[PATCH 00/11] swiotlb: Introduce architecture-specific APIs to replace __weak functions (v2)

[PATCH 00/11] swiotlb: Introduce architecture-specific APIs to replace __weak functions (v2)

[Ian Campbell]

This series:
* removes the swiotlb_(arch_)_phys_to_bus and bus_to_phys __weak
  hooks, replacing them with an architecture-specific phys_to_dma and
  dma_to_phys interface. These are used by both PowerPC and Xen to
  provide the correct mapping from physical to DMA addresses.
* removes the swiotlb_address_needs_mapping and
  swiotlb_range_needs_mapping __weak functions as well as
  is_buffer_dma_capable (which should never have been a generic
  function). All three are replaced by a single architecture-specific
  interface which meets the needs of both PowerPC and Xen.
* removes the swiotlb_virt_to_bus __weak function and replaces it with
  a CONFIG_HIGHMEM compatible version when high memory is in use. This
  is needed for 32 bit PowerPC swiotlb support.
* removes the swiotlb_alloc* __weak functions and replaces them with
  swiotlb_init_with_buffer which allows the use of a caller allocated
  buffer (and emergency pool).

I think these new interfaces are cleaner than the existing __weak
functions and isolate the swiotlb code from architecture internals.

This series does not contain any Xen or PowerPC specific changes, those
will follow in separate postings. The complete patchset has been boot
tested under Xen and native-x86 and compiled for IA64 and PowerPC

Changes since v1: 
- Fixed compile error in swiotlb_dma_to_virt highmem version. Moved
  #ifdef into function to avoid prototype drift.
- checkpatch fixes.
- missed a swiotlb_arch_range_needs_mapping in swiotlb.h and x86
  pci-swiotlb.c and swiotlb_bus_to_phys/phys_to_bus implementations in
  x86.
- additionally replaced __weak swiotlb_alloc* with
  swiotlb_init_with_buffer.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Greg KH <gregkh@suse.de>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Olaf Kirch <okir@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@ozlabs.org
Cc: x86@kernel.org

[PATCH 01/11] ia64: introduce arch-specific dma-mapping interfaces

[Ian Campbell]

dma_map_range is intended to replace usage of both
swiotlb_arch_range_needs_mapping and
swiotlb_arch_address_needs_mapping as __weak functions as well as
replacing is_buffer_dma_capable.

phys_to_dma and dma_to_phys are intended to replace
swiotlb_phys_to_bus and swiotlb_bus_to_phys.  I choose to use dma
rather than bus since a) it matches the parameters and b) avoids
confusion on x86 with the existing (but deprecated) virt_to_bus
function which relates to ISA device DMA.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Tony Luck <tony.luck@intel.com>
Cc: linux-ia64@vger.kernel.org
---
 arch/ia64/include/asm/dma-mapping.h |   23 +++++++++++++++++++++++
 1 files changed, 23 insertions(+), 0 deletions(-)

diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/asm/dma-mapping.h
index 36c0009..47d4107 100644
--- a/arch/ia64/include/asm/dma-mapping.h
+++ b/arch/ia64/include/asm/dma-mapping.h
@@ -174,4 +174,27 @@ dma_cache_sync (struct device *dev, void *vaddr, size_t size,
 
 #define dma_is_consistent(d, h)	(1)	/* all we do is coherent memory... */
 
+static inline dma_addr_t phys_to_dma(struct device *hwdev, phys_addr_t paddr)
+{
+	return paddr;
+}
+
+static inline phys_addr_t dma_to_phys(struct device *hwdev, dma_addr_t daddr)
+{
+	return daddr;
+}
+
+static inline bool dma_map_range(struct device *dev, u64 mask,
+				       phys_addr_t addr, size_t size,
+				       dma_addr_t *dma_addr_p)
+{
+	dma_addr_t dma_addr = phys_to_dma(dev, addr);
+
+	if (dma_addr + size > mask)
+		return false;
+
+	*dma_addr_p = dma_addr;
+	return true;
+}
+
 #endif /* _ASM_IA64_DMA_MAPPING_H */
-- 
1.5.6.5

[PATCH 06/11] swiotlb: use dma_to_phys and phys_to_dma

[Ian Campbell]

These new architecture-specific interfaces subsume the existing __weak
function hooks.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Olaf Kirch <okir@suse.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: x86@kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@ozlabs.org
---
 arch/x86/kernel/pci-swiotlb.c |   10 ----------
 include/linux/swiotlb.h       |    5 -----
 lib/swiotlb.c                 |   18 ++++--------------
 3 files changed, 4 insertions(+), 29 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index a1712f2..e89cf99 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -23,16 +23,6 @@ void *swiotlb_alloc(unsigned order, unsigned long nslabs)
 	return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
 }
 
