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, 165 insertions, 0 deletions

diff --git a/arch/arm/mach-omap1/timer.c b/arch/arm/mach-omap1/timer.c
new file mode 100644
index 000000000..399e6d840
--- /dev/null
+++ b/arch/arm/mach-omap1/timer.c
@@ -0,0 +1,165 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * OMAP1 Dual-Mode Timers - platform device registration
+ *
+ * Contains first level initialization routines which internally
+ * generates timer device information and registers with linux
+ * device model. It also has a low level function to change the timer
+ * input clock source.
+ *
+ * Copyright (C) 2011 Texas Instruments Incorporated - https://www.ti.com/
+ * Tarun Kanti DebBarma <tarun.kanti@ti.com>
+ * Thara Gopinath <thara@ti.com>
+ */
+
+#include <linux/clk.h>
+#include <linux/io.h>
+#include <linux/err.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/platform_data/dmtimer-omap.h>
+#include <linux/soc/ti/omap1-io.h>
+
+#include <clocksource/timer-ti-dm.h>
+
+#include "soc.h"
+
+#define OMAP1610_GPTIMER1_BASE		0xfffb1400
+#define OMAP1610_GPTIMER2_BASE		0xfffb1c00
+#define OMAP1610_GPTIMER3_BASE		0xfffb2400
+#define OMAP1610_GPTIMER4_BASE		0xfffb2c00
+#define OMAP1610_GPTIMER5_BASE		0xfffb3400
+#define OMAP1610_GPTIMER6_BASE		0xfffb3c00
+#define OMAP1610_GPTIMER7_BASE		0xfffb7400
+#define OMAP1610_GPTIMER8_BASE		0xfffbd400
+
+#define OMAP1_DM_TIMER_COUNT		8
+
+static int omap1_dm_timer_set_src(struct platform_device *pdev,
+				int source)
+{
+	int n = (pdev->id - 1) << 1;
+	u32 l;
+
+	l = omap_readl(MOD_CONF_CTRL_1) & ~(0x03 << n);
+	l |= source << n;
+	omap_writel(l, MOD_CONF_CTRL_1);
+
+	return 0;
+}
+
+static int __init omap1_dm_timer_init(void)
+{
+	int i;
+	int ret;
+	struct dmtimer_platform_data *pdata;
+	struct platform_device *pdev;
+
+	if (!cpu_is_omap16xx())
+		return 0;
+
+	for (i = 1; i <= OMAP1_DM_TIMER_COUNT; i++) {
+		struct resource res[2];
+		u32 base, irq;
+
+		switch (i) {
+		case 1:
+			base = OMAP1610_GPTIMER1_BASE;
+			irq = INT_1610_GPTIMER1;
+			break;
+		case 2:
+			base = OMAP1610_GPTIMER2_BASE;
+			irq = INT_1610_GPTIMER2;
+			break;
+		case 3:
+			base = OMAP1610_GPTIMER3_BASE;
+			irq = INT_1610_GPTIMER3;
+			break;
+		case 4:
+			base = OMAP1610_GPTIMER4_BASE;
+			irq = INT_1610_GPTIMER4;
+			break;
+		case 5:
+			base = OMAP1610_GPTIMER5_BASE;
+			irq = INT_1610_GPTIMER5;
+			break;
+		case 6:
+			base = OMAP1610_GPTIMER6_BASE;
+			irq = INT_1610_GPTIMER6;
+			break;
+		case 7:
+			base = OMAP1610_GPTIMER7_BASE;
+			irq = INT_1610_GPTIMER7;
+			break;
+		case 8:
+			base = OMAP1610_GPTIMER8_BASE;
+			irq = INT_1610_GPTIMER8;
+			break;
+		default:
+			/*
+			 * not supposed to reach here.
+			 * this is to remove warning.
+			 */
+			return -EINVAL;
+		}
+
+		pdev = platform_device_alloc("omap_timer", i);
+		if (!pdev) {
+			pr_err("%s: Failed to device alloc for dmtimer%d\n",
+				__func__, i);
+			return -ENOMEM;
+		}
+
+		memset(res, 0, 2 * sizeof(struct resource));
+		res[0].start = base;
+		res[0].end = base + 0x46;
+		res[0].flags = IORESOURCE_MEM;
+		res[1].start = irq;
+		res[1].end = irq;
+		res[1].flags = IORESOURCE_IRQ;
+		ret = platform_device_add_resources(pdev, res,
+				ARRAY_SIZE(res));
+		if (ret) {
+			dev_err(&pdev->dev, "%s: Failed to add resources.\n",
+				__func__);
+			goto err_free_pdev;
+		}
+
+		pdata = kzalloc_obj(*pdata);
+		if (!pdata) {
+			ret = -ENOMEM;
+			goto err_free_pdata;
+		}
+
+		pdata->set_timer_src = omap1_dm_timer_set_src;
+		pdata->timer_capability = OMAP_TIMER_ALWON |
+				OMAP_TIMER_NEEDS_RESET | OMAP_TIMER_HAS_DSP_IRQ;
+
+		ret = platform_device_add_data(pdev, pdata, sizeof(*pdata));
+		if (ret) {
+			dev_err(&pdev->dev, "%s: Failed to add platform data.\n",
+				__func__);
+			goto err_free_pdata;
+		}
+
+		ret = platform_device_add(pdev);
+		if (ret) {
+			dev_err(&pdev->dev, "%s: Failed to add platform device.\n",
+				__func__);
+			goto err_free_pdata;
+		}
+
+		dev_dbg(&pdev->dev, " Registered.\n");
+	}
+
+	return 0;
+
+err_free_pdata:
+	kfree(pdata);
+
+err_free_pdev:
+	platform_device_put(pdev);
+
+	return ret;
+}
+arch_initcall(omap1_dm_timer_init);