Re: aperture_64: use symbolic constants

From: Pavel Machek
Date: Tue May 20 2008 - 10:26:32 EST


Hi!

> * Pavel Machek <pavel@xxxxxxx> wrote:
>
> > Use symbolic constants in aperture_64.c where possible (and make a
> > comment slightly more helpful).
>
> this code has already been changed in the latest -tip tree:
>
> http://people.redhat.com/mingo/tip.git/README
>
> iommu/gart code is covered by the tip/x86/gart subtopic, which carries 7
> commits right now:

Thanks, I have a copy now. And this one is relative to it:

---

Factor-out common aperture_valid code.

Signed-off-by: Pavel Machek <pavel@xxxxxxx>

diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 02f4dba..5373f78 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -109,27 +109,6 @@ static u32 __init allocate_aperture(void
return (u32)__pa(p);
}

-static int __init aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
-{
- if (!aper_base)
- return 0;
-
- if (aper_base + aper_size > 0x100000000UL) {
- printk(KERN_ERR "Aperture beyond 4GB. Ignoring.\n");
- return 0;
- }
- if (e820_any_mapped(aper_base, aper_base + aper_size, E820_RAM)) {
- printk(KERN_ERR "Aperture pointing to e820 RAM. Ignoring.\n");
- return 0;
- }
- if (aper_size < min_size) {
- printk(KERN_ERR "Aperture too small (%d MB) than (%d MB)\n",
- aper_size>>20, min_size>>20);
- return 0;
- }
-
- return 1;
-}

/* Find a PCI capability */
static __u32 __init find_cap(int bus, int slot, int func, int cap)
@@ -344,7 +323,7 @@ out:
if (gart_fix_e820 && !fix && aper_enabled) {
if (!e820_all_mapped(aper_base, aper_base + aper_size,
E820_RESERVED)) {
- /* reserved it, so we can resuse it in second kernel */
+ /* reserve it, so we can reuse it in second kernel */
printk(KERN_INFO "update e820 for GART\n");
add_memory_region(aper_base, aper_size, E820_RESERVED);
update_e820();
diff --git a/drivers/char/agp/amd64-agp.c b/drivers/char/agp/amd64-agp.c
index fea1313..3b53ea0 100644
--- a/drivers/char/agp/amd64-agp.c
+++ b/drivers/char/agp/amd64-agp.c
@@ -228,24 +228,10 @@ static const struct agp_bridge_driver am
};

/* Some basic sanity checks for the aperture. */
-static int __devinit aperture_valid(u64 aper, u32 size)
+static int __devinit agp_aperture_valid(u64 aper, u32 size)
{
- if (aper == 0) {
- printk(KERN_ERR PFX "No aperture\n");
+ if (!aperture_valid(aper, size, 32*1024*1024))
return 0;
- }
- if ((u64)aper + size > 0x100000000ULL) {
- printk(KERN_ERR PFX "Aperture out of bounds\n");
- return 0;
- }
- if (e820_any_mapped(aper, aper + size, E820_RAM)) {
- printk(KERN_ERR PFX "Aperture pointing to RAM\n");
- return 0;
- }
- if (size < 32*1024*1024) {
- printk(KERN_ERR PFX "Aperture too small (%d MB)\n", size>>20);
- return 0;
- }

/* Request the Aperture. This catches cases when someone else
already put a mapping in there - happens with some very broken BIOS
@@ -282,7 +268,7 @@ static __devinit int fix_northbridge(str
nb_order = (nb_order >> 1) & 7;
pci_read_config_dword(nb, AMD64_GARTAPERTUREBASE, &nb_base);
nb_aper = nb_base << 25;
- if (aperture_valid(nb_aper, (32*1024*1024)<<nb_order)) {
+ if (agp_aperture_valid(nb_aper, (32*1024*1024)<<nb_order)) {
return 0;
}

@@ -313,7 +299,7 @@ static __devinit int fix_northbridge(str
}

printk(KERN_INFO PFX "Aperture from AGP @ %Lx size %u MB\n", aper, 32 << order);
- if (order < 0 || !aperture_valid(aper, (32*1024*1024)<<order))
+ if (order < 0 || !agp_aperture_valid(aper, (32*1024*1024)<<order))
return -1;

pci_write_config_dword(nb, AMD64_GARTAPERTURECTL, order << 1);
diff --git a/include/asm-x86/gart.h b/include/asm-x86/gart.h
index 6f22786..854cf7f 100644
--- a/include/asm-x86/gart.h
+++ b/include/asm-x86/gart.h
@@ -1,6 +1,8 @@
#ifndef _ASM_X8664_IOMMU_H
#define _ASM_X8664_IOMMU_H 1

+#include <asm/e820.h>
+
extern void pci_iommu_shutdown(void);
extern void no_iommu_init(void);
extern int force_iommu, no_iommu;
@@ -69,4 +71,26 @@ static inline void enable_gart_translati
pci_write_config_dword(dev, AMD64_GARTAPERTURECTL, ctl);
}

+static inline int aperture_valid(u64 aper_base, u32 aper_size, u32 min_size)
+{
+ if (!aper_base)
+ return 0;
+
+ if (aper_base + aper_size > 0x100000000ULL) {
+ printk(KERN_ERR "Aperture beyond 4GB. Ignoring.\n");
+ return 0;
+ }
+ if (e820_any_mapped(aper_base, aper_base + aper_size, E820_RAM)) {
+ printk(KERN_ERR "Aperture pointing to e820 RAM. Ignoring.\n");
+ return 0;
+ }
+ if (aper_size < min_size) {
+ printk(KERN_ERR "Aperture too small (%d MB) than (%d MB)\n",
+ aper_size>>20, min_size>>20);
+ return 0;
+ }
+
+ return 1;
+}
+
#endif

--
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(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
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