lkml.org 
[lkml]   [2010]   [Mar]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[PATCH 1/4] x86: add get_centaur_ram_top
so we can avoid to access e820.map[] directly.

later we could move e820 to static and _initdata

Signed-off-by: Yinghai Lu <yinghai@kernel.org>



---
arch/x86/include/asm/e820.h | 9 ++++++
arch/x86/kernel/cpu/centaur.c | 53 +--------------------------------------
arch/x86/kernel/e820.c | 57 ++++++++++++++++++++++++++++++++++++++++++
arch/x86/kernel/setup.c | 2 +
4 files changed, 70 insertions(+), 51 deletions(-)

Index: linux-2.6/arch/x86/kernel/e820.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/e820.c
+++ linux-2.6/arch/x86/kernel/e820.c
@@ -1194,3 +1194,60 @@ void __init setup_memory_map(void)
printk(KERN_INFO "BIOS-provided physical RAM map:\n");
e820_print_map(who);
}
+
+#ifdef CONFIG_X86_OOSTORE
+/*
+ * Figure what we can cover with MCR's
+ *
+ * Shortcut: We know you can't put 4Gig of RAM on a winchip
+ */
+void __init get_centaur_ram_top(void)
+{
+ u32 clip = 0xFFFFFFFFUL;
+ u32 top = 0;
+ int i;
+
+ if (boot_cpu_data.x86_vendor != X86_VENDOR_CENTAUR)
+ return;
+
+ for (i = 0; i < e820.nr_map; i++) {
+ unsigned long start, end;
+
+ if (e820.map[i].addr > 0xFFFFFFFFUL)
+ continue;
+ /*
+ * Don't MCR over reserved space. Ignore the ISA hole
+ * we frob around that catastrophe already
+ */
+ if (e820.map[i].type == E820_RESERVED) {
+ if (e820.map[i].addr >= 0x100000UL &&
+ e820.map[i].addr < clip)
+ clip = e820.map[i].addr;
+ continue;
+ }
+ start = e820.map[i].addr;
+ end = e820.map[i].addr + e820.map[i].size;
+ if (start >= end)
+ continue;
+ if (end > top)
+ top = end;
+ }
+ /*
+ * Everything below 'top' should be RAM except for the ISA hole.
+ * Because of the limited MCR's we want to map NV/ACPI into our
+ * MCR range for gunk in RAM
+ *
+ * Clip might cause us to MCR insufficient RAM but that is an
+ * acceptable failure mode and should only bite obscure boxes with
+ * a VESA hole at 15Mb
+ *
+ * The second case Clip sometimes kicks in is when the EBDA is marked
+ * as reserved. Again we fail safe with reasonable results
+ */
+ if (top > clip)
+ top = clip;
+
+ centaur_ram_top = top;
+}
+#endif
+
Index: linux-2.6/arch/x86/kernel/setup.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/setup.c
+++ linux-2.6/arch/x86/kernel/setup.c
@@ -875,6 +875,8 @@ void __init setup_arch(char **cmdline_p)
if (mtrr_trim_uncached_memory(max_pfn))
max_pfn = e820_end_of_ram_pfn();

+ get_centaur_ram_top();
+
#ifdef CONFIG_X86_32
/* max_low_pfn get updated here */
find_low_pfn_range();
Index: linux-2.6/arch/x86/kernel/cpu/centaur.c
===================================================================
--- linux-2.6.orig/arch/x86/kernel/cpu/centaur.c
+++ linux-2.6/arch/x86/kernel/cpu/centaur.c
@@ -37,63 +37,14 @@ static void __cpuinit centaur_mcr_insert
mtrr_centaur_report_mcr(reg, lo, hi); /* Tell the mtrr driver */
}

-/*
- * Figure what we can cover with MCR's
- *
- * Shortcut: We know you can't put 4Gig of RAM on a winchip
- */
-static u32 __cpuinit ramtop(void)
-{
- u32 clip = 0xFFFFFFFFUL;
- u32 top = 0;
- int i;
-
- for (i = 0; i < e820.nr_map; i++) {
- unsigned long start, end;
-
- if (e820.map[i].addr > 0xFFFFFFFFUL)
- continue;
- /*
- * Don't MCR over reserved space. Ignore the ISA hole
- * we frob around that catastrophe already
- */
- if (e820.map[i].type == E820_RESERVED) {
- if (e820.map[i].addr >= 0x100000UL &&
- e820.map[i].addr < clip)
- clip = e820.map[i].addr;
- continue;
- }
- start = e820.map[i].addr;
- end = e820.map[i].addr + e820.map[i].size;
- if (start >= end)
- continue;
- if (end > top)
- top = end;
- }
- /*
- * Everything below 'top' should be RAM except for the ISA hole.
- * Because of the limited MCR's we want to map NV/ACPI into our
- * MCR range for gunk in RAM
- *
- * Clip might cause us to MCR insufficient RAM but that is an
- * acceptable failure mode and should only bite obscure boxes with
- * a VESA hole at 15Mb
- *
- * The second case Clip sometimes kicks in is when the EBDA is marked
- * as reserved. Again we fail safe with reasonable results
- */
- if (top > clip)
- top = clip;
-
- return top;
-}
+int __cpuinitdata centaur_ram_top;

/*
* Compute a set of MCR's to give maximum coverage
*/
static int __cpuinit centaur_mcr_compute(int nr, int key)
{
- u32 mem = ramtop();
+ u32 mem = centaur_ram_top;
u32 root = power2(mem);
u32 base = root;
u32 top = root;
Index: linux-2.6/arch/x86/include/asm/e820.h
===================================================================
--- linux-2.6.orig/arch/x86/include/asm/e820.h
+++ linux-2.6/arch/x86/include/asm/e820.h
@@ -72,6 +72,15 @@ struct e820map {
extern struct e820map e820;
extern struct e820map e820_saved;

+#ifdef CONFIG_X86_OOSTORE
+extern int centaur_ram_top;
+void get_centaur_ram_top(void);
+#else
+static inline void get_centaur_ram_top(void)
+{
+}
+#endif
+
extern unsigned long pci_mem_start;
extern int e820_any_mapped(u64 start, u64 end, unsigned type);
extern int e820_all_mapped(u64 start, u64 end, unsigned type);

\
 
 \ /
  Last update: 2010-03-10 22:29    [W:0.092 / U:1.760 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site