Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Tue, 2012-07-10 at 17:06 -0600, Shuah Khan wrote: > On Tue, 2012-07-10 at 13:32 -0400, Konrad Rzeszutek Wilk wrote: > > On Tue, Jul 10, 2012 at 10:55:07AM -0600, Shuah Khan wrote: > > > On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: > > > > On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: > > > > > Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE > > > > > (a value of zero) to make it consistent with iommu implementation > > > > > on Intel, AMD, and swiotlb-xen. > > > > > > > > While this is a good forward step and this needs to be done eventually, > > > > you should first send out patches for the drivers that don't check > > > > for the DMA_ERROR_CODE when doing mapping. In other words for the > > > > drivers that map but don't call dma_mapping_error to check. > > > > > > > > When that is fixed and *all the drivers that don't call > > > > dma_mapping_error > > > > are fixed, then this patch makes sense. > > > > > > The challenge will be catching all the drivers and have confidence that > > > all of them are covered. I will start looking into this to get a feel > > > for how many drivers needs fixing. > > > > I don't know if all is needed. Some of them might be dead or not used > > at all anymore - who knows? This treasure hunt would give a good idea > > of which ones are not using the PCI/DMA API right at least. > > > > If it is say, CONFIG_ISA enabled, well, we could #ifdef the overflow > > buffer in the swiotlb with that option. And then work through fixing > > up those drivers - except that finding folks with that driver to > > see if it works .. yuck.. I do have some few ISA cards and some boxes > > with ISA slots :-) > > Looking at the history CONFIG_ISA was disabled back in 2002 and > CONFIG_ISA_DMA_API was disabled in 2004. Sounds like it will be fun > finding drivers that could fail. Correction. CONFIG_ISA_DMA_API is made configurable on x86_64 it appears back in 2011. -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Tue, 2012-07-10 at 13:32 -0400, Konrad Rzeszutek Wilk wrote: > On Tue, Jul 10, 2012 at 10:55:07AM -0600, Shuah Khan wrote: > > On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: > > > On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: > > > > Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE > > > > (a value of zero) to make it consistent with iommu implementation > > > > on Intel, AMD, and swiotlb-xen. > > > > > > While this is a good forward step and this needs to be done eventually, > > > you should first send out patches for the drivers that don't check > > > for the DMA_ERROR_CODE when doing mapping. In other words for the > > > drivers that map but don't call dma_mapping_error to check. > > > > > > When that is fixed and *all the drivers that don't call dma_mapping_error > > > are fixed, then this patch makes sense. > > > > The challenge will be catching all the drivers and have confidence that > > all of them are covered. I will start looking into this to get a feel > > for how many drivers needs fixing. > > I don't know if all is needed. Some of them might be dead or not used > at all anymore - who knows? This treasure hunt would give a good idea > of which ones are not using the PCI/DMA API right at least. > > If it is say, CONFIG_ISA enabled, well, we could #ifdef the overflow > buffer in the swiotlb with that option. And then work through fixing > up those drivers - except that finding folks with that driver to > see if it works .. yuck.. I do have some few ISA cards and some boxes > with ISA slots :-) Looking at the history CONFIG_ISA was disabled back in 2002 and CONFIG_ISA_DMA_API was disabled in 2004. Sounds like it will be fun finding drivers that could fail. Would it make sense to make io_tlb_overflow a tunable and disable by default instead of ifdef? Currently it is always enabled, disabling it by default is another way to find problems? Good to know you have a few ISA cards. :) -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Tue, Jul 10, 2012 at 10:55:07AM -0600, Shuah Khan wrote: > On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: > > On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: > > > Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE > > > (a value of zero) to make it consistent with iommu implementation > > > on Intel, AMD, and swiotlb-xen. > > > > While this is a good forward step and this needs to be done eventually, > > you should first send out patches for the drivers that don't check > > for the DMA_ERROR_CODE when doing mapping. In other words for the > > drivers that map but don't call dma_mapping_error to check. > > > > When that is fixed and *all the drivers that don't call dma_mapping_error > > are fixed, then this patch makes sense. > > The challenge will be catching all the drivers and have confidence that > all of them are covered. I will start looking into