[PATCH 06/19] xen mtrr: Add mtrr_ops support for Xen mtrr

From: Jeremy Fitzhardinge
Date: Mon Feb 16 2009 - 18:48:59 EST


From: Stephen Tweedie <sct@xxxxxxxxxx>

Add a Xen mtrr type, and reorganise mtrr initialisation slightly to allow the
mtrr driver to set up num_var_ranges (Xen needs to do this by querying the
hypervisor itself.)

Only the boot path is handled for now: we set up a xen-specific mtrr_if
and set up the mtrr tables based on hypervisor information, but we don't
yet handle mtrr entry add/delete.

Signed-off-by: Stephen Tweedie <sct@xxxxxxxxxx>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@xxxxxxxxxx>
---
arch/x86/kernel/cpu/mtrr/Makefile | 1 +
arch/x86/kernel/cpu/mtrr/amd.c | 1 +
arch/x86/kernel/cpu/mtrr/centaur.c | 1 +
arch/x86/kernel/cpu/mtrr/cyrix.c | 1 +
arch/x86/kernel/cpu/mtrr/generic.c | 1 +
arch/x86/kernel/cpu/mtrr/main.c | 11 +++++--
arch/x86/kernel/cpu/mtrr/mtrr.h | 5 +++
arch/x86/kernel/cpu/mtrr/xen.c | 59 ++++++++++++++++++++++++++++++++++++
8 files changed, 77 insertions(+), 3 deletions(-)
create mode 100644 arch/x86/kernel/cpu/mtrr/xen.c

diff --git a/arch/x86/kernel/cpu/mtrr/Makefile b/arch/x86/kernel/cpu/mtrr/Makefile
index 191fc05..a836f72 100644
--- a/arch/x86/kernel/cpu/mtrr/Makefile
+++ b/arch/x86/kernel/cpu/mtrr/Makefile
@@ -1,3 +1,4 @@
obj-y := main.o if.o generic.o state.o
obj-$(CONFIG_X86_32) += amd.o cyrix.o centaur.o
+obj-$(CONFIG_XEN_DOM0) += xen.o

diff --git a/arch/x86/kernel/cpu/mtrr/amd.c b/arch/x86/kernel/cpu/mtrr/amd.c
index ee2331b..7bf23de 100644
--- a/arch/x86/kernel/cpu/mtrr/amd.c
+++ b/arch/x86/kernel/cpu/mtrr/amd.c
@@ -108,6 +108,7 @@ static struct mtrr_ops amd_mtrr_ops = {
.get_free_region = generic_get_free_region,
.validate_add_page = amd_validate_add_page,
.have_wrcomb = positive_have_wrcomb,
+ .num_var_ranges = common_num_var_ranges,
};

int __init amd_init_mtrr(void)
diff --git a/arch/x86/kernel/cpu/mtrr/centaur.c b/arch/x86/kernel/cpu/mtrr/centaur.c
index cb9aa3a..7e3f74f 100644
--- a/arch/x86/kernel/cpu/mtrr/centaur.c
+++ b/arch/x86/kernel/cpu/mtrr/centaur.c
@@ -213,6 +213,7 @@ static struct mtrr_ops centaur_mtrr_ops = {
.get_free_region = centaur_get_free_region,
.validate_add_page = centaur_validate_add_page,
.have_wrcomb = positive_have_wrcomb,
+ .num_var_ranges = common_num_var_ranges,
};

int __init centaur_init_mtrr(void)
diff --git a/arch/x86/kernel/cpu/mtrr/cyrix.c b/arch/x86/kernel/cpu/mtrr/cyrix.c
index ff14c32..c7bb5e3 100644
--- a/arch/x86/kernel/cpu/mtrr/cyrix.c
+++ b/arch/x86/kernel/cpu/mtrr/cyrix.c
@@ -263,6 +263,7 @@ static struct mtrr_ops cyrix_mtrr_ops = {
.get_free_region = cyrix_get_free_region,
.validate_add_page = generic_validate_add_page,
.have_wrcomb = positive_have_wrcomb,
+ .num_var_ranges = common_num_var_ranges,
};

int __init cyrix_init_mtrr(void)
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index 0c0a455..b06febd 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -663,4 +663,5 @@ struct mtrr_ops generic_mtrr_ops = {
.set = generic_set_mtrr,
.validate_add_page = generic_validate_add_page,
.have_wrcomb = generic_have_wrcomb,
+ .num_var_ranges = common_num_var_ranges,
};
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 236a401..a66a54d 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -99,7 +99,7 @@ static int have_wrcomb(void)
}

/* This function returns the number of variable MTRRs */
-static void __init set_num_var_ranges(void)
+int __init common_num_var_ranges(void)
{
unsigned long config = 0, dummy;

