Release 4.11 arch/x86/pci/pcbios.c

/*
 * BIOS32 and PCI BIOS handling.
 */

#include <linux/pci.h>
#include <linux/init.h>
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <asm/pci_x86.h>
#include <asm/pci-functions.h>
#include <asm/cacheflush.h>

/* BIOS32 signature: "_32_" */

#define BIOS32_SIGNATURE	(('_' << 0) + ('3' << 8) + ('2' << 16) + ('_' << 24))

/* PCI signature: "PCI " */

#define PCI_SIGNATURE		(('P' << 0) + ('C' << 8) + ('I' << 16) + (' ' << 24))

/* PCI service signature: "$PCI" */

#define PCI_SERVICE		(('$' << 0) + ('P' << 8) + ('C' << 16) + ('I' << 24))

/* PCI BIOS hardware mechanism flags */

#define PCIBIOS_HW_TYPE1		0x01

#define PCIBIOS_HW_TYPE2		0x02

#define PCIBIOS_HW_TYPE1_SPEC		0x10

#define PCIBIOS_HW_TYPE2_SPEC		0x20


int pcibios_enabled;

/* According to the BIOS specification at:
 * http://members.datafast.net.au/dft0802/specs/bios21.pdf, we could
 * restrict the x zone to some pages and make it ro. But this may be
 * broken on some bios, complex to handle with static_protections.
 * We could make the 0xe0000-0x100000 range rox, but this can break
 * some ISA mapping.
 *
 * So we let's an rw and x hole when pcibios is used. This shouldn't
 * happen for modern system with mmconfig, and if you don't want it
 * you could disable pcibios...
 */


static inline void set_bios_x(void)
{
	pcibios_enabled = 1;
	set_memory_x(PAGE_OFFSET + BIOS_BEGIN, (BIOS_END - BIOS_BEGIN) >> PAGE_SHIFT);
	if (__supported_pte_mask & _PAGE_NX)
		printk(KERN_INFO "PCI : PCI BIOS area is rw and x. Use pci=nobios if you want it NX.\n");
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Matthieu Castet
39
97.50%
1
50.00%
Wang YanQing
1
2.50%
1
50.00%
Total
40
100.00%
2
100.00%

/*
 * This is the standard structure used to identify the entry point
 * to the BIOS32 Service Directory, as documented in
 *      Standard BIOS 32-bit Service Directory Proposal
 *      Revision 0.4 May 24, 1993
 *      Phoenix Technologies Ltd.
 *      Norwood, MA
 * and the PCI BIOS specification.
 */


union bios32 {
	struct {
		
unsigned long signature;	/* _32_ */
		
unsigned long entry;		/* 32 bit physical address */
		
unsigned char revision;		/* Revision level, 0 */
		
unsigned char length;		/* Length in paragraphs should be 01 */
		
unsigned char checksum;		/* All bytes must add up to zero */
		
unsigned char reserved[5]; 	/* Must be zero */
	} 
fields;
	
char chars[16];
};

/*
 * Physical address of the service directory.  I don't know if we're
 * allowed to have more than one of these or not, so just in case
 * we'll make pcibios_present() take a memory start parameter and store
 * the array there.
 */

static struct {
	
unsigned long address;
	
unsigned short segment;
} 
bios32_indirect __initdata = { 0, __KERNEL_CS };

/*
 * Returns the entry point for the given service, NULL on error
 */



static unsigned long __init bios32_service(unsigned long service)
{
	unsigned char return_code;	/* %al */
	unsigned long address;		/* %ebx */
	unsigned long length;		/* %ecx */
	unsigned long entry;		/* %edx */
	unsigned long flags;

	local_irq_save(flags);
	__asm__("lcall *(%%edi); cld"
                : "=a" (return_code),
                  "=b" (address),
                  "=c" (length),
                  "=d" (entry)
                : "0" (service),
                  "1" (0),
                  "D" (&bios32_indirect));
	local_irq_restore(flags);

	switch (return_code) {
		case 0:
			return address + entry;
		case 0x80:	/* Not present */
			printk(KERN_WARNING "bios32_service(0x%lx): not present\n", service);
			return 0;
		default: /* Shouldn't happen */
			printk(KERN_WARNING "bios32_service(0x%lx): returned 0x%x -- BIOS bug!\n",
				service, return_code);
			return 0;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
86
94.51%
1
20.00%
Greg Kroah-Hartman
2
2.20%
1
20.00%
Ingo Molnar
2
2.20%
2
40.00%
Mathias Krause
1
1.10%
1
20.00%
Total
91
100.00%
5
100.00%