this to get a feel > for how many drivers needs fixing. I don't know if all is needed. Some of them might be dead or not used at all anymore - who knows? This treasure hunt would give a good idea of which ones are not using the PCI/DMA API right at least. If it is say, CONFIG_ISA enabled, well, we could #ifdef the overflow buffer in the swiotlb with that option. And then work through fixing up those drivers - except that finding folks with that driver to see if it works .. yuck.. I do have some few ISA cards and some boxes with ISA slots :-) > > Also, isn't this problem today with other iommu implementations? All of > the other iommu implementation don't have support for overflow buffers? Right, but you are in high likehood not going to run the drivers that don't check this with an IOMMU. Because the drivers are mostly the PCI variants .. or PCMCIA. And the hardware that would use this did not have IOMMU. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: > On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: > > Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE > > (a value of zero) to make it consistent with iommu implementation > > on Intel, AMD, and swiotlb-xen. > > While this is a good forward step and this needs to be done eventually, > you should first send out patches for the drivers that don't check > for the DMA_ERROR_CODE when doing mapping. In other words for the > drivers that map but don't call dma_mapping_error to check. > > When that is fixed and *all the drivers that don't call dma_mapping_error > are fixed, then this patch makes sense. The challenge will be catching all the drivers and have confidence that all of them are covered. I will start looking into this to get a feel for how many drivers needs fixing. Also, isn't this problem today with other iommu implementations? All of the other iommu implementation don't have support for overflow buffers? -- Shuah -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Mon, 9 Jul 2012 16:25:05 -0400 Konrad Rzeszutek Wilk wrote: > On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: >> Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE >> (a value of zero) to make it consistent with iommu implementation >> on Intel, AMD, and swiotlb-xen. > > While this is a good forward step and this needs to be done eventually, > you should first send out patches for the drivers that don't check > for the DMA_ERROR_CODE when doing mapping. In other words for the > drivers that map but don't call dma_mapping_error to check. > > When that is fixed and *all the drivers that don't call dma_mapping_error > are fixed, then this patch makes sense. > > So for right now, NACK. Yeah, I'm not sure we could fix (or remove) *all the drivers though. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Mon, 9 Jul 2012 16:25:05 -0400 Konrad Rzeszutek Wilk konrad.w...@oracle.com wrote: On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE (a value of zero) to make it consistent with iommu implementation on Intel, AMD, and swiotlb-xen. While this is a good forward step and this needs to be done eventually, you should first send out patches for the drivers that don't check for the DMA_ERROR_CODE when doing mapping. In other words for the drivers that map but don't call dma_mapping_error to check. When that is fixed and *all the drivers that don't call dma_mapping_error are fixed, then this patch makes sense. So for right now, NACK. Yeah, I'm not sure we could fix (or remove) *all the drivers though. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE (a value of zero) to make it consistent with iommu implementation on Intel, AMD, and swiotlb-xen. While this is a good forward step and this needs to be done eventually, you should first send out patches for the drivers that don't check for the DMA_ERROR_CODE when doing mapping. In other words for the drivers that map but don't call dma_mapping_error to check. When that is fixed and *all the drivers that don't call dma_mapping_error are fixed, then this patch makes sense. The challenge will be catching all the drivers and have confidence that all of them are covered. I will start looking into this to get a feel for how many drivers needs fixing. Also, isn't this problem today with other iommu implementations? All of the other iommu implementation don't have support for overflow buffers? -- Shuah -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Tue, Jul 10, 2012 at 10:55:07AM -0600, Shuah Khan wrote: On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE (a value of zero) to make it consistent with iommu implementation on Intel, AMD, and swiotlb-xen. While this is a good forward step and this needs to be done eventually, you should first send out patches for the drivers that don't check for the DMA_ERROR_CODE when doing mapping. In other words for the drivers that map but don't call dma_mapping_error to check. When that is fixed and *all