@@ -109,7 +109,7 @@ static void __init set_num_var_ranges(void)
config = 2;
else if (is_cpu(CYRIX) || is_cpu(CENTAUR))
config = 8;
- num_var_ranges = config & 0xff;
+ return config & 0xff;
}

static void __init init_table(void)
@@ -1673,12 +1673,17 @@ int __init mtrr_trim_uncached_memory(unsigned long end_pfn)
void __init mtrr_bp_init(void)
{
u32 phys_addr;
+
init_ifs();

phys_addr = 32;

if (cpu_has_mtrr) {
mtrr_if = &generic_mtrr_ops;
+#ifdef CONFIG_XEN_DOM0
+ xen_init_mtrr();
+#endif
+
size_or_mask = 0xff000000; /* 36 bits */
size_and_mask = 0x00f00000;
phys_addr = 36;
@@ -1736,7 +1741,7 @@ void __init mtrr_bp_init(void)
}

if (mtrr_if) {
- set_num_var_ranges();
+ num_var_ranges = mtrr_if->num_var_ranges();
init_table();
if (use_intel()) {
get_mtrr_state();
diff --git a/arch/x86/kernel/cpu/mtrr/mtrr.h b/arch/x86/kernel/cpu/mtrr/mtrr.h
index ffd6040..eb23ca2 100644
--- a/arch/x86/kernel/cpu/mtrr/mtrr.h
+++ b/arch/x86/kernel/cpu/mtrr/mtrr.h
@@ -41,6 +41,8 @@ struct mtrr_ops {
int (*validate_add_page)(unsigned long base, unsigned long size,
unsigned int type);
int (*have_wrcomb)(void);
+
+ int (*num_var_ranges)(void);
};

extern int generic_get_free_region(unsigned long base, unsigned long size,
@@ -52,6 +54,8 @@ extern struct mtrr_ops generic_mtrr_ops;

extern int positive_have_wrcomb(void);

+extern int __init common_num_var_ranges(void);
+
/* library functions for processor-specific routines */
struct set_mtrr_context {
unsigned long flags;
@@ -88,3 +92,4 @@ void mtrr_wrmsr(unsigned, unsigned, unsigned);
int amd_init_mtrr(void);
int cyrix_init_mtrr(void);
int centaur_init_mtrr(void);
+void xen_init_mtrr(void);
diff --git a/arch/x86/kernel/cpu/mtrr/xen.c b/arch/x86/kernel/cpu/mtrr/xen.c
new file mode 100644
index 0000000..db3ef39
--- /dev/null
+++ b/arch/x86/kernel/cpu/mtrr/xen.c
@@ -0,0 +1,59 @@
+#include <linux/init.h>
+#include <linux/proc_fs.h>
+#include <linux/ctype.h>
+#include <linux/module.h>
+#include <linux/seq_file.h>
+#include <asm/uaccess.h>
+#include <linux/mutex.h>
+
+#include <asm/mtrr.h>
+#include "mtrr.h"
+
+#include <xen/interface/platform.h>
+#include <asm/xen/hypervisor.h>
+#include <asm/xen/hypercall.h>
+
+static int __init xen_num_var_ranges(void);
+
+/* DOM0 TODO: Need to fill in the remaining mtrr methods to have full
+ * working userland mtrr support. */
+static struct mtrr_ops xen_mtrr_ops = {
+ .vendor = X86_VENDOR_UNKNOWN,
+// .set = xen_set_mtrr,
+// .get = xen_get_mtrr,
+ .get_free_region = generic_get_free_region,
+// .validate_add_page = xen_validate_add_page,
+ .have_wrcomb = positive_have_wrcomb,
+ .use_intel_if = 0,
+ .num_var_ranges = xen_num_var_ranges,
+};
+
+static int __init xen_num_var_ranges(void)
+{
+ int ranges;
+ struct xen_platform_op op;
+
+ for (ranges = 0; ; ranges++) {
+ op.cmd = XENPF_read_memtype;
+ op.u.read_memtype.reg = ranges;
+ if (HYPERVISOR_dom0_op(&op) != 0)
+ break;
+ }
+ return ranges;
+}
+
+void __init xen_init_mtrr(void)
+{
+ struct cpuinfo_x86 *c = &boot_cpu_data;
+
+ if (!xen_initial_domain())
+ return;
+
+ if ((!cpu_has(c, X86_FEATURE_MTRR)) &&
+ (!cpu_has(c, X86_FEATURE_K6_MTRR)) &&
+ (!cpu_has(c, X86_FEATURE_CYRIX_ARR)) &&
+ (!cpu_has(c, X86_FEATURE_CENTAUR_MCR)))
+ return;
+
+ mtrr_if = &xen_mtrr_ops;
+}
--
1.6.0.6

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