static struct {
	
unsigned long address;
	
unsigned short segment;
} 
pci_indirect __ro_after_init = {
	.address = 0,
	.segment = __KERNEL_CS,
};


static int pci_bios_present __ro_after_init;



static int __init check_pcibios(void)
{
	u32 signature, eax, ebx, ecx;
	u8 status, major_ver, minor_ver, hw_mech;
	unsigned long flags, pcibios_entry;

	if ((pcibios_entry = bios32_service(PCI_SERVICE))) {
		pci_indirect.address = pcibios_entry + PAGE_OFFSET;

		local_irq_save(flags);
		__asm__(
                        "lcall *(%%edi); cld\n\t"
                        "jc 1f\n\t"
                        "xor %%ah, %%ah\n"
                        "1:"
                        : "=d" (signature),
                          "=a" (eax),
                          "=b" (ebx),
                          "=c" (ecx)
                        : "1" (PCIBIOS_PCI_BIOS_PRESENT),
                          "D" (&pci_indirect)
                        : "memory");
		local_irq_restore(flags);

		status = (eax >> 8) & 0xff;
		hw_mech = eax & 0xff;
		major_ver = (ebx >> 8) & 0xff;
		minor_ver = ebx & 0xff;
		if (pcibios_last_bus < 0)
			pcibios_last_bus = ecx & 0xff;
		DBG("PCI: BIOS probe returned s=%02x hw=%02x ver=%02x.%02x l=%02x\n",
			status, hw_mech, major_ver, minor_ver, pcibios_last_bus);
		if (status || signature != PCI_SIGNATURE) {
			printk (KERN_ERR "PCI: BIOS BUG #%x[%08x] found\n",
				status, signature);
			return 0;
		}
		printk(KERN_INFO "PCI: PCI BIOS revision %x.%02x entry at 0x%lx, last bus=%d\n",
			major_ver, minor_ver, pcibios_entry, pcibios_last_bus);
#ifdef CONFIG_PCI_DIRECT
		if (!(hw_mech & PCIBIOS_HW_TYPE1))
			pci_probe &= ~PCI_PROBE_CONF1;
		if (!(hw_mech & PCIBIOS_HW_TYPE2))
			pci_probe &= ~PCI_PROBE_CONF2;
#endif
		return 1;
	}
	return 0;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
196
98.00%
1
20.00%
Ingo Molnar
2
1.00%
2
40.00%
Mathias Krause
1
0.50%
1
20.00%
Greg Kroah-Hartman
1
0.50%
1
20.00%
Total
200
100.00%
5
100.00%



static int pci_bios_read(unsigned int seg, unsigned int bus,
			 unsigned int devfn, int reg, int len, u32 *value)
{
	unsigned long result = 0;
	unsigned long flags;
	unsigned long bx = (bus << 8) | devfn;
	u16 number = 0, mask = 0;

	WARN_ON(seg);
	if (!value || (bus > 255) || (devfn > 255) || (reg > 255))
		return -EINVAL;

	raw_spin_lock_irqsave(&pci_config_lock, flags);

	switch (len) {
	case 1:
		number = PCIBIOS_READ_CONFIG_BYTE;
		mask = 0xff;
		break;
	case 2:
		number = PCIBIOS_READ_CONFIG_WORD;
		mask = 0xffff;
		break;
	case 4:
		number = PCIBIOS_READ_CONFIG_DWORD;
		break;
	}

	__asm__("lcall *(%%esi); cld\n\t"
                "jc 1f\n\t"
                "xor %%ah, %%ah\n"
                "1:"
                : "=c" (*value),
                  "=a" (result)
                : "1" (number),
                  "b" (bx),
                  "D" ((long)reg),
                  "S" (&pci_indirect));
	/*
         * Zero-extend the result beyond 8 or 16 bits, do not trust the
         * BIOS having done it:
         */
	if (mask)
		*value &= mask;

	raw_spin_unlock_irqrestore(&pci_config_lock, flags);

	return (int)((result & 0xff00) >> 8);
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
115
67.65%
1
12.50%
Geliang Tang
36
21.18%
1
12.50%
Jan Beulich
5
2.94%
1
12.50%
Matthew Wilcox
5
2.94%
2
25.00%
Ingo Molnar
4
2.35%
1
12.50%
Björn Helgaas
3
1.76%
1
12.50%
Thomas Gleixner
2
1.18%
1
12.50%
Total
170
100.00%
8
100.00%



static int pci_bios_write(unsigned int seg, unsigned int bus,
			  unsigned int devfn, int reg, int len, u32 value)
{
	unsigned long result = 0;
	unsigned long flags;
	unsigned long bx = (bus << 8) | devfn;
	u16 number = 0;