the drivers that don't call dma_mapping_error are fixed, then this patch makes sense. The challenge will be catching all the drivers and have confidence that all of them are covered. I will start looking into this to get a feel for how many drivers needs fixing. I don't know if all is needed. Some of them might be dead or not used at all anymore - who knows? This treasure hunt would give a good idea of which ones are not using the PCI/DMA API right at least. If it is say, CONFIG_ISA enabled, well, we could #ifdef the overflow buffer in the swiotlb with that option. And then work through fixing up those drivers - except that finding folks with that driver to see if it works .. yuck.. I do have some few ISA cards and some boxes with ISA slots :-) Also, isn't this problem today with other iommu implementations? All of the other iommu implementation don't have support for overflow buffers? Right, but you are in high likehood not going to run the drivers that don't check this with an IOMMU. Because the drivers are mostly the PCI variants .. or PCMCIA. And the hardware that would use this did not have IOMMU. -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Tue, 2012-07-10 at 13:32 -0400, Konrad Rzeszutek Wilk wrote: On Tue, Jul 10, 2012 at 10:55:07AM -0600, Shuah Khan wrote: On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE (a value of zero) to make it consistent with iommu implementation on Intel, AMD, and swiotlb-xen. While this is a good forward step and this needs to be done eventually, you should first send out patches for the drivers that don't check for the DMA_ERROR_CODE when doing mapping. In other words for the drivers that map but don't call dma_mapping_error to check. When that is fixed and *all the drivers that don't call dma_mapping_error are fixed, then this patch makes sense. The challenge will be catching all the drivers and have confidence that all of them are covered. I will start looking into this to get a feel for how many drivers needs fixing. I don't know if all is needed. Some of them might be dead or not used at all anymore - who knows? This treasure hunt would give a good idea of which ones are not using the PCI/DMA API right at least. If it is say, CONFIG_ISA enabled, well, we could #ifdef the overflow buffer in the swiotlb with that option. And then work through fixing up those drivers - except that finding folks with that driver to see if it works .. yuck.. I do have some few ISA cards and some boxes with ISA slots :-) Looking at the history CONFIG_ISA was disabled back in 2002 and CONFIG_ISA_DMA_API was disabled in 2004. Sounds like it will be fun finding drivers that could fail. Would it make sense to make io_tlb_overflow a tunable and disable by default instead of ifdef? Currently it is always enabled, disabling it by default is another way to find problems? Good to know you have a few ISA cards. :) -- Shuah -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Tue, 2012-07-10 at 17:06 -0600, Shuah Khan wrote: On Tue, 2012-07-10 at 13:32 -0400, Konrad Rzeszutek Wilk wrote: On Tue, Jul 10, 2012 at 10:55:07AM -0600, Shuah Khan wrote: On Mon, 2012-07-09 at 16:25 -0400, Konrad Rzeszutek Wilk wrote: On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote: Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE (a value of zero) to make it consistent with iommu implementation on Intel, AMD, and swiotlb-xen. While this is a good forward step and this needs to be done eventually, you should first send out patches for the drivers that don't check for the DMA_ERROR_CODE when doing mapping. In other words for the drivers that map but don't call dma_mapping_error to check. When that is fixed and *all the drivers that don't call dma_mapping_error are fixed, then this patch makes sense. The challenge will be catching all the drivers and have confidence that all of them are covered. I will start looking into this to get a feel for how many drivers needs fixing. I don't know if all is needed. Some of them might be dead or not used at all anymore - who knows? This treasure hunt would give a good idea of which ones are not using the PCI/DMA API right at least. If it is say, CONFIG_ISA enabled, well, we could #ifdef the overflow buffer in the swiotlb with that option. And then work through fixing up those drivers - except that finding folks with that driver to see if it works .. yuck.. I do have some few ISA cards and some boxes with ISA slots :-) Looking at the history CONFIG_ISA was disabled back in 2002 and CONFIG_ISA_DMA_API was disabled in 2004. Sounds like it will be fun finding drivers that could fail. Correction. CONFIG_ISA_DMA_API is made configurable on x86_64 it appears back in 2011. -- Shuah -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote:
> Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE
> (a value of zero) to make it consistent with iommu implementation
> on Intel, AMD, and swiotlb-xen.
