Re: 2.6.24-rc8-mm1

Siddha, Suresh B
2008-01-18T01:42:23Z

On Thu, Jan 17, 2008 at 03:04:03PM -0800, Balbir Singh wrote:
> I think I found the root cause of the problem and a fix for it.
> The fix works for me.
>

Thanks Balbir. But the appended fix is more clean and appropriate. Can you
please check if it works.
---

>From Balbir Singh:
> With the introduction of reserve_mattr() and free_mattr(), the ioremap*
> routines
> started exploiting it. The recent 2.6.24-rc8-mm1 kernel has a peculiar
> problem
> where in, certain devices disappear. In my case for example
>
> e100: Intel(R) PRO/100 Network Driver, 3. 5.23-k4-NAPI
> e100: Copyright(c) 1999-2006 Intel Corporation
> ACPI: PCI Interrupt 0000:04:08.0[A] -> GSI 20 (level, low) -> IRQ 20
> modprobe:2584 conflicting cache attribute 50000000-50001000
> uncached<->default
> e100: 0000:04:08.0: e100_probe: Cannot map device registers, aborting.
> ACPI: PCI interrupt for device 0000:04:08.0 disabled
>
> On further analysis, it was discovered that quirk_e100_interrupt() calls
> ioremap(), which reserves memory attributes for the e100 card, but
> iounmap()
> does not free it.

Fix the iounmap() to call free_matrr() unconditionally.

Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Balbir Singh <balbir@linux.vnet.ibm.com>
---

diff --git a/arch/x86/mm/ioremap_32.c b/arch/x86/mm/ioremap_32.c
index ae9c8b3..4d5bea8 100644
--- a/arch/x86/mm/ioremap_32.c
+++ b/arch/x86/mm/ioremap_32.c
@@ -201,12 +201,11 @@ void iounmap(volatile void __iomem *addr)
return;
}

+ free_mattr(p->phys_addr, p->phys_addr + get_vm_area_size(p),
+ p->flags>>20);
/* Reset the direct mapping. Can block */
- if (p->flags >> 20) {
- free_mattr(p->phys_addr, p->phys_addr + get_vm_area_size(p),
- p->flags>>20);
+ if (p->flags >> 20)
ioremap_change_attr(p->phys_addr, get_vm_area_size(p), 0);
- }

/* Finally remove it */
o = remove_vm_area((void *)addr);
diff --git a/arch/x86/mm/ioremap_64.c b/arch/x86/mm/ioremap_64.c
index 022b645..c766327 100644
--- a/arch/x86/mm/ioremap_64.c
+++ b/arch/x86/mm/ioremap_64.c
@@ -183,12 +183,11 @@ void iounmap(volatile void __iomem *addr)
return;
}

+ free_mattr(p->phys_addr, p->phys_addr + get_vm_area_size(p),
+ p->flags>>20);
/* Reset the direct mapping. Can block */
- if (p->flags >> 20) {
- free_mattr(p->phys_addr, p->phys_addr + get_vm_area_size(p),
- p->flags>>20);
+ if (p->flags >> 20)
ioremap_change_attr(p->phys_addr, get_vm_area_size(p), 0);
- }

/* Finally remove it */
o = remove_vm_area((void *)addr);

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