centralize SWIOTLB config symbol and misc other cleanups

centralize SWIOTLB config symbol and misc other cleanups

[Christoph Hellwig]

Hi all,

this seris aims for a single defintion of the Kconfig symbol.  To get
there various cleanups, mostly about config symbols are included as well.

[PATCH 01/12] iommu-common: move to arch/sparc

[Christoph Hellwig]

This code is only used by sparc, and all new iommu drivers should use the
drivers/iommu/ framework.  Also remove the unused exports.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 {include/linux => arch/sparc/include/asm}/iommu-common.h | 0
 arch/sparc/include/asm/iommu_64.h                        | 2 +-
 arch/sparc/kernel/Makefile                               | 2 +-
 {lib => arch/sparc/kernel}/iommu-common.c                | 5 +----
 arch/sparc/kernel/iommu.c                                | 2 +-
 arch/sparc/kernel/ldc.c                                  | 2 +-
 arch/sparc/kernel/pci_sun4v.c                            | 2 +-
 lib/Makefile                                             | 2 +-
 8 files changed, 7 insertions(+), 10 deletions(-)
 rename {include/linux => arch/sparc/include/asm}/iommu-common.h (100%)
 rename {lib => arch/sparc/kernel}/iommu-common.c (98%)

diff --git a/include/linux/iommu-common.h b/arch/sparc/include/asm/iommu-common.h
similarity index 100%
rename from include/linux/iommu-common.h
rename to arch/sparc/include/asm/iommu-common.h
diff --git a/arch/sparc/include/asm/iommu_64.h b/arch/sparc/include/asm/iommu_64.h
index 9ed6b54caa4b..0ef6dedf747e 100644
--- a/arch/sparc/include/asm/iommu_64.h
+++ b/arch/sparc/include/asm/iommu_64.h
@@ -17,7 +17,7 @@
 #define IOPTE_WRITE   0x0000000000000002UL
 
 #define IOMMU_NUM_CTXS	4096
-#include <linux/iommu-common.h>
+#include <asm/iommu-common.h>
 
 struct iommu_arena {
 	unsigned long	*map;
diff --git a/arch/sparc/kernel/Makefile b/arch/sparc/kernel/Makefile
index 76cb57750dda..a284662b0e4c 100644
--- a/arch/sparc/kernel/Makefile
+++ b/arch/sparc/kernel/Makefile
@@ -59,7 +59,7 @@ obj-$(CONFIG_SPARC32)   += leon_pmc.o
 
 obj-$(CONFIG_SPARC64)   += reboot.o
 obj-$(CONFIG_SPARC64)   += sysfs.o
-obj-$(CONFIG_SPARC64)   += iommu.o
+obj-$(CONFIG_SPARC64)   += iommu.o iommu-common.o
 obj-$(CONFIG_SPARC64)   += central.o
 obj-$(CONFIG_SPARC64)   += starfire.o
 obj-$(CONFIG_SPARC64)   += power.o
diff --git a/lib/iommu-common.c b/arch/sparc/kernel/iommu-common.c
similarity index 98%
rename from lib/iommu-common.c
rename to arch/sparc/kernel/iommu-common.c
index 55b00de106b5..59cb16691322 100644
--- a/lib/iommu-common.c
+++ b/arch/sparc/kernel/iommu-common.c
@@ -8,9 +8,9 @@
 #include <linux/bitmap.h>
 #include <linux/bug.h>
 #include <linux/iommu-helper.h>
-#include <linux/iommu-common.h>
 #include <linux/dma-mapping.h>
 #include <linux/hash.h>
+#include <asm/iommu-common.h>
 
 static unsigned long iommu_large_alloc = 15;
 
@@ -93,7 +93,6 @@ void iommu_tbl_pool_init(struct iommu_map_table *iommu,
 	p->hint = p->start;
 	p->end = num_entries;
 }
-EXPORT_SYMBOL(iommu_tbl_pool_init);
 
 unsigned long iommu_tbl_range_alloc(struct device *dev,
 				struct iommu_map_table *iommu,
@@ -224,7 +223,6 @@ unsigned long iommu_tbl_range_alloc(struct device *dev,
 
 	return n;
 }
-EXPORT_SYMBOL(iommu_tbl_range_alloc);
 
 static struct iommu_pool *get_pool(struct iommu_map_table *tbl,
 				   unsigned long entry)
@@ -264,4 +262,3 @@ void iommu_tbl_range_free(struct iommu_map_table *iommu, u64 dma_addr,
 	bitmap_clear(iommu->map, entry, npages);
 	spin_unlock_irqrestore(&(pool->lock), flags);
 }
-EXPORT_SYMBOL(iommu_tbl_range_free);
diff --git a/arch/sparc/kernel/iommu.c b/arch/sparc/kernel/iommu.c
index b08dc3416f06..40d008b0bd3e 100644
--- a/arch/sparc/kernel/iommu.c
+++ b/arch/sparc/kernel/iommu.c
@@ -14,7 +14,7 @@
 #include <linux/errno.h>
 #include <linux/iommu-helper.h>
 #include <linux/bitmap.h>
-#include <linux/iommu-common.h>
+#include <asm/iommu-common.h>
 
 #ifdef CONFIG_PCI
 #include <linux/pci.h>
diff --git a/arch/sparc/kernel/ldc.c b/arch/sparc/kernel/ldc.c
index 86b625f9d8dc..c0fa3ef6cf01 100644
--- a/arch/sparc/kernel/ldc.c
+++ b/arch/sparc/kernel/ldc.c
@@ -16,7 +16,7 @@
 #include <linux/list.h>
 #include <linux/init.h>
 #include <linux/bitmap.h>
-#include <linux/iommu-common.h>
+#include <asm/iommu-common.h>
 
 #include <asm/hypervisor.h>
 #include <asm/iommu.h>
diff --git a/arch/sparc/kernel/pci_sun4v.c b/arch/sparc/kernel/pci_sun4v.c
index 249367228c33..565d9ac883d0 100644
--- a/arch/sparc/kernel/pci_sun4v.c
+++ b/arch/sparc/kernel/pci_sun4v.c
@@ -16,7 +16,7 @@
 #include <linux/export.h>
 #include <linux/log2.h>
 #include <linux/of_device.h>
-#include <linux/iommu-common.h>
+#include <asm/iommu-common.h>
 
 #include <asm/iommu.h>
 #include <asm/irq.h>
diff --git a/lib/Makefile b/lib/Makefile
index ce20696d5a92..94203b5eecd4 100644
--- a/lib/Makefile
+++ b/lib/Makefile
@@ -147,7 +147,7 @@ obj-$(CONFIG_AUDIT_GENERIC) += audit.o
 obj-$(CONFIG_AUDIT_COMPAT_GENERIC) += compat_audit.o
 
 obj-$(CONFIG_SWIOTLB) += swiotlb.o
-obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o iommu-common.o
+obj-$(CONFIG_IOMMU_HELPER) += iommu-helper.o
 obj-$(CONFIG_FAULT_INJECTION) += fault-inject.o
 obj-$(CONFIG_NOTIFIER_ERROR_INJECTION) += notifier-error-inject.o
 obj-$(CONFIG_PM_NOTIFIER_ERROR_INJECT) += pm-notifier-error-inject.o
-- 
2.17.0

Re: [PATCH 01/12] iommu-common: move to arch/sparc

[Anshuman Khandual]

On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
> This code is only used by sparc, and all new iommu drivers should use the
> drivers/iommu/ framework.  Also remove the unused exports.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Right, these functions are used only from SPARC architecture. Simple
git grep confirms it as well. Hence it makes sense to move them into
arch code instead.

git grep iommu_tbl_pool_init
----------------------------

arch/sparc/include/asm/iommu-common.h:extern void iommu_tbl_pool_init(struct iommu_map_table *iommu,
arch/sparc/kernel/iommu-common.c:void iommu_tbl_pool_init(struct iommu_map_table *iommu,
arch/sparc/kernel/iommu.c:      iommu_tbl_pool_init(&iommu->tbl, num_tsb_entries, IO_PAGE_SHIFT,
arch/sparc/kernel/ldc.c:        iommu_tbl_pool_init(iommu, num_tsb_entries, PAGE_SHIFT,
arch/sparc/kernel/pci_sun4v.c:  iommu_tbl_pool_init(&atu->tbl, num_iotte, IO_PAGE_SHIFT,
arch/sparc/kernel/pci_sun4v.c:  iommu_tbl_pool_init(&iommu->tbl, num_tsb_entries, IO_PAGE_SHIFT,

git grep iommu_tbl_range_alloc
------------------------------

arch/sparc/include/asm/iommu-common.h:extern unsigned long iommu_tbl_range_alloc(struct device *dev,
arch/sparc/kernel/iommu-common.c:unsigned long iommu_tbl_range_alloc(struct device *dev,
arch/sparc/kernel/iommu.c:      entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages, NULL,
arch/sparc/kernel/iommu.c:              entry = iommu_tbl_range_alloc(dev, &iommu->tbl, npages,
arch/sparc/kernel/ldc.c:        entry = iommu_tbl_range_alloc(NULL, &iommu->iommu_map_table,
arch/sparc/kernel/pci_sun4v.c:  entry = iommu_tbl_range_alloc(dev, tbl, npages, NULL,
arch/sparc/kernel/pci_sun4v.c:  entry = iommu_tbl_range_alloc(dev, tbl, npages, NULL,
arch/sparc/kernel/pci_sun4v.c:          entry = iommu_tbl_range_alloc(dev, tbl, npages,

git grep iommu_tbl_range_free
-----------------------------

arch/sparc/include/asm/iommu-common.h:extern void iommu_tbl_range_free(struct iommu_map_table *iommu,
arch/sparc/kernel/iommu-common.c:void iommu_tbl_range_free(struct iommu_map_table *iommu, u64 dma_addr,
arch/sparc/kernel/iommu.c:      iommu_tbl_range_free(&iommu->tbl, dvma, npages, IOMMU_ERROR_CODE);
arch/sparc/kernel/iommu.c:      iommu_tbl_range_free(&iommu->tbl, bus_addr, npages, IOMMU_ERROR_CODE);
arch/sparc/kernel/iommu.c:                      iommu_tbl_range_free(&iommu->tbl, vaddr, npages,
arch/sparc/kernel/iommu.c:              iommu_tbl_range_free(&iommu->tbl, dma_handle, npages,
arch/sparc/kernel/ldc.c:        iommu_tbl_range_free(&iommu->iommu_map_table, cookie, npages, entry);
arch/sparc/kernel/pci_sun4v.c:  iommu_tbl_range_free(tbl, *dma_addrp, npages, IOMMU_ERROR_CODE);
arch/sparc/kernel/pci_sun4v.c:  iommu_tbl_range_free(tbl, dvma, npages, IOMMU_ERROR_CODE);
arch/sparc/kernel/pci_sun4v.c:  iommu_tbl_range_free(tbl, bus_addr, npages, IOMMU_ERROR_CODE);
arch/sparc/kernel/pci_sun4v.c:  iommu_tbl_range_free(tbl, bus_addr, npages, IOMMU_ERROR_CODE);
arch/sparc/kernel/pci_sun4v.c:                  iommu_tbl_range_free(tbl, vaddr, npages,
arch/sparc/kernel/pci_sun4v.c:          iommu_tbl_range_free(tbl, dma_handle, npages,

Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>

Re: [PATCH 01/12] iommu-common: move to arch/sparc

[David Miller]

From: Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
Date: Mon, 16 Apr 2018 14:26:07 +0530

> On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
>> This code is only used by sparc, and all new iommu drivers should use the
>> drivers/iommu/ framework.  Also remove the unused exports.
>> 
>> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> 
> Right, these functions are used only from SPARC architecture. Simple
> git grep confirms it as well. Hence it makes sense to move them into
> arch code instead.

Well, we put these into a common location and used type friendly for
powerpc because we hoped powerpc would convert over to using this
common piece of code as well.

But nobody did the powerpc work.

If you look at the powerpc iommu support, it's the same code basically
for entry allocation.

Re: [PATCH 01/12] iommu-common: move to arch/sparc

[Anshuman Khandual]

On 04/16/2018 07:28 PM, David Miller wrote:
> From: Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> Date: Mon, 16 Apr 2018 14:26:07 +0530
> 
>> On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
>>> This code is only used by sparc, and all new iommu drivers should use the
>>> drivers/iommu/ framework.  Also remove the unused exports.
>>>
>>> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
>>
>> Right, these functions are used only from SPARC architecture. Simple
>> git grep confirms it as well. Hence it makes sense to move them into
>> arch code instead.
> 
> Well, we put these into a common location and used type friendly for
> powerpc because we hoped powerpc would convert over to using this
> common piece of code as well.
> 
> But nobody did the powerpc work.
> 
> If you look at the powerpc iommu support, it's the same code basically
> for entry allocation.

I understand. But there are some differences in iommu_table structure,
how both regular and large IOMMU pools are being initialized etc. So
if the movement of code into SPARC help cleaning up these generic config
options in general, I guess we should do that. But I will leave it upto
others who have more experience in this area.

+mpe

Re: [PATCH 01/12] iommu-common: move to arch/sparc

[Michael Ellerman]

Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> writes:
> On 04/16/2018 07:28 PM, David Miller wrote:
>> From: Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
>> Date: Mon, 16 Apr 2018 14:26:07 +0530
>> 
>>> On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
>>>> This code is only used by sparc, and all new iommu drivers should use the
>>>> drivers/iommu/ framework.  Also remove the unused exports.
>>>>
>>>> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
>>>
>>> Right, these functions are used only from SPARC architecture. Simple
>>> git grep confirms it as well. Hence it makes sense to move them into
>>> arch code instead.
>> 
>> Well, we put these into a common location and used type friendly for
>> powerpc because we hoped powerpc would convert over to using this
>> common piece of code as well.
>> 
>> But nobody did the powerpc work.
 
Sorry.

>> If you look at the powerpc iommu support, it's the same code basically
>> for entry allocation.
>
> I understand. But there are some differences in iommu_table structure,
> how both regular and large IOMMU pools are being initialized etc. So
> if the movement of code into SPARC help cleaning up these generic config
> options in general, I guess we should do that. But I will leave it upto
> others who have more experience in this area.
>
> +mpe

This is the first I've heard of it, I guess it's probably somewhere on
Ben's append-only TODO list.