While this is a good forward step and this needs to be done eventually,
you should first send out patches for the drivers that don't check
for the DMA_ERROR_CODE when doing mapping. In other words for the
drivers that map but don't call dma_mapping_error to check.
When that is fixed and *all the drivers that don't call dma_mapping_error
are fixed, then this patch makes sense.
So for right now, NACK.
Also you missed CC-ing fujita.tomon...@lab.ntt.co.jp, so let me add
that to this email.
*: for those that it makes sense. I am not sure if folks are still using
ancient drivers..
>
> Tested only on x86.
>
> Signed-off-by: Shuah Khan
> ---
> lib/swiotlb.c | 44
> 1 file changed, 8 insertions(+), 36 deletions(-)
>
> diff --git a/lib/swiotlb.c b/lib/swiotlb.c
> index 45bc1f8..7f0a5d1 100644
> --- a/lib/swiotlb.c
> +++ b/lib/swiotlb.c
> @@ -15,6 +15,7 @@
> * 05/09/10 linville Add support for syncing ranges, support syncing for
> * DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
> * 08/12/11 beckyb Add highmem support
> + * 06/12shuahkhanRemove io tlb overflow support
> */
>
> #include
> @@ -66,13 +67,6 @@ static char *io_tlb_start, *io_tlb_end;
> static unsigned long io_tlb_nslabs;
>
> /*
> - * When the IOMMU overflows we return a fallback buffer. This sets the size.
> - */
> -static unsigned long io_tlb_overflow = 32*1024;
> -
> -static void *io_tlb_overflow_buffer;
> -
> -/*
> * This is a free list describing the number of free entries available from
> * each index
> */
> @@ -108,7 +102,6 @@ setup_io_tlb_npages(char *str)
> return 1;
> }
> __setup("swiotlb=", setup_io_tlb_npages);
> -/* make io_tlb_overflow tunable too? */
>
> unsigned long swiotlb_nr_tbl(void)
> {
> @@ -156,12 +149,6 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned
> long nslabs, int verbose)
> io_tlb_index = 0;
> io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs *
> sizeof(phys_addr_t)));
>
> - /*
> - * Get the overflow emergency buffer
> - */
> - io_tlb_overflow_buffer =
> alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow));
> - if (!io_tlb_overflow_buffer)
> - panic("Cannot allocate SWIOTLB overflow buffer!\n");
> if (verbose)
> swiotlb_print_info();
> }
> @@ -195,7 +182,8 @@ swiotlb_init_with_default_size(size_t default_size, int
> verbose)
> void __init
> swiotlb_init(int verbose)
> {
> - swiotlb_init_with_default_size(64 * (1<<20), verbose); /* default to
> 64MB */
> + /* default to 64MB */
> + swiotlb_init_with_default_size(64 * (1<<20), verbose);
> }
>
> /*
> @@ -264,24 +252,12 @@ swiotlb_late_init_with_default_size(size_t default_size)
>
> memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
>
> - /*
> - * Get the overflow emergency buffer
> - */
> - io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
> - get_order(io_tlb_overflow));
> - if (!io_tlb_overflow_buffer)
> - goto cleanup4;
> -
> swiotlb_print_info();
>
> late_alloc = 1;
>
> return 0;
>
> -cleanup4:
> - free_pages((unsigned long)io_tlb_orig_addr,
> -get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
> - io_tlb_orig_addr = NULL;
> cleanup3:
> free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
>sizeof(int)));
> @@ -297,12 +273,10 @@ cleanup1:
>
> void __init swiotlb_free(void)
> {
> - if (!io_tlb_overflow_buffer)
