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, 253 insertions, 0 deletions

diff --git a/drivers/reset/reset-aspeed.c b/drivers/reset/reset-aspeed.c
new file mode 100644
index 000000000..dd2f860a6
--- /dev/null
+++ b/drivers/reset/reset-aspeed.c
@@ -0,0 +1,253 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (c) 2024 ASPEED Technology Inc.
+ */
+
+#include <linux/auxiliary_bus.h>
+#include <linux/cleanup.h>
+#include <linux/device.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/reset-controller.h>
+#include <linux/slab.h>
+
+#include <dt-bindings/reset/aspeed,ast2700-scu.h>
+
+#define SCU0_RESET_CTRL1 0x200
+#define SCU0_RESET_CTRL2 0x220
+#define SCU1_RESET_CTRL1 0x200
+#define SCU1_RESET_CTRL2 0x220
+#define SCU1_PCIE3_CTRL 0x908
+
+struct ast2700_reset_signal {
+	bool dedicated_clr; /* dedicated reset clr offset */
+	u32 offset, bit;
+};
+
+struct aspeed_reset_info {
+	unsigned int nr_resets;
+	const struct ast2700_reset_signal *signal;
+};
+
+struct aspeed_reset {
+	struct reset_controller_dev rcdev;
+	struct aspeed_reset_info *info;
+	spinlock_t lock; /* Protect read-modify-write cycle */
+	void __iomem *base;
+};
+
+static const struct ast2700_reset_signal ast2700_reset0_signals[] = {
+	[SCU0_RESET_SDRAM] = { true, SCU0_RESET_CTRL1, BIT(0) },
+	[SCU0_RESET_DDRPHY] = { true, SCU0_RESET_CTRL1, BIT(1) },
+	[SCU0_RESET_RSA] = { true, SCU0_RESET_CTRL1, BIT(2) },
+	[SCU0_RESET_SHA3] = { true, SCU0_RESET_CTRL1, BIT(3) },
+	[SCU0_RESET_HACE] = { true, SCU0_RESET_CTRL1, BIT(4) },
+	[SCU0_RESET_SOC] = { true, SCU0_RESET_CTRL1, BIT(5) },
+	[SCU0_RESET_VIDEO] = { true, SCU0_RESET_CTRL1, BIT(6) },
+	[SCU0_RESET_2D] = { true, SCU0_RESET_CTRL1, BIT(7) },
+	[SCU0_RESET_PCIS] = { true, SCU0_RESET_CTRL1, BIT(8) },
+	[SCU0_RESET_RVAS0] = { true, SCU0_RESET_CTRL1, BIT(9) },
+	[SCU0_RESET_RVAS1] = { true, SCU0_RESET_CTRL1, BIT(10) },
+	[SCU0_RESET_SM3] = { true, SCU0_RESET_CTRL1, BIT(11) },
+	[SCU0_RESET_SM4] = { true, SCU0_RESET_CTRL1, BIT(12) },
+	[SCU0_RESET_CRT0] = { true, SCU0_RESET_CTRL1, BIT(13) },
+	[SCU0_RESET_ECC] = { true, SCU0_RESET_CTRL1, BIT(14) },
+	[SCU0_RESET_DP_PCI] = { true, SCU0_RESET_CTRL1, BIT(15) },
+	[SCU0_RESET_UFS] = { true, SCU0_RESET_CTRL1, BIT(16) },
+	[SCU0_RESET_EMMC] = { true, SCU0_RESET_CTRL1, BIT(17) },
+	[SCU0_RESET_PCIE1RST] = { true, SCU0_RESET_CTRL1, BIT(18) },
+	[SCU0_RESET_PCIE1RSTOE] = { true, SCU0_RESET_CTRL1, BIT(19) },
+	[SCU0_RESET_PCIE0RST] = { true, SCU0_RESET_CTRL1, BIT(20) },
+	[SCU0_RESET_PCIE0RSTOE] = { true, SCU0_RESET_CTRL1, BIT(21) },
+	[SCU0_RESET_JTAG] = { true, SCU0_RESET_CTRL1, BIT(22) },
+	[SCU0_RESET_MCTP0] = { true, SCU0_RESET_CTRL1, BIT(23) },
+	[SCU0_RESET_MCTP1] = { true, SCU0_RESET_CTRL1, BIT(24) },
+	[SCU0_RESET_XDMA0] = { true, SCU0_RESET_CTRL1, BIT(25) },
