3 * by Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
5 * This code provides a IOMMU for Xen PV guests with PCI passthrough.
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License v2.0 as published by
9 * the Free Software Foundation
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * PV guests under Xen are running in an non-contiguous memory architecture.
18 * When PCI pass-through is utilized, this necessitates an IOMMU for
19 * translating bus (DMA) to virtual and vice-versa and also providing a
20 * mechanism to have contiguous pages for device drivers operations (say DMA
23 * Specifically, under Xen the Linux idea of pages is an illusion. It
24 * assumes that pages start at zero and go up to the available memory. To
25 * help with that, the Linux Xen MMU provides a lookup mechanism to
26 * translate the page frame numbers (PFN) to machine frame numbers (MFN)
27 * and vice-versa. The MFN are the "real" frame numbers. Furthermore
28 * memory is not contiguous. Xen hypervisor stitches memory for guests
29 * from different pools, which means there is no guarantee that PFN==MFN
30 * and PFN+1==MFN+1. Lastly with Xen 4.0, pages (in debug mode) are
31 * allocated in descending order (high to low), meaning the guest might
32 * never get any MFN's under the 4GB mark.
36 #define pr_fmt(fmt) "xen:" KBUILD_MODNAME ": " fmt
38 #include <linux/bootmem.h>
39 #include <linux/dma-mapping.h>
40 #include <linux/export.h>
41 #include <xen/swiotlb-xen.h>
43 #include <xen/xen-ops.h>
44 #include <xen/hvc-console.h>
46 #include <asm/dma-mapping.h>
47 #include <asm/xen/page-coherent.h>
49 #include <trace/events/swiotlb.h>
51 * Used to do a quick range check in swiotlb_tbl_unmap_single and
52 * swiotlb_tbl_sync_single_*, to see if the memory was in fact allocated by this
57 static unsigned long dma_alloc_coherent_mask(struct device *dev,
60 unsigned long dma_mask = 0;
62 dma_mask = dev->coherent_dma_mask;
64 dma_mask = (gfp & GFP_DMA) ? DMA_BIT_MASK(24) : DMA_BIT_MASK(32);
70 #define XEN_SWIOTLB_ERROR_CODE (~(dma_addr_t)0x0)
72 static char *xen_io_tlb_start, *xen_io_tlb_end;
73 static unsigned long xen_io_tlb_nslabs;
75 * Quick lookup value of the bus address of the IOTLB.
78 static u64 start_dma_addr;
81 * Both of these functions should avoid XEN_PFN_PHYS because phys_addr_t
82 * can be 32bit when dma_addr_t is 64bit leading to a loss in
83 * information if the shift is done before casting to 64bit.
85 static inline dma_addr_t xen_phys_to_bus(phys_addr_t paddr)
87 unsigned long bfn = pfn_to_bfn(XEN_PFN_DOWN(paddr));
88 dma_addr_t dma = (dma_addr_t)bfn << XEN_PAGE_SHIFT;
90 dma |= paddr & ~XEN_PAGE_MASK;
95 static inline phys_addr_t xen_bus_to_phys(dma_addr_t baddr)
97 unsigned long xen_pfn = bfn_to_pfn(XEN_PFN_DOWN(baddr));
98 dma_addr_t dma = (dma_addr_t)xen_pfn << XEN_PAGE_SHIFT;
99 phys_addr_t paddr = dma;
101 paddr |= baddr & ~XEN_PAGE_MASK;
106 static inline dma_addr_t xen_virt_to_bus(void *address)
108 return xen_phys_to_bus(virt_to_phys(address));
111 static int check_pages_physically_contiguous(unsigned long xen_pfn,
115 unsigned long next_bfn;
119 next_bfn = pfn_to_bfn(xen_pfn);
120 nr_pages = (offset + length + XEN_PAGE_SIZE-1) >> XEN_PAGE_SHIFT;
122 for (i = 1; i < nr_pages; i++) {
123 if (pfn_to_bfn(++xen_pfn) != ++next_bfn)
129 static inline int range_straddles_page_boundary(phys_addr_t p, size_t size)
131 unsigned long xen_pfn = XEN_PFN_DOWN(p);
132 unsigned int offset = p & ~XEN_PAGE_MASK;
134 if (offset + size <= XEN_PAGE_SIZE)
136 if (check_pages_physically_contiguous(xen_pfn, offset, size))
141 static int is_xen_swiotlb_buffer(dma_addr_t dma_addr)
143 unsigned long bfn = XEN_PFN_DOWN(dma_addr);
144 unsigned long xen_pfn = bfn_to_local_pfn(bfn);
145 phys_addr_t paddr = XEN_PFN_PHYS(xen_pfn);
147 /* If the address is outside our domain, it CAN
148 * have the same virtual address as another address
149 * in our domain. Therefore _only_ check address within our domain.