-dma_addr_t swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
-{
-	return paddr;
-}
-
-phys_addr_t swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
-{
-	return baddr;
-}
-
 int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
 {
 	return 0;
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index cb1a663..954feec 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -27,11 +27,6 @@ swiotlb_init(void);
 extern void *swiotlb_alloc_boot(size_t bytes, unsigned long nslabs);
 extern void *swiotlb_alloc(unsigned order, unsigned long nslabs);
 
-extern dma_addr_t swiotlb_phys_to_bus(struct device *hwdev,
-				      phys_addr_t address);
-extern phys_addr_t swiotlb_bus_to_phys(struct device *hwdev,
-				       dma_addr_t address);
-
 extern int swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size);
 
 extern void
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index bffe6d7..baa1991 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -124,25 +124,15 @@ void * __weak swiotlb_alloc(unsigned order, unsigned long nslabs)
 	return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
 }
 
-dma_addr_t __weak swiotlb_phys_to_bus(struct device *hwdev, phys_addr_t paddr)
-{
-	return paddr;
-}
-
-phys_addr_t __weak swiotlb_bus_to_phys(struct device *hwdev, dma_addr_t baddr)
-{
-	return baddr;
-}
-
 static dma_addr_t swiotlb_virt_to_bus(struct device *hwdev,
 				      volatile void *address)
 {
-	return swiotlb_phys_to_bus(hwdev, virt_to_phys(address));
+	return phys_to_dma(hwdev, virt_to_phys(address));
 }
 
 void * __weak swiotlb_bus_to_virt(struct device *hwdev, dma_addr_t address)
 {
-	return phys_to_virt(swiotlb_bus_to_phys(hwdev, address));
+	return phys_to_virt(dma_to_phys(hwdev, address));
 }
 
 int __weak swiotlb_arch_address_needs_mapping(struct device *hwdev,
@@ -646,7 +636,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 			    struct dma_attrs *attrs)
 {
 	phys_addr_t phys = page_to_phys(page) + offset;
-	dma_addr_t dev_addr = swiotlb_phys_to_bus(dev, phys);
+	dma_addr_t dev_addr = phys_to_dma(dev, phys);
 	void *map;
 
 	BUG_ON(dir = DMA_NONE);
@@ -817,7 +807,7 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
 
 	for_each_sg(sgl, sg, nelems, i) {
 		phys_addr_t paddr = sg_phys(sg);
-		dma_addr_t dev_addr = swiotlb_phys_to_bus(hwdev, paddr);
+		dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
 
 		if (range_needs_mapping(paddr, sg->length) ||
 		    address_needs_mapping(hwdev, dev_addr, sg->length)) {
-- 
1.5.6.5

[PATCH 07/11] swiotlb: use dma_map_range

[Ian Campbell]

This replaces usages of address_needs_mapping, range_needs_mapping and
is_buffer_dma_capable and the __weak architecture hooks to those
functions with a more flexible single function.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: Olaf Kirch <okir@suse.de>
Cc: Greg KH <gregkh@suse.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Becky Bruce <beckyb@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Kumar Gala <galak@kernel.crashing.org>
Cc: Jeremy Fitzhardinge <jeremy@goop.org>
Cc: x86@kernel.org
Cc: linux-ia64@vger.kernel.org
Cc: linuxppc-dev@ozlabs.org
---
 arch/x86/kernel/pci-swiotlb.c |    5 ---
 include/linux/dma-mapping.h   |    5 ---
 include/linux/swiotlb.h       |    2 -
 lib/swiotlb.c                 |   59 +++++++++++++---------------------------
 4 files changed, 19 insertions(+), 52 deletions(-)

diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c
index e89cf99..fdcc0e2 100644
--- a/arch/x86/kernel/pci-swiotlb.c
+++ b/arch/x86/kernel/pci-swiotlb.c
@@ -23,11 +23,6 @@ void *swiotlb_alloc(unsigned order, unsigned long nslabs)
 	return (void *)__get_free_pages(GFP_DMA | __GFP_NOWARN, order);
 }
 
-int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
-{
-	return 0;
-}
-
 static void *x86_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 					dma_addr_t *dma_handle, gfp_t flags)
 {
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 8083b6a..85dafa1 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -96,11 +96,6 @@ static inline int is_device_dma_capable(struct device *dev)
 	return dev->dma_mask != NULL && *dev->dma_mask != DMA_MASK_NONE;
 }
 
