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, 102 insertions, 0 deletions

diff --git a/drivers/net/phy/et1011c.c b/drivers/net/phy/et1011c.c
new file mode 100644
index 000000000..6cd8d7758
--- /dev/null
+++ b/drivers/net/phy/et1011c.c
@@ -0,0 +1,102 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * drivers/net/phy/et1011c.c
+ *
+ * Driver for LSI ET1011C PHYs
+ *
+ * Author: Chaithrika U S
+ *
+ * Copyright (c) 2008 Texas Instruments
+ */
+#include <linux/kernel.h>
+#include <linux/string.h>
+#include <linux/errno.h>
+#include <linux/unistd.h>
+#include <linux/interrupt.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/skbuff.h>
+#include <linux/spinlock.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/mii.h>
+#include <linux/ethtool.h>
+#include <linux/phy.h>
+#include <linux/io.h>
+#include <linux/uaccess.h>
+#include <asm/irq.h>
+
+#define ET1011C_STATUS_REG	(0x1A)
+#define ET1011C_CONFIG_REG	(0x16)
+#define ET1011C_SPEED_MASK		(0x0300)
+#define ET1011C_GIGABIT_SPEED		(0x0200)
+#define ET1011C_TX_FIFO_MASK		(0x3000)
+#define ET1011C_TX_FIFO_DEPTH_8		(0x0000)
+#define ET1011C_TX_FIFO_DEPTH_16	(0x1000)
+#define ET1011C_INTERFACE_MASK		(0x0007)
+#define ET1011C_GMII_INTERFACE		(0x0002)
+#define ET1011C_SYS_CLK_EN		(0x01 << 4)
+
+
+MODULE_DESCRIPTION("LSI ET1011C PHY driver");
+MODULE_AUTHOR("Chaithrika U S");
+MODULE_LICENSE("GPL");
+
+static int et1011c_config_aneg(struct phy_device *phydev)
+{
+	int ctl = phy_read(phydev, MII_BMCR);
+
+	if (ctl < 0)
+		return ctl;
+	ctl &= ~(BMCR_FULLDPLX | BMCR_SPEED100 | BMCR_SPEED1000 |
+		 BMCR_ANENABLE);
+	/* First clear the PHY */
+	phy_write(phydev, MII_BMCR, ctl | BMCR_RESET);
+
+	return genphy_config_aneg(phydev);
+}
+
+static int et1011c_read_status(struct phy_device *phydev)
+{
+	static int speed;
+	int ret;
+	u32 val;
+
+	ret = genphy_read_status(phydev);
+
+	if (speed != phydev->speed) {
+		speed = phydev->speed;
+		val = phy_read(phydev, ET1011C_STATUS_REG);
+		if ((val & ET1011C_SPEED_MASK) ==
+					ET1011C_GIGABIT_SPEED) {
+			val = phy_read(phydev, ET1011C_CONFIG_REG);
+			val &= ~ET1011C_TX_FIFO_MASK;
+			phy_write(phydev, ET1011C_CONFIG_REG, val |
+					  ET1011C_GMII_INTERFACE |
+					  ET1011C_SYS_CLK_EN |
+					  ET1011C_TX_FIFO_DEPTH_16);
+
+		}
+	}
+	return ret;
+}
+
+static struct phy_driver et1011c_driver[] = { {
+	.phy_id		= 0x0282f014,
+	.name		= "ET1011C",
+	.phy_id_mask	= 0xfffffff0,
+	/* PHY_GBIT_FEATURES */
+	.config_aneg	= et1011c_config_aneg,
+	.read_status	= et1011c_read_status,
+} };
+
+module_phy_driver(et1011c_driver);
+
+static const struct mdio_device_id __maybe_unused et1011c_tbl[] = {
+	{ 0x0282f014, 0xfffffff0 },
+	{ }
+};
+
+MODULE_DEVICE_TABLE(mdio, et1011c_tbl);