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-rw-r--r--arch/x86/lib/bios_pci.S413
1 files changed, 413 insertions, 0 deletions
diff --git a/arch/x86/lib/bios_pci.S b/arch/x86/lib/bios_pci.S
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+/*
+ * (C) Copyright 2002
+ * Daniel Engström, Omicron Ceti AB, daniel@omicron.se
+ *
+ * See file CREDITS for list of people who contributed to this
+ * project.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of
+ * the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston,
+ * MA 02111-1307 USA
+ */
+
+/*
+ * x86 realmode assembly implementation of a PCI BIOS
+ * for platforms that use one PCI hose and configuration
+ * access type 1. (The common case for low-end PC's)
+ */
+
+#include "bios.h"
+
+#define PCI_BIOS_DEBUG
+
+.section .bios, "ax"
+.code16
+.globl realmode_pci_bios_call_entry
+.hidden realmode_pci_bios_call_entry
+.type realmode_pci_bios_call_entry, @function
+realmode_pci_bios_call_entry:
+ MAKE_BIOS_STACK
+ call realmode_pci_bios
+ RESTORE_CALLERS_STACK
+ ret
+
+
+.globl realmode_pci_bios
+realmode_pci_bios:
+gs movw OFFS_AX(%bp), %ax
+ cmpb $1, %al
+ je pci_bios_present
+ cmpb $2, %al
+ je pci_bios_find_device
+ cmpb $3, %al
+ je pci_bios_find_class
+ cmpb $6, %al
+ je pci_bios_generate_special_cycle
+ cmpb $8, %al
+ je pci_bios_read_cfg_byte
+ cmpb $9, %al
+ je pci_bios_read_cfg_word
+ cmpb $10, %al
+ je pci_bios_read_cfg_dword
+ cmpb $11, %al
+ je pci_bios_write_cfg_byte
+ cmpb $12, %al
+ je pci_bios_write_cfg_word
+ cmpb $13, %al
+ je pci_bios_write_cfg_dword
+ cmpb $14, %al
+ je pci_bios_get_irq_routing
+ cmpb $15, %al
+ je pci_bios_set_irq
+ jmp unknown_function
+
+/*****************************************************************************/
+
+pci_bios_present:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_present
+#endif
+ movl $0x20494350, %eax
+gs movl %eax, OFFS_EDX(%bp)
+ movb $0x01, %al
+gs movb %al, OFFS_AL(%bp) /* We support cfg type 1 */
+ movw $0x0210, %ax /* version 2.10 */
+gs movw %ax, OFFS_BX(%bp)
+cs movb pci_last_bus, %al /* last bus number */
+gs movb %al, OFFS_CL(%bp)
+ jmp clear_carry
+
+/*****************************************************************************/
+
+/* device 0-31, function 0-7 */
+pci_bios_find_device:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_find_device
+#endif
+gs movw OFFS_CX(%bp), %di
+ shll $16, %edi
+gs movw OFFS_DX(%bp), %di /* edi now holds device in upper 16
+ * bits and vendor in lower 16 bits */
+gs movw OFFS_SI(%bp), %si
+ xorw %bx, %bx /* start at bus 0 dev 0 function 0 */
+pfd_loop:
+ xorw %ax, %ax /* dword 0 is vendor/device */
+ call __pci_bios_select_register
+ movw $0xcfc, %dx
+ inl %dx, %eax
+ cmpl %edi, %eax /* our device ? */
+ je pfd_found_one
+pfd_next_dev:
+ /* check for multi function devices */
+ movw %bx, %ax
+ andw $3, %ax
+ jnz pfd_function_not_zero
+ movw $0x000c, %ax
+ call __pci_bios_select_register
+ movw $0xcfe, %dx
+ inb %dx, %al
+ andb $0x80, %al
+ jz pfd_not_multi_function
+pfd_function_not_zero:
+ incw %bx /* next function, overflows in to
+ * device number, then bus number */
+ jmp pfd_check_bus
+
+pfd_not_multi_function:
+ andw $0xfff8, %bx /* remove function bits */
+ addw $0x0008, %bx /* next device, overflows in to bus number */
+pfd_check_bus:
+cs movb pci_last_bus, %ah
+ cmpb %ah, %bh
+ ja pfd_not_found
+ jmp pfd_loop
+pfd_found_one:
+ decw %si
+ js pfd_done
+ jmp pfd_next_dev
+
+pfd_done:
+gs movw %bx, OFFS_BX(%bp)
+ jmp clear_carry
+
+pfd_not_found:
+ movb $0x86, %ah /* device not found */
+ jmp set_carry
+
+/*****************************************************************************/
+
+pci_bios_find_class:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_find_class
+#endif
+gs movl OFFS_ECX(%bp), %edi
+ andl $0x00ffffff, %edi /* edi now holds class-code in lower 24 bits */
+gs movw OFFS_SI(%bp), %si
+ xorw %bx, %bx /* start at bus 0 dev 0 function 0 */
+pfc_loop:
+ movw $8, %ax /* dword 8 is class-code high 24bits */
+ call __pci_bios_select_register
+ movw $0xcfc, %dx
+ inl %dx, %eax
+ shrl $8, %eax
+ andl $0x00ffffff, %eax
+ cmpl %edi, %eax /* our device ? */
+ je pfc_found_one
+pfc_next_dev:
+ /* check for multi function devices */
+ andw $3, %bx
+ jnz pfc_function_not_zero
+ movw $0x000c, %ax
+ call __pci_bios_select_register
+ movw $0xcfe, %dx
+ inb %dx, %al
+ andb $0x80, %al
+ jz pfc_not_multi_function
+pfc_function_not_zero:
+ incw %bx /* next function, overflows in to
+ * device number, then bus number */
+ jmp pfc_check_bus
+
+pfc_not_multi_function:
+ andw $0xfff8, %bx /* remove function bits */
+ addw $0x0008, %bx /* next device, overflows in to bus number */
+pfc_check_bus:
+cs movb pci_last_bus, %ah
+ cmpb %ah, %bh
+ ja pfc_not_found
+ jmp pfc_loop
+pfc_found_one:
+ decw %si
+ js pfc_done
+ jmp pfc_next_dev
+
+pfc_done:
+gs movw %bx, OFFS_BX(%bp)
+ jmp clear_carry
+
+pfc_not_found:
+ movb $0x86, %ah /* device not found */
+ jmp set_carry
+
+/*****************************************************************************/
+
+pci_bios_generate_special_cycle:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_generate_special_cycle
+#endif
+ movb $0x81, %ah /* function not supported */
+ jmp set_carry
+
+/*****************************************************************************/
+
+pci_bios_read_cfg_byte:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_read_cfg_byte
+#endif
+ call pci_bios_select_register
+gs movw OFFS_DI(%bp), %dx
+ andw $3, %dx
+ addw $0xcfc, %dx
+ inb %dx, %al
+gs movb %al, OFFS_CL(%bp)
+ jmp clear_carry
+
+/*****************************************************************************/
+
+pci_bios_read_cfg_word:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_read_cfg_word
+#endif
+ call pci_bios_select_register
+gs movw OFFS_DI(%bp), %dx
+ andw $2, %dx
+ addw $0xcfc, %dx
+ inw %dx, %ax
+gs movw %ax, OFFS_CX(%bp)
+ jmp clear_carry
+
+
+/*****************************************************************************/
+
+pci_bios_read_cfg_dword:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_read_cfg_dword
+#endif
+ call pci_bios_select_register
+ movw $0xcfc, %dx
+ inl %dx, %eax
+gs movl %eax, OFFS_ECX(%bp)
+ jmp clear_carry
+
+/*****************************************************************************/
+
+pci_bios_write_cfg_byte:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_write_cfg_byte
+#endif
+ call pci_bios_select_register
+gs movw OFFS_DI(%bp), %dx
+gs movb OFFS_CL(%bp), %al
+ andw $3, %dx
+ addw $0xcfc, %dx
+ outb %al, %dx
+ jmp clear_carry
+
+/*****************************************************************************/
