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      1 /*	$NetBSD: nouveau_nvkm_subdev_bios_shadowacpi.c,v 1.4 2024/04/16 14:34:02 riastradh Exp $	*/
      2 
      3 /*
      4  * Copyright 2012 Red Hat Inc.
      5  *
      6  * Permission is hereby granted, free of charge, to any person obtaining a
      7  * copy of this software and associated documentation files (the "Software"),
      8  * to deal in the Software without restriction, including without limitation
      9  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
     10  * and/or sell copies of the Software, and to permit persons to whom the
     11  * Software is furnished to do so, subject to the following conditions:
     12  *
     13  * The above copyright notice and this permission notice shall be included in
     14  * all copies or substantial portions of the Software.
     15  *
     16  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
     17  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
     18  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
     19  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
     20  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
     21  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
     22  * OTHER DEALINGS IN THE SOFTWARE.
     23  *
     24  */
     25 #include <sys/cdefs.h>
     26 __KERNEL_RCSID(0, "$NetBSD: nouveau_nvkm_subdev_bios_shadowacpi.c,v 1.4 2024/04/16 14:34:02 riastradh Exp $");
     27 
     28 #include "priv.h"
     29 
     30 #if defined(CONFIG_ACPI) && defined(CONFIG_X86)
     31 int nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len);
     32 #ifdef __NetBSD__
     33 bool nouveau_acpi_rom_supported(struct acpi_devnode *);
     34 #else
     35 bool nouveau_acpi_rom_supported(struct device *);
     36 #endif
     37 #else
     38 static inline bool
     39 #ifdef __NetBSD__
     40 nouveau_acpi_rom_supported(struct acpi_devnode *dev)
     41 #else
     42 nouveau_acpi_rom_supported(struct device *dev)
     43 #endif
     44 {
     45 	return false;
     46 }
     47 
     48 static inline int
     49 nouveau_acpi_get_bios_chunk(uint8_t *bios, int offset, int len)
     50 {
     51 	return -EINVAL;
     52 }
     53 #endif
     54 
     55 /* This version of the shadow function disobeys the ACPI spec and tries
     56  * to fetch in units of more than 4KiB at a time.  This is a LOT faster
     57  * on some systems, such as Lenovo W530.
     58  */
     59 static u32
     60 acpi_read_fast(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
     61 {
     62 	u32 limit = (offset + length + 0xfff) & ~0xfff;
     63 	u32 start = offset & ~0x00000fff;
     64 	u32 fetch = limit - start;
     65 
     66 	if (nvbios_extend(bios, limit) >= 0) {
     67 		int ret = nouveau_acpi_get_bios_chunk(bios->data, start, fetch);
     68 		if (ret == fetch)
     69 			return fetch;
     70 	}
     71 
     72 	return 0;
     73 }
     74 
     75 /* Other systems, such as the one in fdo#55948, will report a success
     76  * but only return 4KiB of data.  The common bios fetching logic will
     77  * detect an invalid image, and fall back to this version of the read
     78  * function.
     79  */
     80 static u32
     81 acpi_read_slow(void *data, u32 offset, u32 length, struct nvkm_bios *bios)
     82 {
     83 	u32 limit = (offset + length + 0xfff) & ~0xfff;
     84 	u32 start = offset & ~0xfff;
     85 	u32 fetch = 0;
     86 
     87 	if (nvbios_extend(bios, limit) >= 0) {
     88 		while (start + fetch < limit) {
     89 			int ret = nouveau_acpi_get_bios_chunk(bios->data,
     90 							      start + fetch,
     91 							      0x1000);
     92 			if (ret != 0x1000)
     93 				break;
     94 			fetch += 0x1000;
     95 		}
     96 	}
     97 
     98 	return fetch;
     99 }
    100 
    101 static void *
    102 acpi_init(struct nvkm_bios *bios, const char *name)
    103 {
    104 	if (!nouveau_acpi_rom_supported(bios->subdev.device->acpidev))
    105 		return ERR_PTR(-ENODEV);
    106 	return NULL;
    107 }
    108 
    109 const struct nvbios_source
    110 nvbios_acpi_fast = {
    111 	.name = "ACPI",
    112 	.init = acpi_init,
    113 	.read = acpi_read_fast,
    114 	.rw = false,
    115 	.require_checksum = true,
    116 };
    117 
    118 const struct nvbios_source
    119 nvbios_acpi_slow = {
    120 	.name = "ACPI",
    121 	.init = acpi_init,
    122 	.read = acpi_read_slow,
    123 	.rw = false,
    124 };
    125