	WARN_ON(seg);
	if ((bus > 255) || (devfn > 255) || (reg > 255)) 
		return -EINVAL;

	raw_spin_lock_irqsave(&pci_config_lock, flags);

	switch (len) {
	case 1:
		number = PCIBIOS_WRITE_CONFIG_BYTE;
		break;
	case 2:
		number = PCIBIOS_WRITE_CONFIG_WORD;
		break;
	case 4:
		number = PCIBIOS_WRITE_CONFIG_DWORD;
		break;
	}

	__asm__("lcall *(%%esi); cld\n\t"
                "jc 1f\n\t"
                "xor %%ah, %%ah\n"
                "1:"
                : "=a" (result)
                : "0" (number),
                  "c" (value),
                  "b" (bx),
                  "D" ((long)reg),
                  "S" (&pci_indirect));

	raw_spin_unlock_irqrestore(&pci_config_lock, flags);

	return (int)((result & 0xff00) >> 8);
}


Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
111
77.08%
1
14.29%
Geliang Tang
18
12.50%
1
14.29%
Matthew Wilcox
5
3.47%
2
28.57%
Jan Beulich
5
3.47%
1
14.29%
Björn Helgaas
3
2.08%
1
14.29%
Thomas Gleixner
2
1.39%
1
14.29%
Total
144
100.00%
7
100.00%

/*
 * Function table for BIOS32 access
 */


static const struct pci_raw_ops pci_bios_access = {
	.read =		pci_bios_read,
	.write =	pci_bios_write
};

/*
 * Try to find PCI BIOS.
 */



static const struct pci_raw_ops *__init pci_find_bios(void)
{
	union bios32 *check;
	unsigned char sum;
	int i, length;

	/*
         * Follow the standard procedure for locating the BIOS32 Service
         * directory by scanning the permissible address range from
         * 0xe0000 through 0xfffff for a valid BIOS32 structure.
         */

	for (check = (union bios32 *) __va(0xe0000);
	     check <= (union bios32 *) __va(0xffff0);
	     ++check) {
		long sig;
		if (probe_kernel_address(&check->fields.signature, sig))
			continue;

		if (check->fields.signature != BIOS32_SIGNATURE)
			continue;
		length = check->fields.length * 16;
		if (!length)
			continue;
		sum = 0;
		for (i = 0; i < length ; ++i)
			sum += check->chars[i];
		if (sum != 0)
			continue;
		if (check->fields.revision != 0) {
			printk("PCI: unsupported BIOS32 revision %d at 0x%p\n",
				check->fields.revision, check);
			continue;
		}
		DBG("PCI: BIOS32 Service Directory structure at 0x%p\n", check);
		if (check->fields.entry >= 0x100000) {
			printk("PCI: BIOS32 entry (0x%p) in high memory, "
					"cannot use.\n", check);
			return NULL;
		} else {
			unsigned long bios32_entry = check->fields.entry;
			DBG("PCI: BIOS32 Service Directory entry at 0x%lx\n",
					bios32_entry);
			bios32_indirect.address = bios32_entry + PAGE_OFFSET;
			set_bios_x();
			if (check_pcibios())
				return &pci_bios_access;
		}
		break;	/* Hopefully more than one BIOS32 cannot happen... */
	}

	return NULL;
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
211
89.03%
1
16.67%
Rusty Russell
20
8.44%
1
16.67%
Matthieu Castet
3
1.27%
1
16.67%
Matthew Wilcox
1
0.42%
1
16.67%
Jan Beulich
1
0.42%
1
16.67%
Mathias Krause
1
0.42%
1
16.67%
Total
237
100.00%
6
100.00%

/*
 *  BIOS Functions for IRQ Routing
 */


struct irq_routing_options {
	
u16 size;
	
struct irq_info *table;
	
u16 segment;
} __attribute__((packed));



struct irq_routing_table * pcibios_get_irq_routing_table(void)
{
	struct irq_routing_options opt;
	struct irq_routing_table *rt = NULL;
	int ret, map;
	unsigned long page;

	if (!pci_bios_present)
		return NULL;
	page = __get_free_page(GFP_KERNEL);
	if (!page)
		return NULL;
	opt.table = (struct irq_info *) page;
	opt.size = PAGE_SIZE;
	opt.segment = __KERNEL_DS;

