/* $NetBSD: acpi_dev.c,v 1.4 2024/11/12 21:49:11 riastradh Exp $ */
/*-
* Copyright (c) 2020 Jared McNeill <
[email protected]>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
* BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
* AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: acpi_dev.c,v 1.4 2024/11/12 21:49:11 riastradh Exp $");
#include <sys/param.h>
#include <sys/conf.h>
#include <sys/mman.h>
#include <dev/acpi/acpireg.h>
#include <dev/acpi/acpivar.h>
#define _COMPONENT ACPI_BUS_COMPONENT
ACPI_MODULE_NAME ("acpi_dev")
static dev_type_read(acpi_read);
const struct cdevsw acpi_cdevsw = {
.d_open = nullopen,
.d_close = nullclose,
.d_read = acpi_read,
.d_write = nowrite,
.d_ioctl = noioctl,
.d_stop = nostop,
.d_tty = notty,
.d_poll = nopoll,
.d_mmap = nommap,
.d_kqfilter = nokqfilter,
.d_discard = nodiscard,
.d_flag = D_OTHER | D_MPSAFE,
};
/*
* acpi_find_table_rsdp --
*
* Returns true if the RSDP table is found and overlaps the specified
* physical address. The table's physical start address and length
* are placed in 'paddr' and 'plen' when found.
*
*/
static bool
acpi_find_table_rsdp(ACPI_PHYSICAL_ADDRESS pa,
ACPI_PHYSICAL_ADDRESS *paddr, uint32_t *plen)
{
ACPI_PHYSICAL_ADDRESS table_pa;
table_pa = AcpiOsGetRootPointer();
if (table_pa == 0) {
return false;
}
if (pa >= table_pa && pa < table_pa + sizeof(ACPI_TABLE_RSDP)) {
*paddr = table_pa;
*plen = sizeof(ACPI_TABLE_RSDP);
return true;
}
return false;
}
/*
* acpi_find_table_sdt --
*
* Returns true if the XSDT/RSDT table is found and overlaps the
* specified physical address. The table's physical start address
* and length are placed in 'paddr' and 'plen' when found.
*
*/
static bool
acpi_find_table_sdt(ACPI_PHYSICAL_ADDRESS pa,
ACPI_PHYSICAL_ADDRESS *paddr, uint32_t *plen)
{
ACPI_PHYSICAL_ADDRESS table_pa;
ACPI_TABLE_RSDP *rsdp;
ACPI_TABLE_HEADER *thdr;
uint32_t table_len;
table_pa = AcpiOsGetRootPointer();
KASSERT(table_pa != 0);
/*
* Find the XSDT/RSDT using the RSDP.
*/
rsdp = AcpiOsMapMemory(table_pa, sizeof(ACPI_TABLE_RSDP));
if (rsdp == NULL) {
return false;
}
if (rsdp->Revision > 1 && rsdp->XsdtPhysicalAddress) {
table_pa = rsdp->XsdtPhysicalAddress;
} else {
table_pa = rsdp->RsdtPhysicalAddress;
}
AcpiOsUnmapMemory(rsdp, sizeof(ACPI_TABLE_RSDP));
if (table_pa == 0) {
return false;
}
/*
* Map the XSDT/RSDT and check access.
*/
thdr = AcpiOsMapMemory(table_pa, sizeof(ACPI_TABLE_HEADER));
if (thdr == NULL) {
return false;
}
table_len = thdr->Length;
AcpiOsUnmapMemory(thdr, sizeof(ACPI_TABLE_HEADER));
if (pa >= table_pa && pa < table_pa + table_len) {
*paddr = table_pa;
*plen = table_len;
return true;
}
return false;
}
/*
* acpi_find_table --
*
* Find an ACPI table that overlaps the specified physical address.
* Returns true if the table is found and places the table start
* address into 'paddr' and the length into 'plen'.