+	[SCU0_RESET_XDMA1] = { true, SCU0_RESET_CTRL1, BIT(26) },
+	[SCU0_RESET_H2X1] = { true, SCU0_RESET_CTRL1, BIT(27) },
+	[SCU0_RESET_DP] = { true, SCU0_RESET_CTRL1, BIT(28) },
+	[SCU0_RESET_DP_MCU] = { true, SCU0_RESET_CTRL1, BIT(29) },
+	[SCU0_RESET_SSP] = { true, SCU0_RESET_CTRL1, BIT(30) },
+	[SCU0_RESET_H2X0] = { true, SCU0_RESET_CTRL1, BIT(31) },
+	[SCU0_RESET_PORTA_VHUB] = { true, SCU0_RESET_CTRL2, BIT(0) },
+	[SCU0_RESET_PORTA_PHY3] = { true, SCU0_RESET_CTRL2, BIT(1) },
+	[SCU0_RESET_PORTA_XHCI] = { true, SCU0_RESET_CTRL2, BIT(2) },
+	[SCU0_RESET_PORTB_VHUB] = { true, SCU0_RESET_CTRL2, BIT(3) },
+	[SCU0_RESET_PORTB_PHY3] = { true, SCU0_RESET_CTRL2, BIT(4) },
+	[SCU0_RESET_PORTB_XHCI] = { true, SCU0_RESET_CTRL2, BIT(5) },
+	[SCU0_RESET_PORTA_VHUB_EHCI] = { true, SCU0_RESET_CTRL2, BIT(6) },
+	[SCU0_RESET_PORTB_VHUB_EHCI] = { true, SCU0_RESET_CTRL2, BIT(7) },
+	[SCU0_RESET_UHCI] = { true, SCU0_RESET_CTRL2, BIT(8) },
+	[SCU0_RESET_TSP] = { true, SCU0_RESET_CTRL2, BIT(9) },
+	[SCU0_RESET_E2M0] = { true, SCU0_RESET_CTRL2, BIT(10) },
+	[SCU0_RESET_E2M1] = { true, SCU0_RESET_CTRL2, BIT(11) },
+	[SCU0_RESET_VLINK] = { true, SCU0_RESET_CTRL2, BIT(12) },
+};
+
+static const struct ast2700_reset_signal ast2700_reset1_signals[] = {
+	[SCU1_RESET_LPC0] = { true, SCU1_RESET_CTRL1, BIT(0) },
+	[SCU1_RESET_LPC1] = { true, SCU1_RESET_CTRL1, BIT(1) },
+	[SCU1_RESET_MII] = { true, SCU1_RESET_CTRL1, BIT(2) },
+	[SCU1_RESET_PECI] = { true, SCU1_RESET_CTRL1, BIT(3) },
+	[SCU1_RESET_PWM] = { true, SCU1_RESET_CTRL1, BIT(4) },
+	[SCU1_RESET_MAC0] = { true, SCU1_RESET_CTRL1, BIT(5) },
+	[SCU1_RESET_MAC1] = { true, SCU1_RESET_CTRL1, BIT(6) },
+	[SCU1_RESET_MAC2] = { true, SCU1_RESET_CTRL1, BIT(7) },
+	[SCU1_RESET_ADC] = { true, SCU1_RESET_CTRL1, BIT(8) },
+	[SCU1_RESET_SD] = { true, SCU1_RESET_CTRL1, BIT(9) },
+	[SCU1_RESET_ESPI0] = { true, SCU1_RESET_CTRL1, BIT(10) },
+	[SCU1_RESET_ESPI1] = { true, SCU1_RESET_CTRL1, BIT(11) },
+	[SCU1_RESET_JTAG1] = { true, SCU1_RESET_CTRL1, BIT(12) },
+	[SCU1_RESET_SPI0] = { true, SCU1_RESET_CTRL1, BIT(13) },
+	[SCU1_RESET_SPI1] = { true, SCU1_RESET_CTRL1, BIT(14) },
+	[SCU1_RESET_SPI2] = { true, SCU1_RESET_CTRL1, BIT(15) },
+	[SCU1_RESET_I3C0] = { true, SCU1_RESET_CTRL1, BIT(16) },
+	[SCU1_RESET_I3C1] = { true, SCU1_RESET_CTRL1, BIT(17) },
+	[SCU1_RESET_I3C2] = { true, SCU1_RESET_CTRL1, BIT(18) },
+	[SCU1_RESET_I3C3] = { true, SCU1_RESET_CTRL1, BIT(19) },
+	[SCU1_RESET_I3C4] = { true, SCU1_RESET_CTRL1, BIT(20) },
+	[SCU1_RESET_I3C5] = { true, SCU1_RESET_CTRL1, BIT(21) },
+	[SCU1_RESET_I3C6] = { true, SCU1_RESET_CTRL1, BIT(22) },
+	[SCU1_RESET_I3C7] = { true, SCU1_RESET_CTRL1, BIT(23) },
+	[SCU1_RESET_I3C8] = { true, SCU1_RESET_CTRL1, BIT(24) },
