cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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early_printk.c (9942B)


      1// SPDX-License-Identifier: GPL-2.0
      2#include <linux/console.h>
      3#include <linux/kernel.h>
      4#include <linux/init.h>
      5#include <linux/string.h>
      6#include <linux/screen_info.h>
      7#include <linux/usb/ch9.h>
      8#include <linux/pci_regs.h>
      9#include <linux/pci_ids.h>
     10#include <linux/errno.h>
     11#include <linux/pgtable.h>
     12#include <asm/io.h>
     13#include <asm/processor.h>
     14#include <asm/fcntl.h>
     15#include <asm/setup.h>
     16#include <xen/hvc-console.h>
     17#include <asm/pci-direct.h>
     18#include <asm/fixmap.h>
     19#include <linux/usb/ehci_def.h>
     20#include <linux/usb/xhci-dbgp.h>
     21#include <asm/pci_x86.h>
     22
     23/* Simple VGA output */
     24#define VGABASE		(__ISA_IO_base + 0xb8000)
     25
     26static int max_ypos = 25, max_xpos = 80;
     27static int current_ypos = 25, current_xpos;
     28
     29static void early_vga_write(struct console *con, const char *str, unsigned n)
     30{
     31	char c;
     32	int  i, k, j;
     33
     34	while ((c = *str++) != '\0' && n-- > 0) {
     35		if (current_ypos >= max_ypos) {
     36			/* scroll 1 line up */
     37			for (k = 1, j = 0; k < max_ypos; k++, j++) {
     38				for (i = 0; i < max_xpos; i++) {
     39					writew(readw(VGABASE+2*(max_xpos*k+i)),
     40					       VGABASE + 2*(max_xpos*j + i));
     41				}
     42			}
     43			for (i = 0; i < max_xpos; i++)
     44				writew(0x720, VGABASE + 2*(max_xpos*j + i));
     45			current_ypos = max_ypos-1;
     46		}
     47#ifdef CONFIG_KGDB_KDB
     48		if (c == '\b') {
     49			if (current_xpos > 0)
     50				current_xpos--;
     51		} else if (c == '\r') {
     52			current_xpos = 0;
     53		} else
     54#endif
     55		if (c == '\n') {
     56			current_xpos = 0;
     57			current_ypos++;
     58		} else if (c != '\r')  {
     59			writew(((0x7 << 8) | (unsigned short) c),
     60			       VGABASE + 2*(max_xpos*current_ypos +
     61						current_xpos++));
     62			if (current_xpos >= max_xpos) {
     63				current_xpos = 0;
     64				current_ypos++;
     65			}
     66		}
     67	}
     68}
     69
     70static struct console early_vga_console = {
     71	.name =		"earlyvga",
     72	.write =	early_vga_write,
     73	.flags =	CON_PRINTBUFFER,
     74	.index =	-1,
     75};
     76
     77/* Serial functions loosely based on a similar package from Klaus P. Gerlicher */
     78
     79static unsigned long early_serial_base = 0x3f8;  /* ttyS0 */
     80
     81#define XMTRDY          0x20
     82
     83#define DLAB		0x80
     84
     85#define TXR             0       /*  Transmit register (WRITE) */
     86#define RXR             0       /*  Receive register  (READ)  */
     87#define IER             1       /*  Interrupt Enable          */
     88#define IIR             2       /*  Interrupt ID              */
     89#define FCR             2       /*  FIFO control              */
     90#define LCR             3       /*  Line control              */
     91#define MCR             4       /*  Modem control             */
     92#define LSR             5       /*  Line Status               */
     93#define MSR             6       /*  Modem Status              */
     94#define DLL             0       /*  Divisor Latch Low         */
     95#define DLH             1       /*  Divisor latch High        */
     96
     97static unsigned int io_serial_in(unsigned long addr, int offset)
     98{
     99	return inb(addr + offset);
    100}
    101
    102static void io_serial_out(unsigned long addr, int offset, int value)
    103{
    104	outb(value, addr + offset);
    105}
    106
    107static unsigned int (*serial_in)(unsigned long addr, int offset) = io_serial_in;
    108static void (*serial_out)(unsigned long addr, int offset, int value) = io_serial_out;
    109
    110static int early_serial_putc(unsigned char ch)
    111{