	DBG("PCI: Fetching IRQ routing table... ");
	__asm__("push %%es\n\t"
                "push %%ds\n\t"
                "pop  %%es\n\t"
                "lcall *(%%esi); cld\n\t"
                "pop %%es\n\t"
                "jc 1f\n\t"
                "xor %%ah, %%ah\n"
                "1:"
                : "=a" (ret),
                  "=b" (map),
                  "=m" (opt)
                : "0" (PCIBIOS_GET_ROUTING_OPTIONS),
                  "1" (0),
                  "D" ((long) &opt),
                  "S" (&pci_indirect),
                  "m" (opt)
                : "memory");
	DBG("OK  ret=%d, size=%d, map=%x\n", ret, opt.size, map);
	if (ret & 0xff00)
		printk(KERN_ERR "PCI: Error %02x when fetching IRQ routing table.\n", (ret >> 8) & 0xff);
	else if (opt.size) {
		rt = kmalloc(sizeof(struct irq_routing_table) + opt.size, GFP_KERNEL);
		if (rt) {
			memset(rt, 0, sizeof(struct irq_routing_table));
			rt->size = opt.size + sizeof(struct irq_routing_table);
			rt->exclusive_irqs = map;
			memcpy(rt->slots, (void *) page, opt.size);
			printk(KERN_INFO "PCI: Using BIOS Interrupt Routing Table\n");
		}
	}
	free_page(page);
	return rt;
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
208
99.05%
1
33.33%
Andrew Morton
1
0.48%
1
33.33%
Greg Kroah-Hartman
1
0.48%
1
33.33%
Total
210
100.00%
3
100.00%


EXPORT_SYMBOL(pcibios_get_irq_routing_table);



int pcibios_set_irq_routing(struct pci_dev *dev, int pin, int irq)
{
	int ret;

	__asm__("lcall *(%%esi); cld\n\t"
                "jc 1f\n\t"
                "xor %%ah, %%ah\n"
                "1:"
                : "=a" (ret)
                : "0" (PCIBIOS_SET_PCI_HW_INT),
                  "b" ((dev->bus->number << 8) | dev->devfn),
                  "c" ((irq << 8) | (pin + 10)),
                  "S" (&pci_indirect));
	return !(ret & 0xff00);
}
Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
28
100.00%
1
100.00%
Total
28
100.00%
1
100.00%


EXPORT_SYMBOL(pcibios_set_irq_routing);



void __init pci_pcbios_init(void)
{
	if ((pci_probe & PCI_PROBE_BIOS) 
		&& ((raw_pci_ops = pci_find_bios()))) {
		pci_bios_present = 1;
	}
}

Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
29
93.55%
1
33.33%
Andi Kleen
1
3.23%
1
33.33%
Matthew Wilcox
1
3.23%
1
33.33%
Total
31
100.00%
3
100.00%

Overall Contributors
Person
Tokens
Prop
Commits
CommitProp
Patrick Mochel
1150
83.94%
1
3.85%
Geliang Tang
54
3.94%
1
3.85%
Matthieu Castet
49
3.58%
1
3.85%
Rusty Russell
23
1.68%
1
3.85%
Alexey Dobriyan
13
0.95%
1
3.85%
Matthew Wilcox
13
0.95%
2
7.69%
Jan Beulich
12
0.88%
2
7.69%
Kees Cook
9
0.66%
1
3.85%
Ingo Molnar
9
0.66%
4
15.38%
Matthew Dobson
8
0.58%
1
3.85%
Björn Helgaas
6
0.44%
1
3.85%
Greg Kroah-Hartman
4
0.29%
1
3.85%
Thomas Gleixner
4
0.29%
1
3.85%
Mathias Krause
4
0.29%
1
3.85%
Tom Rini
3
0.22%
1
3.85%
Tejun Heo
3
0.22%
1
3.85%
Alan Cox
2
0.15%
1
3.85%
Andrew Morton
1
0.07%
1
3.85%
Andi Kleen
1
0.07%
1
3.85%
Jaswinder Singh Rajput
1
0.07%
1
3.85%
Wang YanQing
1
0.07%
1
3.85%
Total
1370
100.00%
26
100.00%
Directory: arch/x86/pci

Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.