]> www.pilppa.org Git - linux-2.6-omap-h63xx.git/commitdiff
x86_64: allocate gart aperture from 512M
authorYinghai Lu <yhlu.kernel.send@gmail.com>
Tue, 15 Apr 2008 03:40:37 +0000 (20:40 -0700)
committerIngo Molnar <mingo@elte.hu>
Mon, 12 May 2008 19:28:10 +0000 (21:28 +0200)
because we try to reserve dma32 early, so we have chance to get aperture
from 64M.

with some sequence aperture allocated from RAM, could become E820_RESERVED.

and then if doing a kexec with a big kernel that uncompressed size is above
64M we could have a range conflict with still using gart.

So allocate gart aperture from 512M instead.

Also change the fallback_aper_order to 5, because we don't have chance to get
2G or 4G aperture.

Signed-off-by: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
arch/x86/kernel/aperture_64.c
arch/x86/kernel/pci-dma.c

index 8c325b7f2d9b8e6bf2989c403c2c0a42f907b74a..c63f8d9fad3e224d3e86516c250c85af4e72ca4f 100644 (file)
@@ -55,8 +55,9 @@ static u32 __init allocate_aperture(void)
        u32 aper_size;
        void *p;
 
-       if (fallback_aper_order > 7)
-               fallback_aper_order = 7;
+       /* aper_size should <= 1G */
+       if (fallback_aper_order > 5)
+               fallback_aper_order = 5;
        aper_size = (32 * 1024 * 1024) << fallback_aper_order;
 
        /*
@@ -65,7 +66,20 @@ static u32 __init allocate_aperture(void)
         * memory. Unfortunately we cannot move it up because that would
         * make the IOMMU useless.
         */
-       p = __alloc_bootmem_nopanic(aper_size, aper_size, 0);
+       /*
+        * using 512M as goal, in case kexec will load kernel_big
+        * that will do the on position decompress, and  could overlap with
+        * that positon with gart that is used.
+        * sequende:
+        * kernel_small
+        * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
+        * ==> kernel_small(gart area become e820_reserved)
+        * ==> kexec (with kdump trigger path or previous doesn't shutdown gart)
+        * ==> kerne_big (uncompressed size will be big than 64M or 128M)
+        * so don't use 512M below as gart iommu, leave the space for kernel
+        * code for safe
+        */
+       p = __alloc_bootmem_nopanic(aper_size, aper_size, 512ULL<<20);
        if (!p || __pa(p)+aper_size > 0xffffffff) {
                printk(KERN_ERR
                        "Cannot allocate aperture memory hole (%p,%uK)\n",
index 0c37f16b69502e1fe31f4e94c80775dc1fd22060..1a017f00e8674414c905a9b2cbdf4cbfdbb4ff1a 100644 (file)
@@ -77,10 +77,14 @@ void __init dma32_reserve_bootmem(void)
        if (end_pfn <= MAX_DMA32_PFN)
                return;
 
+       /*
+        * check aperture_64.c allocate_aperture() for reason about
+        * using 512M as goal
+        */
        align = 64ULL<<20;
        size = round_up(dma32_bootmem_size, align);
        dma32_bootmem_ptr = __alloc_bootmem_nopanic(size, align,
-                                __pa(MAX_DMA_ADDRESS));
+                                512ULL<<20);
        if (dma32_bootmem_ptr)
                dma32_bootmem_size = size;
        else