attrs,
-	.unmap_sg		= sba_unmap_sg_attrs,
-	.dma_supported		= sba_dma_supported,
-};
-
-void sba_dma_init(void)
-{
-	dma_ops = &sba_dma_ops;
-}