> + if (!io_tlb_orig_addr)
> return;
>
> if (late_alloc) {
> - free_pages((unsigned long)io_tlb_overflow_buffer,
> -get_order(io_tlb_overflow));
> free_pages((unsigned long)io_tlb_orig_addr,
> get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
> free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
> @@ -310,8 +284,6 @@ void __init swiotlb_free(void)
> free_pages((unsigned long)io_tlb_start,
> get_order(io_tlb_nslabs << IO_TLB_SHIFT));
> } else {
> - free_bootmem_late(__pa(io_tlb_overflow_buffer),
> - PAGE_ALIGN(io_tlb_overflow));
> free_bootmem_late(__pa(io_tlb_orig_addr),
> PAGE_ALIGN(io_tlb_nslabs *
> sizeof(phys_addr_t)));
> free_bootmem_late(__pa(io_tlb_list),
> @@ -639,7 +611,7 @@ swiotlb_full(struct device *dev, size_t size, enum
> dma_data_direction dir,
> printk(KERN_ERR "DMA: Out of
Re: [PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
On Fri, Jul 06, 2012 at 05:06:12PM -0600, Shuah Khan wrote:
Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE
(a value of zero) to make it consistent with iommu implementation
on Intel, AMD, and swiotlb-xen.
While this is a good forward step and this needs to be done eventually,
you should first send out patches for the drivers that don't check
for the DMA_ERROR_CODE when doing mapping. In other words for the
drivers that map but don't call dma_mapping_error to check.
When that is fixed and *all the drivers that don't call dma_mapping_error
are fixed, then this patch makes sense.
So for right now, NACK.
Also you missed CC-ing fujita.tomon...@lab.ntt.co.jp, so let me add
that to this email.
*: for those that it makes sense. I am not sure if folks are still using
ancient drivers..
Tested only on x86.
Signed-off-by: Shuah Khan shuah.k...@hp.com
---
lib/swiotlb.c | 44
1 file changed, 8 insertions(+), 36 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 45bc1f8..7f0a5d1 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -15,6 +15,7 @@
* 05/09/10 linville Add support for syncing ranges, support syncing for
* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
* 08/12/11 beckyb Add highmem support
+ * 06/12shuahkhanRemove io tlb overflow support
*/
#include linux/cache.h
@@ -66,13 +67,6 @@ static char *io_tlb_start, *io_tlb_end;
static unsigned long io_tlb_nslabs;
/*
- * When the IOMMU overflows we return a fallback buffer. This sets the size.
- */
-static unsigned long io_tlb_overflow = 32*1024;
-
-static void *io_tlb_overflow_buffer;
-
-/*
* This is a free list describing the number of free entries available from
* each index
*/
@@ -108,7 +102,6 @@ setup_io_tlb_npages(char *str)
return 1;
}
__setup(swiotlb=, setup_io_tlb_npages);
-/* make io_tlb_overflow tunable too? */
unsigned long swiotlb_nr_tbl(void)
{
@@ -156,12 +149,6 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned
long nslabs, int verbose)
io_tlb_index = 0;
io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs *
sizeof(phys_addr_t)));
- /*
- * Get the overflow emergency buffer
- */
- io_tlb_overflow_buffer =
alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow));
- if (!io_tlb_overflow_buffer)
- panic(Cannot allocate SWIOTLB overflow buffer!\n);
if (verbose)
swiotlb_print_info();
}
@@ -195,7 +182,8 @@ swiotlb_init_with_default_size(size_t default_size, int
verbose)
void __init