+
+pci_bios_write_cfg_word:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_write_cfg_word
+#endif
+ call pci_bios_select_register
+gs movw OFFS_DI(%bp), %dx
+gs movw OFFS_CX(%bp), %ax
+ andw $2, %dx
+ addw $0xcfc, %dx
+ outw %ax, %dx
+ jmp clear_carry
+
+/*****************************************************************************/
+
+pci_bios_write_cfg_dword:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_write_cfg_dword
+#endif
+ call pci_bios_select_register
+gs movl OFFS_ECX(%bp), %eax
+ movw $0xcfc, %dx
+ outl %eax, %dx
+ jmp clear_carry
+
+/*****************************************************************************/
+
+pci_bios_get_irq_routing:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_get_irq_routing
+#endif
+ movb $0x81, %ah /* function not supported */
+ jmp set_carry
+
+/*****************************************************************************/
+
+pci_bios_set_irq:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_set_irq
+#endif
+ movb $0x81, %ah /* function not supported */
+ jmp set_carry
+
+/*****************************************************************************/
+
+unknown_function:
+#ifdef PCI_BIOS_DEBUG
+cs incl num_pci_bios_unknown_function
+#endif
+ movb $0x81, %ah /* function not supported */
+ jmp set_carry
+
+/*****************************************************************************/
+
+pci_bios_select_register:
+gs movw OFFS_BX(%bp), %bx
+gs movw OFFS_DI(%bp), %ax
+/* destroys eax, dx */
+__pci_bios_select_register: /* BX holds device id, AX holds register index */
+ pushl %ebx
+ andl $0xfc, %eax
+ andl $0xffff, %ebx
+ shll $8, %ebx
+ orl %ebx, %eax
+ orl $0x80000000, %eax
+ movw $0xcf8, %dx
+ outl %eax, %dx
+ popl %ebx
+ ret
+
+
+clear_carry:
+gs movw OFFS_FLAGS(%bp), %ax
+ andw $0xfffe, %ax /* clear carry -- function succeeded */
+gs movw %ax, OFFS_FLAGS(%bp)
+ xorw %ax, %ax
+gs movb %ah, OFFS_AH(%bp)
+ ret
+
+set_carry:
+gs movb %ah, OFFS_AH(%bp)
+gs movw OFFS_FLAGS(%bp), %ax
+ orw $1, %ax /* return carry -- function not supported */
+gs movw %ax, OFFS_FLAGS(%bp)
+ movw $-1, %ax
+ ret
+
+/*****************************************************************************/
+
+.globl pci_last_bus
+pci_last_bus:
+ .byte 0
+
+#ifdef PCI_BIOS_DEBUG
+.globl num_pci_bios_present
+num_pci_bios_present:
+ .long 0
+
+.globl num_pci_bios_find_device
+num_pci_bios_find_device:
+ .long 0
+
+.globl num_pci_bios_find_class
+num_pci_bios_find_class:
+ .long 0
+
+.globl num_pci_bios_generate_special_cycle
+num_pci_bios_generate_special_cycle:
+ .long 0
+
+.globl num_pci_bios_read_cfg_byte
+num_pci_bios_read_cfg_byte:
+ .long 0
+
+.globl num_pci_bios_read_cfg_word
+num_pci_bios_read_cfg_word:
+ .long 0
+
+.globl num_pci_bios_read_cfg_dword
+num_pci_bios_read_cfg_dword:
+ .long 0
+
+.globl num_pci_bios_write_cfg_byte
+num_pci_bios_write_cfg_byte:
+ .long 0
+
+.globl num_pci_bios_write_cfg_word
+num_pci_bios_write_cfg_word:
+ .long 0
+
+.globl num_pci_bios_write_cfg_dword
+num_pci_bios_write_cfg_dword:
+ .long 0
+
+.globl num_pci_bios_get_irq_routing
+num_pci_bios_get_irq_routing:
+ .long 0
+
+.globl num_pci_bios_set_irq
+num_pci_bios_set_irq:
+ .long 0
+
+.globl num_pci_bios_unknown_function
+num_pci_bios_unknown_function:
+ .long 0
+#endif