1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3 * Parse the EFI PCDP table to locate the console device.
4 *
5 * (c) Copyright 2002, 2003, 2004 Hewlett-Packard Development Company, L.P.
6 * Khalid Aziz <khalid.aziz@hp.com>
7 * Alex Williamson <alex.williamson@hp.com>
8 * Bjorn Helgaas <bjorn.helgaas@hp.com>
9 */
10
11 #include <linux/acpi.h>
12 #include <linux/console.h>
13 #include <linux/efi.h>
14 #include <linux/serial.h>
15 #include <linux/serial_core.h>
16 #include <asm/vga.h>
17 #include "pcdp.h"
18
19 static int __init
setup_serial_console(struct pcdp_uart * uart)20 setup_serial_console(struct pcdp_uart *uart)
21 {
22 #ifdef CONFIG_SERIAL_8250_CONSOLE
23 int mmio;
24 static char options[64], *p = options;
25 char parity;
26
27 mmio = (uart->addr.space_id == ACPI_ADR_SPACE_SYSTEM_MEMORY);
28 p += sprintf(p, "uart8250,%s,0x%llx",
29 mmio ? "mmio" : "io", uart->addr.address);
30 if (uart->baud) {
31 p += sprintf(p, ",%llu", uart->baud);
32 if (uart->bits) {
33 switch (uart->parity) {
34 case 0x2: parity = 'e'; break;
35 case 0x3: parity = 'o'; break;
36 default: parity = 'n';
37 }
38 p += sprintf(p, "%c%d", parity, uart->bits);
39 }
40 }
41
42 add_preferred_console("uart", 8250, &options[9]);
43 return setup_earlycon(options);
44 #else
45 return -ENODEV;
46 #endif
47 }
48
49 static int __init
setup_vga_console(struct pcdp_device * dev)50 setup_vga_console(struct pcdp_device *dev)
51 {
52 #if defined(CONFIG_VT) && defined(CONFIG_VGA_CONSOLE)
53 u8 *if_ptr;
54
55 if_ptr = ((u8 *)dev + sizeof(struct pcdp_device));
56 if (if_ptr[0] == PCDP_IF_PCI) {
57 struct pcdp_if_pci if_pci;
58
59 /* struct copy since ifptr might not be correctly aligned */
60
61 memcpy(&if_pci, if_ptr, sizeof(if_pci));
62
63 if (if_pci.trans & PCDP_PCI_TRANS_IOPORT)
64 vga_console_iobase = if_pci.ioport_tra;
65
66 if (if_pci.trans & PCDP_PCI_TRANS_MMIO)
67 vga_console_membase = if_pci.mmio_tra;
68 }
69
70 if (efi_mem_type(vga_console_membase + 0xA0000) == EFI_CONVENTIONAL_MEMORY) {
71 printk(KERN_ERR "PCDP: VGA selected, but frame buffer is not MMIO!\n");
72 return -ENODEV;
73 }
74
75 conswitchp = &vga_con;
76 printk(KERN_INFO "PCDP: VGA console\n");
77 return 0;
78 #else
79 return -ENODEV;
80 #endif
81 }
82
83 extern unsigned long hcdp_phys;
84
85 int __init
efi_setup_pcdp_console(char * cmdline)86 efi_setup_pcdp_console(char *cmdline)
87 {
88 struct pcdp *pcdp;
89 struct pcdp_uart *uart;
90 struct pcdp_device *dev, *end;
91 int i, serial = 0;
92 int rc = -ENODEV;
93
94 if (hcdp_phys == EFI_INVALID_TABLE_ADDR)
95 return -ENODEV;
96
97 pcdp = early_memremap(hcdp_phys, 4096);
98 printk(KERN_INFO "PCDP: v%d at 0x%lx\n", pcdp->rev, hcdp_phys);
99
100 if (strstr(cmdline, "console=hcdp")) {
101 if (pcdp->rev < 3)
102 serial = 1;
103 } else if (strstr(cmdline, "console=")) {
104 printk(KERN_INFO "Explicit \"console=\"; ignoring PCDP\n");
105 goto out;
106 }
107
108 if (pcdp->rev < 3 && efi_uart_console_only())
109 serial = 1;
110
111 for (i = 0, uart = pcdp->uart; i < pcdp->num_uarts; i++, uart++) {
112 if (uart->flags & PCDP_UART_PRIMARY_CONSOLE || serial) {
113 if (uart->type == PCDP_CONSOLE_UART) {
114 rc = setup_serial_console(uart);
115 goto out;
116 }
117 }
118 }
119
120 end = (struct pcdp_device *) ((u8 *) pcdp + pcdp->length);
121 for (dev = (struct pcdp_device *) (pcdp->uart + pcdp->num_uarts);
122 dev < end;
123 dev = (struct pcdp_device *) ((u8 *) dev + dev->length)) {
124 if (dev->flags & PCDP_PRIMARY_CONSOLE) {
125 if (dev->type == PCDP_CONSOLE_VGA) {
126 rc = setup_vga_console(dev);
127 goto out;
128 }
129 }
130 }
131
132 out:
133 early_memunmap(pcdp, 4096);
134 return rc;
135 }
136