diff options
Diffstat (limited to 'arch/arc')
| -rw-r--r-- | arch/arc/kernel/time.c | 19 | ||||
| -rw-r--r-- | arch/arc/mm/dma.c | 26 |
2 files changed, 37 insertions, 8 deletions
diff --git a/arch/arc/kernel/time.c b/arch/arc/kernel/time.c index f927b8dc6..c10390d1d 100644 --- a/arch/arc/kernel/time.c +++ b/arch/arc/kernel/time.c @@ -152,14 +152,17 @@ static cycle_t arc_read_rtc(struct clocksource *cs) cycle_t full; } stamp; - - __asm__ __volatile( - "1: \n" - " lr %0, [AUX_RTC_LOW] \n" - " lr %1, [AUX_RTC_HIGH] \n" - " lr %2, [AUX_RTC_CTRL] \n" - " bbit0.nt %2, 31, 1b \n" - : "=r" (stamp.low), "=r" (stamp.high), "=r" (status)); + /* + * hardware has an internal state machine which tracks readout of + * low/high and updates the CTRL.status if + * - interrupt/exception taken between the two reads + * - high increments after low has been read + */ + do { + stamp.low = read_aux_reg(AUX_RTC_LOW); + stamp.high = read_aux_reg(AUX_RTC_HIGH); + status = read_aux_reg(AUX_RTC_CTRL); + } while (!(status & _BITUL(31))); return stamp.full; } diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c index 20afc65e2..9288851d4 100644 --- a/arch/arc/mm/dma.c +++ b/arch/arc/mm/dma.c @@ -105,6 +105,31 @@ static void arc_dma_free(struct device *dev, size_t size, void *vaddr, __free_pages(page, get_order(size)); } +static int arc_dma_mmap(struct device *dev, struct vm_area_struct *vma, + void *cpu_addr, dma_addr_t dma_addr, size_t size, + unsigned long attrs) +{ + unsigned long user_count = vma_pages(vma); + unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT; + unsigned long pfn = __phys_to_pfn(plat_dma_to_phys(dev, dma_addr)); + unsigned long off = vma->vm_pgoff; + int ret = -ENXIO; + + vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot); + + if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret)) + return ret; + + if (off < count && user_count <= (count - off)) { + ret = remap_pfn_range(vma, vma->vm_start, + pfn + off, + user_count << PAGE_SHIFT, + vma->vm_page_prot); + } + + return ret; +} + /* * streaming DMA Mapping API... * CPU accesses page via normal paddr, thus needs to explicitly made @@ -193,6 +218,7 @@ static int arc_dma_supported(struct device *dev, u64 dma_mask) struct dma_map_ops arc_dma_ops = { .alloc = arc_dma_alloc, .free = arc_dma_free, + .mmap = arc_dma_mmap, .map_page = arc_dma_map_page, .map_sg = arc_dma_map_sg, .sync_single_for_device = arc_dma_sync_single_for_device, |