diff options
Diffstat (limited to 'arch/x86')
| -rw-r--r-- | arch/x86/kernel/early_printk.c | 182 |
1 files changed, 166 insertions, 16 deletions
diff --git a/arch/x86/kernel/early_printk.c b/arch/x86/kernel/early_printk.c index de814df..a62536a 100644 --- a/arch/x86/kernel/early_printk.c +++ b/arch/x86/kernel/early_printk.c @@ -19,6 +19,7 @@ #include <linux/usb/ehci_def.h> #include <linux/efi.h> #include <asm/efi.h> +#include <asm/pci_x86.h> /* Simple VGA output */ #define VGABASE (__ISA_IO_base + 0xb8000) @@ -76,7 +77,7 @@ static struct console early_vga_console = { /* Serial functions loosely based on a similar package from Klaus P. Gerlicher */ -static int early_serial_base = 0x3f8; /* ttyS0 */ +static unsigned long early_serial_base = 0x3f8; /* ttyS0 */ #define XMTRDY 0x20 @@ -94,13 +95,40 @@ static int early_serial_base = 0x3f8; /* ttyS0 */ #define DLL 0 /* Divisor Latch Low */ #define DLH 1 /* Divisor latch High */ +static void mem32_serial_out(unsigned long addr, int offset, int value) +{ + uint32_t *vaddr = (uint32_t *)addr; + /* shift implied by pointer type */ + writel(value, vaddr + offset); +} + +static unsigned int mem32_serial_in(unsigned long addr, int offset) +{ + uint32_t *vaddr = (uint32_t *)addr; + /* shift implied by pointer type */ + return readl(vaddr + offset); +} + +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 ((inb(early_serial_base + LSR) & XMTRDY) == 0 && --timeout) + while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout) cpu_relax(); - outb(ch, early_serial_base + TXR); + serial_out(early_serial_base, TXR, ch); return timeout ? 0 : -1; } @@ -114,13 +142,28 @@ static void early_serial_write(struct console *con, const char *s, unsigned n) } } +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 char c; unsigned divisor; - unsigned baud = DEFAULT_BAUD; + unsigned long baud = DEFAULT_BAUD; char *e; if (*s == ',') @@ -145,24 +188,124 @@ static __init void early_serial_init(char *s) s++; } - outb(0x3, early_serial_base + LCR); /* 8n1 */ - outb(0, early_serial_base + IER); /* no interrupt */ - outb(0, early_serial_base + FCR); /* no fifo */ - outb(0x3, early_serial_base + MCR); /* DTR + RTS */ + if (*s) { + if (kstrtoul(s, 0, &baud) < 0 || baud == 0) + 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 +/* + * early_pci_serial_init() + * + * This function is invoked when the early_printk param starts with "pciserial" + * The rest of the param should be ",B:D.F,baud" where B, D & F describe the + * location of a PCI device that must be a UART device. + */ +static __init void early_pci_serial_init(char *s) +{ + unsigned divisor; + unsigned long baud = DEFAULT_BAUD; + u8 bus, slot, func; + uint32_t classcode, bar0; + uint16_t cmdreg; + char *e; + + + /* + * First, part the param to get the BDF values + */ + if (*s == ',') + ++s; + + if (*s == 0) + return; + + 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++; + + /* + * Second, 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 */ + 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); + } + + /* + * Lastly, initalize the hardware + */ if (*s) { - baud = simple_strtoul(s, &e, 0); - if (baud == 0 || s == e) + 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; - c = inb(early_serial_base + LCR); - outb(c | DLAB, early_serial_base + LCR); - outb(divisor & 0xff, early_serial_base + DLL); - outb((divisor >> 8) & 0xff, early_serial_base + DLH); - outb(c & ~DLAB, early_serial_base + LCR); + + /* Set up the HW */ + early_serial_hw_init(divisor); } +#endif static struct console early_serial_console = { .name = "earlyser", @@ -210,6 +353,13 @@ static int __init setup_early_printk(char *buf) 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; |