-static inline int is_buffer_dma_capable(u64 mask, dma_addr_t addr, size_t size)
-{
-	return addr + size <= mask;
-}
-
 #ifdef CONFIG_HAS_DMA
 #include <asm/dma-mapping.h>
 #else
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h
index 954feec..1b56dbf 100644
--- a/include/linux/swiotlb.h
+++ b/include/linux/swiotlb.h
@@ -27,8 +27,6 @@ swiotlb_init(void);
 extern void *swiotlb_alloc_boot(size_t bytes, unsigned long nslabs);
 extern void *swiotlb_alloc(unsigned order, unsigned long nslabs);
 
-extern int swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size);
-
 extern void
 *swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 			dma_addr_t *dma_handle, gfp_t flags);
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index baa1991..d37499b 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -135,17 +135,6 @@ void * __weak swiotlb_bus_to_virt(struct device *hwdev, dma_addr_t address)
 	return phys_to_virt(dma_to_phys(hwdev, address));
 }
 
-int __weak swiotlb_arch_address_needs_mapping(struct device *hwdev,
-					       dma_addr_t addr, size_t size)
-{
-	return !is_buffer_dma_capable(dma_get_mask(hwdev), addr, size);
-}
-
-int __weak swiotlb_arch_range_needs_mapping(phys_addr_t paddr, size_t size)
-{
-	return 0;
-}
-
 static void swiotlb_print_info(unsigned long bytes)
 {
 	phys_addr_t pstart, pend;
@@ -305,17 +294,6 @@ cleanup1:
 	return -ENOMEM;
 }
 
-static inline int
-address_needs_mapping(struct device *hwdev, dma_addr_t addr, size_t size)
-{
-	return swiotlb_arch_address_needs_mapping(hwdev, addr, size);
-}
-
-static inline int range_needs_mapping(phys_addr_t paddr, size_t size)
-{
-	return swiotlb_force || swiotlb_arch_range_needs_mapping(paddr, size);
-}
-
 static int is_swiotlb_buffer(char *addr)
 {
 	return addr >= io_tlb_start && addr < io_tlb_end;
@@ -542,7 +520,7 @@ void *
 swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 		       dma_addr_t *dma_handle, gfp_t flags)
 {
-	dma_addr_t dev_addr;
+	phys_addr_t phys;
 	void *ret;
 	int order = get_order(size);
 	u64 dma_mask = DMA_BIT_MASK(32);
@@ -551,9 +529,8 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 		dma_mask = hwdev->coherent_dma_mask;
 
 	ret = (void *)__get_free_pages(flags, order);
-	if (ret &&
-	    !is_buffer_dma_capable(dma_mask, swiotlb_virt_to_bus(hwdev, ret),
-				   size)) {
+	if (ret && !dma_map_range(hwdev, dma_mask, virt_to_phys(ret),
+				  size, dma_handle)) {
 		/*
 		 * The allocated memory isn't reachable by the device.
 		 */
@@ -572,19 +549,19 @@ swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 	}
 
 	memset(ret, 0, size);
-	dev_addr = swiotlb_virt_to_bus(hwdev, ret);
+	phys = virt_to_phys(ret);
 
 	/* Confirm address can be DMA'd by device */
-	if (!is_buffer_dma_capable(dma_mask, dev_addr, size)) {
-		printk("hwdev DMA mask = 0x%016Lx, dev_addr = 0x%016Lx\n",
+	if (!dma_map_range(hwdev, dma_mask, phys, size, dma_handle)) {
+		printk(KERN_WARNING "hwdev DMA mask = 0x%016Lx, "
+				    "physical addr = 0x%016Lx\n",
 		       (unsigned long long)dma_mask,
-		       (unsigned long long)dev_addr);
+		       (unsigned long long)phys);
 
 		/* DMA_TO_DEVICE to avoid memcpy in unmap_single */
 		do_unmap_single(hwdev, ret, size, DMA_TO_DEVICE);
 		return NULL;
 	}
-	*dma_handle = dev_addr;
 	return ret;
 }
 EXPORT_SYMBOL(swiotlb_alloc_coherent);
@@ -636,7 +613,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 			    struct dma_attrs *attrs)
 {
 	phys_addr_t phys = page_to_phys(page) + offset;
-	dma_addr_t dev_addr = phys_to_dma(dev, phys);
+	dma_addr_t dev_addr;
 	void *map;
 