151 if (pfn_valid(PFN_DOWN(paddr))) {
152 return paddr >= virt_to_phys(xen_io_tlb_start) &&
153 paddr < virt_to_phys(xen_io_tlb_end);
158 static int max_dma_bits = 32;
161 xen_swiotlb_fixup(void *buf, size_t size, unsigned long nslabs)
165 dma_addr_t dma_handle;
166 phys_addr_t p = virt_to_phys(buf);
168 dma_bits = get_order(IO_TLB_SEGSIZE << IO_TLB_SHIFT) + PAGE_SHIFT;
172 int slabs = min(nslabs - i, (unsigned long)IO_TLB_SEGSIZE);
175 rc = xen_create_contiguous_region(
176 p + (i << IO_TLB_SHIFT),
177 get_order(slabs << IO_TLB_SHIFT),
178 dma_bits, &dma_handle);
179 } while (rc && dma_bits++ < max_dma_bits);
184 } while (i < nslabs);
187 static unsigned long xen_set_nslabs(unsigned long nr_tbl)
190 xen_io_tlb_nslabs = (64 * 1024 * 1024 >> IO_TLB_SHIFT);
191 xen_io_tlb_nslabs = ALIGN(xen_io_tlb_nslabs, IO_TLB_SEGSIZE);
193 xen_io_tlb_nslabs = nr_tbl;
195 return xen_io_tlb_nslabs << IO_TLB_SHIFT;
198 enum xen_swiotlb_err {
199 XEN_SWIOTLB_UNKNOWN = 0,
204 static const char *xen_swiotlb_error(enum xen_swiotlb_err err)
207 case XEN_SWIOTLB_ENOMEM:
208 return "Cannot allocate Xen-SWIOTLB buffer\n";
209 case XEN_SWIOTLB_EFIXUP:
210 return "Failed to get contiguous memory for DMA from Xen!\n"\
211 "You either: don't have the permissions, do not have"\
212 " enough free memory under 4GB, or the hypervisor memory"\
213 " is too fragmented!";
219 int __ref xen_swiotlb_init(int verbose, bool early)
221 unsigned long bytes, order;
223 enum xen_swiotlb_err m_ret = XEN_SWIOTLB_UNKNOWN;
224 unsigned int repeat = 3;
226 xen_io_tlb_nslabs = swiotlb_nr_tbl();
228 bytes = xen_set_nslabs(xen_io_tlb_nslabs);
229 order = get_order(xen_io_tlb_nslabs << IO_TLB_SHIFT);
231 * Get IO TLB memory from any location.
234 xen_io_tlb_start = alloc_bootmem_pages(PAGE_ALIGN(bytes));
236 #define SLABS_PER_PAGE (1 << (PAGE_SHIFT - IO_TLB_SHIFT))
237 #define IO_TLB_MIN_SLABS ((1<<20) >> IO_TLB_SHIFT)
238 while ((SLABS_PER_PAGE << order) > IO_TLB_MIN_SLABS) {
239 xen_io_tlb_start = (void *)xen_get_swiotlb_free_pages(order);
240 if (xen_io_tlb_start)
244 if (order != get_order(bytes)) {
245 pr_warn("Warning: only able to allocate %ld MB for software IO TLB\n",
246 (PAGE_SIZE << order) >> 20);
247 xen_io_tlb_nslabs = SLABS_PER_PAGE << order;
248 bytes = xen_io_tlb_nslabs << IO_TLB_SHIFT;
251 if (!xen_io_tlb_start) {
252 m_ret = XEN_SWIOTLB_ENOMEM;
255 xen_io_tlb_end = xen_io_tlb_start + bytes;
257 * And replace that memory with pages under 4GB.