Some of the code does look very similar, but not 100%. So someone would
need to do some work to reconcile the two and test the result. TBH I
doubt we're going to get around to it any time soon. Unless we have a
volunteer?

cheers

Re: [PATCH 01/12] iommu-common: move to arch/sparc

[Christoph Hellwig]

On Mon, Apr 16, 2018 at 09:58:33AM -0400, David Miller wrote:
> From: Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>
> Date: Mon, 16 Apr 2018 14:26:07 +0530
> 
> > On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
> >> This code is only used by sparc, and all new iommu drivers should use the
> >> drivers/iommu/ framework.  Also remove the unused exports.
> >> 
> >> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> > 
> > Right, these functions are used only from SPARC architecture. Simple
> > git grep confirms it as well. Hence it makes sense to move them into
> > arch code instead.
> 
> Well, we put these into a common location and used type friendly for
> powerpc because we hoped powerpc would convert over to using this
> common piece of code as well.
> 
> But nobody did the powerpc work.
> 
> If you look at the powerpc iommu support, it's the same code basically
> for entry allocation.

I could also introduce a new config symbol and keep it in common code,
but it has been there for a while without any new user.

Right now it just means we built the code for everyone who selects
CONFIG_IOMMU_HELPER, which is just about anyone these days.

[PATCH 02/12] iommu-helper: unexport iommu_area_alloc

[Christoph Hellwig]

This function is only used by built-in code.

Reviewed-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 lib/iommu-helper.c | 2 --
 1 file changed, 2 deletions(-)

diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index 23633c0fda4a..ded1703e7e64 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -3,7 +3,6 @@
  * IOMMU helper functions for the free area management
  */
 
-#include <linux/export.h>
 #include <linux/bitmap.h>
 #include <linux/bug.h>
 
@@ -38,4 +37,3 @@ unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
 	}
 	return -1;
 }
-EXPORT_SYMBOL(iommu_area_alloc);
-- 
2.17.0

Re: [PATCH 02/12] iommu-helper: unexport iommu_area_alloc

[Sam Ravnborg]

On Sun, Apr 15, 2018 at 04:59:37PM +0200, Christoph Hellwig wrote:
> This function is only used by built-in code.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by:....

	Sam

Re: [PATCH 02/12] iommu-helper: unexport iommu_area_alloc

[Anshuman Khandual]

On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
> This function is only used by built-in code.
> 
> Reviewed-by: Christoph Hellwig <hch@lst.de>

Reviewed-by: Anshuman Khandual <khandual@linux.vnet.ibm.com>

[PATCH 03/12] iommu-helper: mark iommu_is_span_boundary as inline

[Christoph Hellwig]

This avoids selecting IOMMU_HELPER just for this function.  And we only
use it once or twice in normal builds so this often even is a size
reduction.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/alpha/Kconfig              |  3 ---
 arch/arm/Kconfig                |  3 ---
 arch/arm64/Kconfig              |  3 ---
 arch/ia64/Kconfig               |  3 ---
 arch/mips/cavium-octeon/Kconfig |  4 ----
 arch/mips/loongson64/Kconfig    |  4 ----
 arch/mips/netlogic/Kconfig      |  3 ---
 arch/powerpc/Kconfig            |  1 -
 arch/unicore32/mm/Kconfig       |  3 ---
 arch/x86/Kconfig                |  2 +-
 drivers/parisc/Kconfig          |  5 -----
 include/linux/iommu-helper.h    | 13 ++++++++++---
 lib/iommu-helper.c              | 12 +-----------
 13 files changed, 12 insertions(+), 47 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index b2022885ced8..3ff735a722af 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -345,9 +345,6 @@ config PCI_DOMAINS
 config PCI_SYSCALL
 	def_bool PCI
 
-config IOMMU_HELPER
-	def_bool PCI
-
 config ALPHA_NONAME
 	bool
 	depends on ALPHA_BOOK1 || ALPHA_NONAME_CH
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index a7f8e7f4b88f..2f79222c5c02 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1781,9 +1781,6 @@ config SECCOMP
 config SWIOTLB
 	def_bool y
 
-config IOMMU_HELPER
-	def_bool SWIOTLB
-
 config PARAVIRT
 	bool "Enable paravirtualization code"
 	help
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index eb2cf4938f6d..fbef5d3de83f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -252,9 +252,6 @@ config SMP
 config SWIOTLB
 	def_bool y
 
-config IOMMU_HELPER
-	def_bool SWIOTLB
-
 config KERNEL_MODE_NEON
 	def_bool y
 
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index bbe12a038d21..862c5160c09d 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -613,6 +613,3 @@ source "security/Kconfig"
 source "crypto/Kconfig"
 
 source "lib/Kconfig"
-
-config IOMMU_HELPER
-	def_bool (IA64_HP_ZX1 || IA64_HP_ZX1_SWIOTLB || IA64_GENERIC || SWIOTLB)
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index b5eee1a57d6c..647ed158ac98 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -67,16 +67,12 @@ config CAVIUM_OCTEON_LOCK_L2_MEMCPY
 	help
 	  Lock the kernel's implementation of memcpy() into L2.
 
-config IOMMU_HELPER
-	bool
-
 config NEED_SG_DMA_LENGTH
 	bool
 
 config SWIOTLB
 	def_bool y
 	select DMA_DIRECT_OPS
-	select IOMMU_HELPER
 	select NEED_SG_DMA_LENGTH
 
 config OCTEON_ILM
diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
index 72af0c183969..5efb2e63878e 100644
--- a/arch/mips/loongson64/Kconfig
+++ b/arch/mips/loongson64/Kconfig
@@ -130,9 +130,6 @@ config LOONGSON_UART_BASE
 	default y
 	depends on EARLY_PRINTK || SERIAL_8250
 
-config IOMMU_HELPER
-	bool
-
 config NEED_SG_DMA_LENGTH
 	bool
 
@@ -141,7 +138,6 @@ config SWIOTLB
 	default y
 	depends on CPU_LOONGSON3
 	select DMA_DIRECT_OPS
-	select IOMMU_HELPER
 	select NEED_SG_DMA_LENGTH
 	select NEED_DMA_MAP_STATE
 
diff --git a/arch/mips/netlogic/Kconfig b/arch/mips/netlogic/Kconfig
index 7fcfc7fe9f14..5c5ee0e05a17 100644
--- a/arch/mips/netlogic/Kconfig
+++ b/arch/mips/netlogic/Kconfig
@@ -83,9 +83,6 @@ endif
 config NLM_COMMON
 	bool
 
-config IOMMU_HELPER
-	bool
-
 config NEED_SG_DMA_LENGTH
 	bool
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 73ce5dd07642..eb23f2949bf6 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -484,7 +484,6 @@ config IOMMU_HELPER
 config SWIOTLB
 	bool "SWIOTLB support"
 	default n
-	select IOMMU_HELPER
 	---help---
 	  Support for IO bounce buffering for systems without an IOMMU.
 	  This allows us to DMA to the full physical address space on
diff --git a/arch/unicore32/mm/Kconfig b/arch/unicore32/mm/Kconfig
index e9154a59d561..3f105e00c432 100644
--- a/arch/unicore32/mm/Kconfig
+++ b/arch/unicore32/mm/Kconfig
@@ -44,9 +44,6 @@ config SWIOTLB
 	def_bool y
 	select DMA_DIRECT_OPS
 
-config IOMMU_HELPER
-	def_bool SWIOTLB
-
 config NEED_SG_DMA_LENGTH
 	def_bool SWIOTLB
 
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index d234cca296db..336b1378ee62 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -930,7 +930,7 @@ config SWIOTLB
 
 config IOMMU_HELPER
 	def_bool y
-	depends on CALGARY_IOMMU || GART_IOMMU || SWIOTLB || AMD_IOMMU
+	depends on CALGARY_IOMMU || GART_IOMMU
 
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
diff --git a/drivers/parisc/Kconfig b/drivers/parisc/Kconfig
index 3a102a84d637..5a48b5606110 100644
--- a/drivers/parisc/Kconfig
+++ b/drivers/parisc/Kconfig
@@ -103,11 +103,6 @@ config IOMMU_SBA
 	depends on PCI_LBA
 	default PCI_LBA
 
-config IOMMU_HELPER
-	bool
-	depends on IOMMU_SBA || IOMMU_CCIO
-	default y
-
 source "drivers/pcmcia/Kconfig"
 
 endmenu
diff --git a/include/linux/iommu-helper.h b/include/linux/iommu-helper.h
index cb9a9248c8c0..70d01edcbf8b 100644
--- a/include/linux/iommu-helper.h
+++ b/include/linux/iommu-helper.h
@@ -2,6 +2,7 @@
 #ifndef _LINUX_IOMMU_HELPER_H
 #define _LINUX_IOMMU_HELPER_H
 
+#include <linux/bug.h>
 #include <linux/kernel.h>
 
 static inline unsigned long iommu_device_max_index(unsigned long size,
@@ -14,9 +15,15 @@ static inline unsigned long iommu_device_max_index(unsigned long size,
 		return size;
 }
 
-extern int iommu_is_span_boundary(unsigned int index, unsigned int nr,
-				  unsigned long shift,
-				  unsigned long boundary_size);
+static inline int iommu_is_span_boundary(unsigned int index, unsigned int nr,
+		unsigned long shift, unsigned long boundary_size)
+{
+	BUG_ON(!is_power_of_2(boundary_size));
+
+	shift = (shift + index) & (boundary_size - 1);
+	return shift + nr > boundary_size;
+}
+
 extern unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
 				      unsigned long start, unsigned int nr,
 				      unsigned long shift,
diff --git a/lib/iommu-helper.c b/lib/iommu-helper.c
index ded1703e7e64..92a9f243c0e2 100644
--- a/lib/iommu-helper.c
+++ b/lib/iommu-helper.c
@@ -4,17 +4,7 @@
  */
 
 #include <linux/bitmap.h>
-#include <linux/bug.h>
-
-int iommu_is_span_boundary(unsigned int index, unsigned int nr,
-			   unsigned long shift,
-			   unsigned long boundary_size)
-{
-	BUG_ON(!is_power_of_2(boundary_size));
-
-	shift = (shift + index) & (boundary_size - 1);
-	return shift + nr > boundary_size;
-}
+#include <linux/iommu-helper.h>
 
 unsigned long iommu_area_alloc(unsigned long *map, unsigned long size,
 			       unsigned long start, unsigned int nr,
-- 
2.17.0

[PATCH 04/12] iommu-helper: move the IOMMU_HELPER config symbol to lib/

[Christoph Hellwig]

This way we have one central definition of it, and user can select it as
needed.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/powerpc/Kconfig | 4 +---
 arch/s390/Kconfig    | 5 ++---
 arch/sparc/Kconfig   | 5 +----
 arch/x86/Kconfig     | 6 ++----
 lib/Kconfig          | 3 +++
 5 files changed, 9 insertions(+), 14 deletions(-)

diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index eb23f2949bf6..3ca617cd4807 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -223,6 +223,7 @@ config PPC
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_VIRT_CPU_ACCOUNTING
 	select HAVE_IRQ_TIME_ACCOUNTING
+	select IOMMU_HELPER			if PPC64
 	select IRQ_DOMAIN
 	select IRQ_FORCED_THREADING
 	select MODULES_USE_ELF_RELA
@@ -478,9 +479,6 @@ config MPROFILE_KERNEL
 	depends on PPC64 && CPU_LITTLE_ENDIAN
 	def_bool !DISABLE_MPROFILE_KERNEL
 
-config IOMMU_HELPER
-	def_bool PPC64
-
 config SWIOTLB
 	bool "SWIOTLB support"
 	default n
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 32a0d5b958bf..bfa449fdeb19 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -693,7 +693,9 @@ config QDIO
 menuconfig PCI
 	bool "PCI support"
 	select PCI_MSI
+	select IOMMU_HELPER
 	select IOMMU_SUPPORT
+
 	help
 	  Enable PCI support.
 
@@ -717,9 +719,6 @@ config PCI_DOMAINS
 config HAS_IOMEM
 	def_bool PCI
 
-config IOMMU_HELPER
-	def_bool PCI
-
 config NEED_SG_DMA_LENGTH
 	def_bool PCI
 
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 8767e45f1b2b..44e0f3cd7988 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -67,6 +67,7 @@ config SPARC64
 	select HAVE_SYSCALL_TRACEPOINTS
 	select HAVE_CONTEXT_TRACKING
 	select HAVE_DEBUG_KMEMLEAK
+	select IOMMU_HELPER
 	select SPARSE_IRQ
 	select RTC_DRV_CMOS
 	select RTC_DRV_BQ4802
@@ -106,10 +107,6 @@ config ARCH_DMA_ADDR_T_64BIT
 	bool
 	default y if ARCH_ATU
 
-config IOMMU_HELPER
-	bool
-	default y if SPARC64
-
 config STACKTRACE_SUPPORT
 	bool
 	default y if SPARC64
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 336b1378ee62..06ca29e70d6b 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -870,6 +870,7 @@ config DMI
 
 config GART_IOMMU
 	bool "Old AMD GART IOMMU support"
+	select IOMMU_HELPER
 	select SWIOTLB
 	depends on X86_64 && PCI && AMD_NB
 	---help---
@@ -891,6 +892,7 @@ config GART_IOMMU
 
 config CALGARY_IOMMU
 	bool "IBM Calgary IOMMU support"
+	select IOMMU_HELPER
 	select SWIOTLB
 	depends on X86_64 && PCI
 	---help---
@@ -928,10 +930,6 @@ config SWIOTLB
 	  with more than 3 GB of memory.
 	  If unsure, say Y.
 
