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Diffstat (limited to '')
| -rw-r--r-- | arch/x86/kernel/early_printk.c | 405 |
1 files changed, 405 insertions, 0 deletions
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c new file mode 100644 index 000000000..374a52fa5 --- /dev/null +++ b/arch/x86/kernel/early_printk.c @@ -0,0 +1,405 @@ +// SPDX-License-Identifier: GPL-2.0 +#include <linux/console.h> +#include <linux/kernel.h> +#include <linux/init.h> +#include <linux/string.h> +#include <linux/screen_info.h> +#include <linux/usb/ch9.h> +#include <linux/pci_regs.h> +#include <linux/pci_ids.h> +#include <linux/errno.h> +#include <asm/io.h> +#include <asm/processor.h> +#include <asm/fcntl.h> +#include <asm/setup.h> +#include <xen/hvc-console.h> +#include <asm/pci-direct.h> +#include <asm/fixmap.h> +#include <asm/intel-mid.h> +#include <asm/pgtable.h> +#include <linux/usb/ehci_def.h> +#include <linux/usb/xhci-dbgp.h> +#include <linux/efi.h> +#include <asm/efi.h> +#include <asm/pci_x86.h> + +/* Simple VGA output */ +#define VGABASE (__ISA_IO_base + 0xb8000) + +static int max_ypos = 25, max_xpos = 80; +static int current_ypos = 25, current_xpos; + +static void early_vga_write(struct console *con, const char *str, unsigned n) +{ + char c; + int i, k, j; + + while ((c = *str++) != '\0' && n-- > 0) { + if (current_ypos >= max_ypos) { + /* scroll 1 line up */ + for (k = 1, j = 0; k < max_ypos; k++, j++) { + for (i = 0; i < max_xpos; i++) { + writew(readw(VGABASE+2*(max_xpos*k+i)), + VGABASE + 2*(max_xpos*j + i)); + } + } + for (i = 0; i < max_xpos; i++) + writew(0x720, VGABASE + 2*(max_xpos*j + i)); + current_ypos = max_ypos-1; + } +#ifdef CONFIG_KGDB_KDB + if (c == '\b') { + if (current_xpos > 0) + current_xpos--; + } else if (c == '\r') { + current_xpos = 0; + } else +#endif + if (c == '\n') { + current_xpos = 0; + current_ypos++; + } else if (c != '\r') { + writew(((0x7 << 8) | (unsigned short) c), + VGABASE + 2*(max_xpos*current_ypos + + current_xpos++)); + if (current_xpos >= max_xpos) { + current_xpos = 0; + current_ypos++; + } + } + } +} + +static struct console early_vga_console = { + .name = "earlyvga", + .write = early_vga_write, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +/* Serial functions loosely based on a similar package from Klaus P. Gerlicher */ + +static unsigned long early_serial_base = 0x3f8; /* ttyS0 */ + +#define XMTRDY 0x20 + +#define DLAB 0x80 + +#define TXR 0 /* Transmit register (WRITE) */ +#define RXR 0 /* Receive register (READ) */ +#define IER 1 /* Interrupt Enable */ +#define IIR 2 /* Interrupt ID */ +#define FCR 2 /* FIFO control */ +#define LCR 3 /* Line control */ +#define MCR 4 /* Modem control */ +#define LSR 5 /* Line Status */ +#define MSR 6 /* Modem Status */ +#define DLL 0 /* Divisor Latch Low */ +#define DLH 1 /* Divisor latch High */ + +static unsigned int io_serial_in(unsigned long addr, int offset) +{ + return inb(addr + offset); +} + +static void io_serial_out(unsigned long addr, int offset, int value) +{ + outb(value, addr + offset); +} + +static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in; +static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out; + +static int early_serial_putc(unsigned char ch) +{ + unsigned timeout = 0xffff; + + while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout) + cpu_relax(); + serial_out(early_serial_base, TXR, ch); + return timeout ? 0 : -1; +} + +static void early_serial_write(struct console *con, const char *s, unsigned n) +{ + while (*s && n-- > 0) { + if (*s == '\n') + early_serial_putc('\r'); + early_serial_putc(*s); + s++; + } +} + +static __init void early_serial_hw_init(unsigned divisor) +{ + unsigned char c; + + serial_out(early_serial_base, LCR, 0x3); /* 8n1 */ + serial_out(early_serial_base, IER, 0); /* no interrupt */ + serial_out(early_serial_base, FCR, 0); /* no fifo */ + serial_out(early_serial_base, MCR, 0x3); /* DTR + RTS */ + + c = serial_in(early_serial_base, LCR); + serial_out(early_serial_base, LCR, c | DLAB); + serial_out(early_serial_base, DLL, divisor & 0xff); + serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff); + serial_out(early_serial_base, LCR, c & ~DLAB); +} + +#define DEFAULT_BAUD 9600 + +static __init void early_serial_init(char *s) +{ + unsigned divisor; + unsigned long baud = DEFAULT_BAUD; + char *e; + + if (*s == ',') + ++s; + + if (*s) { + unsigned port; + if (!strncmp(s, "0x", 2)) { + early_serial_base = simple_strtoul(s, &e, 16); + } else { + static const int __initconst bases[] = { 0x3f8, 0x2f8 }; + + if (!strncmp(s, "ttyS", 4)) + s += 4; + port = simple_strtoul(s, &e, 10); + if (port > 1 || s == e) + port = 0; + early_serial_base = bases[port]; + } + s += strcspn(s, ","); + if (*s == ',') + s++; + } + + if (*s) { + baud = simple_strtoull(s, &e, 0); + + if (baud == 0 || s == e) + baud = DEFAULT_BAUD; + } + + /* Convert from baud to divisor value */ + divisor = 115200 / baud; + + /* These will always be IO based ports */ + serial_in = io_serial_in; + serial_out = io_serial_out; + + /* Set up the HW */ + early_serial_hw_init(divisor); +} + +#ifdef CONFIG_PCI +static void