Re: [PATCH v3] swiotlb: Make SWIOTLB_NO_FORCE perform no allocation
On 4/9/2021 12:32 PM, Konrad Rzeszutek Wilk wrote: > On Thu, Apr 08, 2021 at 08:13:07PM -0700, Florian Fainelli wrote: >> >> >> On 3/24/2021 1:42 AM, Christoph Hellwig wrote: >>> On Mon, Mar 22, 2021 at 06:53:49PM -0700, Florian Fainelli wrote: When SWIOTLB_NO_FORCE is used, there should really be no allocations of default_nslabs to occur since we are not going to use those slabs. If a platform was somehow setting swiotlb_no_force and a later call to swiotlb_init() was to be made we would still be proceeding with allocating the default SWIOTLB size (64MB), whereas if swiotlb=noforce was set on the kernel command line we would have only allocated 2KB. This would be inconsistent and the point of initializing default_nslabs to 1, was intended to allocate the minimum amount of memory possible, so simply remove that minimal allocation period. Signed-off-by: Florian Fainelli >>> >>> Looks good, >>> >>> Reviewed-by: Christoph Hellwig >>> >> >> Thanks! Konrad, can you apply this patch to your for-linus-5.13 branch >> if you are also happy with it? > > It should be now visible? Not seeing it here: https://git.kernel.org/pub/scm/linux/kernel/git/konrad/swiotlb.git/log/?h=devel/for-linus-5.13 -- Florian ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3] swiotlb: Make SWIOTLB_NO_FORCE perform no allocation
On Thu, Apr 08, 2021 at 08:13:07PM -0700, Florian Fainelli wrote: > > > On 3/24/2021 1:42 AM, Christoph Hellwig wrote: > > On Mon, Mar 22, 2021 at 06:53:49PM -0700, Florian Fainelli wrote: > >> When SWIOTLB_NO_FORCE is used, there should really be no allocations of > >> default_nslabs to occur since we are not going to use those slabs. If a > >> platform was somehow setting swiotlb_no_force and a later call to > >> swiotlb_init() was to be made we would still be proceeding with > >> allocating the default SWIOTLB size (64MB), whereas if swiotlb=noforce > >> was set on the kernel command line we would have only allocated 2KB. > >> > >> This would be inconsistent and the point of initializing default_nslabs > >> to 1, was intended to allocate the minimum amount of memory possible, so > >> simply remove that minimal allocation period. > >> > >> Signed-off-by: Florian Fainelli > > > > Looks good, > > > > Reviewed-by: Christoph Hellwig > > > > Thanks! Konrad, can you apply this patch to your for-linus-5.13 branch > if you are also happy with it? It should be now visible? > -- > Florian ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3] swiotlb: Make SWIOTLB_NO_FORCE perform no allocation
On 3/24/2021 1:42 AM, Christoph Hellwig wrote: > On Mon, Mar 22, 2021 at 06:53:49PM -0700, Florian Fainelli wrote: >> When SWIOTLB_NO_FORCE is used, there should really be no allocations of >> default_nslabs to occur since we are not going to use those slabs. If a >> platform was somehow setting swiotlb_no_force and a later call to >> swiotlb_init() was to be made we would still be proceeding with >> allocating the default SWIOTLB size (64MB), whereas if swiotlb=noforce >> was set on the kernel command line we would have only allocated 2KB. >> >> This would be inconsistent and the point of initializing default_nslabs >> to 1, was intended to allocate the minimum amount of memory possible, so >> simply remove that minimal allocation period. >> >> Signed-off-by: Florian Fainelli > > Looks good, > > Reviewed-by: Christoph Hellwig > Thanks! Konrad, can you apply this patch to your for-linus-5.13 branch if you are also happy with it? -- Florian ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
Re: [PATCH v3] swiotlb: Make SWIOTLB_NO_FORCE perform no allocation
On Mon, Mar 22, 2021 at 06:53:49PM -0700, Florian Fainelli wrote: > When SWIOTLB_NO_FORCE is used, there should really be no allocations of > default_nslabs to occur since we are not going to use those slabs. If a > platform was somehow setting swiotlb_no_force and a later call to > swiotlb_init() was to be made we would still be proceeding with > allocating the default SWIOTLB size (64MB), whereas if swiotlb=noforce > was set on the kernel command line we would have only allocated 2KB. > > This would be inconsistent and the point of initializing default_nslabs > to 1, was intended to allocate the minimum amount of memory possible, so > simply remove that minimal allocation period. > > Signed-off-by: Florian Fainelli Looks good, Reviewed-by: Christoph Hellwig ___ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
[PATCH v3] swiotlb: Make SWIOTLB_NO_FORCE perform no allocation
When SWIOTLB_NO_FORCE is used, there should really be no allocations of
default_nslabs to occur since we are not going to use those slabs. If a
platform was somehow setting swiotlb_no_force and a later call to
swiotlb_init() was to be made we would still be proceeding with
allocating the default SWIOTLB size (64MB), whereas if swiotlb=noforce
was set on the kernel command line we would have only allocated 2KB.