-config IOMMU_HELPER
-	def_bool y
-	depends on CALGARY_IOMMU || GART_IOMMU
-
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 	depends on X86_64 && SMP && DEBUG_KERNEL
diff --git a/lib/Kconfig b/lib/Kconfig
index 5fe577673b98..2f6908577534 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -429,6 +429,9 @@ config SGL_ALLOC
 	bool
 	default n
 
+config IOMMU_HELPER
+	bool
+
 config DMA_DIRECT_OPS
 	bool
 	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
-- 
2.17.0

Re: [PATCH 04/12] iommu-helper: move the IOMMU_HELPER config symbol to lib/

[Anshuman Khandual]

On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>

Reviewed-by: Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>

[PATCH 05/12] scatterlist: move the NEED_SG_DMA_LENGTH config symbol to lib/Kconfig

[Christoph Hellwig]

This way we have one central definition of it, and user can select it as
needed.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/alpha/Kconfig              | 4 +---
 arch/arm/Kconfig                | 3 ---
 arch/arm64/Kconfig              | 4 +---
 arch/hexagon/Kconfig            | 4 +---
 arch/ia64/Kconfig               | 4 +---
 arch/mips/cavium-octeon/Kconfig | 3 ---
 arch/mips/loongson64/Kconfig    | 3 ---
 arch/mips/netlogic/Kconfig      | 3 ---
 arch/parisc/Kconfig             | 4 +---
 arch/powerpc/Kconfig            | 4 +---
 arch/s390/Kconfig               | 4 +---
 arch/sh/Kconfig                 | 5 ++---
 arch/sparc/Kconfig              | 4 +---
 arch/unicore32/mm/Kconfig       | 5 +----
 arch/x86/Kconfig                | 4 +---
 lib/Kconfig                     | 3 +++
 16 files changed, 15 insertions(+), 46 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 3ff735a722af..8e6a67ecf069 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -10,6 +10,7 @@ config ALPHA
 	select HAVE_OPROFILE
 	select HAVE_PCSPKR_PLATFORM
 	select HAVE_PERF_EVENTS
+	select NEED_SG_DMA_LENGTH
 	select VIRT_TO_BUS
 	select GENERIC_IRQ_PROBE
 	select AUTO_IRQ_AFFINITY if SMP
@@ -70,9 +71,6 @@ config ARCH_DMA_ADDR_T_64BIT
 config NEED_DMA_MAP_STATE
        def_bool y
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config GENERIC_ISA_DMA
 	bool
 	default y
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 2f79222c5c02..602c8320282f 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -119,9 +119,6 @@ config ARM_HAS_SG_CHAIN
 	select ARCH_HAS_SG_CHAIN
 	bool
 
-config NEED_SG_DMA_LENGTH
-	bool
-
 config ARM_DMA_USE_IOMMU
 	bool
 	select ARM_HAS_SG_CHAIN
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index fbef5d3de83f..3b441c5587f1 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -133,6 +133,7 @@ config ARM64
 	select IRQ_FORCED_THREADING
 	select MODULES_USE_ELF_RELA
 	select MULTI_IRQ_HANDLER
+	select NEED_SG_DMA_LENGTH
 	select NO_BOOTMEM
 	select OF
 	select OF_EARLY_FLATTREE
@@ -243,9 +244,6 @@ config ARCH_DMA_ADDR_T_64BIT
 config NEED_DMA_MAP_STATE
 	def_bool y
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config SMP
 	def_bool y
 
diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index 76d2f20d525e..37adb2003033 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -19,6 +19,7 @@ config HEXAGON
 	select GENERIC_IRQ_SHOW
 	select HAVE_ARCH_KGDB
 	select HAVE_ARCH_TRACEHOOK
+	select NEED_SG_DMA_LENGTH
 	select NO_IOPORT_MAP
 	select GENERIC_IOMAP
 	select GENERIC_SMP_IDLE_THREAD
@@ -63,9 +64,6 @@ config GENERIC_CSUM
 config GENERIC_IRQ_PROBE
 	def_bool y
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config RWSEM_GENERIC_SPINLOCK
 	def_bool n
 
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 862c5160c09d..333917676f7f 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -54,6 +54,7 @@ config IA64
 	select MODULES_USE_ELF_RELA
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_AUDITSYSCALL
+	select NEED_SG_DMA_LENGTH
 	default y
 	help
 	  The Itanium Processor Family is Intel's 64-bit successor to
@@ -84,9 +85,6 @@ config ARCH_DMA_ADDR_T_64BIT
 config NEED_DMA_MAP_STATE
 	def_bool y
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config SWIOTLB
        bool
 
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 647ed158ac98..5d73041547a7 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -67,9 +67,6 @@ config CAVIUM_OCTEON_LOCK_L2_MEMCPY
 	help
 	  Lock the kernel's implementation of memcpy() into L2.
 
-config NEED_SG_DMA_LENGTH
-	bool
-
 config SWIOTLB
 	def_bool y
 	select DMA_DIRECT_OPS
diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
index 5efb2e63878e..641a1477031e 100644
--- a/arch/mips/loongson64/Kconfig
+++ b/arch/mips/loongson64/Kconfig
@@ -130,9 +130,6 @@ config LOONGSON_UART_BASE
 	default y
 	depends on EARLY_PRINTK || SERIAL_8250
 
-config NEED_SG_DMA_LENGTH
-	bool
-
 config SWIOTLB
 	bool "Soft IOMMU Support for All-Memory DMA"
 	default y
diff --git a/arch/mips/netlogic/Kconfig b/arch/mips/netlogic/Kconfig
index 5c5ee0e05a17..412351c5acc6 100644
--- a/arch/mips/netlogic/Kconfig
+++ b/arch/mips/netlogic/Kconfig
@@ -83,7 +83,4 @@ endif
 config NLM_COMMON
 	bool
 
-config NEED_SG_DMA_LENGTH
-	bool
-
 endif
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 7e0bb9836b58..491912f9b978 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -51,6 +51,7 @@ config PARISC
 	select GENERIC_CLOCKEVENTS
 	select ARCH_NO_COHERENT_DMA_MMAP
 	select CPU_NO_EFFICIENT_FFS
+	select NEED_SG_DMA_LENGTH
 
 	help
 	  The PA-RISC microprocessor is designed by Hewlett-Packard and used
@@ -114,9 +115,6 @@ config STACKTRACE_SUPPORT
 config NEED_DMA_MAP_STATE
 	def_bool y
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config ISA_DMA_API
 	bool
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 3ca617cd4807..39c5377a5460 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -227,6 +227,7 @@ config PPC
 	select IRQ_DOMAIN
 	select IRQ_FORCED_THREADING
 	select MODULES_USE_ELF_RELA
+	select NEED_SG_DMA_LENGTH
 	select NO_BOOTMEM
 	select OF
 	select OF_EARLY_FLATTREE
@@ -907,9 +908,6 @@ config ZONE_DMA
 config NEED_DMA_MAP_STATE
 	def_bool (PPC64 || NOT_COHERENT_CACHE)
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config GENERIC_ISA_DMA
 	bool
 	depends on ISA_DMA_API
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index bfa449fdeb19..4fa47b1445a2 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -695,6 +695,7 @@ menuconfig PCI
 	select PCI_MSI
 	select IOMMU_HELPER
 	select IOMMU_SUPPORT
+	select NEED_SG_DMA_LENGTH
 
 	help
 	  Enable PCI support.
@@ -719,9 +720,6 @@ config PCI_DOMAINS
 config HAS_IOMEM
 	def_bool PCI
 
-config NEED_SG_DMA_LENGTH
-	def_bool PCI
-
 config NEED_DMA_MAP_STATE
 	def_bool PCI
 
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index 97fe29316476..e127e0cbe30f 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,8 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select NEED_SG_DMA_LENGTH
+
 	help
 	  The SuperH is a RISC processor targeted for use in embedded systems
 	  and consumer electronics; it was also used in the Sega Dreamcast
@@ -163,9 +165,6 @@ config DMA_NONCOHERENT
 config NEED_DMA_MAP_STATE
 	def_bool DMA_NONCOHERENT
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config PGTABLE_LEVELS
 	default 3 if X2TLB
 	default 2
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index 44e0f3cd7988..e79badc8a682 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -44,6 +44,7 @@ config SPARC
 	select ARCH_HAS_SG_CHAIN
 	select CPU_NO_EFFICIENT_FFS
 	select LOCKDEP_SMALL if LOCKDEP
+	select NEED_SG_DMA_LENGTH
 
 config SPARC32
 	def_bool !64BIT
@@ -146,9 +147,6 @@ config ZONE_DMA
 config NEED_DMA_MAP_STATE
 	def_bool y
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config GENERIC_ISA_DMA
 	bool
 	default y if SPARC32
diff --git a/arch/unicore32/mm/Kconfig b/arch/unicore32/mm/Kconfig
index 3f105e00c432..1d9fed0ada71 100644
--- a/arch/unicore32/mm/Kconfig
+++ b/arch/unicore32/mm/Kconfig
@@ -43,7 +43,4 @@ config CPU_TLB_SINGLE_ENTRY_DISABLE
 config SWIOTLB
 	def_bool y
 	select DMA_DIRECT_OPS
-
-config NEED_SG_DMA_LENGTH
-	def_bool SWIOTLB
-
+	select NEED_SG_DMA_LENGTH
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 06ca29e70d6b..491a723bc2b3 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -182,6 +182,7 @@ config X86
 	select HAVE_UNSTABLE_SCHED_CLOCK
 	select HAVE_USER_RETURN_NOTIFIER
 	select IRQ_FORCED_THREADING
+	select NEED_SG_DMA_LENGTH
 	select PCI_LOCKLESS_CONFIG
 	select PERF_EVENTS
 	select RTC_LIB
@@ -238,9 +239,6 @@ config NEED_DMA_MAP_STATE
 	def_bool y
 	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
 
-config NEED_SG_DMA_LENGTH
-	def_bool y
-
 config GENERIC_ISA_DMA
 	def_bool y
 	depends on ISA_DMA_API
diff --git a/lib/Kconfig b/lib/Kconfig
index 2f6908577534..aeb7fae16bc2 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -429,6 +429,9 @@ config SGL_ALLOC
 	bool
 	default n
 
+config NEED_SG_DMA_LENGTH
+	bool
+
 config IOMMU_HELPER
 	bool
 
-- 
2.17.0

Re: [PATCH 05/12] scatterlist: move the NEED_SG_DMA_LENGTH config symbol to lib/Kconfig

[Anshuman Khandual]

On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>

Reviewed-by: Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>

[PATCH 06/12] dma-mapping: move the NEED_DMA_MAP_STATE config symbol to lib/Kconfig

[Christoph Hellwig]

This way we have one central definition of it, and user can select it as
needed.  Note that we now also always select it when CONFIG_DMA_API_DEBUG
is select, which fixes some incorrect checks in a few network drivers.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/alpha/Kconfig          | 4 +---
 arch/arm/Kconfig            | 4 +---
 arch/arm64/Kconfig          | 4 +---
 arch/ia64/Kconfig           | 4 +---
 arch/mips/Kconfig           | 3 ---
 arch/parisc/Kconfig         | 4 +---
 arch/s390/Kconfig           | 4 +---
 arch/sh/Kconfig             | 4 +---
 arch/sparc/Kconfig          | 4 +---
 arch/unicore32/Kconfig      | 4 +---
 arch/x86/Kconfig            | 6 ++----
 drivers/iommu/Kconfig       | 1 +
 include/linux/dma-mapping.h | 2 +-
 lib/Kconfig                 | 3 +++
 lib/Kconfig.debug           | 1 +
 15 files changed, 17 insertions(+), 35 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 8e6a67ecf069..1fd9645b0c67 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -10,6 +10,7 @@ config ALPHA
 	select HAVE_OPROFILE
 	select HAVE_PCSPKR_PLATFORM
 	select HAVE_PERF_EVENTS
+	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 	select VIRT_TO_BUS
 	select GENERIC_IRQ_PROBE
@@ -68,9 +69,6 @@ config ZONE_DMA
 config ARCH_DMA_ADDR_T_64BIT
 	def_bool y
 
-config NEED_DMA_MAP_STATE
-       def_bool y
-
 config GENERIC_ISA_DMA
 	bool
 	default y
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 602c8320282f..aa1c187d756d 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -96,6 +96,7 @@ config ARM
 	select HAVE_VIRT_CPU_ACCOUNTING_GEN
 	select IRQ_FORCED_THREADING
 	select MODULES_USE_ELF_REL
+	select NEED_DMA_MAP_STATE
 	select NO_BOOTMEM
 	select OF_EARLY_FLATTREE if OF
 	select OF_RESERVED_MEM if OF
@@ -221,9 +222,6 @@ config ARCH_MAY_HAVE_PC_FDC
 config ZONE_DMA
 	bool
 
-config NEED_DMA_MAP_STATE
-       def_bool y
-
 config ARCH_SUPPORTS_UPROBES
 	def_bool y
 
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 3b441c5587f1..940adfb9a2bc 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -133,6 +133,7 @@ config ARM64
 	select IRQ_FORCED_THREADING
 	select MODULES_USE_ELF_RELA
 	select MULTI_IRQ_HANDLER
+	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 	select NO_BOOTMEM
 	select OF
@@ -241,9 +242,6 @@ config HAVE_GENERIC_GUP
 config ARCH_DMA_ADDR_T_64BIT
 	def_bool y
 
-config NEED_DMA_MAP_STATE
-	def_bool y
-
 config SMP
 	def_bool y
 
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 333917676f7f..0e42731adaf1 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -54,6 +54,7 @@ config IA64
 	select MODULES_USE_ELF_RELA
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_AUDITSYSCALL
+	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 	default y
 	help
@@ -82,9 +83,6 @@ config MMU
 config ARCH_DMA_ADDR_T_64BIT
 	def_bool y
 
-config NEED_DMA_MAP_STATE
-	def_bool y
-
 config SWIOTLB
        bool
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 225c95da23ce..47d72c64d687 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1122,9 +1122,6 @@ config DMA_NONCOHERENT
 	bool
 	select NEED_DMA_MAP_STATE
 
-config NEED_DMA_MAP_STATE
-	bool
-
 config SYS_HAS_EARLY_PRINTK
 	bool
 
diff --git a/arch/parisc/Kconfig b/arch/parisc/Kconfig
index 491912f9b978..47047f0cbe35 100644
--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -51,6 +51,7 @@ config PARISC
 	select GENERIC_CLOCKEVENTS
 	select ARCH_NO_COHERENT_DMA_MMAP
 	select CPU_NO_EFFICIENT_FFS
+	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 
 	help
@@ -112,9 +113,6 @@ config PM
 config STACKTRACE_SUPPORT
 	def_bool y
 
