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, 239 insertions, 0 deletions

diff --git a/drivers/usb/host/ohci-ps3.c b/drivers/usb/host/ohci-ps3.c
new file mode 100644
index 000000000..4f5af929c
--- /dev/null
+++ b/drivers/usb/host/ohci-ps3.c
@@ -0,0 +1,239 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  PS3 OHCI Host Controller driver
+ *
+ *  Copyright (C) 2006 Sony Computer Entertainment Inc.
+ *  Copyright 2006 Sony Corp.
+ */
+
+#include <asm/firmware.h>
+#include <asm/ps3.h>
+
+static int ps3_ohci_hc_reset(struct usb_hcd *hcd)
+{
+	struct ohci_hcd *ohci = hcd_to_ohci(hcd);
+
+	ohci->flags |= OHCI_QUIRK_BE_MMIO;
+	ohci_hcd_init(ohci);
+	return ohci_init(ohci);
+}
+
+static int ps3_ohci_hc_start(struct usb_hcd *hcd)
+{
+	int result;
+	struct ohci_hcd *ohci = hcd_to_ohci(hcd);
+
+	/* Handle root hub init quirk in spider south bridge. */
+	/* Also set PwrOn2PwrGood to 0x7f (254ms). */
+
+	ohci_writel(ohci, 0x7f000000 | RH_A_PSM | RH_A_OCPM,
+		&ohci->regs->roothub.a);
+	ohci_writel(ohci, 0x00060000, &ohci->regs->roothub.b);
+
+	result = ohci_run(ohci);
+
+	if (result < 0) {
+		dev_err(hcd->self.controller, "can't start %s\n",
+			hcd->self.bus_name);
+		ohci_stop(hcd);
+	}
+
+	return result;
+}
+
+static const struct hc_driver ps3_ohci_hc_driver = {
+	.description		= hcd_name,
+	.product_desc		= "PS3 OHCI Host Controller",
+	.hcd_priv_size		= sizeof(struct ohci_hcd),
+	.irq			= ohci_irq,
+	.flags			= HCD_MEMORY | HCD_DMA | HCD_USB11,
+	.reset			= ps3_ohci_hc_reset,
+	.start			= ps3_ohci_hc_start,
+	.stop			= ohci_stop,
+	.shutdown		= ohci_shutdown,
+	.urb_enqueue		= ohci_urb_enqueue,
+	.urb_dequeue		= ohci_urb_dequeue,
+	.endpoint_disable	= ohci_endpoint_disable,
+	.get_frame_number	= ohci_get_frame,
+	.hub_status_data	= ohci_hub_status_data,
+	.hub_control		= ohci_hub_control,
+	.start_port_reset	= ohci_start_port_reset,
+#if defined(CONFIG_PM)
+	.bus_suspend 		= ohci_bus_suspend,
+	.bus_resume 		= ohci_bus_resume,
+#endif
+};
+
+static int ps3_ohci_probe(struct ps3_system_bus_device *dev)
+{
+	int result;
+	struct usb_hcd *hcd;
+	unsigned int virq;
+	static u64 dummy_mask;
+
+	if (usb_disabled()) {
+		result = -ENODEV;
+		goto fail_start;
+	}
+
+	result = ps3_open_hv_device(dev);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_open_hv_device failed: %s\n",
+			__func__, __LINE__, ps3_result(result));
+		result = -EPERM;
+		goto fail_open;
+	}
+
+	result = ps3_dma_region_create(dev->d_region);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_dma_region_create failed: "
+			"(%d)\n", __func__, __LINE__, result);
+		BUG_ON("check region type");
+		goto fail_dma_region;
+	}
+
+	result = ps3_mmio_region_create(dev->m_region);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_map_mmio_region failed\n",
+			__func__, __LINE__);
+		result = -EPERM;
+		goto fail_mmio_region;
+	}
+
+	dev_dbg(&dev->core, "%s:%d: mmio mapped_addr %lxh\n", __func__,
+		__LINE__, dev->m_region->lpar_addr);
+
+	result = ps3_io_irq_setup(PS3_BINDING_CPU_ANY, dev->interrupt_id, &virq);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: ps3_construct_io_irq(%d) failed.\n",
+			__func__, __LINE__, virq);
+		result = -EPERM;
+		goto fail_irq;
+	}
+
