1ea4c85781
like open, close and fault using the character device pager. Some notes about the implementation: 1) Linux drivers set the vm_ops and vm_private_data fields during a mmap() call to indicate that the driver wants to use the LinuxKPI VM operations. Else these operations are not used. 2) The vm_private_data pointer is associated with a VM area structure and inserted into an internal LinuxKPI list. If the vm_private_data pointer already exists, the existing VM area structure is used instead of the allocated one which gets freed. 3) The LinuxKPI's vm_private_data pointer is used as the callback handle for the FreeBSD VM object. The VM subsystem in FreeBSD has a similar list to identify equal handles and will only call the character device pager's close function once. 4) All LinuxKPI VM operations are serialized through the mmap_sem sempaphore, which is per procedure, which prevents simultaneous access to the shared VM area structure when receiving page faults. Obtained from: kmacy @ MFC after: 1 week Sponsored by: Mellanox Technologies
96 lines
3.2 KiB
C
96 lines
3.2 KiB
C
/*-
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* Copyright (c) 2010 Isilon Systems, Inc.
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* Copyright (c) 2010 iX Systems, Inc.
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* Copyright (c) 2010 Panasas, Inc.
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* Copyright (c) 2013-2016 Mellanox Technologies, Ltd.
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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* 1. Redistributions of source code must retain the above copyright
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* notice unmodified, this list of conditions, and the following
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* disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
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* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
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* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
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* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
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* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
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* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
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* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
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* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
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* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
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* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*
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* $FreeBSD$
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*/
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#ifndef _LINUX_PAGE_H_
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#define _LINUX_PAGE_H_
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#include <linux/types.h>
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#include <sys/param.h>
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#include <machine/atomic.h>
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#include <vm/vm.h>
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#include <vm/vm_page.h>
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#include <vm/pmap.h>
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typedef unsigned long pte_t;
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typedef unsigned long pmd_t;
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typedef unsigned long pgd_t;
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typedef unsigned long pgprot_t;
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#define page vm_page
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#define LINUXKPI_PROT_VALID (1 << 4)
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#define LINUXKPI_CACHE_MODE_SHIFT 3
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static inline pgprot_t
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cachemode2protval(vm_memattr_t attr)
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{
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return ((attr | LINUXKPI_PROT_VALID) << LINUXKPI_CACHE_MODE_SHIFT);
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}
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static inline vm_memattr_t
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pgprot2cachemode(pgprot_t prot)
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{
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int val;
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val = prot >> LINUXKPI_CACHE_MODE_SHIFT;
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if (val & LINUXKPI_PROT_VALID)
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return (val & ~LINUXKPI_PROT_VALID);
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else
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return (VM_MEMATTR_DEFAULT);
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}
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#define virt_to_page(x) PHYS_TO_VM_PAGE(vtophys((x)))
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#define page_to_pfn(pp) (VM_PAGE_TO_PHYS((pp)) >> PAGE_SHIFT)
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#define pfn_to_page(pfn) (PHYS_TO_VM_PAGE((pfn) << PAGE_SHIFT))
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#define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
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#define clear_page(page) memset((page), 0, PAGE_SIZE)
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#define pgprot_noncached(prot) ((pgprot_t)VM_MEMATTR_UNCACHEABLE)
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#define pgprot_writecombine(prot) ((pgprot_t)VM_MEMATTR_WRITE_COMBINING)
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#undef PAGE_MASK
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#define PAGE_MASK (~(PAGE_SIZE-1))
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/*
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* Modifying PAGE_MASK in the above way breaks trunc_page, round_page,
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* and btoc macros. Therefore, redefine them in a way that makes sense
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* so the LinuxKPI consumers don't get totally broken behavior.
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*/
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#undef btoc
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#define btoc(x) (((vm_offset_t)(x) + PAGE_SIZE - 1) >> PAGE_SHIFT)
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#undef round_page
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#define round_page(x) ((((uintptr_t)(x)) + PAGE_SIZE - 1) & ~(PAGE_SIZE - 1))
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#undef trunc_page
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#define trunc_page(x) ((uintptr_t)(x) & ~(PAGE_SIZE - 1))
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#endif /* _LINUX_PAGE_H_ */
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