xref: /xnu-8792.61.2/osfmk/arm64/iofilter_asm.s (revision 42e220869062b56f8d7d0726fd4c88954f87902c)
1*42e22086SApple OSS Distributions/*
2*42e22086SApple OSS Distributions * Copyright (c) 2022 Apple Inc. All rights reserved.
3*42e22086SApple OSS Distributions *
4*42e22086SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_START@
5*42e22086SApple OSS Distributions *
6*42e22086SApple OSS Distributions * This file contains Original Code and/or Modifications of Original Code
7*42e22086SApple OSS Distributions * as defined in and that are subject to the Apple Public Source License
8*42e22086SApple OSS Distributions * Version 2.0 (the 'License'). You may not use this file except in
9*42e22086SApple OSS Distributions * compliance with the License. The rights granted to you under the License
10*42e22086SApple OSS Distributions * may not be used to create, or enable the creation or redistribution of,
11*42e22086SApple OSS Distributions * unlawful or unlicensed copies of an Apple operating system, or to
12*42e22086SApple OSS Distributions * circumvent, violate, or enable the circumvention or violation of, any
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14*42e22086SApple OSS Distributions *
15*42e22086SApple OSS Distributions * Please obtain a copy of the License at
16*42e22086SApple OSS Distributions * http://www.opensource.apple.com/apsl/ and read it before using this file.
17*42e22086SApple OSS Distributions *
18*42e22086SApple OSS Distributions * The Original Code and all software distributed under the License are
19*42e22086SApple OSS Distributions * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
20*42e22086SApple OSS Distributions * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
21*42e22086SApple OSS Distributions * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
22*42e22086SApple OSS Distributions * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
23*42e22086SApple OSS Distributions * Please see the License for the specific language governing rights and
24*42e22086SApple OSS Distributions * limitations under the License.
25*42e22086SApple OSS Distributions *
26*42e22086SApple OSS Distributions * @APPLE_OSREFERENCE_LICENSE_HEADER_END@
27*42e22086SApple OSS Distributions */
28*42e22086SApple OSS Distributions
29*42e22086SApple OSS Distributions
30*42e22086SApple OSS Distributions#include <machine/asm.h>
31*42e22086SApple OSS Distributions#include <mach/kern_return.h>
32*42e22086SApple OSS Distributions#include <arm64/proc_reg.h>
33*42e22086SApple OSS Distributions#include <arm64/exception_asm.h>
34*42e22086SApple OSS Distributions#include <pexpert/arm64/board_config.h>
35*42e22086SApple OSS Distributions
36*42e22086SApple OSS Distributions#include "assym.s"
37*42e22086SApple OSS Distributions
38*42e22086SApple OSS Distributions#if HAS_GUARDED_IO_FILTER
39*42e22086SApple OSS Distributions
40*42e22086SApple OSS Distributions    .section __PPLTEXT,__text,regular,pure_instructions
41*42e22086SApple OSS Distributions    .align 2
42*42e22086SApple OSS Distributions    .globl EXT(io_filter_vtop)
43*42e22086SApple OSS DistributionsLEXT(io_filter_vtop)
44*42e22086SApple OSS Distributions    ARM64_STACK_PROLOG
45*42e22086SApple OSS Distributions    /* x9 - temp reg for the physical addr of the ioreg, x10 - draft reg. */
46*42e22086SApple OSS Distributions    at      s1e1w, x0                 // Get PA of the addr passed in for comparison.
47*42e22086SApple OSS Distributions                                      // Use s1e1w flavor of at so permission is checked for writing from EL1.
48*42e22086SApple OSS Distributions    isb     sy
49*42e22086SApple OSS Distributions    mrs     x9, PAR_EL1
50*42e22086SApple OSS Distributions    and     x10, x9, #0x7ffffffffc000 // Extract the page-aligned address from PAR_EL1.PA[51:48] | PAR_EL1.PA[47:14].
51*42e22086SApple OSS Distributions    bfxil   x10, x0, #0, #14          // Copy the page offset from the VA to assemble the PA.
52*42e22086SApple OSS Distributions    tst     x9, #0x1                  // Check PAR_EL1.F to see if translation was successful.
53*42e22086SApple OSS Distributions    csel    x0, x10, xzr, eq          // If translation was successful return PA, else 0.
54*42e22086SApple OSS Distributions
55*42e22086SApple OSS Distributions    ARM64_STACK_EPILOG
56*42e22086SApple OSS Distributions#endif /* HAS_GUARDED_IO_FILTER */
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