    112	unsigned timeout = 0xffff;
    113
    114	while ((serial_in(early_serial_base, LSR) & XMTRDY) == 0 && --timeout)
    115		cpu_relax();
    116	serial_out(early_serial_base, TXR, ch);
    117	return timeout ? 0 : -1;
    118}
    119
    120static void early_serial_write(struct console *con, const char *s, unsigned n)
    121{
    122	while (*s && n-- > 0) {
    123		if (*s == '\n')
    124			early_serial_putc('\r');
    125		early_serial_putc(*s);
    126		s++;
    127	}
    128}
    129
    130static __init void early_serial_hw_init(unsigned divisor)
    131{
    132	unsigned char c;
    133
    134	serial_out(early_serial_base, LCR, 0x3);	/* 8n1 */
    135	serial_out(early_serial_base, IER, 0);	/* no interrupt */
    136	serial_out(early_serial_base, FCR, 0);	/* no fifo */
    137	serial_out(early_serial_base, MCR, 0x3);	/* DTR + RTS */
    138
    139	c = serial_in(early_serial_base, LCR);
    140	serial_out(early_serial_base, LCR, c | DLAB);
    141	serial_out(early_serial_base, DLL, divisor & 0xff);
    142	serial_out(early_serial_base, DLH, (divisor >> 8) & 0xff);
    143	serial_out(early_serial_base, LCR, c & ~DLAB);
    144}
    145
    146#define DEFAULT_BAUD 9600
    147
    148static __init void early_serial_init(char *s)
    149{
    150	unsigned divisor;
    151	unsigned long baud = DEFAULT_BAUD;
    152	char *e;
    153
    154	if (*s == ',')
    155		++s;
    156
    157	if (*s) {
    158		unsigned port;
    159		if (!strncmp(s, "0x", 2)) {
    160			early_serial_base = simple_strtoul(s, &e, 16);
    161		} else {
    162			static const int __initconst bases[] = { 0x3f8, 0x2f8 };
    163
    164			if (!strncmp(s, "ttyS", 4))
    165				s += 4;
    166			port = simple_strtoul(s, &e, 10);
    167			if (port > 1 || s == e)
    168				port = 0;
    169			early_serial_base = bases[port];
    170		}
    171		s += strcspn(s, ",");
    172		if (*s == ',')
    173			s++;
    174	}
    175
    176	if (*s) {
    177		baud = simple_strtoull(s, &e, 0);
    178
    179		if (baud == 0 || s == e)
    180			baud = DEFAULT_BAUD;
    181	}
    182
    183	/* Convert from baud to divisor value */
    184	divisor = 115200 / baud;
    185
    186	/* These will always be IO based ports */
    187	serial_in = io_serial_in;
    188	serial_out = io_serial_out;
    189
    190	/* Set up the HW */
    191	early_serial_hw_init(divisor);
    192}
    193
    194#ifdef CONFIG_PCI
    195static void mem32_serial_out(unsigned long addr, int offset, int value)
    196{
    197	u32 __iomem *vaddr = (u32 __iomem *)addr;
    198	/* shift implied by pointer type */
    199	writel(value, vaddr + offset);
    200}
    201
    202static unsigned int mem32_serial_in(unsigned long addr, int offset)
    203{
    204	u32 __iomem *vaddr = (u32 __iomem *)addr;
    205	/* shift implied by pointer type */
    206	return readl(vaddr + offset);
    207}
    208
    209/*
    210 * early_pci_serial_init()
    211 *
    212 * This function is invoked when the early_printk param starts with "pciserial"
    213 * The rest of the param should be "[force],B:D.F,baud", where B, D & F describe
    214 * the location of a PCI device that must be a UART device. "force" is optional
    215 * and overrides the use of an UART device with a wrong PCI class code.
    216 */
    217static __init void early_pci_serial_init(char *s)
    218{
    219	unsigned divisor;
    220	unsigned long baud = DEFAULT_BAUD;
    221	u8 bus, slot, func;
    222	u32 classcode, bar0;
    223	u16 cmdreg;
    224	char *e;
    225	int force = 0;
    226
    227	if (*s == ',')
    228		++s;
    229
    230	if (*s == 0)
    231		return;
    232
    233	/* Force the use of an UART device with wrong class code */
    234	if (!strncmp(s, "force,", 6)) {
    235		force = 1;
    236		s += 6;
    237	}
    238
    239	/*
    240	 * Part the param to get the BDF values
    241	 */
    242	bus = (u8)simple_strtoul(s, &e, 16);
    243	s = e;
    244	if (*s != ':')
    245		return;
    246	++s;
    247	slot = (u8)simple_strtoul(s, &e, 16);
    248	s = e;
    249	if (*s != '.')
