lkml.org 
[lkml]   [2015]   [Dec]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] x86/PCI: simplify pci_bios_{read,write}
Date
There are some repetitive code in the switch/case statement in
pci_bios_read() and pci_bios_write(). I drop it to simplify the
code.

Signed-off-by: Geliang Tang <geliangtang@163.com>
---
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);
--
2.5.0



\
 
 \ /
  Last update: 2015-12-07 15:01    [W:0.386 / U:0.136 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site