From 119e9db233ad0f4cbd4cfb9f9385a7bca378b37d Mon Sep 17 00:00:00 2001 From: Zeng Chi Date: Mon, 21 Sep 2026 18:24:42 +0800 Subject: KVM: Don't pre-reserve xarray entries when storing empty/NULL attributes 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 Cc: David Ballesteros Signed-off-by: Zeng Chi Link: https://patch.msgid.link/20260921102442.1232375-1-zeng_chi911@163.com [sean: split to separate patch] Signed-off-by: Sean Christopherson --- drivers/nvmem/layouts/fixed-layout.c | 58 ++++++++++++++++++++++++++++++++++++ 1 file changed, 58 insertions(+) create mode 100644 drivers/nvmem/layouts/fixed-layout.c (limited to 'drivers/nvmem/layouts/fixed-layout.c') diff --git a/drivers/nvmem/layouts/fixed-layout.c b/drivers/nvmem/layouts/fixed-layout.c new file mode 100644 index 000000000..635d448b3 --- /dev/null +++ b/drivers/nvmem/layouts/fixed-layout.c @@ -0,0 +1,58 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2026 Bootlin + * + * Authors: Mathieu Dubois-Briand + */ + +#include +#include + +#include "../internals.h" + +static int fixed_layout_add_cells(struct nvmem_layout *layout) +{ + struct device_node *np; + int ret; + + np = of_nvmem_layout_get_container(layout->nvmem); + if (!np) + return -ENOENT; + + ret = nvmem_add_cells_from_dt(layout->nvmem, np); + of_node_put(np); + + return ret; +} + +static int fixed_layout_probe(struct nvmem_layout *layout) +{ + layout->add_cells = fixed_layout_add_cells; + + return nvmem_layout_register(layout); +} + +static void fixed_layout_remove(struct nvmem_layout *layout) +{ + nvmem_layout_unregister(layout); +} + +static const struct of_device_id fixed_layout_of_match_table[] = { + { .compatible = "fixed-layout", }, + {}, +}; + +static struct nvmem_layout_driver fixed_layout_layout = { + .driver = { + .name = "fixed-layout", + .of_match_table = fixed_layout_of_match_table, + }, + .probe = fixed_layout_probe, + .remove = fixed_layout_remove, +}; +module_nvmem_layout_driver(fixed_layout_layout); + +MODULE_AUTHOR("Mathieu Dubois-Briand"); +MODULE_LICENSE("GPL"); +MODULE_DEVICE_TABLE(of, fixed_layout_of_match_table); +MODULE_DESCRIPTION("NVMEM fixed-layout driver"); -- cgit v1.3.1