-config NEED_DMA_MAP_STATE
-	def_bool y
-
 config ISA_DMA_API
 	bool
 
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index 4fa47b1445a2..f682dd8d381d 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -695,6 +695,7 @@ menuconfig PCI
 	select PCI_MSI
 	select IOMMU_HELPER
 	select IOMMU_SUPPORT
+	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 
 	help
@@ -720,9 +721,6 @@ config PCI_DOMAINS
 config HAS_IOMEM
 	def_bool PCI
 
-config NEED_DMA_MAP_STATE
-	def_bool PCI
-
 config CHSC_SCH
 	def_tristate m
 	prompt "Support for CHSC subchannels"
diff --git a/arch/sh/Kconfig b/arch/sh/Kconfig
index e127e0cbe30f..9417f70e008e 100644
--- a/arch/sh/Kconfig
+++ b/arch/sh/Kconfig
@@ -50,6 +50,7 @@ config SUPERH
 	select HAVE_ARCH_AUDITSYSCALL
 	select HAVE_FUTEX_CMPXCHG if FUTEX
 	select HAVE_NMI
+	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 
 	help
@@ -162,9 +163,6 @@ config DMA_COHERENT
 config DMA_NONCOHERENT
 	def_bool !DMA_COHERENT
 
-config NEED_DMA_MAP_STATE
-	def_bool DMA_NONCOHERENT
-
 config PGTABLE_LEVELS
 	default 3 if X2TLB
 	default 2
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index e79badc8a682..be770b511ddd 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -44,6 +44,7 @@ config SPARC
 	select ARCH_HAS_SG_CHAIN
 	select CPU_NO_EFFICIENT_FFS
 	select LOCKDEP_SMALL if LOCKDEP
+	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
 
 config SPARC32
@@ -144,9 +145,6 @@ config ZONE_DMA
 	bool
 	default y if SPARC32
 
-config NEED_DMA_MAP_STATE
-	def_bool y
-
 config GENERIC_ISA_DMA
 	bool
 	default y if SPARC32
diff --git a/arch/unicore32/Kconfig b/arch/unicore32/Kconfig
index 462e59a7ae78..82195714d20b 100644
--- a/arch/unicore32/Kconfig
+++ b/arch/unicore32/Kconfig
@@ -19,6 +19,7 @@ config UNICORE32
 	select ARCH_WANT_FRAME_POINTERS
 	select GENERIC_IOMAP
 	select MODULES_USE_ELF_REL
+	select NEED_DMA_MAP_STATE
 	help
 	  UniCore-32 is 32-bit Instruction Set Architecture,
 	  including a series of low-power-consumption RISC chip
@@ -61,9 +62,6 @@ config ARCH_MAY_HAVE_PC_FDC
 config ZONE_DMA
 	def_bool y
 
-config NEED_DMA_MAP_STATE
-       def_bool y
-
 source "init/Kconfig"
 
 source "kernel/Kconfig.freezer"
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 491a723bc2b3..414043303ea1 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -28,6 +28,7 @@ config X86_64
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_SOFT_DIRTY
 	select MODULES_USE_ELF_RELA
+	select NEED_DMA_MAP_STATE
 	select X86_DEV_DMA_OPS
 
 #
@@ -235,10 +236,6 @@ config ARCH_MMAP_RND_COMPAT_BITS_MAX
 config SBUS
 	bool
 
-config NEED_DMA_MAP_STATE
-	def_bool y
-	depends on X86_64 || INTEL_IOMMU || DMA_API_DEBUG || SWIOTLB
-
 config GENERIC_ISA_DMA
 	def_bool y
 	depends on ISA_DMA_API
@@ -921,6 +918,7 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 # need this always selected by IOMMU for the VIA workaround
 config SWIOTLB
 	def_bool y if X86_64
+	select NEED_DMA_MAP_STATE
 	---help---
 	  Support for software bounce buffers used on x86-64 systems
 	  which don't have a hardware IOMMU. Using this PCI devices
diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig
index df171cb85822..5b714a062fa7 100644
--- a/drivers/iommu/Kconfig
+++ b/drivers/iommu/Kconfig
@@ -146,6 +146,7 @@ config INTEL_IOMMU
 	select DMA_DIRECT_OPS
 	select IOMMU_API
 	select IOMMU_IOVA
+	select NEED_DMA_MAP_STATE
 	select DMAR_TABLE
 	help
 	  DMA remapping (DMAR) devices support enables independent address
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index f8ab1c0f589e..14269d25498b 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -839,7 +839,7 @@ static inline int dma_mmap_wc(struct device *dev,
 #define dma_mmap_writecombine dma_mmap_wc
 #endif
 
-#if defined(CONFIG_NEED_DMA_MAP_STATE) || defined(CONFIG_DMA_API_DEBUG)
+#ifdef CONFIG_NEED_DMA_MAP_STATE
 #define DEFINE_DMA_UNMAP_ADDR(ADDR_NAME)        dma_addr_t ADDR_NAME
 #define DEFINE_DMA_UNMAP_LEN(LEN_NAME)          __u32 LEN_NAME
 #define dma_unmap_addr(PTR, ADDR_NAME)           ((PTR)->ADDR_NAME)
diff --git a/lib/Kconfig b/lib/Kconfig
index aeb7fae16bc2..ce9fa962d59b 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -432,6 +432,9 @@ config SGL_ALLOC
 config NEED_SG_DMA_LENGTH
 	bool
 
+config NEED_DMA_MAP_STATE
+	bool
+
 config IOMMU_HELPER
 	bool
 
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c40c7b734cd1..685ed2dd4384 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -1635,6 +1635,7 @@ config PROVIDE_OHCI1394_DMA_INIT
 config DMA_API_DEBUG
 	bool "Enable debugging of DMA-API usage"
 	depends on HAVE_DMA_API_DEBUG
+	select NEED_DMA_MAP_STATE
 	help
 	  Enable this option to debug the use of the DMA API by device drivers.
 	  With this option you will be able to detect common bugs in device
-- 
2.17.0

Re: [PATCH 06/12] dma-mapping: move the NEED_DMA_MAP_STATE config symbol to lib/Kconfig

[Anshuman Khandual]

On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.  Note that we now also always select it when CONFIG_DMA_API_DEBUG
> is select, which fixes some incorrect checks in a few network drivers.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>

Reviewed-by: Anshuman Khandual <khandual-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org>

[PATCH 07/12] arch: remove the ARCH_PHYS_ADDR_T_64BIT config symbol

[Christoph Hellwig]

Instead select the PHYS_ADDR_T_64BIT for 32-bit architectures that need a
64-bit phys_addr_t type directly.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/arc/Kconfig                       |  4 +---
 arch/arm/kernel/setup.c                |  2 +-
 arch/arm/mm/Kconfig                    |  4 +---
 arch/arm64/Kconfig                     |  3 ---
 arch/mips/Kconfig                      | 15 ++++++---------
 arch/powerpc/Kconfig                   |  5 +----
 arch/powerpc/platforms/Kconfig.cputype |  1 +
 arch/riscv/Kconfig                     |  6 ++----
 arch/x86/Kconfig                       |  5 +----
 mm/Kconfig                             |  2 +-
 10 files changed, 15 insertions(+), 32 deletions(-)

diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index d76bf4a83740..f94c61da682a 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -453,13 +453,11 @@ config ARC_HAS_PAE40
 	default n
 	depends on ISA_ARCV2
 	select HIGHMEM
+	select PHYS_ADDR_T_64BIT
 	help
 	  Enable access to physical memory beyond 4G, only supported on
 	  ARC cores with 40 bit Physical Addressing support
 
-config ARCH_PHYS_ADDR_T_64BIT
-	def_bool ARC_HAS_PAE40
-
 config ARCH_DMA_ADDR_T_64BIT
 	bool
 
diff --git a/arch/arm/kernel/setup.c b/arch/arm/kernel/setup.c
index fc40a2b40595..35ca494c028c 100644
--- a/arch/arm/kernel/setup.c
+++ b/arch/arm/kernel/setup.c
@@ -754,7 +754,7 @@ int __init arm_add_memory(u64 start, u64 size)
 	else
 		size -= aligned_start - start;
 
-#ifndef CONFIG_ARCH_PHYS_ADDR_T_64BIT
+#ifndef CONFIG_PHYS_ADDR_T_64BIT
 	if (aligned_start > ULONG_MAX) {
 		pr_crit("Ignoring memory at 0x%08llx outside 32-bit physical address space\n",
 			(long long)start);
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 7f14acf67caf..2f77c6344ef1 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -661,6 +661,7 @@ config ARM_LPAE
 	bool "Support for the Large Physical Address Extension"
 	depends on MMU && CPU_32v7 && !CPU_32v6 && !CPU_32v5 && \
 		!CPU_32v4 && !CPU_32v3
+	select PHYS_ADDR_T_64BIT
 	help
 	  Say Y if you have an ARMv7 processor supporting the LPAE page
 	  table format and you would like to access memory beyond the
@@ -673,9 +674,6 @@ config ARM_PV_FIXUP
 	def_bool y
 	depends on ARM_LPAE && ARM_PATCH_PHYS_VIRT && ARCH_KEYSTONE
 
-config ARCH_PHYS_ADDR_T_64BIT
-	def_bool ARM_LPAE
-
 config ARCH_DMA_ADDR_T_64BIT
 	bool
 
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 940adfb9a2bc..b6aa33e642cc 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -152,9 +152,6 @@ config ARM64
 config 64BIT
 	def_bool y
 
-config ARCH_PHYS_ADDR_T_64BIT
-	def_bool y
-
 config MMU
 	def_bool y
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 47d72c64d687..985388078872 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -132,7 +132,7 @@ config MIPS_GENERIC
 
 config MIPS_ALCHEMY
 	bool "Alchemy processor based machines"
-	select ARCH_PHYS_ADDR_T_64BIT
+	select PHYS_ADDR_T_64BIT
 	select CEVT_R4K
 	select CSRC_R4K
 	select IRQ_MIPS_CPU
@@ -890,7 +890,7 @@ config CAVIUM_OCTEON_SOC
 	bool "Cavium Networks Octeon SoC based boards"
 	select CEVT_R4K
 	select ARCH_HAS_PHYS_TO_DMA
-	select ARCH_PHYS_ADDR_T_64BIT
+	select PHYS_ADDR_T_64BIT
 	select DMA_COHERENT
 	select SYS_SUPPORTS_64BIT_KERNEL
 	select SYS_SUPPORTS_BIG_ENDIAN
@@ -936,7 +936,7 @@ config NLM_XLR_BOARD
 	select SWAP_IO_SPACE
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
-	select ARCH_PHYS_ADDR_T_64BIT
+	select PHYS_ADDR_T_64BIT
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_HIGHMEM
 	select DMA_COHERENT
@@ -962,7 +962,7 @@ config NLM_XLP_BOARD
 	select HW_HAS_PCI
 	select SYS_SUPPORTS_32BIT_KERNEL
 	select SYS_SUPPORTS_64BIT_KERNEL
-	select ARCH_PHYS_ADDR_T_64BIT
+	select PHYS_ADDR_T_64BIT
 	select GPIOLIB
 	select SYS_SUPPORTS_BIG_ENDIAN
 	select SYS_SUPPORTS_LITTLE_ENDIAN
@@ -1102,7 +1102,7 @@ config FW_CFE
 	bool
 
 config ARCH_DMA_ADDR_T_64BIT
-	def_bool (HIGHMEM && ARCH_PHYS_ADDR_T_64BIT) || 64BIT
+	def_bool (HIGHMEM && PHYS_ADDR_T_64BIT) || 64BIT
 
 config ARCH_SUPPORTS_UPROBES
 	bool
@@ -1767,7 +1767,7 @@ config CPU_MIPS32_R5_XPA
 	depends on SYS_SUPPORTS_HIGHMEM
 	select XPA
 	select HIGHMEM
-	select ARCH_PHYS_ADDR_T_64BIT
+	select PHYS_ADDR_T_64BIT
 	default n
 	help
 	  Choose this option if you want to enable the Extended Physical
@@ -2399,9 +2399,6 @@ config SB1_PASS_2_1_WORKAROUNDS
 	default y
 
 
-config ARCH_PHYS_ADDR_T_64BIT
-       bool
-
 choice
 	prompt "SmartMIPS or microMIPS ASE support"
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 39c5377a5460..8bdcd7e44838 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -13,11 +13,8 @@ config 64BIT
 	bool
 	default y if PPC64
 
-config ARCH_PHYS_ADDR_T_64BIT
-       def_bool PPC64 || PHYS_64BIT
-
 config ARCH_DMA_ADDR_T_64BIT
-	def_bool ARCH_PHYS_ADDR_T_64BIT
+	def_bool PHYS_ADDR_T_64BIT
 
 config MMU
 	bool
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 67d3125d0610..84b58abc08ee 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -222,6 +222,7 @@ config PTE_64BIT
 config PHYS_64BIT
 	bool 'Large physical address support' if E500 || PPC_86xx
 	depends on (44x || E500 || PPC_86xx) && !PPC_83xx && !PPC_82xx
+	select PHYS_ADDR_T_64BIT
 	---help---
 	  This option enables kernel support for larger than 32-bit physical
 	  addresses.  This feature may not be available on all cores.
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 23d8acca5c90..f52f86f43a4b 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -5,6 +5,8 @@
 
 config RISCV
 	def_bool y
+	# even on 32-bit, physical (and DMA) addresses are > 32-bits
+	select PHYS_ADDR_T_64BIT
 	select OF
 	select OF_EARLY_FLATTREE
 	select OF_IRQ
@@ -38,10 +40,6 @@ config RISCV
 config MMU
 	def_bool y
 
-# even on 32-bit, physical (and DMA) addresses are > 32-bits
-config ARCH_PHYS_ADDR_T_64BIT
-	def_bool y
-
 config ZONE_DMA32
 	bool
 	default y
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 414043303ea1..15f228984e70 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1447,6 +1447,7 @@ config HIGHMEM
 config X86_PAE
 	bool "PAE (Physical Address Extension) Support"
 	depends on X86_32 && !HIGHMEM4G
+	select PHYS_ADDR_T_64BIT
 	select SWIOTLB
 	---help---
 	  PAE is required for NX support, and furthermore enables
@@ -1474,10 +1475,6 @@ config X86_5LEVEL
 
 	  Say N if unsure.
 