+	[SCU1_RESET_I3C9] = { true, SCU1_RESET_CTRL1, BIT(25) },
+	[SCU1_RESET_I3C10] = { true, SCU1_RESET_CTRL1, BIT(26) },
+	[SCU1_RESET_I3C11] = { true, SCU1_RESET_CTRL1, BIT(27) },
+	[SCU1_RESET_I3C12] = { true, SCU1_RESET_CTRL1, BIT(28) },
+	[SCU1_RESET_I3C13] = { true, SCU1_RESET_CTRL1, BIT(29) },
+	[SCU1_RESET_I3C14] = { true, SCU1_RESET_CTRL1, BIT(30) },
+	[SCU1_RESET_I3C15] = { true, SCU1_RESET_CTRL1, BIT(31) },
+	[SCU1_RESET_MCU0] = { true, SCU1_RESET_CTRL2, BIT(0) },
+	[SCU1_RESET_MCU1] = { true, SCU1_RESET_CTRL2, BIT(1) },
+	[SCU1_RESET_H2A_SPI1] = { true, SCU1_RESET_CTRL2, BIT(2) },
+	[SCU1_RESET_H2A_SPI2] = { true, SCU1_RESET_CTRL2, BIT(3) },
+	[SCU1_RESET_UART0] = { true, SCU1_RESET_CTRL2, BIT(4) },
+	[SCU1_RESET_UART1] = { true, SCU1_RESET_CTRL2, BIT(5) },
+	[SCU1_RESET_UART2] = { true, SCU1_RESET_CTRL2, BIT(6) },
+	[SCU1_RESET_UART3] = { true, SCU1_RESET_CTRL2, BIT(7) },
+	[SCU1_RESET_I2C_FILTER] = { true, SCU1_RESET_CTRL2, BIT(8) },
+	[SCU1_RESET_CALIPTRA] = { true, SCU1_RESET_CTRL2, BIT(9) },
+	[SCU1_RESET_XDMA] = { true, SCU1_RESET_CTRL2, BIT(10) },
+	[SCU1_RESET_FSI] = { true, SCU1_RESET_CTRL2, BIT(12) },
+	[SCU1_RESET_CAN] = { true, SCU1_RESET_CTRL2, BIT(13) },
+	[SCU1_RESET_MCTP] = { true, SCU1_RESET_CTRL2, BIT(14) },
+	[SCU1_RESET_I2C] = { true, SCU1_RESET_CTRL2, BIT(15) },
+	[SCU1_RESET_UART6] = { true, SCU1_RESET_CTRL2, BIT(16) },
+	[SCU1_RESET_UART7] = { true, SCU1_RESET_CTRL2, BIT(17) },
+	[SCU1_RESET_UART8] = { true, SCU1_RESET_CTRL2, BIT(18) },
+	[SCU1_RESET_UART9] = { true, SCU1_RESET_CTRL2, BIT(19) },
+	[SCU1_RESET_LTPI0] = { true, SCU1_RESET_CTRL2, BIT(20) },
+	[SCU1_RESET_VGAL] = { true, SCU1_RESET_CTRL2, BIT(21) },
+	[SCU1_RESET_LTPI1] = { true, SCU1_RESET_CTRL2, BIT(22) },
+	[SCU1_RESET_ACE] = { true, SCU1_RESET_CTRL2, BIT(23) },
+	[SCU1_RESET_E2M] = { true, SCU1_RESET_CTRL2, BIT(24) },
+	[SCU1_RESET_UHCI] = { true, SCU1_RESET_CTRL2, BIT(25) },
+	[SCU1_RESET_PORTC_USB2UART] = { true, SCU1_RESET_CTRL2, BIT(26) },
+	[SCU1_RESET_PORTC_VHUB_EHCI] = { true, SCU1_RESET_CTRL2, BIT(27) },
+	[SCU1_RESET_PORTD_USB2UART] = { true, SCU1_RESET_CTRL2, BIT(28) },
+	[SCU1_RESET_PORTD_VHUB_EHCI] = { true, SCU1_RESET_CTRL2, BIT(29) },
+	[SCU1_RESET_H2X] = { true, SCU1_RESET_CTRL2, BIT(30) },
+	[SCU1_RESET_I3CDMA] = { true, SCU1_RESET_CTRL2, BIT(31) },
+	[SCU1_RESET_PCIE2RST] = { false, SCU1_PCIE3_CTRL, BIT(0) },
+};
+
+static inline struct aspeed_reset *to_aspeed_reset(struct reset_controller_dev *rcdev)
+{
+	return container_of(rcdev, struct aspeed_reset, rcdev);
+}
+
+static int aspeed_reset_assert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct aspeed_reset *rc = to_aspeed_reset(rcdev);
+	void __iomem *reg_offset = rc->base + rc->info->signal[id].offset;
+
+	if (rc->info->signal[id].dedicated_clr) {