259 rc = xen_swiotlb_fixup(xen_io_tlb_start,
264 free_bootmem(__pa(xen_io_tlb_start), PAGE_ALIGN(bytes));
266 free_pages((unsigned long)xen_io_tlb_start, order);
267 xen_io_tlb_start = NULL;
269 m_ret = XEN_SWIOTLB_EFIXUP;
272 start_dma_addr = xen_virt_to_bus(xen_io_tlb_start);
274 if (swiotlb_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs,
276 panic("Cannot allocate SWIOTLB buffer");
279 rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs);
282 swiotlb_set_max_segment(PAGE_SIZE);
287 xen_io_tlb_nslabs = max(1024UL, /* Min is 2MB */
288 (xen_io_tlb_nslabs >> 1));
289 pr_info("Lowering to %luMB\n",
290 (xen_io_tlb_nslabs << IO_TLB_SHIFT) >> 20);
293 pr_err("%s (rc:%d)\n", xen_swiotlb_error(m_ret), rc);
295 panic("%s (rc:%d)", xen_swiotlb_error(m_ret), rc);
297 free_pages((unsigned long)xen_io_tlb_start, order);
302 xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
303 dma_addr_t *dma_handle, gfp_t flags,
307 int order = get_order(size);
308 u64 dma_mask = DMA_BIT_MASK(32);
313 * Ignore region specifiers - the kernel's ideas of
314 * pseudo-phys memory layout has nothing to do with the
315 * machine physical layout. We can't allocate highmem
316 * because we can't return a pointer to it.
318 flags &= ~(__GFP_DMA | __GFP_HIGHMEM);
320 /* Convert the size to actually allocated. */
321 size = 1UL << (order + XEN_PAGE_SHIFT);
323 /* On ARM this function returns an ioremap'ped virtual address for
324 * which virt_to_phys doesn't return the corresponding physical
325 * address. In fact on ARM virt_to_phys only works for kernel direct
326 * mapped RAM memory. Also see comment below.
328 ret = xen_alloc_coherent_pages(hwdev, size, dma_handle, flags, attrs);
333 if (hwdev && hwdev->coherent_dma_mask)
334 dma_mask = dma_alloc_coherent_mask(hwdev, flags);
336 /* At this point dma_handle is the physical address, next we are
337 * going to set it to the machine address.
338 * Do not use virt_to_phys(ret) because on ARM it doesn't correspond
341 dev_addr = xen_phys_to_bus(phys);
342 if (((dev_addr + size - 1 <= dma_mask)) &&
343 !range_straddles_page_boundary(phys, size))
344 *dma_handle = dev_addr;
346 if (xen_create_contiguous_region(phys, order,
347 fls64(dma_mask), dma_handle) != 0) {
348 xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs);
352 memset(ret, 0, size);
357 xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
358 dma_addr_t dev_addr, unsigned long attrs)
360 int order = get_order(size);
362 u64 dma_mask = DMA_BIT_MASK(32);
364 if (hwdev && hwdev->coherent_dma_mask)
365 dma_mask = hwdev->coherent_dma_mask;
367 /* do not use virt_to_phys because on ARM it doesn't return you the
368 * physical address */
369 phys = xen_bus_to_phys(dev_addr);
371 /* Convert the size to actually allocated. */
372 size = 1UL << (order + XEN_PAGE_SHIFT);
374 if (!WARN_ON((dev_addr + size - 1 > dma_mask) ||
375 range_straddles_page_boundary(phys, size)))
376 xen_destroy_contiguous_region(phys, order);
378 xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);
382 * Map a single buffer of the indicated size for DMA in streaming mode. The
383 * physical address to use is returned.