 	BUG_ON(dir = DMA_NONE);
@@ -645,8 +622,8 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 	 * we can safely return the device addr and not worry about bounce
 	 * buffering it.
 	 */
-	if (!address_needs_mapping(dev, dev_addr, size) &&
-	    !range_needs_mapping(phys, size))
+	if (dma_map_range(dev, dma_get_mask(dev), phys, size, &dev_addr) &&
+	    !swiotlb_force)
 		return dev_addr;
 
 	/*
@@ -658,12 +635,12 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page *page,
 		map = io_tlb_overflow_buffer;
 	}
 
-	dev_addr = swiotlb_virt_to_bus(dev, map);
+	phys = virt_to_phys(map);
 
 	/*
 	 * Ensure that the address returned is DMA'ble
 	 */
-	if (address_needs_mapping(dev, dev_addr, size))
+	if (!dma_map_range(dev, dma_get_mask(dev), phys, size, &dev_addr))
 		panic("map_single: bounce buffer is not DMA'ble");
 
 	return dev_addr;
@@ -807,10 +784,11 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
 
 	for_each_sg(sgl, sg, nelems, i) {
 		phys_addr_t paddr = sg_phys(sg);
-		dma_addr_t dev_addr = phys_to_dma(hwdev, paddr);
+		dma_addr_t uninitialized_var(dev_addr);
 
-		if (range_needs_mapping(paddr, sg->length) ||
-		    address_needs_mapping(hwdev, dev_addr, sg->length)) {
+		if (!dma_map_range(hwdev, dma_get_mask(hwdev), dev_addr,
+				   sg->length, &dev_addr) ||
+		    swiotlb_force) {
 			void *map = map_single(hwdev, sg_phys(sg),
 					       sg->length, dir);
 			if (!map) {
@@ -822,7 +800,8 @@ swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, int nelems,
 				sgl[0].dma_length = 0;
 				return 0;
 			}
-			sg->dma_address = swiotlb_virt_to_bus(hwdev, map);
+			paddr = virt_to_phys(map);
+			sg->dma_address = phys_to_dma(hwdev, paddr);
 		} else
 			sg->dma_address = dev_addr;
 		sg->dma_length = sg->length;
-- 
1.5.6.5

Re: [PATCH 01/11] ia64: introduce arch-specific dma-mapping

[FUJITA Tomonori]

On Mon, 1 Jun 2009 16:32:53 +0100
Ian Campbell <ian.campbell@citrix.com> wrote:

> dma_map_range is intended to replace usage of both
> swiotlb_arch_range_needs_mapping and
> swiotlb_arch_address_needs_mapping as __weak functions as well as
> replacing is_buffer_dma_capable.
> 
> phys_to_dma and dma_to_phys are intended to replace
> swiotlb_phys_to_bus and swiotlb_bus_to_phys.  I choose to use dma
> rather than bus since a) it matches the parameters and b) avoids
> confusion on x86 with the existing (but deprecated) virt_to_bus
> function which relates to ISA device DMA.
> 
> Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
> Cc: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
> Cc: Ingo Molnar <mingo@elte.hu>
> Cc: Jeremy Fitzhardinge <jeremy@goop.org>
> Cc: Tony Luck <tony.luck@intel.com>
> Cc: linux-ia64@vger.kernel.org
> ---
>  arch/ia64/include/asm/dma-mapping.h |   23 +++++++++++++++++++++++
>  1 files changed, 23 insertions(+), 0 deletions(-)
> 
> diff --git a/arch/ia64/include/asm/dma-mapping.h b/arch/ia64/include/asm/dma-mapping.h
> index 36c0009..47d4107 100644
> --- a/arch/ia64/include/asm/dma-mapping.h
> +++ b/arch/ia64/include/asm/dma-mapping.h
> @@ -174,4 +174,27 @@ dma_cache_sync (struct device *dev, void *vaddr, size_t size,
>  
>  #define dma_is_consistent(d, h)	(1)	/* all we do is coherent memory... */
>  
> +static inline dma_addr_t phys_to_dma(struct device *hwdev, phys_addr_t paddr)
> +{
> +	return paddr;
> +}
> +
> +static inline phys_addr_t dma_to_phys(struct device *hwdev, dma_addr_t daddr)
> +{
> +	return daddr;
> +}
> +
> +static inline bool dma_map_range(struct device *dev, u64 mask,
> +				       phys_addr_t addr, size_t size,
> +				       dma_addr_t *dma_addr_p)
> +{
> +	dma_addr_t dma_addr = phys_to_dma(dev, addr);
> +
> +	if (dma_addr + size > mask)
> +		return false;
> +
> +	*dma_addr_p = dma_addr;
> +	return true;
> +}
> +

dma_map_range is a really confusing name. We have dma_map_single and
dma_map_sg, they are the DMA mapping API.

dma_map_range sounds like the DMA mapping API but it isn't. As I said,
Xen dom0 needs to implement something like xen_map_sg, xen_map_single,
etc, which uses some of swiotlb functions internally. Then we don't
need functions like the above.