+	dummy_mask = DMA_BIT_MASK(32);
+	dev->core.dma_mask = &dummy_mask;
+	dma_set_coherent_mask(&dev->core, dummy_mask);
+
+	hcd = usb_create_hcd(&ps3_ohci_hc_driver, &dev->core, dev_name(&dev->core));
+
+	if (!hcd) {
+		dev_dbg(&dev->core, "%s:%d: usb_create_hcd failed\n", __func__,
+			__LINE__);
+		result = -ENOMEM;
+		goto fail_create_hcd;
+	}
+
+	hcd->rsrc_start = dev->m_region->lpar_addr;
+	hcd->rsrc_len = dev->m_region->len;
+
+	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name))
+		dev_dbg(&dev->core, "%s:%d: request_mem_region failed\n",
+			__func__, __LINE__);
+
+	hcd->regs = ioremap(dev->m_region->lpar_addr, dev->m_region->len);
+
+	if (!hcd->regs) {
+		dev_dbg(&dev->core, "%s:%d: ioremap failed\n", __func__,
+			__LINE__);
+		result = -EPERM;
+		goto fail_ioremap;
+	}
+
+	dev_dbg(&dev->core, "%s:%d: hcd->rsrc_start %lxh\n", __func__, __LINE__,
+		(unsigned long)hcd->rsrc_start);
+	dev_dbg(&dev->core, "%s:%d: hcd->rsrc_len   %lxh\n", __func__, __LINE__,
+		(unsigned long)hcd->rsrc_len);
+	dev_dbg(&dev->core, "%s:%d: hcd->regs       %lxh\n", __func__, __LINE__,
+		(unsigned long)hcd->regs);
+	dev_dbg(&dev->core, "%s:%d: virq            %lu\n", __func__, __LINE__,
+		(unsigned long)virq);
+
+	ps3_system_bus_set_drvdata(dev, hcd);
+
+	result = usb_add_hcd(hcd, virq, 0);
+
+	if (result) {
+		dev_dbg(&dev->core, "%s:%d: usb_add_hcd failed (%d)\n",
+			__func__, __LINE__, result);
+		goto fail_add_hcd;
+	}
+
+	device_wakeup_enable(hcd->self.controller);
+	return result;
+
+fail_add_hcd:
+	iounmap(hcd->regs);
+fail_ioremap:
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+	usb_put_hcd(hcd);
+fail_create_hcd:
+	ps3_io_irq_destroy(virq);
+fail_irq:
+	ps3_free_mmio_region(dev->m_region);
+fail_mmio_region:
+	ps3_dma_region_free(dev->d_region);
+fail_dma_region:
+	ps3_close_hv_device(dev);
+fail_open:
+fail_start:
+	return result;
+}
+
+static void ps3_ohci_remove(struct ps3_system_bus_device *dev)
+{
+	unsigned int tmp;
+	struct usb_hcd *hcd = ps3_system_bus_get_drvdata(dev);
+
+	BUG_ON(!hcd);
+
+	dev_dbg(&dev->core, "%s:%d: regs %p\n", __func__, __LINE__, hcd->regs);
+	dev_dbg(&dev->core, "%s:%d: irq %u\n", __func__, __LINE__, hcd->irq);
+
+	tmp = hcd->irq;
+
+	ohci_shutdown(hcd);
+	usb_remove_hcd(hcd);
+
+	ps3_system_bus_set_drvdata(dev, NULL);
+
+	BUG_ON(!hcd->regs);
+	iounmap(hcd->regs);
+
+	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
+	usb_put_hcd(hcd);
+
+	ps3_io_irq_destroy(tmp);
+	ps3_free_mmio_region(dev->m_region);
+
+	ps3_dma_region_free(dev->d_region);
+	ps3_close_hv_device(dev);
+}
+
+static int __init ps3_ohci_driver_register(struct ps3_system_bus_driver *drv)
+{
+	return firmware_has_feature(FW_FEATURE_PS3_LV1)
+		? ps3_system_bus_driver_register(drv)
+		: 0;
+}
+
+static void ps3_ohci_driver_unregister(struct ps3_system_bus_driver *drv)
+{
+	if (firmware_has_feature(FW_FEATURE_PS3_LV1))
+		ps3_system_bus_driver_unregister(drv);
+}
+
+MODULE_ALIAS(PS3_MODULE_ALIAS_OHCI);
+
+static struct ps3_system_bus_driver ps3_ohci_driver = {
+	.core.name = "ps3-ohci-driver",
+	.core.owner = THIS_MODULE,
+	.match_id = PS3_MATCH_ID_OHCI,
+	.probe = ps3_ohci_probe,
+	.remove = ps3_ohci_remove,
+	.shutdown = ps3_ohci_remove,
+};