385 * Once the device is given the dma address, the device owns this memory until
386 * either xen_swiotlb_unmap_page or xen_swiotlb_dma_sync_single is performed.
388 static dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page,
389 unsigned long offset, size_t size,
390 enum dma_data_direction dir,
393 phys_addr_t map, phys = page_to_phys(page) + offset;
394 dma_addr_t dev_addr = xen_phys_to_bus(phys);
396 BUG_ON(dir == DMA_NONE);
398 * If the address happens to be in the device's DMA window,
399 * we can safely return the device addr and not worry about bounce
402 if (dma_capable(dev, dev_addr, size) &&
403 !range_straddles_page_boundary(phys, size) &&
404 !xen_arch_need_swiotlb(dev, phys, dev_addr) &&
405 (swiotlb_force != SWIOTLB_FORCE)) {
406 /* we are not interested in the dma_addr returned by
407 * xen_dma_map_page, only in the potential cache flushes executed
408 * by the function. */
409 xen_dma_map_page(dev, page, dev_addr, offset, size, dir, attrs);
414 * Oh well, have to allocate and map a bounce buffer.
416 trace_swiotlb_bounced(dev, dev_addr, size, swiotlb_force);
418 map = swiotlb_tbl_map_single(dev, start_dma_addr, phys, size, dir,
420 if (map == SWIOTLB_MAP_ERROR)
421 return XEN_SWIOTLB_ERROR_CODE;
423 dev_addr = xen_phys_to_bus(map);
424 xen_dma_map_page(dev, pfn_to_page(map >> PAGE_SHIFT),
425 dev_addr, map & ~PAGE_MASK, size, dir, attrs);
428 * Ensure that the address returned is DMA'ble
430 if (dma_capable(dev, dev_addr, size))
433 attrs |= DMA_ATTR_SKIP_CPU_SYNC;
434 swiotlb_tbl_unmap_single(dev, map, size, dir, attrs);
436 return XEN_SWIOTLB_ERROR_CODE;
440 * Unmap a single streaming mode DMA translation. The dma_addr and size must
441 * match what was provided for in a previous xen_swiotlb_map_page call. All
442 * other usages are undefined.
444 * After this call, reads by the cpu to the buffer are guaranteed to see
445 * whatever the device wrote there.
447 static void xen_unmap_single(struct device *hwdev, dma_addr_t dev_addr,
448 size_t size, enum dma_data_direction dir,
451 phys_addr_t paddr = xen_bus_to_phys(dev_addr);
453 BUG_ON(dir == DMA_NONE);
455 xen_dma_unmap_page(hwdev, dev_addr, size, dir, attrs);
457 /* NOTE: We use dev_addr here, not paddr! */
458 if (is_xen_swiotlb_buffer(dev_addr)) {
459 swiotlb_tbl_unmap_single(hwdev, paddr, size, dir, attrs);
463 if (dir != DMA_FROM_DEVICE)
467 * phys_to_virt doesn't work with hihgmem page but we could
468 * call dma_mark_clean() with hihgmem page here. However, we
469 * are fine since dma_mark_clean() is null on POWERPC. We can
470 * make dma_mark_clean() take a physical address if necessary.
