/* * allow user processes to MMAP some memory sections * instead of going through read/write */ int memmmap(struct cdev *dev, vm_ooffset_t offset, vm_paddr_t *paddr, int prot, vm_memattr_t *memattr) { int i; /* * /dev/mem is the only one that makes sense through this * interface. For /dev/kmem any physaddr we return here * could be transient and hence incorrect or invalid at * a later time. */ if (dev2unit(dev) != CDEV_MINOR_MEM) return (-1); /* Only direct-mapped addresses. */ if (mem_valid(offset, 0) && pmap_dev_direct_mapped(offset, 0)) return (EFAULT); *paddr = offset; for (i = 0; i < mem_range_softc.mr_ndesc; i++) { if (!(mem_range_softc.mr_desc[i].mr_flags & MDF_ACTIVE)) continue; if (offset >= mem_range_softc.mr_desc[i].mr_base && offset < mem_range_softc.mr_desc[i].mr_base + mem_range_softc.mr_desc[i].mr_len) { switch (mem_range_softc.mr_desc[i].mr_flags & MDF_ATTRMASK) { case MDF_WRITEBACK: *memattr = VM_MEMATTR_WRITE_BACK; break; case MDF_WRITECOMBINE: *memattr = VM_MEMATTR_WRITE_COMBINING; break; case MDF_UNCACHEABLE: *memattr = VM_MEMATTR_UNCACHEABLE; break; case MDF_WRITETHROUGH: *memattr = VM_MEMATTR_WRITE_THROUGH; break; } break; } } return (0); }
/* ARGSUSED */ int memrw(struct cdev *dev, struct uio *uio, int flags) { struct iovec *iov; int error = 0; vm_offset_t va, eva, off, v; vm_prot_t prot; struct vm_page m; vm_page_t marr; vm_size_t cnt; cnt = 0; error = 0; GIANT_REQUIRED; while (uio->uio_resid > 0 && !error) { iov = uio->uio_iov; if (iov->iov_len == 0) { uio->uio_iov++; uio->uio_iovcnt--; if (uio->uio_iovcnt < 0) panic("memrw"); continue; } if (dev2unit(dev) == CDEV_MINOR_MEM) { kmem_direct_mapped: v = uio->uio_offset; off = uio->uio_offset & PAGE_MASK; cnt = PAGE_SIZE - ((vm_offset_t)iov->iov_base & PAGE_MASK); cnt = min(cnt, PAGE_SIZE - off); cnt = min(cnt, iov->iov_len); if (mem_valid(v, cnt)) { error = EFAULT; break; } if (!pmap_dev_direct_mapped(v, cnt)) { error = uiomove((void *)v, cnt, uio); } else { m.phys_addr = trunc_page(v); marr = &m; error = uiomove_fromphys(&marr, off, cnt, uio); } } else if (dev2unit(dev) == CDEV_MINOR_KMEM) { va = uio->uio_offset; if ((va < VM_MIN_KERNEL_ADDRESS) || (va > virtual_end)) goto kmem_direct_mapped; va = trunc_page(uio->uio_offset); eva = round_page(uio->uio_offset + iov->iov_len); /* * Make sure that all the pages are currently resident * so that we don't create any zero-fill pages. */ for (; va < eva; va += PAGE_SIZE) if (pmap_extract(kernel_pmap, va) == 0) return (EFAULT); prot = (uio->uio_rw == UIO_READ) ? VM_PROT_READ : VM_PROT_WRITE; va = uio->uio_offset; if (kernacc((void *) va, iov->iov_len, prot) == FALSE) return (EFAULT); error = uiomove((void *)va, iov->iov_len, uio); continue; } } return (error); }