From: Suresh Siddha <suresh.b.siddha@intel.com>
Subject: [patch 1/2] x86: track memtype for RAM in page struct
Track the memtype for RAM pages in page struct instead of using the memtype
list. This avoids the explosion in the number of entries in memtype list
(of the order of 20,000 with AGP) and makes the PAT tracking simpler. We are
using PG_arch_1 bit in page->flags.
We still use the memtype list for non RAM pages.
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
---
arch/x86/mm/ioremap.c | 19 +++++++++++
arch/x86/mm/pat.c | 83 +++++++++++++++++++++++++++++++++++++++++++++++++
include/asm-x86/page.h | 1
3 files changed, 103 insertions(+)
Index: tip/arch/x86/mm/ioremap.c
===================================================================
--- tip.orig/arch/x86/mm/ioremap.c 2008-09-12 16:03:33.000000000 -0700
+++ tip/arch/x86/mm/ioremap.c 2008-09-12 16:23:33.000000000 -0700
@@ -102,6 +102,25 @@ int page_is_ram(unsigned long pagenr)
return 0;
}
+int pagerange_is_ram(unsigned long start, unsigned long end)
+{
+ int ram_page = 0, not_rampage = 0;
+ unsigned long page_nr;
+
+ for (page_nr = (start >> PAGE_SHIFT); page_nr < (end >> PAGE_SHIFT);
+ ++page_nr) {
+ if (page_is_ram(page_nr))
+ ram_page = 1;
+ else
+ not_rampage = 1;
+
+ if (ram_page == not_rampage)
+ return -1;
+ }
+
+ return ram_page;
+}
+
/*
* Fix up the linear direct mapping of the kernel to avoid cache attribute
* conflicts.
Index: tip/arch/x86/mm/pat.c
===================================================================
--- tip.orig/arch/x86/mm/pat.c 2008-09-12 16:03:33.000000000 -0700
+++ tip/arch/x86/mm/pat.c 2008-09-12 16:23:33.000000000 -0700
@@ -211,6 +211,75 @@ static struct memtype *cached_entry;
static u64 cached_start;
/*
+ * RED-PEN: TODO: Add PageReserved() check aswell here,
+ * once we add SetPageReserved() to all the drivers using
+ * set_memory_* or ...