This would be inconsistent and the point of initializing default_nslabs
to 1, was intended to allocate the minimum amount of memory possible, so
simply remove that minimal allocation period.
Signed-off-by: Florian Fainelli
---
Changes in v3:
- patch all call sites that can allocate SWIOTLB memory
Changes in v2:
- rebased against devel/for-linus-5.13
- updated commit message to reflect variable names
kernel/dma/swiotlb.c | 18 ++
1 file changed, 14 insertions(+), 4 deletions(-)
diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c
index 539c76beb52e..0a5b6f7e75bc 100644
--- a/kernel/dma/swiotlb.c
+++ b/kernel/dma/swiotlb.c
@@ -83,12 +83,10 @@ setup_io_tlb_npages(char *str)
}
if (*str == ',')
++str;
- if (!strcmp(str, "force")) {
+ if (!strcmp(str, "force"))
swiotlb_force = SWIOTLB_FORCE;
- } else if (!strcmp(str, "noforce")) {
+ else if (!strcmp(str, "noforce"))
swiotlb_force = SWIOTLB_NO_FORCE;
- default_nslabs = 1;
- }
return 0;
}
@@ -174,6 +172,9 @@ int __init swiotlb_init_with_tbl(char *tlb, unsigned long
nslabs, int verbose)
struct io_tlb_mem *mem;
size_t alloc_size;
+ if (swiotlb_force == SWIOTLB_NO_FORCE)
+ return 0;
+
/* protect against double initialization */
if (WARN_ON_ONCE(io_tlb_default_mem))
return -ENOMEM;
@@ -211,6 +212,9 @@ swiotlb_init(int verbose)
size_t bytes = PAGE_ALIGN(default_nslabs << IO_TLB_SHIFT);
void *tlb;
+ if (swiotlb_force == SWIOTLB_NO_FORCE)
+ return;
+
/* Get IO TLB memory from the low pages */
tlb = memblock_alloc_low(bytes, PAGE_SIZE);
if (!tlb)
@@ -240,6 +244,9 @@ swiotlb_late_init_with_default_size(size_t default_size)
unsigned int order;
int rc = 0;
+ if (swiotlb_force == SWIOTLB_NO_FORCE)
+ return 0;
+
/*
* Get IO TLB memory from the low pages
*/
@@ -276,6 +283,9 @@ swiotlb_late_init_with_tbl(char *tlb, unsigned long nslabs)
unsigned long bytes = nslabs << IO_TLB_SHIFT, i;
struct io_tlb_mem *mem;
+ if (swiotlb_force == SWIOTLB_NO_FORCE)
+ return 0;
+
/* protect against double initialization */
if (WARN_ON_ONCE(io_tlb_default_mem))
return -ENOMEM;
--
2.25.1
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