+		writel(rc->info->signal[id].bit, reg_offset);
+	} else {
+		guard(spinlock_irqsave)(&rc->lock);
+		writel(readl(reg_offset) & ~rc->info->signal[id].bit, reg_offset);
+	}
+
+	return 0;
+}
+
+static int aspeed_reset_deassert(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct aspeed_reset *rc = to_aspeed_reset(rcdev);
+	void __iomem *reg_offset = rc->base + rc->info->signal[id].offset;
+
+	if (rc->info->signal[id].dedicated_clr) {
+		writel(rc->info->signal[id].bit, reg_offset + 0x04);
+	} else {
+		guard(spinlock_irqsave)(&rc->lock);
+		writel(readl(reg_offset) | rc->info->signal[id].bit, reg_offset);
+	}
+
+	return 0;
+}
+
+static int aspeed_reset_status(struct reset_controller_dev *rcdev, unsigned long id)
+{
+	struct aspeed_reset *rc = to_aspeed_reset(rcdev);
+	void __iomem *reg_offset = rc->base + rc->info->signal[id].offset;
+
+	return (readl(reg_offset) & rc->info->signal[id].bit) ? 1 : 0;
+}
+
+static const struct reset_control_ops aspeed_reset_ops = {
+	.assert = aspeed_reset_assert,
+	.deassert = aspeed_reset_deassert,
+	.status = aspeed_reset_status,
+};
+
+static int aspeed_reset_probe(struct auxiliary_device *adev,
+			      const struct auxiliary_device_id *id)
+{
+	struct aspeed_reset *reset;
+	struct device *dev = &adev->dev;
+
+	reset = devm_kzalloc(dev, sizeof(*reset), GFP_KERNEL);
+	if (!reset)
+		return -ENOMEM;
+
+	spin_lock_init(&reset->lock);
+
+	reset->info = (struct aspeed_reset_info *)id->driver_data;
+	reset->rcdev.owner = THIS_MODULE;
+	reset->rcdev.nr_resets = reset->info->nr_resets;
+	reset->rcdev.ops = &aspeed_reset_ops;
+	reset->rcdev.of_node = dev->parent->of_node;
+	reset->rcdev.dev = dev;
+	reset->rcdev.of_reset_n_cells = 1;
+	reset->base = (void __iomem *)adev->dev.platform_data;
+
+	return devm_reset_controller_register(dev, &reset->rcdev);
+}
+
+static const struct aspeed_reset_info ast2700_reset0_info = {
+	.nr_resets = ARRAY_SIZE(ast2700_reset0_signals),
+	.signal = ast2700_reset0_signals,
+};
+
+static const struct aspeed_reset_info ast2700_reset1_info = {
+	.nr_resets = ARRAY_SIZE(ast2700_reset1_signals),
+	.signal = ast2700_reset1_signals,
+};
+
+static const struct auxiliary_device_id aspeed_reset_ids[] = {
+	{ .name = "clk_ast2700.reset0", .driver_data = (kernel_ulong_t)&ast2700_reset0_info },
+	{ .name = "clk_ast2700.reset1", .driver_data = (kernel_ulong_t)&ast2700_reset1_info },
+	{ }
+};
+MODULE_DEVICE_TABLE(auxiliary, aspeed_reset_ids);
+
+static struct auxiliary_driver aspeed_reset_driver = {
+	.probe		= aspeed_reset_probe,
+	.id_table	= aspeed_reset_ids,
+};
+
+module_auxiliary_driver(aspeed_reset_driver);
+
+MODULE_AUTHOR("Ryan Chen <ryan_chen@aspeedtech.com>");
+MODULE_DESCRIPTION("ASPEED SoC Reset Controller Driver");
+MODULE_LICENSE("GPL");