From: hch@xxxxxxxxxxxxx <hch@xxxxxxxxxxxxx> Sent: Thursday, July 21, 2022 10:05 PM > > On Fri, Jul 22, 2022 at 04:03:21AM +0000, Michael Kelley (LINUX) wrote: > > I think you missed one of the bugs I pointed out in my previous > > comments. In the function rmem_swiotlb_device_init(), the two > > calls to kfree() in the error path are in the wrong order. It's a > > path that will probably never happen, but it still should be fixed. > > That is already fixed in the dma-mapping tree: > > http://git.infradead.org/users/hch/dma-mapping.git/commitdiff/4a97739474c402e0a14cf6a432f1920262f6811c Indeed. > > > The other fixes look good to me. > > Can you make that a formal Reviewed-by? Yes. Reviewed-by: Michael Kelley <mikelley@xxxxxxxxxxxxx> > > > > > Michael > > > > > Fixes: 26ffb91fa5e0 ("swiotlb: split up the global swiotlb lock") > > > Signed-off-by: Tianyu Lan <tiala@xxxxxxxxxxxxx> > > > --- > > > .../admin-guide/kernel-parameters.txt | 3 +- > > > kernel/dma/swiotlb.c | 42 ++++++++++++------- > > > 2 files changed, 30 insertions(+), 15 deletions(-) > > > > > > diff --git a/Documentation/admin-guide/kernel-parameters.txt > > > b/Documentation/admin-guide/kernel-parameters.txt > > > index 4a6ad177d4b8..ddca09550f76 100644 > > > --- a/Documentation/admin-guide/kernel-parameters.txt > > > +++ b/Documentation/admin-guide/kernel-parameters.txt > > > @@ -5907,7 +5907,8 @@ > > > Format: { <int> [,<int>] | force | noforce } > > > <int> -- Number of I/O TLB slabs > > > <int> -- Second integer after comma. Number of swiotlb > > > - areas with their own lock. Must be power of 2. > > > + areas with their own lock. Will be rounded up > > > + to a power of 2. > > > force -- force using of bounce buffers even if they > > > wouldn't be automatically used by the kernel > > > noforce -- Never use bounce buffers (for debugging) > > > diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c > > > index c39483bf067d..5752db98a1f2 100644 > > > --- a/kernel/dma/swiotlb.c > > > +++ b/kernel/dma/swiotlb.c > > > @@ -96,7 +96,13 @@ struct io_tlb_slot { > > > > > > static void swiotlb_adjust_nareas(unsigned int nareas) > > > { > > > - if (!is_power_of_2(nareas)) > > > + /* > > > + * Set area number to 1 when input area number > > > + * is zero. > > > + */ > > > + if (!nareas) > > > + nareas = 1; > > > + else if (!is_power_of_2(nareas)) > > > nareas = roundup_pow_of_two(nareas); > > > > > > default_nareas = nareas; > > > @@ -270,6 +276,7 @@ static void swiotlb_init_io_tlb_mem(struct io_tlb_mem > *mem, > > > phys_addr_t start, > > > for (i = 0; i < mem->nareas; i++) { > > > spin_lock_init(&mem->areas[i].lock); > > > mem->areas[i].index = 0; > > > + mem->areas[i].used = 0; > > > } > > > > > > for (i = 0; i < mem->nslabs; i++) { > > > @@ -353,8 +360,8 @@ void __init swiotlb_init_remap(bool addressing_limit, > unsigned > > > int flags, > > > panic("%s: Failed to allocate %zu bytes align=0x%lx\n", > > > __func__, alloc_size, PAGE_SIZE); > > > > > > - mem->areas = memblock_alloc(sizeof(struct io_tlb_area) * > > > - default_nareas, SMP_CACHE_BYTES); > > > + mem->areas = memblock_alloc(array_size(sizeof(struct io_tlb_area), > > > + default_nareas), SMP_CACHE_BYTES); > > > if (!mem->areas) > > > panic("%s: Failed to allocate mem->areas.