-config ARCH_PHYS_ADDR_T_64BIT
-	def_bool y
-	depends on X86_64 || X86_PAE
-
 config ARCH_DMA_ADDR_T_64BIT
 	def_bool y
 	depends on X86_64 || HIGHMEM64G
diff --git a/mm/Kconfig b/mm/Kconfig
index d5004d82a1d6..a3f0005ac212 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -266,7 +266,7 @@ config ARCH_ENABLE_THP_MIGRATION
 	bool
 
 config PHYS_ADDR_T_64BIT
-	def_bool 64BIT || ARCH_PHYS_ADDR_T_64BIT
+	def_bool 64BIT
 
 config BOUNCE
 	bool "Enable bounce buffers"
-- 
2.17.0

[PATCH 08/12] arch: define the ARCH_DMA_ADDR_T_64BIT config symbol in lib/Kconfig

[Christoph Hellwig]

Define this symbol if the architecture either uses 64-bit pointers or the
PHYS_ADDR_T_64BIT is set.  This covers 95% of the old arch magic.  We only
need an additional select for Xen on ARM (why anyway?), and we now always
set ARCH_DMA_ADDR_T_64BIT on mips boards with 64-bit physical addressing
instead of only doing it when highmem is set.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/alpha/Kconfig             | 3 ---
 arch/arc/Kconfig               | 3 ---
 arch/arm/mach-axxia/Kconfig    | 1 -
 arch/arm/mach-bcm/Kconfig      | 1 -
 arch/arm/mach-exynos/Kconfig   | 1 -
 arch/arm/mach-highbank/Kconfig | 1 -
 arch/arm/mach-rockchip/Kconfig | 1 -
 arch/arm/mach-shmobile/Kconfig | 1 -
 arch/arm/mach-tegra/Kconfig    | 1 -
 arch/arm/mm/Kconfig            | 3 ---
 arch/arm64/Kconfig             | 3 ---
 arch/ia64/Kconfig              | 3 ---
 arch/mips/Kconfig              | 3 ---
 arch/powerpc/Kconfig           | 3 ---
 arch/riscv/Kconfig             | 3 ---
 arch/s390/Kconfig              | 3 ---
 arch/sparc/Kconfig             | 4 ----
 arch/x86/Kconfig               | 4 ----
 lib/Kconfig                    | 3 +++
 19 files changed, 3 insertions(+), 42 deletions(-)

diff --git a/arch/alpha/Kconfig b/arch/alpha/Kconfig
index 1fd9645b0c67..aa7df1a36fd0 100644
--- a/arch/alpha/Kconfig
+++ b/arch/alpha/Kconfig
@@ -66,9 +66,6 @@ config ZONE_DMA
 	bool
 	default y
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool y
-
 config GENERIC_ISA_DMA
 	bool
 	default y
diff --git a/arch/arc/Kconfig b/arch/arc/Kconfig
index f94c61da682a..7498aca4b887 100644
--- a/arch/arc/Kconfig
+++ b/arch/arc/Kconfig
@@ -458,9 +458,6 @@ config ARC_HAS_PAE40
 	  Enable access to physical memory beyond 4G, only supported on
 	  ARC cores with 40 bit Physical Addressing support
 
-config ARCH_DMA_ADDR_T_64BIT
-	bool
-
 config ARC_KVADDR_SIZE
 	int "Kernel Virtual Address Space size (MB)"
 	range 0 512
diff --git a/arch/arm/mach-axxia/Kconfig b/arch/arm/mach-axxia/Kconfig
index bb2ce1c63fd9..d3eae6037913 100644
--- a/arch/arm/mach-axxia/Kconfig
+++ b/arch/arm/mach-axxia/Kconfig
@@ -2,7 +2,6 @@
 config ARCH_AXXIA
 	bool "LSI Axxia platforms"
 	depends on ARCH_MULTI_V7 && ARM_LPAE
-	select ARCH_DMA_ADDR_T_64BIT
 	select ARM_AMBA
 	select ARM_GIC
 	select ARM_TIMER_SP804
diff --git a/arch/arm/mach-bcm/Kconfig b/arch/arm/mach-bcm/Kconfig
index c2f3b0d216a4..c46a728df44e 100644
--- a/arch/arm/mach-bcm/Kconfig
+++ b/arch/arm/mach-bcm/Kconfig
@@ -211,7 +211,6 @@ config ARCH_BRCMSTB
 	select BRCMSTB_L2_IRQ
 	select BCM7120_L2_IRQ
 	select ARCH_HAS_HOLES_MEMORYMODEL
-	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
 	select ZONE_DMA if ARM_LPAE
 	select SOC_BRCMSTB
 	select SOC_BUS
diff --git a/arch/arm/mach-exynos/Kconfig b/arch/arm/mach-exynos/Kconfig
index 647c319f9f5f..2ca405816846 100644
--- a/arch/arm/mach-exynos/Kconfig
+++ b/arch/arm/mach-exynos/Kconfig
@@ -112,7 +112,6 @@ config SOC_EXYNOS5440
 	bool "SAMSUNG EXYNOS5440"
 	default y
 	depends on ARCH_EXYNOS5
-	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
 	select HAVE_ARM_ARCH_TIMER
 	select AUTO_ZRELADDR
 	select PINCTRL_EXYNOS5440
diff --git a/arch/arm/mach-highbank/Kconfig b/arch/arm/mach-highbank/Kconfig
index 81110ec34226..5552968f07f8 100644
--- a/arch/arm/mach-highbank/Kconfig
+++ b/arch/arm/mach-highbank/Kconfig
@@ -1,7 +1,6 @@
 config ARCH_HIGHBANK
 	bool "Calxeda ECX-1000/2000 (Highbank/Midway)"
 	depends on ARCH_MULTI_V7
-	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
 	select ARCH_HAS_HOLES_MEMORYMODEL
 	select ARCH_SUPPORTS_BIG_ENDIAN
 	select ARM_AMBA
diff --git a/arch/arm/mach-rockchip/Kconfig b/arch/arm/mach-rockchip/Kconfig
index a4065966881a..fafd3d7f9f8c 100644
--- a/arch/arm/mach-rockchip/Kconfig
+++ b/arch/arm/mach-rockchip/Kconfig
@@ -3,7 +3,6 @@ config ARCH_ROCKCHIP
 	depends on ARCH_MULTI_V7
 	select PINCTRL
 	select PINCTRL_ROCKCHIP
-	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
 	select ARCH_HAS_RESET_CONTROLLER
 	select ARM_AMBA
 	select ARM_GIC
diff --git a/arch/arm/mach-shmobile/Kconfig b/arch/arm/mach-shmobile/Kconfig
index 280e7312a9e1..fe60cd09a5ca 100644
--- a/arch/arm/mach-shmobile/Kconfig
+++ b/arch/arm/mach-shmobile/Kconfig
@@ -29,7 +29,6 @@ config ARCH_RMOBILE
 menuconfig ARCH_RENESAS
 	bool "Renesas ARM SoCs"
 	depends on ARCH_MULTI_V7 && MMU
-	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
 	select ARCH_SHMOBILE
 	select ARM_GIC
 	select GPIOLIB
diff --git a/arch/arm/mach-tegra/Kconfig b/arch/arm/mach-tegra/Kconfig
index 1e0aeb47bac6..7f3b83e0d324 100644
--- a/arch/arm/mach-tegra/Kconfig
+++ b/arch/arm/mach-tegra/Kconfig
@@ -15,6 +15,5 @@ menuconfig ARCH_TEGRA
 	select RESET_CONTROLLER
 	select SOC_BUS
 	select ZONE_DMA if ARM_LPAE
-	select ARCH_DMA_ADDR_T_64BIT if ARM_LPAE
 	help
 	  This enables support for NVIDIA Tegra based systems.
diff --git a/arch/arm/mm/Kconfig b/arch/arm/mm/Kconfig
index 2f77c6344ef1..5a016bc80e26 100644
--- a/arch/arm/mm/Kconfig
+++ b/arch/arm/mm/Kconfig
@@ -674,9 +674,6 @@ config ARM_PV_FIXUP
 	def_bool y
 	depends on ARM_LPAE && ARM_PATCH_PHYS_VIRT && ARCH_KEYSTONE
 
-config ARCH_DMA_ADDR_T_64BIT
-	bool
-
 config ARM_THUMB
 	bool "Support Thumb user binaries" if !CPU_THUMBONLY && EXPERT
 	depends on CPU_THUMB_CAPABLE
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index b6aa33e642cc..4d924eb32e7f 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -236,9 +236,6 @@ config ZONE_DMA32
 config HAVE_GENERIC_GUP
 	def_bool y
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool y
-
 config SMP
 	def_bool y
 
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 0e42731adaf1..685d557eea48 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -80,9 +80,6 @@ config MMU
 	bool
 	default y
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool y
-
 config SWIOTLB
        bool
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 985388078872..e10cc5c7be69 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -1101,9 +1101,6 @@ config GPIO_TXX9
 config FW_CFE
 	bool
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool (HIGHMEM && PHYS_ADDR_T_64BIT) || 64BIT
-
 config ARCH_SUPPORTS_UPROBES
 	bool
 
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 8bdcd7e44838..b85a537421b8 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -13,9 +13,6 @@ config 64BIT
 	bool
 	default y if PPC64
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool PHYS_ADDR_T_64BIT
-
 config MMU
 	bool
 	default y
diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index f52f86f43a4b..17212ba54ee3 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -44,9 +44,6 @@ config ZONE_DMA32
 	bool
 	default y
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool y
-
 config PAGE_OFFSET
 	hex
 	default 0xC0000000 if 32BIT && MAXPHYSMEM_2GB
diff --git a/arch/s390/Kconfig b/arch/s390/Kconfig
index f682dd8d381d..567a130f8db4 100644
--- a/arch/s390/Kconfig
+++ b/arch/s390/Kconfig
@@ -35,9 +35,6 @@ config GENERIC_BUG
 config GENERIC_BUG_RELATIVE_POINTERS
 	def_bool y
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool y
-
 config GENERIC_LOCKBREAK
 	def_bool y if SMP && PREEMPT
 
diff --git a/arch/sparc/Kconfig b/arch/sparc/Kconfig
index be770b511ddd..c1cfc17eb504 100644
--- a/arch/sparc/Kconfig
+++ b/arch/sparc/Kconfig
@@ -105,10 +105,6 @@ config ARCH_ATU
 	bool
 	default y if SPARC64
 
-config ARCH_DMA_ADDR_T_64BIT
-	bool
-	default y if ARCH_ATU
-
 config STACKTRACE_SUPPORT
 	bool
 	default y if SPARC64
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 15f228984e70..a95eb9ef3311 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -1475,10 +1475,6 @@ config X86_5LEVEL
 
 	  Say N if unsure.
 
-config ARCH_DMA_ADDR_T_64BIT
-	def_bool y
-	depends on X86_64 || HIGHMEM64G
-
 config X86_DIRECT_GBPAGES
 	def_bool y
 	depends on X86_64 && !DEBUG_PAGEALLOC
diff --git a/lib/Kconfig b/lib/Kconfig
index ce9fa962d59b..1f12faf03819 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -435,6 +435,9 @@ config NEED_SG_DMA_LENGTH
 config NEED_DMA_MAP_STATE
 	bool
 
+config ARCH_DMA_ADDR_T_64BIT
+	def_bool 64BIT || PHYS_ADDR_T_64BIT
+
 config IOMMU_HELPER
 	bool
 
-- 
2.17.0

[PATCH 09/12] PCI: remove CONFIG_PCI_BUS_ADDR_T_64BIT

[Christoph Hellwig]

This symbol is now always identical to CONFIG_ARCH_DMA_ADDR_T_64BIT, so
remove it.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 drivers/pci/Kconfig | 4 ----
 drivers/pci/bus.c   | 4 ++--
 include/linux/pci.h | 2 +-
 3 files changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 34b56a8f8480..29a487f31dae 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -5,10 +5,6 @@
 
 source "drivers/pci/pcie/Kconfig"
 
-config PCI_BUS_ADDR_T_64BIT
-	def_bool y if (ARCH_DMA_ADDR_T_64BIT || 64BIT)
-	depends on PCI
-
 config PCI_MSI
 	bool "Message Signaled Interrupts (MSI and MSI-X)"
 	depends on PCI
diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
index bc2ded4c451f..35b7fc87eac5 100644
--- a/drivers/pci/bus.c
+++ b/drivers/pci/bus.c
@@ -120,7 +120,7 @@ int devm_request_pci_bus_resources(struct device *dev,
 EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
 
 static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
-#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 static struct pci_bus_region pci_64_bit = {0,
 				(pci_bus_addr_t) 0xffffffffffffffffULL};
 static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
@@ -230,7 +230,7 @@ int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
 					  resource_size_t),
 		void *alignf_data)
 {
-#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 	int rc;
 
 	if (res->flags & IORESOURCE_MEM_64) {
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 73178a2fcee0..55371cb827ad 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -670,7 +670,7 @@ int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
 int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
 		  int reg, int len, u32 val);
 
-#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
+#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
 typedef u64 pci_bus_addr_t;
 #else
 typedef u32 pci_bus_addr_t;
-- 
2.17.0

Re: [PATCH 09/12] PCI: remove CONFIG_PCI_BUS_ADDR_T_64BIT

[Bjorn Helgaas]

On Sun, Apr 15, 2018 at 04:59:44PM +0200, Christoph Hellwig wrote:
> This symbol is now always identical to CONFIG_ARCH_DMA_ADDR_T_64BIT, so
> remove it.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>

Acked-by: Bjorn Helgaas <bhelgaas-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>

Please merge this along with the rest of the series; let me know if you
need anything more from me.