Re: [PATCH 01/11] ia64: introduce arch-specific dma-mapping

[Ian Campbell]

On Tue, 2009-06-02 at 00:08 -0400, FUJITA Tomonori wrote:
> dma_map_range is a really confusing name. We have dma_map_single and
> dma_map_sg, they are the DMA mapping API.
> dma_map_range sounds like the DMA mapping API but it isn't.

Yes, it's not such a good name. I wonder what would be better? 

Perhaps dma_range_mapped? The return value indicates whether the range
is mapped or not so this makes some sense. It also makes it clearer that
this function is not intended to actually perform the mapping if it does
not exist.

> As I said,
> Xen dom0 needs to implement something like xen_map_sg, xen_map_single,
> etc, which uses some of swiotlb functions internally. Then we don't
> need functions like the above.

xen_map_sg would be literally identical to swiotlb_map_sg in every way
apart from the additional phys<->dma address translations. Similarly for
the other swiotlb interfaces. The phys<->dma address translation is also
required for the PowerPC architecture so duplicating all that code just
for Xen doesn't really solve the problem.

Ian.

Re: [PATCH 00/11] swiotlb: Introduce architecture-specific APIs to

[Benjamin Herrenschmidt]

On Mon, 2009-06-01 at 16:32 +0100, Ian Campbell wrote:
> This series:
> * removes the swiotlb_(arch_)_phys_to_bus and bus_to_phys __weak
>   hooks, replacing them with an architecture-specific phys_to_dma and
>   dma_to_phys interface. These are used by both PowerPC and Xen to
>   provide the correct mapping from physical to DMA addresses.
> * removes the swiotlb_address_needs_mapping and
>   swiotlb_range_needs_mapping __weak functions as well as
>   is_buffer_dma_capable (which should never have been a generic
>   function). All three are replaced by a single architecture-specific
>   interface which meets the needs of both PowerPC and Xen.
> * removes the swiotlb_virt_to_bus __weak function and replaces it with
>   a CONFIG_HIGHMEM compatible version when high memory is in use. This
>   is needed for 32 bit PowerPC swiotlb support.
> * removes the swiotlb_alloc* __weak functions and replaces them with
>   swiotlb_init_with_buffer which allows the use of a caller allocated
>   buffer (and emergency pool).
> 
> I think these new interfaces are cleaner than the existing __weak
> functions and isolate the swiotlb code from architecture internals.
> 
> This series does not contain any Xen or PowerPC specific changes, those
> will follow in separate postings. The complete patchset has been boot
> tested under Xen and native-x86 and compiled for IA64 and PowerPC
> 
> Changes since v1: 
> - Fixed compile error in swiotlb_dma_to_virt highmem version. Moved
>   #ifdef into function to avoid prototype drift.
> - checkpatch fixes.
> - missed a swiotlb_arch_range_needs_mapping in swiotlb.h and x86
>   pci-swiotlb.c and swiotlb_bus_to_phys/phys_to_bus implementations in
>   x86.
> - additionally replaced __weak swiotlb_alloc* with
>   swiotlb_init_with_buffer.

Looks like I was only CCed on part of them... it's not very handy for me
as I end up having some of the patches in one folder and some
elsewhere :-)

I don't have a firm objection but they will have to go through Becky
and Kumar since they are the one who need swiotlb for their embedded
platforms.

Cheers,
Ben.

Re: [PATCH 00/11] swiotlb: Introduce architecture-specific APIs to

[Ian Campbell]

On Fri, 2009-07-10 at 15:55 +1000, Benjamin Herrenschmidt wrote:
> On Mon, 2009-06-01 at 16:32 +0100, Ian Campbell wrote:
> > This series:[...]

> Looks like I was only CCed on part of them... it's not very handy for me
> as I end up having some of the patches in one folder and some
> elsewhere :-)

Sorry about that -- I was concerned about spamming the world and his dog
with patches which didn't directly interest them. For any future series
of this type I'll CC everyone on everything.

Ian.