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| author |   Florian Fainelli <f.fainelli@gmail.com> | 2021-03-22 18:53:49 -0700 |
|---|---|---|
| committer |   Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2021-04-01 20:46:38 +0000 |
| commit | 2726bf3ff2520dba61fafc90a055640f7ad54e05 (patch) | |
| tree | 97e589d7005a07c5b58f4f0f6650f0c0a1645469 /kernel/dma | |
| parent | ARM: Qualify enabling of swiotlb_init() (diff) | |
| download | linux-dev-2726bf3ff2520dba61fafc90a055640f7ad54e05.tar.xz linux-dev-2726bf3ff2520dba61fafc90a055640f7ad54e05.zip | |
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 <f.fainelli@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/swiotlb.c | 18 |
1 files 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; |