    250		return;
    251	++s;
    252	func = (u8)simple_strtoul(s, &e, 16);
    253	s = e;
    254
    255	/* A baud might be following */
    256	if (*s == ',')
    257		s++;
    258
    259	/*
    260	 * Find the device from the BDF
    261	 */
    262	cmdreg = read_pci_config(bus, slot, func, PCI_COMMAND);
    263	classcode = read_pci_config(bus, slot, func, PCI_CLASS_REVISION);
    264	bar0 = read_pci_config(bus, slot, func, PCI_BASE_ADDRESS_0);
    265
    266	/*
    267	 * Verify it is a UART type device
    268	 */
    269	if (((classcode >> 16 != PCI_CLASS_COMMUNICATION_MODEM) &&
    270	     (classcode >> 16 != PCI_CLASS_COMMUNICATION_SERIAL)) ||
    271	   (((classcode >> 8) & 0xff) != 0x02)) /* 16550 I/F at BAR0 */ {
    272		if (!force)
    273			return;
    274	}
    275
    276	/*
    277	 * Determine if it is IO or memory mapped
    278	 */
    279	if (bar0 & 0x01) {
    280		/* it is IO mapped */
    281		serial_in = io_serial_in;
    282		serial_out = io_serial_out;
    283		early_serial_base = bar0&0xfffffffc;
    284		write_pci_config(bus, slot, func, PCI_COMMAND,
    285						cmdreg|PCI_COMMAND_IO);
    286	} else {
    287		/* It is memory mapped - assume 32-bit alignment */
    288		serial_in = mem32_serial_in;
    289		serial_out = mem32_serial_out;
    290		/* WARNING! assuming the address is always in the first 4G */
    291		early_serial_base =
    292			(unsigned long)early_ioremap(bar0 & 0xfffffff0, 0x10);
    293		write_pci_config(bus, slot, func, PCI_COMMAND,
    294						cmdreg|PCI_COMMAND_MEMORY);
    295	}
    296
    297	/*
    298	 * Initialize the hardware
    299	 */
    300	if (*s) {
    301		if (strcmp(s, "nocfg") == 0)
    302			/* Sometimes, we want to leave the UART alone
    303			 * and assume the BIOS has set it up correctly.
    304			 * "nocfg" tells us this is the case, and we
    305			 * should do no more setup.
    306			 */
    307			return;
    308		if (kstrtoul(s, 0, &baud) < 0 || baud == 0)
    309			baud = DEFAULT_BAUD;
    310	}
    311
    312	/* Convert from baud to divisor value */
    313	divisor = 115200 / baud;
    314
    315	/* Set up the HW */
    316	early_serial_hw_init(divisor);
    317}
    318#endif
    319
    320static struct console early_serial_console = {
    321	.name =		"earlyser",
    322	.write =	early_serial_write,
    323	.flags =	CON_PRINTBUFFER,
    324	.index =	-1,
    325};
    326
    327static void early_console_register(struct console *con, int keep_early)
    328{
    329	if (con->index != -1) {
    330		printk(KERN_CRIT "ERROR: earlyprintk= %s already used\n",
    331		       con->name);
    332		return;
    333	}
    334	early_console = con;
    335	if (keep_early)
    336		early_console->flags &= ~CON_BOOT;
    337	else
    338		early_console->flags |= CON_BOOT;
    339	register_console(early_console);
    340}
    341
    342static int __init setup_early_printk(char *buf)
    343{
    344	int keep;
    345
    346	if (!buf)
    347		return 0;
    348
    349	if (early_console)
    350		return 0;
    351
    352	keep = (strstr(buf, "keep") != NULL);
    353
    354	while (*buf != '\0') {
    355		if (!strncmp(buf, "serial", 6)) {
    356			buf += 6;
    357			early_serial_init(buf);
    358			early_console_register(&early_serial_console, keep);
    359			if (!strncmp(buf, ",ttyS", 5))
    360				buf += 5;
    361		}
    362		if (!strncmp(buf, "ttyS", 4)) {
    363			early_serial_init(buf + 4);
    364			early_console_register(&early_serial_console, keep);
    365		}
    366#ifdef CONFIG_PCI
    367		if (!strncmp(buf, "pciserial", 9)) {
    368			early_pci_serial_init(buf + 9);
    369			early_console_register(&early_serial_console, keep);
    370			buf += 9; /* Keep from match the above "serial" */
    371		}
    372#endif
    373		if (!strncmp(buf, "vga", 3) &&
    374		    boot_params.screen_info.orig_video_isVGA == 1) {
    375			max_xpos = boot_params.screen_info.orig_video_cols;
    376			max_ypos = boot_params.screen_info.orig_video_lines;
    377			current_ypos = boot_params.screen_info.orig_y;
    378			early_console_register(&early_vga_console, keep);
    379		}
    380#ifdef CONFIG_EARLY_PRINTK_DBGP
    381		if (!strncmp(buf, "dbgp", 4) && !early_dbgp_init(buf + 4))
    382			early_console_register(&early_dbgp_console, keep);
    383#endif
    384#ifdef CONFIG_HVC_XEN
    385		if (!strncmp(buf, "xen", 3))
    386			early_console_register(&xenboot_console, keep);
    387#endif
    388#ifdef CONFIG_EARLY_PRINTK_USB_XDBC
    389		if (!strncmp(buf, "xdbc", 4))
    390			early_xdbc_parse_parameter(buf + 4, keep);
    391#endif
    392
    393		buf++;
    394	}
    395	return 0;
    396}
    397
    398early_param("earlyprintk", setup_early_printk);