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      1 /* $NetBSD: acpi_pci_smccc.c,v 1.2 2022/10/15 10:45:40 jmcneill Exp $ */
      2 
      3 /*-
      4  * Copyright (c) 2021 Jared McNeill <jmcneill (at) invisible.ca>
      5  * All rights reserved.
      6  *
      7  * Redistribution and use in source and binary forms, with or without
      8  * modification, are permitted provided that the following conditions
      9  * are met:
     10  * 1. Redistributions of source code must retain the above copyright
     11  *    notice, this list of conditions and the following disclaimer.
     12  * 2. Redistributions in binary form must reproduce the above copyright
     13  *    notice, this list of conditions and the following disclaimer in the
     14  *    documentation and/or other materials provided with the distribution.
     15  *
     16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
     17  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
     18  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
     19  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
     20  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
     21  * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
     22  * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
     23  * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
     24  * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     26  * SUCH DAMAGE.
     27  */
     28 
     29 #include <sys/cdefs.h>
     30 __KERNEL_RCSID(0, "$NetBSD: acpi_pci_smccc.c,v 1.2 2022/10/15 10:45:40 jmcneill Exp $");
     31 
     32 #include <sys/param.h>
     33 #include <sys/kernel.h>
     34 
     35 #include <dev/pci/pcireg.h>
     36 #include <dev/pci/pcivar.h>
     37 #include <dev/pci/pciconf.h>
     38 
     39 #include <dev/acpi/acpivar.h>
     40 #include <dev/acpi/acpi_pci.h>
     41 #include <dev/acpi/acpi_mcfg.h>
     42 
     43 #include <arm/acpi/acpi_pci_machdep.h>
     44 
     45 #include <arm/pci/pci_smccc.h>
     46 
     47 static int
     48 acpi_pci_smccc_conf_read(pci_chipset_tag_t pc, pcitag_t tag, int reg,
     49     pcireg_t *data)
     50 {
     51 	struct acpi_pci_context *ap = pc->pc_conf_v;
     52 	int b, d, f;
     53 	int status;
     54 
     55 	pci_decompose_tag(pc, tag, &b, &d, &f);
     56 
     57 	if (b < ap->ap_bus || b > ap->ap_maxbus) {
     58 		*data = -1;
     59 		return EINVAL;
     60 	}
     61 
     62 	status = pci_smccc_read(PCI_SMCCC_SBDF(ap->ap_seg, b, d, f), reg,
     63 				PCI_SMCCC_ACCESS_32BIT, data);
     64 	if (!PCI_SMCCC_SUCCESS(status)) {
     65 		*data = -1;
     66 		return EINVAL;
     67 	}
     68 
     69 	return 0;
     70 }
     71 
     72 static int
     73 acpi_pci_smccc_conf_write(pci_chipset_tag_t pc, pcitag_t tag, int reg,
     74     pcireg_t data)
     75 {
     76 	struct acpi_pci_context *ap = pc->pc_conf_v;
     77 	int b, d, f;
     78 	int status;
     79 
     80 	pci_decompose_tag(pc, tag, &b, &d, &f);
     81 
     82 	if (b < ap->ap_bus || b > ap->ap_maxbus) {
     83 		return EINVAL;
     84 	}
     85 
     86 	status = pci_smccc_write(PCI_SMCCC_SBDF(ap->ap_seg, b, d, f), reg,
     87 				 PCI_SMCCC_ACCESS_32BIT, data);
     88 	if (!PCI_SMCCC_SUCCESS(status)) {
     89 		return EINVAL;
     90 	}
     91 
     92 	return 0;
     93 }
     94 
     95 
     96 void
     97 acpi_pci_smccc_init(struct acpi_pci_context *ap)
     98 {
     99 	int status, ver;
    100 	uint8_t bus_start, bus_end;
    101 	uint16_t next_seg;
    102 
    103 	ver = pci_smccc_version();
    104 	if (!PCI_SMCCC_SUCCESS(ver)) {
    105 		aprint_error_dev(ap->ap_dev,
    106 		    "SMCCC: PCI_VERSION call failed, status %#x\n", ver);
    107 		return;
    108 	}
    109 	aprint_normal_dev(ap->ap_dev, "SMCCC: PCI impl. version %u.%u\n",
    110 	    (ver >> 16) & 0x7fff, ver & 0xffff);
    111 
    112 	status = pci_smccc_get_seg_info(ap->ap_seg, &bus_start, &bus_end,
    113 	    &next_seg);
    114 	if (!PCI_SMCCC_SUCCESS(status)) {
    115 		aprint_error_dev(ap->ap_dev,
    116 		    "SMCCC: No info for segment %u, status %#x\n",
    117 		    ap->ap_seg, status);
    118 		return;
    119 	}
    120 	aprint_normal_dev(ap->ap_dev, "SMCCC: segment %u, bus %u-%u\n",
    121 	    ap->ap_seg, bus_start, bus_end);
    122 
    123 	ap->ap_bus = bus_start;
    124 	ap->ap_maxbus = bus_end;
    125 	ap->ap_conf_read = acpi_pci_smccc_conf_read;
    126 	ap->ap_conf_write = acpi_pci_smccc_conf_write;
    127 	ap->ap_flags |= ACPI_PCI_FLAG_NO_MCFG;
    128 	ap->ap_pciflags_clear = PCI_FLAGS_MSI_OKAY | PCI_FLAGS_MSIX_OKAY;
    129 }
    130