/* * mmap.c * * Copyright (C) 1995, 1996 by Volker Lendecke * Modified 1997 Peter Waltenberg, Bill Hawes, David Woodhouse for 2.1 dcache * */ #include #include #include #include #include #include #include #include #include #include #include #include #include "ncp_fs.h" /* * Fill in the supplied page for mmap * XXX: how are we excluding truncate/invalidate here? Maybe need to lock * page? */ static int ncp_file_mmap_fault(struct vm_area_struct *area, struct vm_fault *vmf) { struct inode *inode = file_inode(area->vm_file); char *pg_addr; unsigned int already_read; unsigned int count; int bufsize; int pos; /* XXX: loff_t ? */ /* * ncpfs has nothing against high pages as long * as recvmsg and memset works on it */ vmf->page = alloc_page(GFP_HIGHUSER); if (!vmf->page) return VM_FAULT_OOM; pg_addr = kmap(vmf->page); pos = vmf->pgoff << PAGE_SHIFT; count = PAGE_SIZE; /* what we can read in one go */ bufsize = NCP_SERVER(inode)->buffer_size; already_read = 0; if (ncp_make_open(inode, O_RDONLY) >= 0) { while (already_read < count) { int read_this_time; int to_read; to_read = bufsize - (pos % bufsize); to_read = min_t(unsigned int, to_read, count - already_read); if (ncp_read_kernel(NCP_SERVER(inode), NCP_FINFO(inode)->file_handle, pos, to_read, pg_addr + already_read, &read_this_time) != 0) { read_this_time = 0; } pos += read_this_time; already_read += read_this_time; if (read_this_time < to_read) { break; } } ncp_inode_close(inode); } if (already_read < PAGE_SIZE) memset(pg_addr + already_read, 0, PAGE_SIZE - already_read); flush_dcache_page(vmf->page); kunmap(vmf->page); /* * If I understand ncp_read_kernel() properly, the above always * fetches from the network, here the analogue of disk. * -- nyc */ count_vm_event(PGMAJFAULT); mem_cgroup_count_vm_event(area->vm_mm, PGMAJFAULT); return VM_FAULT_MAJOR; } static const struct vm_operations_struct ncp_file_mmap = { .fault = ncp_file_mmap_fault, }; /* This is used for a general mmap of a ncp file */ int ncp_mmap(struct file *file, struct vm_area_struct *vma) { struct inode *inode = file_inode(file); ncp_dbg(1, "called\n"); if (!ncp_conn_valid(NCP_SERVER(inode))) return -EIO; /* only PAGE_COW or read-only supported now */ if (vma->vm_flags & VM_SHARED) return -EINVAL; /* we do not support files bigger than 4GB... We eventually supports just 4GB... */ if (vma_pages(vma) + vma->vm_pgoff > (1U << (32 - PAGE_SHIFT))) return -EFBIG; vma->vm_ops = &ncp_file_mmap; file_accessed(file); return 0; } >path: root/include/dt-bindings/i2c

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