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Date: Mon, 7 Dec 2015 22:24:24 +0800
From: Geliang Tang <geliangtang@....com>
To: Bjorn Helgaas <bhelgaas@...gle.com>,
Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>
Cc: Geliang Tang <geliangtang@....com>, x86@...nel.org,
linux-pci@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH] x86/PCI: simplify pci_bios_{read,write}
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@....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
--
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