> ---
>  drivers/pci/Kconfig | 4 ----
>  drivers/pci/bus.c   | 4 ++--
>  include/linux/pci.h | 2 +-
>  3 files changed, 3 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
> index 34b56a8f8480..29a487f31dae 100644
> --- a/drivers/pci/Kconfig
> +++ b/drivers/pci/Kconfig
> @@ -5,10 +5,6 @@
>  
>  source "drivers/pci/pcie/Kconfig"
>  
> -config PCI_BUS_ADDR_T_64BIT
> -	def_bool y if (ARCH_DMA_ADDR_T_64BIT || 64BIT)
> -	depends on PCI
> -
>  config PCI_MSI
>  	bool "Message Signaled Interrupts (MSI and MSI-X)"
>  	depends on PCI
> diff --git a/drivers/pci/bus.c b/drivers/pci/bus.c
> index bc2ded4c451f..35b7fc87eac5 100644
> --- a/drivers/pci/bus.c
> +++ b/drivers/pci/bus.c
> @@ -120,7 +120,7 @@ int devm_request_pci_bus_resources(struct device *dev,
>  EXPORT_SYMBOL_GPL(devm_request_pci_bus_resources);
>  
>  static struct pci_bus_region pci_32_bit = {0, 0xffffffffULL};
> -#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
> +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
>  static struct pci_bus_region pci_64_bit = {0,
>  				(pci_bus_addr_t) 0xffffffffffffffffULL};
>  static struct pci_bus_region pci_high = {(pci_bus_addr_t) 0x100000000ULL,
> @@ -230,7 +230,7 @@ int pci_bus_alloc_resource(struct pci_bus *bus, struct resource *res,
>  					  resource_size_t),
>  		void *alignf_data)
>  {
> -#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
> +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
>  	int rc;
>  
>  	if (res->flags & IORESOURCE_MEM_64) {
> diff --git a/include/linux/pci.h b/include/linux/pci.h
> index 73178a2fcee0..55371cb827ad 100644
> --- a/include/linux/pci.h
> +++ b/include/linux/pci.h
> @@ -670,7 +670,7 @@ int raw_pci_read(unsigned int domain, unsigned int bus, unsigned int devfn,
>  int raw_pci_write(unsigned int domain, unsigned int bus, unsigned int devfn,
>  		  int reg, int len, u32 val);
>  
> -#ifdef CONFIG_PCI_BUS_ADDR_T_64BIT
> +#ifdef CONFIG_ARCH_DMA_ADDR_T_64BIT
>  typedef u64 pci_bus_addr_t;
>  #else
>  typedef u32 pci_bus_addr_t;
> -- 
> 2.17.0
> 

[PATCH 10/12] arm: don't build swiotlb by default

[Christoph Hellwig]

swiotlb is only used as a library of helper for xen-swiotlb if Xen support
is enabled on arm, so don't build it by default.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/arm/Kconfig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index aa1c187d756d..90b81a3a28a7 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1774,7 +1774,7 @@ config SECCOMP
 	  defined by each seccomp mode.
 
 config SWIOTLB
-	def_bool y
+	bool
 
 config PARAVIRT
 	bool "Enable paravirtualization code"
@@ -1807,6 +1807,7 @@ config XEN
 	depends on MMU
 	select ARCH_DMA_ADDR_T_64BIT
 	select ARM_PSCI
+	select SWIOTLB
 	select SWIOTLB_XEN
 	select PARAVIRT
 	help
-- 
2.17.0

[PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Christoph Hellwig]

This way we have one central definition of it, and user can select it as
needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
indicate the architecture supports swiotlb at all, so that we can still
make the usage optional for a few architectures that want this feature
to be user selectable.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/arm/Kconfig                |  4 +---
 arch/arm64/Kconfig              |  5 ++---
 arch/ia64/Kconfig               |  9 +--------
 arch/mips/Kconfig               |  3 +++
 arch/mips/cavium-octeon/Kconfig |  5 -----
 arch/mips/loongson64/Kconfig    |  8 --------
 arch/powerpc/Kconfig            |  9 ---------
 arch/unicore32/mm/Kconfig       |  5 -----
 arch/x86/Kconfig                | 14 +++-----------
 lib/Kconfig                     | 15 +++++++++++++++
 10 files changed, 25 insertions(+), 52 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 90b81a3a28a7..f91f69174630 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -106,6 +106,7 @@ config ARM
 	select REFCOUNT_FULL
 	select RTC_LIB
 	select SYS_SUPPORTS_APM_EMULATION
+	select ARCH_HAS_SWIOTLB
 	# Above selects are sorted alphabetically; please add new ones
 	# according to that.  Thanks.
 	help
@@ -1773,9 +1774,6 @@ config SECCOMP
 	  and the task is only allowed to execute a few safe syscalls
 	  defined by each seccomp mode.
 
-config SWIOTLB
-	bool
-
 config PARAVIRT
 	bool "Enable paravirtualization code"
 	help
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4d924eb32e7f..056bc7365adf 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -21,6 +21,7 @@ config ARM64
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_STRICT_MODULE_RWX
+	select ARCH_HAS_SWIOTLB
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK if !PREEMPT
@@ -144,6 +145,7 @@ config ARM64
 	select POWER_SUPPLY
 	select REFCOUNT_FULL
 	select SPARSE_IRQ
+	select SWIOTLB
 	select SYSCTL_EXCEPTION_TRACE
 	select THREAD_INFO_IN_TASK
 	help
@@ -239,9 +241,6 @@ config HAVE_GENERIC_GUP
 config SMP
 	def_bool y
 
-config SWIOTLB
-	def_bool y
-
 config KERNEL_MODE_NEON
 	def_bool y
 
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 685d557eea48..d396230913e6 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -56,6 +56,7 @@ config IA64
 	select HAVE_ARCH_AUDITSYSCALL
 	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
+	select ARCH_HAS_SWIOTLB
 	default y
 	help
 	  The Itanium Processor Family is Intel's 64-bit successor to
@@ -80,9 +81,6 @@ config MMU
 	bool
 	default y
 
-config SWIOTLB
-       bool
-
 config STACKTRACE_SUPPORT
 	def_bool y
 
@@ -139,7 +137,6 @@ config IA64_GENERIC
 	bool "generic"
 	select NUMA
 	select ACPI_NUMA
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	select PCI_MSI
 	help
@@ -160,7 +157,6 @@ config IA64_GENERIC
 
 config IA64_DIG
 	bool "DIG-compliant"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 
 config IA64_DIG_VTD
@@ -176,7 +172,6 @@ config IA64_HP_ZX1
 
 config IA64_HP_ZX1_SWIOTLB
 	bool "HP-zx1/sx1000 with software I/O TLB"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	help
 	  Build a kernel that runs on HP zx1 and sx1000 systems even when they
@@ -200,7 +195,6 @@ config IA64_SGI_UV
 	bool "SGI-UV"
 	select NUMA
 	select ACPI_NUMA
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	help
 	  Selecting this option will optimize the kernel for use on UV based
@@ -211,7 +205,6 @@ config IA64_SGI_UV
 
 config IA64_HP_SIM
 	bool "Ski-simulator"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	depends on !PM
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e10cc5c7be69..b6b4c1e154f8 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -912,6 +912,8 @@ config CAVIUM_OCTEON_SOC
 	select MIPS_NR_CPU_NR_MAP_1024
 	select BUILTIN_DTB
 	select MTD_COMPLEX_MAPPINGS
+	select ARCH_HAS_SWIOTLB
+	select SWIOTLB
 	select SYS_SUPPORTS_RELOCATABLE
 	help
 	  This option supports all of the Octeon reference boards from Cavium
@@ -1367,6 +1369,7 @@ config CPU_LOONGSON3
 	select MIPS_PGD_C0_CONTEXT
 	select MIPS_L1_CACHE_SHIFT_6
 	select GPIOLIB
+	select ARCH_HAS_SWIOTLB
 	help
 		The Loongson 3 processor implements the MIPS64R2 instruction
 		set with many extensions.
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 5d73041547a7..4984e462be30 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -67,11 +67,6 @@ config CAVIUM_OCTEON_LOCK_L2_MEMCPY
 	help
 	  Lock the kernel's implementation of memcpy() into L2.
 
-config SWIOTLB
-	def_bool y
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
-
 config OCTEON_ILM
 	tristate "Module to measure interrupt latency using Octeon CIU Timer"
 	help
diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
index 641a1477031e..c79e6a565572 100644
--- a/arch/mips/loongson64/Kconfig
+++ b/arch/mips/loongson64/Kconfig
@@ -130,14 +130,6 @@ config LOONGSON_UART_BASE
 	default y
 	depends on EARLY_PRINTK || SERIAL_8250
 
-config SWIOTLB
-	bool "Soft IOMMU Support for All-Memory DMA"
-	default y
-	depends on CPU_LOONGSON3
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
-	select NEED_DMA_MAP_STATE
-
 config PHYS48_TO_HT40
 	bool
 	default y if CPU_LOONGSON3
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index b85a537421b8..beb28153fcb2 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -474,15 +474,6 @@ config MPROFILE_KERNEL
 	depends on PPC64 && CPU_LITTLE_ENDIAN
 	def_bool !DISABLE_MPROFILE_KERNEL
 
-config SWIOTLB
-	bool "SWIOTLB support"
-	default n
-	---help---
-	  Support for IO bounce buffering for systems without an IOMMU.
-	  This allows us to DMA to the full physical address space on
-	  platforms where the size of a physical address is larger
-	  than the bus address.  Not all platforms support this.
-
 config HOTPLUG_CPU
 	bool "Support for enabling/disabling CPUs"
 	depends on SMP && (PPC_PSERIES || \
diff --git a/arch/unicore32/mm/Kconfig b/arch/unicore32/mm/Kconfig
index 1d9fed0ada71..82759b6aba67 100644
--- a/arch/unicore32/mm/Kconfig
+++ b/arch/unicore32/mm/Kconfig
@@ -39,8 +39,3 @@ config CPU_TLB_SINGLE_ENTRY_DISABLE
 	default y
 	help
 	  Say Y here to disable the TLB single entry operations.
-
-config SWIOTLB
-	def_bool y
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index a95eb9ef3311..063bef5f830f 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -24,6 +24,7 @@ config X86_64
 	depends on 64BIT
 	# Options that are inherently 64-bit kernel only:
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
+	select ARCH_HAS_SWIOTLB
 	select ARCH_SUPPORTS_INT128
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_SOFT_DIRTY
@@ -676,6 +677,7 @@ config STA2X11
 	bool "STA2X11 Companion Chip Support"
 	depends on X86_32_NON_STANDARD && PCI
 	select ARCH_HAS_PHYS_TO_DMA
+	select ARCH_HAS_SWIOTLB
 	select X86_DEV_DMA_OPS
 	select X86_DMA_REMAP
 	select SWIOTLB
@@ -915,17 +917,6 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 	  If unsure, say Y.
 
-# need this always selected by IOMMU for the VIA workaround
-config SWIOTLB
-	def_bool y if X86_64
-	select NEED_DMA_MAP_STATE
-	---help---
-	  Support for software bounce buffers used on x86-64 systems
-	  which don't have a hardware IOMMU. Using this PCI devices
-	  which can only access 32-bits of memory can be used on systems
-	  with more than 3 GB of memory.
-	  If unsure, say Y.
-
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 	depends on X86_64 && SMP && DEBUG_KERNEL
@@ -1447,6 +1438,7 @@ config HIGHMEM
 config X86_PAE
 	bool "PAE (Physical Address Extension) Support"
 	depends on X86_32 && !HIGHMEM4G
+	select ARCH_HAS_SWIOTLB
 	select PHYS_ADDR_T_64BIT
 	select SWIOTLB
 	---help---
diff --git a/lib/Kconfig b/lib/Kconfig
index 1f12faf03819..01a37920949c 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -451,6 +451,21 @@ config DMA_VIRT_OPS
 	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
 	default n
 
+config ARCH_HAS_SWIOTLB
+	bool
+
+config SWIOTLB
+	bool "SWIOTLB support"
+	default ARCH_HAS_SWIOTLB
+	select DMA_DIRECT_OPS
+	select NEED_DMA_MAP_STATE
+	select NEED_SG_DMA_LENGTH
+	---help---
+	  Support for IO bounce buffering for systems without an IOMMU.
+	  This allows us to DMA to the full physical address space on
+	  platforms where the size of a physical address is larger
+	  than the bus address.  If unsure, say Y.
+
 config CHECK_SIGNATURE
 	bool
 
-- 
2.17.0

Re: [PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Anshuman Khandual]

On 04/15/2018 08:29 PM, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> indicate the architecture supports swiotlb at all, so that we can still
> make the usage optional for a few architectures that want this feature
> to be user selectable.
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>


snip

> +
> +config SWIOTLB
> +	bool "SWIOTLB support"
> +	default ARCH_HAS_SWIOTLB
> +	select DMA_DIRECT_OPS
> +	select NEED_DMA_MAP_STATE
> +	select NEED_SG_DMA_LENGTH
> +	---help---
> +	  Support for IO bounce buffering for systems without an IOMMU.
> +	  This allows us to DMA to the full physical address space on
> +	  platforms where the size of a physical address is larger
> +	  than the bus address.  If unsure, say Y.
> +
>  config CHECK_SIGNATURE
>  	bool

Pulling DMA_DIRECT_OPS config option by default when SWIOTLB is enabled
makes sense. This option was also needed to be enabled separately even
to use swiotlb_dma_ops.

[PATCH 12/12] swiotlb: remove the CONFIG_DMA_DIRECT_OPS ifdefs

[Christoph Hellwig]

swiotlb now selects the DMA_DIRECT_OPS config symbol, so this will
always be true.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 lib/swiotlb.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 47aeb04c1997..07f260319b82 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -692,7 +692,6 @@ void swiotlb_tbl_sync_single(struct device *hwdev, phys_addr_t tlb_addr,
 	}
 }
 
-#ifdef CONFIG_DMA_DIRECT_OPS
 static inline bool dma_coherent_ok(struct device *dev, dma_addr_t addr,
 		size_t size)
 {
@@ -764,7 +763,6 @@ static bool swiotlb_free_buffer(struct device *dev, size_t size,
 				 DMA_ATTR_SKIP_CPU_SYNC);
 	return true;
 }
-#endif
 
 static void
 swiotlb_full(struct device *dev, size_t size, enum dma_data_direction dir,
@@ -1045,7 +1043,6 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask)
 	return __phys_to_dma(hwdev, io_tlb_end - 1) <= mask;
 }
 
-#ifdef CONFIG_DMA_DIRECT_OPS
 void *swiotlb_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle,
 		gfp_t gfp, unsigned long attrs)
 {
@@ -1089,4 +1086,3 @@ const struct dma_map_ops swiotlb_dma_ops = {
 	.unmap_page		= swiotlb_unmap_page,
 	.dma_supported		= swiotlb_dma_supported,
 };
-#endif /* CONFIG_DMA_DIRECT_OPS */
-- 
2.17.0

centralize SWIOTLB config symbol and misc other cleanups V2

[Christoph Hellwig]

Hi all,

this seris aims for a single defintion of the Kconfig symbol.  To get
there various cleanups, mostly about config symbols are included as well.

