| Message ID | 011801cf4d4c$f7ba51f0$e72ef5d0$@samsung.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Apr 01, 2014 at 10:51:58AM +0900, Jungseok Lee wrote: > This patch corrects kernel command line handler when io_tlb_nslabs > is set to 0. > > A current implementation allocates default size memory (64MB) when > 0 is given to io_tlb_nslabs ("swiotlb=0") by kernel command line. > In other words, memory is allocated unintentionally. What are the other IOMMUs that end up taking over the DMA ops? Or do you end up with no DMA ops? > > Signed-off-by: Jungseok Lee <jays.lee@samsung.com> > Signed-off-by: Sungjinn Chung <sungjinn.chung@samsung.com> > --- > lib/swiotlb.c | 8 ++++++-- > 1 file changed, 6 insertions(+), 2 deletions(-) > > diff --git a/lib/swiotlb.c b/lib/swiotlb.c > index b604b83..9fe9f71 100644 > --- a/lib/swiotlb.c > +++ b/lib/swiotlb.c > @@ -55,6 +55,8 @@ > > int swiotlb_force; > > +static int swiotlb_no_use; > + > /* > * Used to do a quick range check in swiotlb_tbl_unmap_single and > * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this > @@ -102,6 +104,8 @@ setup_io_tlb_npages(char *str) > io_tlb_nslabs = simple_strtoul(str, &str, 0); > /* avoid tail segment of size < IO_TLB_SEGSIZE */ > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > + if (!io_tlb_nslabs) > + swiotlb_no_use = 1; > } > if (*str == ',') > ++str; > @@ -212,7 +216,7 @@ swiotlb_init(int verbose) > unsigned char *vstart; > unsigned long bytes; > > - if (!io_tlb_nslabs) { > + if (!swiotlb_no_use && !io_tlb_nslabs) { > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > } > @@ -244,7 +248,7 @@ swiotlb_late_init_with_default_size(size_t default_size) > unsigned int order; > int rc = 0; > > - if (!io_tlb_nslabs) { > + if (!swiotlb_no_use && !io_tlb_nslabs) { > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > } > -- > 1.7.10.4 > > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Tuesday, April 01, 2014 9:46 PM, Konrad Rzeszutek Wilk wrote: > On Tue, Apr 01, 2014 at 10:51:58AM +0900, Jungseok Lee wrote: > > This patch corrects kernel command line handler when io_tlb_nslabs is > > set to 0. > > > > A current implementation allocates default size memory (64MB) when > > 0 is given to io_tlb_nslabs ("swiotlb=0") by kernel command line. > > In other words, memory is allocated unintentionally. > > What are the other IOMMUs that end up taking over the DMA ops? I think that no other IOMMUs take over it on ARM64 system, except Xen. > Or do you end up with no DMA ops? I focus on ARM64 system which uses swiotlb as default DMA ops. If some ARM64 platforms would like to use memory only from __get_free_pages in swiotlb_alloc_coherent function, an interface would be needed to configure reserved memory size. Thus, I add it to kernel command line handler. Best Regards Jungseok Lee > > > > Signed-off-by: Jungseok Lee <jays.lee@samsung.com> > > Signed-off-by: Sungjinn Chung <sungjinn.chung@samsung.com> > > --- > > lib/swiotlb.c | 8 ++++++-- > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > diff --git a/lib/swiotlb.c b/lib/swiotlb.c index b604b83..9fe9f71 > > 100644 > > --- a/lib/swiotlb.c > > +++ b/lib/swiotlb.c > > @@ -55,6 +55,8 @@ > > > > int swiotlb_force; > > > > +static int swiotlb_no_use; > > + > > /* > > * Used to do a quick range check in swiotlb_tbl_unmap_single and > > * swiotlb_tbl_sync_single_*, to see if the memory was in fact > > allocated by this @@ -102,6 +104,8 @@ setup_io_tlb_npages(char *str) > > io_tlb_nslabs = simple_strtoul(str, &str, 0); > > /* avoid tail segment of size < IO_TLB_SEGSIZE */ > > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > > + if (!io_tlb_nslabs) > > + swiotlb_no_use = 1; > > } > > if (*str == ',') > > ++str; > > @@ -212,7 +216,7 @@ swiotlb_init(int verbose) > > unsigned char *vstart; > > unsigned long bytes; > > > > - if (!io_tlb_nslabs) { > > + if (!swiotlb_no_use && !io_tlb_nslabs) { > > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > > } > > @@ -244,7 +248,7 @@ swiotlb_late_init_with_default_size(size_t default_size) > > unsigned int order; > > int rc = 0; > > > > - if (!io_tlb_nslabs) { > > + if (!swiotlb_no_use && !io_tlb_nslabs) { > > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > > } > > -- > > 1.7.10.4 > > > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message > to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Wed, Apr 