From 96ae6469ba16ae502d2b2db4b5c9b7c846262999 Mon Sep 17 00:00:00 2001 From: Geliang Tang Date: Mon, 7 Dec 2015 22:24:24 +0800 Subject: [PATCH] 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: Geliang Tang Signed-off-by: Bjorn Helgaas Reviewed-by: Thomas Gleixner --- arch/x86/pci/pcbios.c | 108 ++++++++++++++++++-------------------------------- 1 file changed, 38 insertions(+), 70 deletions(-) diff --git a/arch/x86/pci/pcbios.c b/arch/x86/pci/pcbios.c index 9b83b90..9770e55 100644 --- a/arch/x86/pci/pcbios.c +++ b/arch/x86/pci/pcbios.c @@ -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)) @@ -189,53 +190,35 @@ 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: - __asm__("lcall *(%%esi); cld\n\t" - "jc 1f\n\t" - "xor %%ah, %%ah\n" - "1:" - : "=c" (*value), - "=a" (result) - : "1" (PCIBIOS_READ_CONFIG_WORD), - "b" (bx), - "D" ((long)reg), - "S" (&pci_indirect)); - /* - * Zero-extend the result beyond 16 bits, do not trust the - * BIOS having done it: - */ - *value &= 0xffff; + number = PCIBIOS_READ_CONFIG_WORD; + mask = 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)); + 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); @@ -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)) @@ -256,43 +240,27 @@ 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: - __asm__("lcall *(%%esi); cld\n\t" - "jc 1f\n\t" - "xor %%ah, %%ah\n" - "1:" - : "=a" (result) - : "0" (PCIBIOS_WRITE_CONFIG_DWORD), - "c" (value), - "b" (bx), - "D" ((long)reg), - "S" (&pci_indirect)); + 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); -- 2.7.4