Chances since V2 are a fixed s/Reviewed/Signed-Off/ for me, and a few
reviewed-by tags.  I'd like to start merging this into the dma-mapping
tree rather sooner than later given that quite a bit of material for
this series depends on it.

[PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Christoph Hellwig]

This way we have one central definition of it, and user can select it as
needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
indicate the architecture supports swiotlb at all, so that we can still
make the usage optional for a few architectures that want this feature
to be user selectable.

Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
---
 arch/arm/Kconfig                |  4 +---
 arch/arm64/Kconfig              |  5 ++---
 arch/ia64/Kconfig               |  9 +--------
 arch/mips/Kconfig               |  3 +++
 arch/mips/cavium-octeon/Kconfig |  5 -----
 arch/mips/loongson64/Kconfig    |  8 --------
 arch/powerpc/Kconfig            |  9 ---------
 arch/unicore32/mm/Kconfig       |  5 -----
 arch/x86/Kconfig                | 14 +++-----------
 lib/Kconfig                     | 15 +++++++++++++++
 10 files changed, 25 insertions(+), 52 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 90b81a3a28a7..f91f69174630 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -106,6 +106,7 @@ config ARM
 	select REFCOUNT_FULL
 	select RTC_LIB
 	select SYS_SUPPORTS_APM_EMULATION
+	select ARCH_HAS_SWIOTLB
 	# Above selects are sorted alphabetically; please add new ones
 	# according to that.  Thanks.
 	help
@@ -1773,9 +1774,6 @@ config SECCOMP
 	  and the task is only allowed to execute a few safe syscalls
 	  defined by each seccomp mode.
 
-config SWIOTLB
-	bool
-
 config PARAVIRT
 	bool "Enable paravirtualization code"
 	help
diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
index 4d924eb32e7f..056bc7365adf 100644
--- a/arch/arm64/Kconfig
+++ b/arch/arm64/Kconfig
@@ -21,6 +21,7 @@ config ARM64
 	select ARCH_HAS_SG_CHAIN
 	select ARCH_HAS_STRICT_KERNEL_RWX
 	select ARCH_HAS_STRICT_MODULE_RWX
+	select ARCH_HAS_SWIOTLB
 	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
 	select ARCH_HAVE_NMI_SAFE_CMPXCHG
 	select ARCH_INLINE_READ_LOCK if !PREEMPT
@@ -144,6 +145,7 @@ config ARM64
 	select POWER_SUPPLY
 	select REFCOUNT_FULL
 	select SPARSE_IRQ
+	select SWIOTLB
 	select SYSCTL_EXCEPTION_TRACE
 	select THREAD_INFO_IN_TASK
 	help
@@ -239,9 +241,6 @@ config HAVE_GENERIC_GUP
 config SMP
 	def_bool y
 
-config SWIOTLB
-	def_bool y
-
 config KERNEL_MODE_NEON
 	def_bool y
 
diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
index 685d557eea48..d396230913e6 100644
--- a/arch/ia64/Kconfig
+++ b/arch/ia64/Kconfig
@@ -56,6 +56,7 @@ config IA64
 	select HAVE_ARCH_AUDITSYSCALL
 	select NEED_DMA_MAP_STATE
 	select NEED_SG_DMA_LENGTH
+	select ARCH_HAS_SWIOTLB
 	default y
 	help
 	  The Itanium Processor Family is Intel's 64-bit successor to
@@ -80,9 +81,6 @@ config MMU
 	bool
 	default y
 
-config SWIOTLB
-       bool
-
 config STACKTRACE_SUPPORT
 	def_bool y
 
@@ -139,7 +137,6 @@ config IA64_GENERIC
 	bool "generic"
 	select NUMA
 	select ACPI_NUMA
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	select PCI_MSI
 	help
@@ -160,7 +157,6 @@ config IA64_GENERIC
 
 config IA64_DIG
 	bool "DIG-compliant"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 
 config IA64_DIG_VTD
@@ -176,7 +172,6 @@ config IA64_HP_ZX1
 
 config IA64_HP_ZX1_SWIOTLB
 	bool "HP-zx1/sx1000 with software I/O TLB"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	help
 	  Build a kernel that runs on HP zx1 and sx1000 systems even when they
@@ -200,7 +195,6 @@ config IA64_SGI_UV
 	bool "SGI-UV"
 	select NUMA
 	select ACPI_NUMA
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	help
 	  Selecting this option will optimize the kernel for use on UV based
@@ -211,7 +205,6 @@ config IA64_SGI_UV
 
 config IA64_HP_SIM
 	bool "Ski-simulator"
-	select DMA_DIRECT_OPS
 	select SWIOTLB
 	depends on !PM
 
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index e10cc5c7be69..b6b4c1e154f8 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -912,6 +912,8 @@ config CAVIUM_OCTEON_SOC
 	select MIPS_NR_CPU_NR_MAP_1024
 	select BUILTIN_DTB
 	select MTD_COMPLEX_MAPPINGS
+	select ARCH_HAS_SWIOTLB
+	select SWIOTLB
 	select SYS_SUPPORTS_RELOCATABLE
 	help
 	  This option supports all of the Octeon reference boards from Cavium
@@ -1367,6 +1369,7 @@ config CPU_LOONGSON3
 	select MIPS_PGD_C0_CONTEXT
 	select MIPS_L1_CACHE_SHIFT_6
 	select GPIOLIB
+	select ARCH_HAS_SWIOTLB
 	help
 		The Loongson 3 processor implements the MIPS64R2 instruction
 		set with many extensions.
diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
index 5d73041547a7..4984e462be30 100644
--- a/arch/mips/cavium-octeon/Kconfig
+++ b/arch/mips/cavium-octeon/Kconfig
@@ -67,11 +67,6 @@ config CAVIUM_OCTEON_LOCK_L2_MEMCPY
 	help
 	  Lock the kernel's implementation of memcpy() into L2.
 
-config SWIOTLB
-	def_bool y
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
-
 config OCTEON_ILM
 	tristate "Module to measure interrupt latency using Octeon CIU Timer"
 	help
diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
index 641a1477031e..c79e6a565572 100644
--- a/arch/mips/loongson64/Kconfig
+++ b/arch/mips/loongson64/Kconfig
@@ -130,14 +130,6 @@ config LOONGSON_UART_BASE
 	default y
 	depends on EARLY_PRINTK || SERIAL_8250
 
-config SWIOTLB
-	bool "Soft IOMMU Support for All-Memory DMA"
-	default y
-	depends on CPU_LOONGSON3
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
-	select NEED_DMA_MAP_STATE
-
 config PHYS48_TO_HT40
 	bool
 	default y if CPU_LOONGSON3
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a4b2ac7c3d2e..1887f8f86a77 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -474,15 +474,6 @@ config MPROFILE_KERNEL
 	depends on PPC64 && CPU_LITTLE_ENDIAN
 	def_bool !DISABLE_MPROFILE_KERNEL
 
-config SWIOTLB
-	bool "SWIOTLB support"
-	default n
-	---help---
-	  Support for IO bounce buffering for systems without an IOMMU.
-	  This allows us to DMA to the full physical address space on
-	  platforms where the size of a physical address is larger
-	  than the bus address.  Not all platforms support this.
-
 config HOTPLUG_CPU
 	bool "Support for enabling/disabling CPUs"
 	depends on SMP && (PPC_PSERIES || \
diff --git a/arch/unicore32/mm/Kconfig b/arch/unicore32/mm/Kconfig
index 1d9fed0ada71..82759b6aba67 100644
--- a/arch/unicore32/mm/Kconfig
+++ b/arch/unicore32/mm/Kconfig
@@ -39,8 +39,3 @@ config CPU_TLB_SINGLE_ENTRY_DISABLE
 	default y
 	help
 	  Say Y here to disable the TLB single entry operations.
-
-config SWIOTLB
-	def_bool y
-	select DMA_DIRECT_OPS
-	select NEED_SG_DMA_LENGTH
diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
index 07b031f99eb1..7a5fec800992 100644
--- a/arch/x86/Kconfig
+++ b/arch/x86/Kconfig
@@ -24,6 +24,7 @@ config X86_64
 	depends on 64BIT
 	# Options that are inherently 64-bit kernel only:
 	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
+	select ARCH_HAS_SWIOTLB
 	select ARCH_SUPPORTS_INT128
 	select ARCH_USE_CMPXCHG_LOCKREF
 	select HAVE_ARCH_SOFT_DIRTY
@@ -677,6 +678,7 @@ config STA2X11
 	bool "STA2X11 Companion Chip Support"
 	depends on X86_32_NON_STANDARD && PCI
 	select ARCH_HAS_PHYS_TO_DMA
+	select ARCH_HAS_SWIOTLB
 	select X86_DEV_DMA_OPS
 	select X86_DMA_REMAP
 	select SWIOTLB
@@ -916,17 +918,6 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
 	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
 	  If unsure, say Y.
 
-# need this always selected by IOMMU for the VIA workaround
-config SWIOTLB
-	def_bool y if X86_64
-	select NEED_DMA_MAP_STATE
-	---help---
-	  Support for software bounce buffers used on x86-64 systems
-	  which don't have a hardware IOMMU. Using this PCI devices
-	  which can only access 32-bits of memory can be used on systems
-	  with more than 3 GB of memory.
-	  If unsure, say Y.
-
 config MAXSMP
 	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
 	depends on X86_64 && SMP && DEBUG_KERNEL
@@ -1448,6 +1439,7 @@ config HIGHMEM
 config X86_PAE
 	bool "PAE (Physical Address Extension) Support"
 	depends on X86_32 && !HIGHMEM4G
+	select ARCH_HAS_SWIOTLB
 	select PHYS_ADDR_T_64BIT
 	select SWIOTLB
 	---help---
diff --git a/lib/Kconfig b/lib/Kconfig
index 1f12faf03819..01a37920949c 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -451,6 +451,21 @@ config DMA_VIRT_OPS
 	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
 	default n
 
+config ARCH_HAS_SWIOTLB
+	bool
+
+config SWIOTLB
+	bool "SWIOTLB support"
+	default ARCH_HAS_SWIOTLB
+	select DMA_DIRECT_OPS
+	select NEED_DMA_MAP_STATE
+	select NEED_SG_DMA_LENGTH
+	---help---
+	  Support for IO bounce buffering for systems without an IOMMU.
+	  This allows us to DMA to the full physical address space on
+	  platforms where the size of a physical address is larger
+	  than the bus address.  If unsure, say Y.
+
 config CHECK_SIGNATURE
 	bool
 
-- 
2.17.0

Re: [PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Konrad Rzeszutek Wilk]

On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> indicate the architecture supports swiotlb at all, so that we can still
> make the usage optional for a few architectures that want this feature
> to be user selectable.

If I follow this select business this will enable it on ARM and x86 by default.

As such:
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk-QHcLZuEGTsvQT0dZR+AlfA@public.gmane.org>

