diff options
author | Christoph Hellwig <hch@lst.de> | 2022-03-14 07:58:45 +0100 |
---|---|---|
committer | Christoph Hellwig <hch@lst.de> | 2022-04-18 07:21:13 +0200 |
commit | 3f70356edf5611c28a68d8d5a9c2b442c9eb81e6 (patch) | |
tree | 37c2b84bffa935c4c46eacf6a554aba36982fc1f /drivers/xen | |
parent | swiotlb: provide swiotlb_init variants that remap the buffer (diff) | |
download | linux-3f70356edf5611c28a68d8d5a9c2b442c9eb81e6.tar.xz linux-3f70356edf5611c28a68d8d5a9c2b442c9eb81e6.zip |
swiotlb: merge swiotlb-xen initialization into swiotlb
Reuse the generic swiotlb initialization for xen-swiotlb. For ARM/ARM64
this works trivially, while for x86 xen_swiotlb_fixup needs to be passed
as the remap argument to swiotlb_init_remap/swiotlb_init_late.
Note that the lower bound of the swiotlb size is changed to the smaller
IO_TLB_MIN_SLABS based value with this patch, but that is fine as the
2MB value used in Xen before was just an optimization and is not the
hard lower bound.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Tested-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r-- | drivers/xen/swiotlb-xen.c | 128 |
1 files changed, 1 insertions, 127 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index c2da3eb4826e..df8085b50df1 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -104,7 +104,7 @@ static int is_xen_swiotlb_buffer(struct device *dev, dma_addr_t dma_addr) return 0; } -static int xen_swiotlb_fixup(void *buf, unsigned long nslabs) +int xen_swiotlb_fixup(void *buf, unsigned long nslabs) { int rc; unsigned int order = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT); @@ -130,132 +130,6 @@ static int xen_swiotlb_fixup(void *buf, unsigned long nslabs) return 0; } -enum xen_swiotlb_err { - XEN_SWIOTLB_UNKNOWN = 0, - XEN_SWIOTLB_ENOMEM, - XEN_SWIOTLB_EFIXUP -}; - -static const char *xen_swiotlb_error(enum xen_swiotlb_err err) -{ - switch (err) { - case XEN_SWIOTLB_ENOMEM: - return "Cannot allocate Xen-SWIOTLB buffer\n"; - case XEN_SWIOTLB_EFIXUP: - return "Failed to get contiguous memory for DMA from Xen!\n"\ - "You either: don't have the permissions, do not have"\ - " enough free memory under 4GB, or the hypervisor memory"\ - " is too fragmented!"; - default: - break; - } - return ""; -} - -int xen_swiotlb_init(void) -{ - enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN; - unsigned long bytes = swiotlb_size_or_default(); - unsigned long nslabs = bytes >> IO_TLB_SHIFT; - unsigned int order, repeat = 3; - int rc = -ENOMEM; - char *start; - - if (io_tlb_default_mem.nslabs) { - pr_warn("swiotlb buffer already initialized\n"); - return -EEXIST; - } - -retry: - m_ret = XEN_SWIOTLB_ENOMEM; - order = get_order(bytes); - - /* - * Get IO TLB memory from any location. - */ -#define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT)) -#define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT) - while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) { - start = (void *)xen_get_swiotlb_free_pages(order); - if (start) - break; - order--; - } - if (!start) - goto exit; - if (order != get_order(bytes)) { - pr_warn("Warning: only able to allocate %ld MB for software IO TLB\n", - (PAGE_SIZE << order) >> 20); - nslabs = SLABS_PER_PAGE << order; - bytes = nslabs << IO_TLB_SHIFT; - } - - /* - * And replace that memory with pages under 4GB. - */ - rc = xen_swiotlb_fixup(start, nslabs); - if (rc) { - free_pages((unsigned long)start, order); - m_ret = XEN_SWIOTLB_EFIXUP; - goto error; - } - rc = swiotlb_late_init_with_tbl(start, nslabs); - if (rc) - return rc; - return 0; -error: - if (nslabs > 1024 && repeat--) { - /* Min is 2MB */ - nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE)); - bytes = nslabs << IO_TLB_SHIFT; - pr_info("Lowering to %luMB\n", bytes >> 20); - goto retry; - } -exit: - pr_err("%s (rc:%d)\n", xen_swiotlb_error(m_ret), rc); - return rc; -} - -#ifdef CONFIG_X86 -void __init xen_swiotlb_init_early(void) -{ - unsigned long bytes = swiotlb_size_or_default(); - unsigned long nslabs = bytes >> IO_TLB_SHIFT; - unsigned int repeat = 3; - char *start; - int rc; - -retry: - /* - * Get IO TLB memory from any location. - */ - start = memblock_alloc(PAGE_ALIGN(bytes), - IO_TLB_SEGSIZE << IO_TLB_SHIFT); - if (!start) - panic("%s: Failed to allocate %lu bytes\n", - __func__, PAGE_ALIGN(bytes)); - - /* - * And replace that memory with pages under 4GB. - */ - rc = xen_swiotlb_fixup(start, nslabs); - if (rc) { - memblock_free(start, PAGE_ALIGN(bytes)); - if (nslabs > 1024 && repeat--) { - /* Min is 2MB */ - nslabs = max(1024UL, ALIGN(nslabs >> 1, IO_TLB_SEGSIZE)); - bytes = nslabs << IO_TLB_SHIFT; - pr_info("Lowering to %luMB\n", bytes >> 20); - goto retry; - } - panic("%s (rc:%d)", xen_swiotlb_error(XEN_SWIOTLB_EFIXUP), rc); - } - - if (swiotlb_init_with_tbl(start, nslabs, SWIOTLB_VERBOSE)) - panic("Cannot allocate SWIOTLB buffer"); -} -#endif /* CONFIG_X86 */ - static void * xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size, dma_addr_t *dma_handle, gfp_t flags, |