swiotlb_init(int verbose)
{
- swiotlb_init_with_default_size(64 * (120), verbose); /* default to
64MB */
+ /* default to 64MB */
+ swiotlb_init_with_default_size(64 * (120), verbose);
}
/*
@@ -264,24 +252,12 @@ swiotlb_late_init_with_default_size(size_t default_size)
memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
- /*
- * Get the overflow emergency buffer
- */
- io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
- get_order(io_tlb_overflow));
- if (!io_tlb_overflow_buffer)
- goto cleanup4;
-
swiotlb_print_info();
late_alloc = 1;
return 0;
-cleanup4:
- free_pages((unsigned long)io_tlb_orig_addr,
-get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
- io_tlb_orig_addr = NULL;
cleanup3:
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
sizeof(int)));
@@ -297,12 +273,10 @@ cleanup1:
void __init swiotlb_free(void)
{
- if (!io_tlb_overflow_buffer)
+ if (!io_tlb_orig_addr)
return;
if (late_alloc) {
- free_pages((unsigned long)io_tlb_overflow_buffer,
-get_order(io_tlb_overflow));
free_pages((unsigned long)io_tlb_orig_addr,
get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
@@ -310,8 +284,6 @@ void __init swiotlb_free(void)
free_pages((unsigned long)io_tlb_start,
get_order(io_tlb_nslabs IO_TLB_SHIFT));
} else {
- free_bootmem_late(__pa(io_tlb_overflow_buffer),
- PAGE_ALIGN(io_tlb_overflow));
free_bootmem_late(__pa(io_tlb_orig_addr),
PAGE_ALIGN(io_tlb_nslabs *
sizeof(phys_addr_t)));
free_bootmem_late(__pa(io_tlb_list),
@@ -639,7 +611,7 @@ swiotlb_full(struct device *dev, size_t size, enum
dma_data_direction dir,
printk(KERN_ERR DMA: Out of SW-IOMMU space for %zu bytes at
device %s\n, size, dev ? dev_name(dev) : ?);
- if
[PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE
(a value of zero) to make it consistent with iommu implementation
on Intel, AMD, and swiotlb-xen.
Tested only on x86.
Signed-off-by: Shuah Khan
---
lib/swiotlb.c | 44
1 file changed, 8 insertions(+), 36 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 45bc1f8..7f0a5d1 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -15,6 +15,7 @@
* 05/09/10 linville Add support for syncing ranges, support syncing for
* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
* 08/12/11 beckyb Add highmem support
+ * 06/12shuahkhan Remove io tlb overflow support
*/
#include
@@ -66,13 +67,6 @@ static char *io_tlb_start, *io_tlb_end;
static unsigned long io_tlb_nslabs;
/*
- * When the IOMMU overflows we return a fallback buffer. This sets the size.
- */
-static unsigned long io_tlb_overflow = 32*1024;
-
-static void *io_tlb_overflow_buffer;
-
-/*
* This is a free list describing the number of free entries available from
* each index
*/
@@ -108,7 +102,6 @@ setup_io_tlb_npages(char *str)
return 1;
}
__setup("swiotlb=", setup_io_tlb_npages);
-/* make io_tlb_overflow tunable too? */
unsigned long swiotlb_nr_tbl(void)
{
@@ -156,12 +149,6 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long
nslabs, int verbose)
io_tlb_index = 0;
io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs *
sizeof(phys_addr_t)));
- /*
-* Get the overflow emergency buffer
-*/
- io_tlb_overflow_buffer =
alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow));
- if (!io_tlb_overflow_buffer)
- panic("Cannot allocate SWIOTLB overflow buffer!\n");