Thank you!
> 
> Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> ---
>  arch/arm/Kconfig                |  4 +---
>  arch/arm64/Kconfig              |  5 ++---
>  arch/ia64/Kconfig               |  9 +--------
>  arch/mips/Kconfig               |  3 +++
>  arch/mips/cavium-octeon/Kconfig |  5 -----
>  arch/mips/loongson64/Kconfig    |  8 --------
>  arch/powerpc/Kconfig            |  9 ---------
>  arch/unicore32/mm/Kconfig       |  5 -----
>  arch/x86/Kconfig                | 14 +++-----------
>  lib/Kconfig                     | 15 +++++++++++++++
>  10 files changed, 25 insertions(+), 52 deletions(-)
> 
> diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
> index 90b81a3a28a7..f91f69174630 100644
> --- a/arch/arm/Kconfig
> +++ b/arch/arm/Kconfig
> @@ -106,6 +106,7 @@ config ARM
>  	select REFCOUNT_FULL
>  	select RTC_LIB
>  	select SYS_SUPPORTS_APM_EMULATION
> +	select ARCH_HAS_SWIOTLB
>  	# Above selects are sorted alphabetically; please add new ones
>  	# according to that.  Thanks.
>  	help
> @@ -1773,9 +1774,6 @@ config SECCOMP
>  	  and the task is only allowed to execute a few safe syscalls
>  	  defined by each seccomp mode.
>  
> -config SWIOTLB
> -	bool
> -
>  config PARAVIRT
>  	bool "Enable paravirtualization code"
>  	help
> diff --git a/arch/arm64/Kconfig b/arch/arm64/Kconfig
> index 4d924eb32e7f..056bc7365adf 100644
> --- a/arch/arm64/Kconfig
> +++ b/arch/arm64/Kconfig
> @@ -21,6 +21,7 @@ config ARM64
>  	select ARCH_HAS_SG_CHAIN
>  	select ARCH_HAS_STRICT_KERNEL_RWX
>  	select ARCH_HAS_STRICT_MODULE_RWX
> +	select ARCH_HAS_SWIOTLB
>  	select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST
>  	select ARCH_HAVE_NMI_SAFE_CMPXCHG
>  	select ARCH_INLINE_READ_LOCK if !PREEMPT
> @@ -144,6 +145,7 @@ config ARM64
>  	select POWER_SUPPLY
>  	select REFCOUNT_FULL
>  	select SPARSE_IRQ
> +	select SWIOTLB
>  	select SYSCTL_EXCEPTION_TRACE
>  	select THREAD_INFO_IN_TASK
>  	help
> @@ -239,9 +241,6 @@ config HAVE_GENERIC_GUP
>  config SMP
>  	def_bool y
>  
> -config SWIOTLB
> -	def_bool y
> -
>  config KERNEL_MODE_NEON
>  	def_bool y
>  
> diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig
> index 685d557eea48..d396230913e6 100644
> --- a/arch/ia64/Kconfig
> +++ b/arch/ia64/Kconfig
> @@ -56,6 +56,7 @@ config IA64
>  	select HAVE_ARCH_AUDITSYSCALL
>  	select NEED_DMA_MAP_STATE
>  	select NEED_SG_DMA_LENGTH
> +	select ARCH_HAS_SWIOTLB
>  	default y
>  	help
>  	  The Itanium Processor Family is Intel's 64-bit successor to
> @@ -80,9 +81,6 @@ config MMU
>  	bool
>  	default y
>  
> -config SWIOTLB
> -       bool
> -
>  config STACKTRACE_SUPPORT
>  	def_bool y
>  
> @@ -139,7 +137,6 @@ config IA64_GENERIC
>  	bool "generic"
>  	select NUMA
>  	select ACPI_NUMA
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	select PCI_MSI
>  	help
> @@ -160,7 +157,6 @@ config IA64_GENERIC
>  
>  config IA64_DIG
>  	bool "DIG-compliant"
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  
>  config IA64_DIG_VTD
> @@ -176,7 +172,6 @@ config IA64_HP_ZX1
>  
>  config IA64_HP_ZX1_SWIOTLB
>  	bool "HP-zx1/sx1000 with software I/O TLB"
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	help
>  	  Build a kernel that runs on HP zx1 and sx1000 systems even when they
> @@ -200,7 +195,6 @@ config IA64_SGI_UV
>  	bool "SGI-UV"
>  	select NUMA
>  	select ACPI_NUMA
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	help
>  	  Selecting this option will optimize the kernel for use on UV based
> @@ -211,7 +205,6 @@ config IA64_SGI_UV
>  
>  config IA64_HP_SIM
>  	bool "Ski-simulator"
> -	select DMA_DIRECT_OPS
>  	select SWIOTLB
>  	depends on !PM
>  
> diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
> index e10cc5c7be69..b6b4c1e154f8 100644
> --- a/arch/mips/Kconfig
> +++ b/arch/mips/Kconfig
> @@ -912,6 +912,8 @@ config CAVIUM_OCTEON_SOC
>  	select MIPS_NR_CPU_NR_MAP_1024
>  	select BUILTIN_DTB
>  	select MTD_COMPLEX_MAPPINGS
> +	select ARCH_HAS_SWIOTLB
> +	select SWIOTLB
>  	select SYS_SUPPORTS_RELOCATABLE
>  	help
>  	  This option supports all of the Octeon reference boards from Cavium
> @@ -1367,6 +1369,7 @@ config CPU_LOONGSON3
>  	select MIPS_PGD_C0_CONTEXT
>  	select MIPS_L1_CACHE_SHIFT_6
>  	select GPIOLIB
> +	select ARCH_HAS_SWIOTLB
>  	help
>  		The Loongson 3 processor implements the MIPS64R2 instruction
>  		set with many extensions.
> diff --git a/arch/mips/cavium-octeon/Kconfig b/arch/mips/cavium-octeon/Kconfig
> index 5d73041547a7..4984e462be30 100644
> --- a/arch/mips/cavium-octeon/Kconfig
> +++ b/arch/mips/cavium-octeon/Kconfig
> @@ -67,11 +67,6 @@ config CAVIUM_OCTEON_LOCK_L2_MEMCPY
>  	help
>  	  Lock the kernel's implementation of memcpy() into L2.
>  
> -config SWIOTLB
> -	def_bool y
> -	select DMA_DIRECT_OPS
> -	select NEED_SG_DMA_LENGTH
> -
>  config OCTEON_ILM
>  	tristate "Module to measure interrupt latency using Octeon CIU Timer"
>  	help
> diff --git a/arch/mips/loongson64/Kconfig b/arch/mips/loongson64/Kconfig
> index 641a1477031e..c79e6a565572 100644
> --- a/arch/mips/loongson64/Kconfig
> +++ b/arch/mips/loongson64/Kconfig
> @@ -130,14 +130,6 @@ config LOONGSON_UART_BASE
>  	default y
>  	depends on EARLY_PRINTK || SERIAL_8250
>  
> -config SWIOTLB
> -	bool "Soft IOMMU Support for All-Memory DMA"
> -	default y
> -	depends on CPU_LOONGSON3
> -	select DMA_DIRECT_OPS
> -	select NEED_SG_DMA_LENGTH
> -	select NEED_DMA_MAP_STATE
> -
>  config PHYS48_TO_HT40
>  	bool
>  	default y if CPU_LOONGSON3
> diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
> index a4b2ac7c3d2e..1887f8f86a77 100644
> --- a/arch/powerpc/Kconfig
> +++ b/arch/powerpc/Kconfig
> @@ -474,15 +474,6 @@ config MPROFILE_KERNEL
>  	depends on PPC64 && CPU_LITTLE_ENDIAN
>  	def_bool !DISABLE_MPROFILE_KERNEL
>  
> -config SWIOTLB
> -	bool "SWIOTLB support"
> -	default n
> -	---help---
> -	  Support for IO bounce buffering for systems without an IOMMU.
> -	  This allows us to DMA to the full physical address space on
> -	  platforms where the size of a physical address is larger
> -	  than the bus address.  Not all platforms support this.
> -
>  config HOTPLUG_CPU
>  	bool "Support for enabling/disabling CPUs"
>  	depends on SMP && (PPC_PSERIES || \
> diff --git a/arch/unicore32/mm/Kconfig b/arch/unicore32/mm/Kconfig
> index 1d9fed0ada71..82759b6aba67 100644
> --- a/arch/unicore32/mm/Kconfig
> +++ b/arch/unicore32/mm/Kconfig
> @@ -39,8 +39,3 @@ config CPU_TLB_SINGLE_ENTRY_DISABLE
>  	default y
>  	help
>  	  Say Y here to disable the TLB single entry operations.
> -
> -config SWIOTLB
> -	def_bool y
> -	select DMA_DIRECT_OPS
> -	select NEED_SG_DMA_LENGTH
> diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig
> index 07b031f99eb1..7a5fec800992 100644
> --- a/arch/x86/Kconfig
> +++ b/arch/x86/Kconfig
> @@ -24,6 +24,7 @@ config X86_64
>  	depends on 64BIT
>  	# Options that are inherently 64-bit kernel only:
>  	select ARCH_HAS_GIGANTIC_PAGE if (MEMORY_ISOLATION && COMPACTION) || CMA
> +	select ARCH_HAS_SWIOTLB
>  	select ARCH_SUPPORTS_INT128
>  	select ARCH_USE_CMPXCHG_LOCKREF
>  	select HAVE_ARCH_SOFT_DIRTY
> @@ -677,6 +678,7 @@ config STA2X11
>  	bool "STA2X11 Companion Chip Support"
>  	depends on X86_32_NON_STANDARD && PCI
>  	select ARCH_HAS_PHYS_TO_DMA
> +	select ARCH_HAS_SWIOTLB
>  	select X86_DEV_DMA_OPS
>  	select X86_DMA_REMAP
>  	select SWIOTLB
> @@ -916,17 +918,6 @@ config CALGARY_IOMMU_ENABLED_BY_DEFAULT
>  	  Calgary anyway, pass 'iommu=calgary' on the kernel command line.
>  	  If unsure, say Y.
>  
> -# need this always selected by IOMMU for the VIA workaround
> -config SWIOTLB
> -	def_bool y if X86_64
> -	select NEED_DMA_MAP_STATE
> -	---help---
> -	  Support for software bounce buffers used on x86-64 systems
> -	  which don't have a hardware IOMMU. Using this PCI devices
> -	  which can only access 32-bits of memory can be used on systems
> -	  with more than 3 GB of memory.
> -	  If unsure, say Y.
> -
>  config MAXSMP
>  	bool "Enable Maximum number of SMP Processors and NUMA Nodes"
>  	depends on X86_64 && SMP && DEBUG_KERNEL
> @@ -1448,6 +1439,7 @@ config HIGHMEM
>  config X86_PAE
>  	bool "PAE (Physical Address Extension) Support"
>  	depends on X86_32 && !HIGHMEM4G
> +	select ARCH_HAS_SWIOTLB
>  	select PHYS_ADDR_T_64BIT
>  	select SWIOTLB
>  	---help---
> diff --git a/lib/Kconfig b/lib/Kconfig
> index 1f12faf03819..01a37920949c 100644
> --- a/lib/Kconfig
> +++ b/lib/Kconfig
> @@ -451,6 +451,21 @@ config DMA_VIRT_OPS
>  	depends on HAS_DMA && (!64BIT || ARCH_DMA_ADDR_T_64BIT)
>  	default n
>  
> +config ARCH_HAS_SWIOTLB
> +	bool
> +
> +config SWIOTLB
> +	bool "SWIOTLB support"
> +	default ARCH_HAS_SWIOTLB
> +	select DMA_DIRECT_OPS
> +	select NEED_DMA_MAP_STATE
> +	select NEED_SG_DMA_LENGTH
> +	---help---
> +	  Support for IO bounce buffering for systems without an IOMMU.
> +	  This allows us to DMA to the full physical address space on
> +	  platforms where the size of a physical address is larger
> +	  than the bus address.  If unsure, say Y.
> +
>  config CHECK_SIGNATURE
>  	bool
>  
> -- 
> 2.17.0
> 

Re: [PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Russell King - ARM Linux]

On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> This way we have one central definition of it, and user can select it as
> needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> indicate the architecture supports swiotlb at all, so that we can still
> make the usage optional for a few architectures that want this feature
> to be user selectable.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>

Hmm, this looks like we end up with NEED_SG_DMA_LENGTH=y on ARM by
default, which probably isn't a good idea - ARM pre-dates the dma_length
parameter in scatterlists, and I don't think all code is guaranteed to
do the right thing if this is enabled.

For example, arch/arm/mach-rpc/dma.c doesn't use the dma_length
member of struct scatterlist.

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Re: [PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Christoph Hellwig]

On Tue, Apr 24, 2018 at 12:52:05AM +0100, Russell King - ARM Linux wrote:
> On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> > This way we have one central definition of it, and user can select it as
> > needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> > indicate the architecture supports swiotlb at all, so that we can still
> > make the usage optional for a few architectures that want this feature
> > to be user selectable.
> > 
> > Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> 
> Hmm, this looks like we end up with NEED_SG_DMA_LENGTH=y on ARM by
> default, which probably isn't a good idea - ARM pre-dates the dma_length
> parameter in scatterlists, and I don't think all code is guaranteed to
> do the right thing if this is enabled.

We shouldn't end up with NEED_SG_DMA_LENGTH=y on ARM by default.
It is only select by ARM_DMA_USE_IOMMU before the patch, and it will
now also be selected by SWIOTLB, which for arm is never used or seleted
directly by anything but xen-swiotlb.

Then again looking at the series there shouldn't be any need to
even select NEED_SG_DMA_LENGTH for swiotlb, as we'll never merge segments,
so I'll fix that up.

Re: [PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Russell King - ARM Linux]

On Tue, Apr 24, 2018 at 08:55:49AM +0200, Christoph Hellwig wrote:
> On Tue, Apr 24, 2018 at 12:52:05AM +0100, Russell King - ARM Linux wrote:
> > On Mon, Apr 23, 2018 at 07:04:18PM +0200, Christoph Hellwig wrote:
> > > This way we have one central definition of it, and user can select it as
> > > needed.  Note that we also add a second ARCH_HAS_SWIOTLB symbol to
> > > indicate the architecture supports swiotlb at all, so that we can still
> > > make the usage optional for a few architectures that want this feature
> > > to be user selectable.
> > > 
> > > Signed-off-by: Christoph Hellwig <hch-jcswGhMUV9g@public.gmane.org>
> > 
> > Hmm, this looks like we end up with NEED_SG_DMA_LENGTH=y on ARM by
> > default, which probably isn't a good idea - ARM pre-dates the dma_length
> > parameter in scatterlists, and I don't think all code is guaranteed to
> > do the right thing if this is enabled.
> 
> We shouldn't end up with NEED_SG_DMA_LENGTH=y on ARM by default.

Your patch as sent would end up with:

ARM selects ARCH_HAS_SWIOTLB
SWIOTLB is defaulted to ARCH_HAS_SWIOTLB
SWIOTLB selects NEED_SG_DMA_LENGTH

due to:

@@ -106,6 +106,7 @@ config ARM
        select REFCOUNT_FULL
        select RTC_LIB
        select SYS_SUPPORTS_APM_EMULATION
+       select ARCH_HAS_SWIOTLB

and:

+config SWIOTLB
+       bool "SWIOTLB support"
+       default ARCH_HAS_SWIOTLB
+       select NEED_SG_DMA_LENGTH

Therefore, the default state for SWIOTLB and hence NEED_SG_DMA_LENGTH
becomes 'y' on ARM, and any defconfig file that does not mention SWIOTLB
explicitly ends up with both these enabled.

> It is only select by ARM_DMA_USE_IOMMU before the patch, and it will
> now also be selected by SWIOTLB, which for arm is never used or seleted
> directly by anything but xen-swiotlb.

See above.

> Then again looking at the series there shouldn't be any need to
> even select NEED_SG_DMA_LENGTH for swiotlb, as we'll never merge segments,
> so I'll fix that up.

That would help to avoid any regressions along the lines I've spotted
by review.

It does look a bit weird though - patch 10 arranged stuff so that we
didn't end up with SWIOTLB always enabled, but this patch reintroduces
that with the allowance that the user can disable if so desired.

-- 
RMK's Patch system: http://www.armlinux.org.uk/developer/patches/
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Re: [PATCH 11/12] swiotlb: move the SWIOTLB config symbol to lib/Kconfig

[Christoph Hellwig]

On Tue, Apr 24, 2018 at 08:47:27AM +0100, Russell King - ARM Linux wrote:
> Therefore, the default state for SWIOTLB and hence NEED_SG_DMA_LENGTH
> becomes 'y' on ARM, and any defconfig file that does not mention SWIOTLB
> explicitly ends up with both these enabled.

Indeed, sorry.

> It does look a bit weird though - patch 10 arranged stuff so that we
> didn't end up with SWIOTLB always enabled, but this patch reintroduces
> that with the allowance that the user can disable if so desired.

I am not very happy with that patch, but I have a hard time coming
up with something saner.

Bascially x86_64 and mips/loongson default to SWIOTLB=y but allow to
deselect it, powerpc has it optional without any real dependency
and defaults to n and everyone just selects it otherwise.

I suspect the right thing is to just have it always one for x86_64
and loongson and have a ppc-specific option to enable it on powerpc
so that we can always use select statements.  I'll do that for the
next round.