[PATCH 19/19] xen mtrr: Add xen_{get,set}_mtrr() implementations

From: Jeremy Fitzhardinge
Date: Mon Feb 16 2009 - 18:51:55 EST


From: Mark McLoughlin <markmc@xxxxxxxxxx>

Straightforward apart from the hack to turn mtrr_ops->set()
into a no-op on all but one CPU.

Signed-off-by: Mark McLoughlin <markmc@xxxxxxxxxx>
---
arch/x86/kernel/cpu/mtrr/xen.c | 52 ++++++++++++++++++++++++++++++++++++---
1 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/arch/x86/kernel/cpu/mtrr/xen.c b/arch/x86/kernel/cpu/mtrr/xen.c
index d715843..50a45db 100644
--- a/arch/x86/kernel/cpu/mtrr/xen.c
+++ b/arch/x86/kernel/cpu/mtrr/xen.c
@@ -9,6 +9,52 @@

static int __init xen_num_var_ranges(void);

+static void xen_set_mtrr(unsigned int reg, unsigned long base,
+ unsigned long size, mtrr_type type)
+{
+ struct xen_platform_op op;
+ int error;
+
+ /* mtrr_ops->set() is called once per CPU,
+ * but Xen's ops apply to all CPUs.
+ */
+ if (smp_processor_id())
+ return;
+
+ if (size == 0) {
+ op.cmd = XENPF_del_memtype;
+ op.u.del_memtype.handle = 0;
+ op.u.del_memtype.reg = reg;
+ } else {
+ op.cmd = XENPF_add_memtype;
+ op.u.add_memtype.mfn = base;
+ op.u.add_memtype.nr_mfns = size;
+ op.u.add_memtype.type = type;
+ }
+
+ error = HYPERVISOR_dom0_op(&op);
+ BUG_ON(error != 0);
+}
+
+static void xen_get_mtrr(unsigned int reg, unsigned long *base,
+ unsigned long *size, mtrr_type *type)
+{
+ struct xen_platform_op op;
+
+ op.cmd = XENPF_read_memtype;
+ op.u.read_memtype.reg = reg;
+ if (HYPERVISOR_dom0_op(&op) != 0) {
+ *base = 0;
+ *size = 0;
+ *type = 0;
+ return;
+ }
+
+ *size = op.u.read_memtype.nr_mfns;
+ *base = op.u.read_memtype.mfn;
+ *type = op.u.read_memtype.type;
+}
+
static int xen_get_free_region(unsigned long base, unsigned long size, int replace_reg)
{
struct xen_platform_op op;
@@ -34,12 +80,10 @@ static int xen_get_free_region(unsigned long base, unsigned long size, int repla
return replace_reg;
}

-/* 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,
+ .set = xen_set_mtrr,
+ .get = xen_get_mtrr,
.get_free_region = xen_get_free_region,
.validate_add_page = generic_validate_add_page,
.have_wrcomb = positive_have_wrcomb,
--
1.6.0.6

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