diff options
Diffstat (limited to 'kernel/dma/direct.c')
| -rw-r--r-- | kernel/dma/direct.c | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index ed3056eb20b8..73c95815789a 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -587,6 +587,46 @@ int dma_direct_supported(struct device *dev, u64 mask) return mask >= phys_to_dma_unencrypted(dev, min_mask); } +/* + * To check whether all ram resource ranges are covered by dma range map + * Returns 0 when further check is needed + * Returns 1 if there is some RAM range can't be covered by dma_range_map + */ +static int check_ram_in_range_map(unsigned long start_pfn, + unsigned long nr_pages, void *data) +{ + unsigned long end_pfn = start_pfn + nr_pages; + const struct bus_dma_region *bdr = NULL; + const struct bus_dma_region *m; + struct device *dev = data; + + while (start_pfn < end_pfn) { + for (m = dev->dma_range_map; PFN_DOWN(m->size); m++) { + unsigned long cpu_start_pfn = PFN_DOWN(m->cpu_start); + + if (start_pfn >= cpu_start_pfn && + start_pfn - cpu_start_pfn < PFN_DOWN(m->size)) { + bdr = m; + break; + } + } + if (!bdr) + return 1; + + start_pfn = PFN_DOWN(bdr->cpu_start) + PFN_DOWN(bdr->size); + } + + return 0; +} + +bool dma_direct_all_ram_mapped(struct device *dev) +{ + if (!dev->dma_range_map) + return true; + return !walk_system_ram_range(0, PFN_DOWN(ULONG_MAX) + 1, dev, + check_ram_in_range_map); +} + size_t dma_direct_max_mapping_size(struct device *dev) { /* If SWIOTLB is active, use its maximum mapping size */ |