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Commit 96ae6469 authored by Geliang Tang's avatar Geliang Tang Committed by Bjorn Helgaas
Browse files

x86/PCI: Simplify pci_bios_{read,write} 



There is some repetitive code in the switch/case statements in
pci_bios_read() and pci_bios_write().  Factor out the BIOS function
IDs and the result widths to simplify the code.

Signed-off-by: default avatarGeliang Tang <geliangtang@163.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 8e5a395a

arch/x86/pci/pcbios.c

+38 −70
Original line number Diff line number Diff line
@@ -180,6 +180,7 @@ static int pci_bios_read(unsigned int seg, unsigned int bus, 
	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))
@@ -189,52 +190,34 @@ static int pci_bios_read(unsigned int seg, unsigned int bus, 


	switch (len) {

	case 1:

		__asm__("lcall *(%%esi); cld\n\t"

			"jc 1f\n\t"

			"xor %%ah, %%ah\n"

			"1:"

			: "=c" (*value),

			  "=a" (result)

			: "1" (PCIBIOS_READ_CONFIG_BYTE),

			  "b" (bx),

			  "D" ((long)reg),

			  "S" (&pci_indirect));

		/*

		 * Zero-extend the result beyond 8 bits, do not trust the

		 * BIOS having done it:

		 */

		*value &= 0xff;

		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" (PCIBIOS_READ_CONFIG_WORD),

		: "1" (number),

		  "b" (bx),

		  "D" ((long)reg),

		  "S" (&pci_indirect));

	/*

		 * Zero-extend the result beyond 16 bits, do not trust the

	 * Zero-extend the result beyond 8 or 16 bits, do not trust the

	 * BIOS having done it:

	 */

		*value &= 0xffff;

		break;

	case 4:

		__asm__("lcall *(%%esi); cld\n\t"

			"jc 1f\n\t"

			"xor %%ah, %%ah\n"

			"1:"

			: "=c" (*value),

			  "=a" (result)

			: "1" (PCIBIOS_READ_CONFIG_DWORD),

			  "b" (bx),

			  "D" ((long)reg),

			  "S" (&pci_indirect));

		break;

	}

	if (mask)

		*value &= mask;



	raw_spin_unlock_irqrestore(&pci_config_lock, flags);
@@ -247,6 +230,7 @@ static int pci_bios_write(unsigned int seg, unsigned int bus, 
	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))
@@ -256,42 +240,26 @@ static int pci_bios_write(unsigned int seg, unsigned int bus, 


	switch (len) {

	case 1:

		__asm__("lcall *(%%esi); cld\n\t"

			"jc 1f\n\t"

			"xor %%ah, %%ah\n"

			"1:"

			: "=a" (result)

			: "0" (PCIBIOS_WRITE_CONFIG_BYTE),

			  "c" (value),

			  "b" (bx),

			  "D" ((long)reg),

			  "S" (&pci_indirect));

		number = PCIBIOS_WRITE_CONFIG_BYTE;

		break;

	case 2:

		__asm__("lcall *(%%esi); cld\n\t"

			"jc 1f\n\t"

			"xor %%ah, %%ah\n"

			"1:"

			: "=a" (result)

			: "0" (PCIBIOS_WRITE_CONFIG_WORD),

			  "c" (value),

			  "b" (bx),

			  "D" ((long)reg),

			  "S" (&pci_indirect));

		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" (PCIBIOS_WRITE_CONFIG_DWORD),

		: "0" (number),

		  "c" (value),

		  "b" (bx),

		  "D" ((long)reg),

		  "S" (&pci_indirect));

		break;

	}



	raw_spin_unlock_irqrestore(&pci_config_lock, flags);