if (verbose)
swiotlb_print_info();
}
@@ -195,7 +182,8 @@ swiotlb_init_with_default_size(size_t default_size, int
verbose)
void __init
swiotlb_init(int verbose)
{
- swiotlb_init_with_default_size(64 * (1<<20), verbose); /* default to
64MB */
+ /* default to 64MB */
+ swiotlb_init_with_default_size(64 * (1<<20), verbose);
}
/*
@@ -264,24 +252,12 @@ swiotlb_late_init_with_default_size(size_t default_size)
memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
- /*
-* Get the overflow emergency buffer
-*/
- io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
- get_order(io_tlb_overflow));
- if (!io_tlb_overflow_buffer)
- goto cleanup4;
-
swiotlb_print_info();
late_alloc = 1;
return 0;
-cleanup4:
- free_pages((unsigned long)io_tlb_orig_addr,
- get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
- io_tlb_orig_addr = NULL;
cleanup3:
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
sizeof(int)));
@@ -297,12 +273,10 @@ cleanup1:
void __init swiotlb_free(void)
{
- if (!io_tlb_overflow_buffer)
+ if (!io_tlb_orig_addr)
return;
if (late_alloc) {
- free_pages((unsigned long)io_tlb_overflow_buffer,
- get_order(io_tlb_overflow));
free_pages((unsigned long)io_tlb_orig_addr,
get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
@@ -310,8 +284,6 @@ void __init swiotlb_free(void)
free_pages((unsigned long)io_tlb_start,
get_order(io_tlb_nslabs << IO_TLB_SHIFT));
} else {
- free_bootmem_late(__pa(io_tlb_overflow_buffer),
- PAGE_ALIGN(io_tlb_overflow));
free_bootmem_late(__pa(io_tlb_orig_addr),
PAGE_ALIGN(io_tlb_nslabs *
sizeof(phys_addr_t)));
free_bootmem_late(__pa(io_tlb_list),
@@ -639,7 +611,7 @@ swiotlb_full(struct device *dev, size_t size, enum
dma_data_direction dir,
printk(KERN_ERR "DMA: Out of SW-IOMMU space for %zu bytes at "
"device %s\n", size, dev ? dev_name(dev) : "?");
- if (size <= io_tlb_overflow || !do_panic)
+ if (!do_panic)
return;
if (dir == DMA_BIDIRECTIONAL)
@@ -681,7 +653,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page
*page,
map = map_single(dev, phys, size, dir);
if (!map) {
swiotlb_full(dev, size, dir, 1);
- map = io_tlb_overflow_buffer;
+ return DMA_ERROR_CODE;
}
dev_addr = swiotlb_virt_to_bus(dev, map);
@@ -691,7 +663,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page
*page,
*/
if (!dma_capable(dev, dev_addr, size)) {
swiotlb_tbl_unmap_single(dev, map, size, dir);
-
[PATCH RFC] swiotlb: Remove SWIOTLB overflow buffer support
Remove SWIOTLB overflow buffer support and return DMA_ERROR_CODE
(a value of zero) to make it consistent with iommu implementation
on Intel, AMD, and swiotlb-xen.
Tested only on x86.
Signed-off-by: Shuah Khan shuah.k...@hp.com
---
lib/swiotlb.c | 44
1 file changed, 8 insertions(+), 36 deletions(-)
diff --git a/lib/swiotlb.c b/lib/swiotlb.c
index 45bc1f8..7f0a5d1 100644
--- a/lib/swiotlb.c
+++ b/lib/swiotlb.c
@@ -15,6 +15,7 @@
* 05/09/10 linville Add support for syncing ranges, support syncing for
* DMA_BIDIRECTIONAL mappings, miscellaneous cleanup.
* 08/12/11 beckyb Add highmem support
+ * 06/12shuahkhan Remove io tlb overflow support
*/
#include linux/cache.h
@@ -66,13 +67,6 @@ static char *io_tlb_start, *io_tlb_end;
static unsigned long io_tlb_nslabs;
/*
- * When the IOMMU overflows we return a fallback buffer. This sets the size.