mem32_serial_out(unsigned long addr, int offset, int value) +{ + u32 __iomem *vaddr = (u32 __iomem *)addr; + /* shift implied by pointer type */ + writel(value, vaddr + offset); +} + +static unsigned int mem32_serial_in(unsigned long addr, int offset) +{ + u32 __iomem *vaddr = (u32 __iomem *)addr; + /* shift implied by pointer type */ + return readl(vaddr + offset); +} + +/* + * early_pci_serial_init() + * + * This function is invoked when the early_printk param starts with "pciserial" + * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe + * the location of a PCI device that must be a UART device. "force" is optional + * and overrides the use of an UART device with a wrong PCI class code. + */ +static __init void early_pci_serial_init(char *s) +{ + unsigned divisor; + unsigned long baud = DEFAULT_BAUD; + u8 bus, slot, func; + u32 classcode, bar0; + u16 cmdreg; + char *e; + int force = 0; + + if (*s == ',') + ++s; + + if (*s == 0) + return; + + /* Force the use of an UART device with wrong class code */ + if (!strncmp(s, "force,", 6)) { + force = 1; + s += 6; + } + + /* + * Part the param to get the BDF values + */ + bus = (u8)simple_strtoul(s, &e, 16); + s = e; + if (*s != ':') + return; + ++s; + slot = (u8)simple_strtoul(s, &e, 16); + s = e; + if (*s != '.') + return; + ++s; + func = (u8)simple_strtoul(s, &e, 16); + s = e; + + /* A baud might be following */ + if (*s == ',') + s++; + + /* + * Find the device from the BDF + */ + cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND); + classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION); + bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0); + + /* + * Verify it is a UART type device + */ + if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) && + (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) || + (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ { + if (!force) + return; + } + + /* + * Determine if it is IO or memory mapped + */ + if (bar0 & 0x01) { + /* it is IO mapped */ + serial_in = io_serial_in; + serial_out = io_serial_out; + early_serial_base = bar0&0xfffffffc; + write_pci_config(bus, slot, func, PCI_COMMAND, + cmdreg|PCI_COMMAND_IO); + } else { + /* It is memory mapped - assume 32-bit alignment */ + serial_in = mem32_serial_in; + serial_out = mem32_serial_out; + /* WARNING! assuming the address is always in the first 4G */ + early_serial_base = + (unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10); + write_pci_config(bus, slot, func, PCI_COMMAND, + cmdreg|PCI_COMMAND_MEMORY); + } + + /* + * Initialize the hardware + */ + if (*s) { + if (strcmp(s, "nocfg") == 0) + /* Sometimes, we want to leave the UART alone + * and assume the BIOS has set it up correctly. + * "nocfg" tells us this is the case, and we + * should do no more setup. + */ + return; + if (kstrtoul(s, 0, &baud) < 0 || baud == 0) + baud = DEFAULT_BAUD; + } + + /* Convert from baud to divisor value */ + divisor = 115200 / baud; + + /* Set up the HW */ + early_serial_hw_init(divisor); +} +#endif + +static struct console early_serial_console = { + .name = "earlyser", + .write = early_serial_write, + .flags = CON_PRINTBUFFER, + .index = -1, +}; + +static void early_console_register(struct console *con, int keep_early) +{ + if (con->index != -1) { + printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n", + con->name); + return; + } + early_console = con; + if (keep_early) + early_console->flags &= ~CON_BOOT; + else + early_console->flags |= CON_BOOT; + register_console(early_console); +} + +static int __init setup_early_printk(char *buf) +{ + int keep; + + if (!buf) + return 0; + + if (early_console) + return 0; + + keep = (strstr(buf, "keep") != NULL); + + while (*buf != '\0') { + if (!strncmp(buf, "serial", 6)) { + buf += 6; + early_serial_init(buf); + early_console_register(&early_serial_console, keep); + if (!strncmp(buf, ",ttyS", 5)) + buf += 5; + } + if (!strncmp(buf, "ttyS", 4)) { + early_serial_init(buf + 4); + early_console_register(&early_serial_console, keep); + } +#ifdef CONFIG_PCI + if (!strncmp(buf, "pciserial", 9)) { + early_pci_serial_init(buf + 9); + early_console_register(&early_serial_console, keep); + buf += 9; /* Keep from match the above "serial" */ + } +#endif + if (!strncmp(buf, "vga", 3) && + boot_params.screen_info.orig_video_isVGA == 1) { + max_xpos = boot_params.screen_info.orig_video_cols; + max_ypos = boot_params.screen_info.orig_video_lines; + current_ypos = boot_params.screen_info.orig_y; + early_console_register(&early_vga_console, keep); + } +#ifdef CONFIG_EARLY_PRINTK_DBGP + if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4)) + early_console_register(&early_dbgp_console, keep); +#endif +#ifdef CONFIG_HVC_XEN + if (!strncmp(buf, "xen", 3)) + early_console_register(&xenboot_console, keep); +#endif +#ifdef CONFIG_EARLY_PRINTK_EFI + if (!strncmp(buf, "efi", 3)) + early_console_register(&early_efi_console, keep); +#endif +#ifdef CONFIG_EARLY_PRINTK_USB_XDBC + if (!strncmp(buf, "xdbc", 4)) + early_xdbc_parse_parameter(buf + 4); +#endif + + buf++; + } + return 0; +} + +early_param("earlyprintk", setup_early_printk); |