\n", __func__); > > > > > > @@ -479,7 +486,7 @@ void __init swiotlb_exit(void) > > > free_pages((unsigned long)mem->slots, get_order(slots_size)); > > > } else { > > > memblock_free_late(__pa(mem->areas), > > > - mem->nareas * sizeof(struct io_tlb_area)); > > > + array_size(sizeof(*mem->areas), mem->nareas)); > > > memblock_free_late(mem->start, tbl_size); > > > memblock_free_late(__pa(mem->slots), slots_size); > > > } > > > @@ -593,11 +600,12 @@ static unsigned int wrap_area_index(struct io_tlb_mem > > > *mem, unsigned int index) > > > * Find a suitable number of IO TLB entries size that will fit this request and > > > * allocate a buffer from that IO TLB pool. > > > */ > > > -static int swiotlb_do_find_slots(struct io_tlb_mem *mem, > > > - struct io_tlb_area *area, int area_index, > > > - struct device *dev, phys_addr_t orig_addr, > > > +static int swiotlb_do_find_slots(struct device *dev, > > > + int area_index, phys_addr_t orig_addr, > > > size_t alloc_size, unsigned int alloc_align_mask) > > > { > > > + struct io_tlb_mem *mem = dev->dma_io_tlb_mem; > > > + struct io_tlb_area *area = mem->areas + area_index; > > > unsigned long boundary_mask = dma_get_seg_boundary(dev); > > > dma_addr_t tbl_dma_addr = > > > phys_to_dma_unencrypted(dev, mem->start) & boundary_mask; > > > @@ -686,13 +694,12 @@ static int swiotlb_find_slots(struct device *dev, > phys_addr_t > > > orig_addr, > > > size_t alloc_size, unsigned int alloc_align_mask) > > > { > > > struct io_tlb_mem *mem = dev->dma_io_tlb_mem; > > > - int start = raw_smp_processor_id() & ((1U << __fls(mem->nareas)) - 1); > > > + int start = raw_smp_processor_id() & (mem->nareas - 1); > > > int i = start, index; > > > > > > do { > > > - index = swiotlb_do_find_slots(mem, mem->areas + i, i, > > > - dev, orig_addr, alloc_size, > > > - alloc_align_mask); > > > + index = swiotlb_do_find_slots(dev, i, orig_addr, > > > + alloc_size, alloc_align_mask); > > > if (index >= 0) > > > return index; > > > if (++i >= mem->nareas) > > > @@ -903,17 +910,24 @@ bool is_swiotlb_active(struct device *dev) > > > } > > > EXPORT_SYMBOL_GPL(is_swiotlb_active); > > > > > > +static int io_tlb_used_get(void *data, u64 *val) > > > +{ > > > + *val = mem_used(&io_tlb_default_mem); > > > + > > > + return 0; > > > +} > > > +DEFINE_DEBUGFS_ATTRIBUTE(fops_io_tlb_used, io_tlb_used_get, NULL, "%llu\n"); > > > + > > > static void swiotlb_create_debugfs_files(struct io_tlb_mem *mem, > > > const char *dirname) > > > { > > > - unsigned long used = mem_used(mem); > > > - > > > mem->debugfs = debugfs_create_dir(dirname, io_tlb_default_mem.debugfs); > > > if (!mem->nslabs) > > > return; > > > > > > debugfs_create_ulong("io_tlb_nslabs", 0400, mem->debugfs, &mem->nslabs); > > > - debugfs_create_ulong("io_tlb_used", 0400, mem->debugfs, &used); > > > + debugfs_create_file_unsafe("io_tlb_used", 0400, mem->debugfs, NULL, > > > + &fops_io_tlb_used); > > > } > > > > > > static int __init __maybe_unused swiotlb_create_default_debugfs(void) > > > -- > > > 2.25.1 > > > ---end quoted text---
