Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 274e1bbd authored by Siddha, Suresh B's avatar Siddha, Suresh B Committed by Andi Kleen
Browse files

[PATCH] x86: add write_pci_config_byte() to direct PCI access routines 

Mechanism of selecting physical mode in genapic when cpu hotplug is enabled on
x86_64, broke the quirk(quirk_intel_irqbalance()) introduced for working
around the transposing interrupt message errata in E7520/E7320/E7525 (revision
ID 0x9 and below.  errata #23 in
http://download.intel.com/design/chipsets/specupdt/30304203.pdf

).

This errata requires the mode to be in logical flat, so that interrupts can be
directed to more than one cpu(and thus use hardware IRQ balancing enabled by
BIOS on these platforms).

Following four patches fixes this by moving the quirk to early quirk and
forcing the x86_64 genapic selection to logical flat on these platforms.

Thanks to Shaohua for pointing out the breakage.

This patch:

Add write_pci_config_byte() to direct PCI access  routines

Signed-off-by: default avatarSuresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: default avatarAndi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: "Li, Shaohua" <shaohua.li@intel.com>
Signed-off-by: default avatarAndrew Morton <akpm@osdl.org>
parent 79929fd1

arch/i386/pci/early.c

+7 −0
Original line number Diff line number Diff line
@@ -45,6 +45,13 @@ void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, 
	outl(val, 0xcfc);

}



void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val)

{

	PDprintk("%x writing to %x: %x\n", slot, offset, val);

	outl(0x80000000 | (bus<<16) | (slot<<11) | (func<<8) | offset, 0xcf8);

	outb(val, 0xcfc);

}



int early_pci_allowed(void)

{

	return (pci_probe & (PCI_PROBE_CONF1|PCI_PROBE_NOEARLY)) ==

include/asm-x86_64/pci-direct.h

+1 −0
Original line number Diff line number Diff line
@@ -10,6 +10,7 @@ extern u32 read_pci_config(u8 bus, u8 slot, u8 func, u8 offset); 
extern u8 read_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset);

extern u16 read_pci_config_16(u8 bus, u8 slot, u8 func, u8 offset);

extern void write_pci_config(u8 bus, u8 slot, u8 func, u8 offset, u32 val);

extern void write_pci_config_byte(u8 bus, u8 slot, u8 func, u8 offset, u8 val);



extern int early_pci_allowed(void);