- */
-static unsigned long io_tlb_overflow = 32*1024;
-
-static void *io_tlb_overflow_buffer;
-
-/*
* This is a free list describing the number of free entries available from
* each index
*/
@@ -108,7 +102,6 @@ setup_io_tlb_npages(char *str)
return 1;
}
__setup(swiotlb=, setup_io_tlb_npages);
-/* make io_tlb_overflow tunable too? */
unsigned long swiotlb_nr_tbl(void)
{
@@ -156,12 +149,6 @@ void __init swiotlb_init_with_tbl(char *tlb, unsigned long
nslabs, int verbose)
io_tlb_index = 0;
io_tlb_orig_addr = alloc_bootmem_pages(PAGE_ALIGN(io_tlb_nslabs *
sizeof(phys_addr_t)));
- /*
-* Get the overflow emergency buffer
-*/
- io_tlb_overflow_buffer =
alloc_bootmem_low_pages(PAGE_ALIGN(io_tlb_overflow));
- if (!io_tlb_overflow_buffer)
- panic(Cannot allocate SWIOTLB overflow buffer!\n);
if (verbose)
swiotlb_print_info();
}
@@ -195,7 +182,8 @@ swiotlb_init_with_default_size(size_t default_size, int
verbose)
void __init
swiotlb_init(int verbose)
{
- swiotlb_init_with_default_size(64 * (120), verbose); /* default to
64MB */
+ /* default to 64MB */
+ swiotlb_init_with_default_size(64 * (120), verbose);
}
/*
@@ -264,24 +252,12 @@ swiotlb_late_init_with_default_size(size_t default_size)
memset(io_tlb_orig_addr, 0, io_tlb_nslabs * sizeof(phys_addr_t));
- /*
-* Get the overflow emergency buffer
-*/
- io_tlb_overflow_buffer = (void *)__get_free_pages(GFP_DMA,
- get_order(io_tlb_overflow));
- if (!io_tlb_overflow_buffer)
- goto cleanup4;
-
swiotlb_print_info();
late_alloc = 1;
return 0;
-cleanup4:
- free_pages((unsigned long)io_tlb_orig_addr,
- get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
- io_tlb_orig_addr = NULL;
cleanup3:
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
sizeof(int)));
@@ -297,12 +273,10 @@ cleanup1:
void __init swiotlb_free(void)
{
- if (!io_tlb_overflow_buffer)
+ if (!io_tlb_orig_addr)
return;
if (late_alloc) {
- free_pages((unsigned long)io_tlb_overflow_buffer,
- get_order(io_tlb_overflow));
free_pages((unsigned long)io_tlb_orig_addr,
get_order(io_tlb_nslabs * sizeof(phys_addr_t)));
free_pages((unsigned long)io_tlb_list, get_order(io_tlb_nslabs *
@@ -310,8 +284,6 @@ void __init swiotlb_free(void)
free_pages((unsigned long)io_tlb_start,
get_order(io_tlb_nslabs IO_TLB_SHIFT));
} else {
- free_bootmem_late(__pa(io_tlb_overflow_buffer),
- PAGE_ALIGN(io_tlb_overflow));
free_bootmem_late(__pa(io_tlb_orig_addr),
PAGE_ALIGN(io_tlb_nslabs *
sizeof(phys_addr_t)));
free_bootmem_late(__pa(io_tlb_list),
@@ -639,7 +611,7 @@ swiotlb_full(struct device *dev, size_t size, enum
dma_data_direction dir,
printk(KERN_ERR DMA: Out of SW-IOMMU space for %zu bytes at
device %s\n, size, dev ? dev_name(dev) : ?);
- if (size = io_tlb_overflow || !do_panic)
+ if (!do_panic)
return;
if (dir == DMA_BIDIRECTIONAL)
@@ -681,7 +653,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page
*page,
map = map_single(dev, phys, size, dir);
if (!map) {
swiotlb_full(dev, size, dir, 1);
- map = io_tlb_overflow_buffer;
+ return DMA_ERROR_CODE;
}
dev_addr = swiotlb_virt_to_bus(dev, map);
@@ -691,7 +663,7 @@ dma_addr_t swiotlb_map_page(struct device *dev, struct page
*page,
*/
if (!dma_capable(dev, dev_addr, size)) {
swiotlb_tbl_unmap_single(dev, map,