472 dma_mark_clean(phys_to_virt(paddr), size);
475 static void xen_swiotlb_unmap_page(struct device *hwdev, dma_addr_t dev_addr,
476 size_t size, enum dma_data_direction dir,
479 xen_unmap_single(hwdev, dev_addr, size, dir, attrs);
483 * Make physical memory consistent for a single streaming mode DMA translation
486 * If you perform a xen_swiotlb_map_page() but wish to interrogate the buffer
487 * using the cpu, yet do not wish to teardown the dma mapping, you must
488 * call this function before doing so. At the next point you give the dma
489 * address back to the card, you must first perform a
490 * xen_swiotlb_dma_sync_for_device, and then the device again owns the buffer
493 xen_swiotlb_sync_single(struct device *hwdev, dma_addr_t dev_addr,
494 size_t size, enum dma_data_direction dir,
495 enum dma_sync_target target)
497 phys_addr_t paddr = xen_bus_to_phys(dev_addr);
499 BUG_ON(dir == DMA_NONE);
501 if (target == SYNC_FOR_CPU)
502 xen_dma_sync_single_for_cpu(hwdev, dev_addr, size, dir);
504 /* NOTE: We use dev_addr here, not paddr! */
505 if (is_xen_swiotlb_buffer(dev_addr))
506 swiotlb_tbl_sync_single(hwdev, paddr, size, dir, target);
508 if (target == SYNC_FOR_DEVICE)
509 xen_dma_sync_single_for_device(hwdev, dev_addr, size, dir);
511 if (dir != DMA_FROM_DEVICE)
514 dma_mark_clean(phys_to_virt(paddr), size);
518 xen_swiotlb_sync_single_for_cpu(struct device *hwdev, dma_addr_t dev_addr,
519 size_t size, enum dma_data_direction dir)
521 xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_CPU);
525 xen_swiotlb_sync_single_for_device(struct device *hwdev, dma_addr_t dev_addr,
526 size_t size, enum dma_data_direction dir)
528 xen_swiotlb_sync_single(hwdev, dev_addr, size, dir, SYNC_FOR_DEVICE);
532 * Unmap a set of streaming mode DMA translations. Again, cpu read rules
533 * concerning calls here are the same as for swiotlb_unmap_page() above.
536 xen_swiotlb_unmap_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
537 int nelems, enum dma_data_direction dir,
540 struct scatterlist *sg;
543 BUG_ON(dir == DMA_NONE);
545 for_each_sg(sgl, sg, nelems, i)
546 xen_unmap_single(hwdev, sg->dma_address, sg_dma_len(sg), dir, attrs);
551 * Map a set of buffers described by scatterlist in streaming mode for DMA.
552 * This is the scatter-gather version of the above xen_swiotlb_map_page
553 * interface. Here the scatter gather list elements are each tagged with the
554 * appropriate dma address and length. They are obtained via
555 * sg_dma_{address,length}(SG).
557 * NOTE: An implementation may be able to use a smaller number of
558 * DMA address/length pairs than there are SG table elements.
559 * (for example via virtual mapping capabilities)
560 * The routine returns the number of addr/length pairs actually
561 * used, at most nents.
563 * Device ownership issues as mentioned above for xen_swiotlb_map_page are the
567 xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl,
568 int nelems, enum dma_data_direction dir,
571 struct scatterlist *sg;
574 BUG_ON(dir == DMA_NONE);
576 for_each_sg(sgl, sg, nelems, i) {
577 phys_addr_t paddr = sg_phys(sg);
578 dma_addr_t dev_addr = xen_phys_to_bus(paddr);
580 if (swiotlb_force == SWIOTLB_FORCE ||
581 xen_arch_need_swiotlb(hwdev, paddr, dev_addr) ||
582 !dma_capable(hwdev, dev_addr, sg->length) ||
583 range_straddles_page_boundary(paddr, sg->length)) {
584 phys_addr_t map = swiotlb_tbl_map_single(hwdev,
589 if (map == SWIOTLB_MAP_ERROR) {
590 dev_warn(hwdev, "swiotlb buffer is full\n");
591 /* Don't panic here, we expect map_sg users
592 to do proper error handling. */
593 attrs |= DMA_ATTR_SKIP_CPU_SYNC;
594 xen_swiotlb_unmap_sg_attrs(hwdev, sgl, i, dir,
599 dev_addr = xen_phys_to_bus(map);
600 xen_dma_map_page(hwdev, pfn_to_page(map >> PAGE_SHIFT),