*
*/
static bool
acpi_find_table(ACPI_PHYSICAL_ADDRESS pa,
ACPI_PHYSICAL_ADDRESS *paddr, uint32_t *plen)
{
ACPI_TABLE_DESC *tdesc;
ACPI_TABLE_TCPA_HDR *tcpa = NULL;
size_t tcpa_tdesc_len = 0;
bool found_table;
uint32_t i;
/* Check for RSDP access. */
if (acpi_find_table_rsdp(pa, paddr, plen)) {
return true;
}
/* Check for XSDT/RSDT access. */
if (acpi_find_table_sdt(pa, paddr, plen)) {
return true;
}
/* Check for root table access. */
found_table = false;
AcpiUtAcquireMutex(ACPI_MTX_TABLES);
for (i = 0; i < AcpiGbl_RootTableList.CurrentTableCount; i++) {
tdesc = &AcpiGbl_RootTableList.Tables[i];
if (pa >= tdesc->Address &&
pa < tdesc->Address + tdesc->Length) {
/*
* allow access to all root table objects
*/
*paddr = tdesc->Address;
*plen = tdesc->Length;
found_table = true;
break;
} else if (memcmp(tdesc->Signature.Ascii, ACPI_SIG_TCPA, 4)
== 0) {
/*
* allow acces to TCPA (which requires mapping)
*/
/* duplicate TCPA table? buggy firmware? */
if (tcpa != NULL && tcpa_tdesc_len > 0)
AcpiOsUnmapMemory(tcpa, tcpa_tdesc_len);
tcpa = AcpiOsMapMemory(tdesc->Address, tdesc->Length);
if (tcpa != NULL)
tcpa_tdesc_len = tdesc->Length;
}
}
if (!found_table && tcpa != NULL) {
ACPI_PHYSICAL_ADDRESS tcpa_addr = 0;
uint32_t tcpa_len = 0;
if (tcpa->PlatformClass == ACPI_TCPA_CLIENT_TABLE) {
ACPI_TABLE_TCPA_CLIENT *t =
(ACPI_TABLE_TCPA_CLIENT *)(tcpa + 1);
tcpa_addr = t->LogAddress;
tcpa_len = t->MinimumLogLength;
} else if (tcpa->PlatformClass == ACPI_TCPA_SERVER_TABLE) {
ACPI_TABLE_TCPA_SERVER *t =
(ACPI_TABLE_TCPA_SERVER *)(tcpa + 1);
tcpa_addr = t->LogAddress;
tcpa_len = t->MinimumLogLength;
}
if (tcpa_len != 0 &&
pa >= tcpa_addr &&
pa < tcpa_addr + tcpa_len) {
*paddr = tcpa_addr;
*plen = tcpa_len;
found_table = true;
}
}
if (tcpa != NULL && tcpa_tdesc_len != 0)
AcpiOsUnmapMemory(tcpa, tcpa_tdesc_len);
AcpiUtReleaseMutex(ACPI_MTX_TABLES);
return found_table;
}
/*
* acpi_read --
*
* Read data from an ACPI configuration table that resides in
* physical memory. Only supports reading one table at a time.
*
*/
static int
acpi_read(dev_t dev, struct uio *uio, int flag)
{
ACPI_PHYSICAL_ADDRESS pa, table_pa;
uint32_t table_len;
uint8_t *data;
int error;
size_t len;
if (uio->uio_rw != UIO_READ) {
return EPERM;
}
/* Make sure this is a read of a known table */
if (!acpi_find_table(uio->uio_offset, &table_pa, &table_len)) {
return EIO;
}
/* Copy the contents of the table to user-space */
pa = uio->uio_offset;
len = uimin(table_len - (pa - table_pa), uio->uio_resid);
data = AcpiOsMapMemory(pa, len);
if (data == NULL) {
return ENOMEM;
}
error = uiomove(data, len, uio);
AcpiOsUnmapMemory(data, len);
return error;
}
