6 files changed, 114 insertions, 0 deletions

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 40db7dd1d92..860a9087549 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -660,6 +660,10 @@ and is between 256 and 4096 characters. It is defined in the file
 
         gamma=          [HW,DRM]
 
+        gart_fix_e820=  [X86_64] disable the fix e820 for K8 GART
+                        Format: off | on
+                        default: on
+
         gdth=           [HW,SCSI]
                         See header of drivers/scsi/gdth.c.
 
diff --git a/arch/x86/kernel/aperture_64.c b/arch/x86/kernel/aperture_64.c
index 52d2beac455..bf1b469d584 100644
--- a/arch/x86/kernel/aperture_64.c
+++ b/arch/x86/kernel/aperture_64.c
@@ -218,6 +218,95 @@ static __u32 __init search_agp_bridge(u32 *order, int *valid_agp)
         return 0;
 }
 
+static int gart_fix_e820 __initdata = 1;
+
+static int __init parse_gart_mem(char *p)
+{
+        if (!p)
+                return -EINVAL;
+
+        if (!strncmp(p, "off", 3))
+                gart_fix_e820 = 0;
+        else if (!strncmp(p, "on", 2))
+                gart_fix_e820 = 1;
+
+        return 0;
+}
+early_param("gart_fix_e820", parse_gart_mem);
+
+void __init early_gart_iommu_check(void)
+{
+        /*
+         * in case it is enabled before, esp for kexec/kdump,
+         * previous kernel already enable that. memset called
+         * by allocate_aperture/__alloc_bootmem_nopanic cause restart.
+         * or second kernel have different position for GART hole. and new
+         * kernel could use hole as RAM that is still used by GART set by
+         * first kernel
+         * or BIOS forget to put that in reserved.
+         * try to update e820 to make that region as reserved.
+         */
+        int fix, num;
+        u32 ctl;
+        u32 aper_size = 0, aper_order = 0, last_aper_order = 0;
+        u64 aper_base = 0, last_aper_base = 0;
+        int aper_enabled = 0, last_aper_enabled = 0;
+
+        if (!early_pci_allowed())
+                return;
+
+        fix = 0;
+        for (num = 24; num < 32; num++) {
+                if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00)))
+                        continue;
+
+                ctl = read_pci_config(0, num, 3, 0x90);
+                aper_enabled = ctl & 1;
+                aper_order = (ctl >> 1) & 7;
+                aper_size = (32 * 1024 * 1024) << aper_order;
+                aper_base = read_pci_config(0, num, 3, 0x94) & 0x7fff;
+                aper_base <<= 25;
+
+                if ((last_aper_order && aper_order != last_aper_order) ||
+                    (last_aper_base && aper_base != last_aper_base) ||
+                    (last_aper_enabled && aper_enabled != last_aper_enabled)) {
+                        fix = 1;
+                        break;
+                }
+                last_aper_order = aper_order;
+                last_aper_base = aper_base;
+                last_aper_enabled = aper_enabled;
+        }
+
+        if (!fix && !aper_enabled)
+                return;
+
+        if (!aper_base || !aper_size || aper_base + aper_size > 0x100000000UL)
+                fix = 1;
+
+        if (gart_fix_e820 && !fix && aper_enabled) {
+                if (e820_any_mapped(aper_base, aper_base + aper_size,
+                                    E820_RAM)) {
+                        /* reserved it, so we can resuse it in second kernel */
+                        printk(KERN_INFO "update e820 for GART\n");
+                        add_memory_region(aper_base, aper_size, E820_RESERVED);
+                        update_e820();
+                }
+                return;
+        }
+
+        /* different nodes have different setting, disable them all at first*/
+        for (num = 24; num < 32; num++) {
+                if (!early_is_k8_nb(read_pci_config(0, num, 3, 0x00)))
+                        continue;
+
+                ctl = read_pci_config(0, num, 3, 0x90);
+                ctl &= ~1;
+                write_pci_config(0, num, 3, 0x90, ctl);
+        }
+
+}
+
 void __init gart_iommu_hole_init(void)
 {
         u32 aper_size, aper_alloc = 0, aper_order = 0, last_aper_order = 0;
diff --git a/arch/x86/kernel/e820_64.c b/arch/x86/kernel/e820_64.c
index abc473bcabe..07cfaae7ab0 100644
--- a/arch/x86/kernel/e820_64.c
+++ b/arch/x86/kernel/e820_64.c
@@ -728,6 +728,18 @@ void __init finish_e820_parsing(void)
         }
 }
 
+void __init update_e820(void)
+{
+        u8 nr_map;
+
+        nr_map = e820.nr_map;
+        if (sanitize_e820_map(e820.map, &nr_map))
+                return;
+        e820.nr_map = nr_map;
+        printk(KERN_INFO "modified physical RAM map:\n");
+        e820_print_map("modified");
+}
+
 unsigned long pci_mem_start = 0xaeedbabe;
 EXPORT_SYMBOL(pci_mem_start);
 
diff --git a/arch/x86/kernel/setup_64.c b/arch/x86/kernel/setup_64.c
index 07547febac7..12bad27d66f 100644
--- a/arch/x86/kernel/setup_64.c
+++ b/arch/x86/kernel/setup_64.c
@@ -53,6 +53,7 @@
 #include <video/edid.h>
 #include <asm/e820.h>
 #include <asm/dma.h>
+#include <asm/gart.h>
 #include <asm/mpspec.h>
 #include <asm/mmu_context.h>
 #include <asm/proto.h>
@@ -335,6 +336,8 @@ void __init setup_arch(char **cmdline_p)
 
         finish_e820_parsing();
 
+        early_gart_iommu_check();
+
         e820_register_active_regions(0, 0, -1UL);
         /*
          * partially used pages are not usable - thus
diff --git a/include/asm-x86/e820_64.h b/include/asm-x86/e820_64.h
index 8cba49da479..ff36f434f00 100644
--- a/include/asm-x86/e820_64.h
+++ b/include/asm-x86/e820_64.h
@@ -39,6 +39,7 @@ extern void e820_register_active_regions(int nid,
 extern void finish_e820_parsing(void);
 
 extern struct e820map e820;
+extern void update_e820(void);
 
 extern unsigned ebda_addr, ebda_size;
 extern unsigned long nodemap_addr, nodemap_size;
diff --git a/include/asm-x86/gart.h b/include/asm-x86/gart.h
index f704c50519b..90958ed993f 100644
--- a/include/asm-x86/gart.h
+++ b/include/asm-x86/gart.h
@@ -9,6 +9,7 @@ extern int iommu_detected;
 extern void gart_iommu_init(void);
 extern void gart_iommu_shutdown(void);
 extern void __init gart_parse_options(char *);
+extern void early_gart_iommu_check(void);
 extern void gart_iommu_hole_init(void);
 extern int fallback_aper_order;
 extern int fallback_aper_force;
@@ -20,6 +21,10 @@ extern int fix_aperture;
 #define gart_iommu_aperture 0
 #define gart_iommu_aperture_allowed 0
 
+static inline void early_gart_iommu_check(void)
+{
+}
+
 static inline void gart_iommu_shutdown(void)
 {
 }