606 sg->dma_address = dev_addr;
608 /* we are not interested in the dma_addr returned by
609 * xen_dma_map_page, only in the potential cache flushes executed
610 * by the function. */
611 xen_dma_map_page(hwdev, pfn_to_page(paddr >> PAGE_SHIFT),
617 sg->dma_address = dev_addr;
619 sg_dma_len(sg) = sg->length;
625 * Make physical memory consistent for a set of streaming mode DMA translations
628 * The same as swiotlb_sync_single_* but for a scatter-gather list, same rules
632 xen_swiotlb_sync_sg(struct device *hwdev, struct scatterlist *sgl,
633 int nelems, enum dma_data_direction dir,
634 enum dma_sync_target target)
636 struct scatterlist *sg;
639 for_each_sg(sgl, sg, nelems, i)
640 xen_swiotlb_sync_single(hwdev, sg->dma_address,
641 sg_dma_len(sg), dir, target);
645 xen_swiotlb_sync_sg_for_cpu(struct device *hwdev, struct scatterlist *sg,
646 int nelems, enum dma_data_direction dir)
648 xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_CPU);
652 xen_swiotlb_sync_sg_for_device(struct device *hwdev, struct scatterlist *sg,
653 int nelems, enum dma_data_direction dir)
655 xen_swiotlb_sync_sg(hwdev, sg, nelems, dir, SYNC_FOR_DEVICE);
659 * Return whether the given device DMA address mask can be supported
660 * properly. For example, if your device can only drive the low 24-bits
661 * during bus mastering, then you would pass 0x00ffffff as the mask to
665 xen_swiotlb_dma_supported(struct device *hwdev, u64 mask)
667 return xen_virt_to_bus(xen_io_tlb_end - 1) <= mask;
671 * Create userspace mapping for the DMA-coherent memory.
672 * This function should be called with the pages from the current domain only,
673 * passing pages mapped from other domains would lead to memory corruption.
676 xen_swiotlb_dma_mmap(struct device *dev, struct vm_area_struct *vma,
677 void *cpu_addr, dma_addr_t dma_addr, size_t size,
680 #if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
681 if (xen_get_dma_ops(dev)->mmap)
682 return xen_get_dma_ops(dev)->mmap(dev, vma, cpu_addr,
683 dma_addr, size, attrs);
685 return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
689 * This function should be called with the pages from the current domain only,
690 * passing pages mapped from other domains would lead to memory corruption.
693 xen_swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
694 void *cpu_addr, dma_addr_t handle, size_t size,
697 #if defined(CONFIG_ARM) || defined(CONFIG_ARM64)
698 if (xen_get_dma_ops(dev)->get_sgtable) {
701 * This check verifies that the page belongs to the current domain and
702 * is not one mapped from another domain.
703 * This check is for debug only, and should not go to production build
705 unsigned long bfn = PHYS_PFN(dma_to_phys(dev, handle));
706 BUG_ON (!page_is_ram(bfn));
708 return xen_get_dma_ops(dev)->get_sgtable(dev, sgt, cpu_addr,
709 handle, size, attrs);
712 return dma_common_get_sgtable(dev, sgt, cpu_addr, handle, size);
715 static int xen_swiotlb_mapping_error(struct device *dev, dma_addr_t dma_addr)
717 return dma_addr == XEN_SWIOTLB_ERROR_CODE;
720 const struct dma_map_ops xen_swiotlb_dma_ops = {
721 .alloc = xen_swiotlb_alloc_coherent,
722 .free = xen_swiotlb_free_coherent,
723 .sync_single_for_cpu = xen_swiotlb_sync_single_for_cpu,
724 .sync_single_for_device = xen_swiotlb_sync_single_for_device,
725 .sync_sg_for_cpu = xen_swiotlb_sync_sg_for_cpu,
726 .sync_sg_for_device = xen_swiotlb_sync_sg_for_device,
727 .map_sg = xen_swiotlb_map_sg_attrs,
728 .unmap_sg = xen_swiotlb_unmap_sg_attrs,
729 .map_page = xen_swiotlb_map_page,
730 .unmap_page = xen_swiotlb_unmap_page,
731 .dma_supported = xen_swiotlb_dma_supported,
732 .mmap = xen_swiotlb_dma_mmap,
733 .get_sgtable = xen_swiotlb_get_sgtable,
734 .mapping_error = xen_swiotlb_mapping_error,