KVM: Don't pre-reserve xarray entries when storing empty/NULL attributesgrafted

Skip the xarray reservation loop when clearing all memory attributes, as
storing NULL only erases the entry and never needs to allocate, so no
reservation (and no cleanup of a failed one) is required in that case.

Suggested-by: Sean Christopherson <seanjc@google.com>
Cc: David Ballesteros <davimaba.v@proton.me>
Signed-off-by: Zeng Chi <zengchi@kylinos.cn>
Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com
[sean: split to separate patch]
Signed-off-by: Sean Christopherson <seanjc@google.com>

1 files changed, 98 insertions, 0 deletions

diff --git a/drivers/clk/versatile/clk-versatile.c b/drivers/clk/versatile/clk-versatile.c
new file mode 100644
index 000000000..8ed7a179f
--- /dev/null
+++ b/drivers/clk/versatile/clk-versatile.c
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Clock driver for the ARM Integrator/AP, Integrator/CP, Versatile AB and
+ * Versatile PB boards.
+ * Copyright (C) 2012 Linus Walleij
+ */
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+#include "icst.h"
+#include "clk-icst.h"
+
+#define INTEGRATOR_HDR_LOCK_OFFSET	0x14
+
+#define VERSATILE_SYS_OSCCLCD_OFFSET	0x1c
+#define VERSATILE_SYS_LOCK_OFFSET	0x20
+
+/* Base offset for the core module */
+static void __iomem *cm_base;
+
+static const struct icst_params cp_auxosc_params = {
+	.vco_max	= ICST525_VCO_MAX_5V,
+	.vco_min	= ICST525_VCO_MIN,
+	.vd_min 	= 8,
+	.vd_max 	= 263,
+	.rd_min 	= 3,
+	.rd_max 	= 65,
+	.s2div		= icst525_s2div,
+	.idx2s		= icst525_idx2s,
+};
+
+static const struct clk_icst_desc cm_auxosc_desc __initconst = {
+	.params = &cp_auxosc_params,
+	.vco_offset = 0x1c,
+	.lock_offset = INTEGRATOR_HDR_LOCK_OFFSET,
+};
+
+static const struct icst_params versatile_auxosc_params = {
+	.vco_max	= ICST307_VCO_MAX,
+	.vco_min	= ICST307_VCO_MIN,
+	.vd_min		= 4 + 8,
+	.vd_max		= 511 + 8,
+	.rd_min		= 1 + 2,
+	.rd_max		= 127 + 2,
+	.s2div		= icst307_s2div,
+	.idx2s		= icst307_idx2s,
+};
+
+static const struct clk_icst_desc versatile_auxosc_desc __initconst = {
+	.params = &versatile_auxosc_params,
+	.vco_offset = VERSATILE_SYS_OSCCLCD_OFFSET,
+	.lock_offset = VERSATILE_SYS_LOCK_OFFSET,
+};
+static void __init cm_osc_setup(struct device_node *np,
+				const struct clk_icst_desc *desc)
+{
+	struct clk *clk;
+	const char *clk_name = np->name;
+	const char *parent_name;
+
+	if (!cm_base) {
+		/* Remap the core module base if not done yet */
+		struct device_node *parent;
+
+		parent = of_get_parent(np);
+		if (!parent) {
+			pr_err("no parent on core module clock\n");
+			return;
+		}
+		cm_base = of_iomap(parent, 0);
+		of_node_put(parent);
+		if (!cm_base) {
+			pr_err("could not remap core module base\n");
+			return;
+		}
+	}
+
+	parent_name = of_clk_get_parent_name(np, 0);
+	clk = icst_clk_register(NULL, desc, clk_name, parent_name, cm_base);
+	if (!IS_ERR(clk))
+		of_clk_add_provider(np, of_clk_src_simple_get, clk);
+}
+
+static void __init of_integrator_cm_osc_setup(struct device_node *np)
+{
+	cm_osc_setup(np, &cm_auxosc_desc);
+}
+CLK_OF_DECLARE(integrator_cm_auxosc_clk,
+	"arm,integrator-cm-auxosc", of_integrator_cm_osc_setup);
+
+static void __init of_versatile_cm_osc_setup(struct device_node *np)
+{
+	cm_osc_setup(np, &versatile_auxosc_desc);
+}
+CLK_OF_DECLARE(versatile_cm_auxosc_clk,
+	       "arm,versatile-cm-auxosc", of_versatile_cm_osc_setup);