02, 2014 at 01:36:29PM +0900, Jungseok Lee wrote: > On Tuesday, April 01, 2014 9:46 PM, Konrad Rzeszutek Wilk wrote: > > On Tue, Apr 01, 2014 at 10:51:58AM +0900, Jungseok Lee wrote: > > > This patch corrects kernel command line handler when io_tlb_nslabs is > > > set to 0. > > > > > > A current implementation allocates default size memory (64MB) when > > > 0 is given to io_tlb_nslabs ("swiotlb=0") by kernel command line. > > > In other words, memory is allocated unintentionally. > > > > What are the other IOMMUs that end up taking over the DMA ops? > > I think that no other IOMMUs take over it on ARM64 system, except Xen. > > > Or do you end up with no DMA ops? > > I focus on ARM64 system which uses swiotlb as default DMA ops. > > If some ARM64 platforms would like to use memory only from > __get_free_pages in swiotlb_alloc_coherent function, an > interface would be needed to configure reserved memory size. > > Thus, I add it to kernel command line handler. OK. I somehow have lost track of this patch. Is this patch still valid? > > Best Regards > Jungseok Lee > > > > > > > Signed-off-by: Jungseok Lee <jays.lee@samsung.com> > > > Signed-off-by: Sungjinn Chung <sungjinn.chung@samsung.com> > > > --- > > > lib/swiotlb.c | 8 ++++++-- > > > 1 file changed, 6 insertions(+), 2 deletions(-) > > > > > > diff --git a/lib/swiotlb.c b/lib/swiotlb.c index b604b83..9fe9f71 > > > 100644 > > > --- a/lib/swiotlb.c > > > +++ b/lib/swiotlb.c > > > @@ -55,6 +55,8 @@ > > > > > > int swiotlb_force; > > > > > > +static int swiotlb_no_use; > > > + > > > /* > > > * Used to do a quick range check in swiotlb_tbl_unmap_single and > > > * swiotlb_tbl_sync_single_*, to see if the memory was in fact > > > allocated by this @@ -102,6 +104,8 @@ setup_io_tlb_npages(char *str) > > > io_tlb_nslabs = simple_strtoul(str, &str, 0); > > > /* avoid tail segment of size < IO_TLB_SEGSIZE */ > > > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > > > + if (!io_tlb_nslabs) > > > + swiotlb_no_use = 1; > > > } > > > if (*str == ',') > > > ++str; > > > @@ -212,7 +216,7 @@ swiotlb_init(int verbose) > > > unsigned char *vstart; > > > unsigned long bytes; > > > > > > - if (!io_tlb_nslabs) { > > > + if (!swiotlb_no_use && !io_tlb_nslabs) { > > > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > > > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > > > } > > > @@ -244,7 +248,7 @@ swiotlb_late_init_with_default_size(size_t default_size) > > > unsigned int order; > > > int rc = 0; > > > > > > - if (!io_tlb_nslabs) { > > > + if (!swiotlb_no_use && !io_tlb_nslabs) { > > > io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); > > > io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); > > > } > > > -- > > > 1.7.10.4 > > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message > > to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/lib/swiotlb.c b/lib/swiotlb.c index b604b83..9fe9f71 100644 --- a/lib/swiotlb.c +++ b/lib/swiotlb.c @@ -55,6 +55,8 @@ int swiotlb_force; +static int swiotlb_no_use; + /* * Used to do a quick range check in swiotlb_tbl_unmap_single and * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this @@ -102,6 +104,8 @@ setup_io_tlb_npages(char *str) io_tlb_nslabs = simple_strtoul(str, &str, 0); /* avoid tail segment of size < IO_TLB_SEGSIZE */ io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); + if (!io_tlb_nslabs) + swiotlb_no_use = 1; } if (*str == ',') ++str; @@ -212,7 +216,7 @@ swiotlb_init(int verbose) unsigned char *vstart; unsigned long bytes; - if (!io_tlb_nslabs) { + if (!swiotlb_no_use && !io_tlb_nslabs) { io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); } @@ -244,7 +248,7 @@ swiotlb_late_init_with_default_size(size_t default_size) unsigned int order; int rc = 0; - if (!io_tlb_nslabs) { + if (!swiotlb_no_use && !io_tlb_nslabs) { io_tlb_nslabs = (default_size >> IO_TLB_SHIFT); io_tlb_nslabs = ALIGN(io_tlb_nslabs, IO_TLB_SEGSIZE); }
This patch corrects kernel command line handler when io_tlb_nslabs is set to 0. A current implementation allocates default size memory (64MB) when 0 is given to io_tlb_nslabs ("swiotlb=0") by kernel command line. In other words, memory is allocated unintentionally. Signed-off-by: Jungseok Lee <jays.lee@samsung.com> Signed-off-by: Sungjinn Chung <sungjinn.chung@samsung.com> --- lib/swiotlb.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)