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/rcar-efuse.c | 142 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 drivers/nvmem/rcar-efuse.c (limited to 'drivers/nvmem/rcar-efuse.c') diff --git a/drivers/nvmem/rcar-efuse.c b/drivers/nvmem/rcar-efuse.c new file mode 100644 index 000000000..b94ff83b7 --- /dev/null +++ b/drivers/nvmem/rcar-efuse.c @@ -0,0 +1,142 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Renesas R-Car E-FUSE/OTP Driver + * + * Copyright (C) 2024 Glider bv + */ + +#include +#include +#include +#include +#include +#include +#include + +struct rcar_fuse { + struct nvmem_keepout keepouts[2]; + struct nvmem_device *nvmem; + struct device *dev; + void __iomem *base; +}; + +struct rcar_fuse_data { + unsigned int bank; /* 0: PFC + E-FUSE, 1: OPT_MEM + E-FUSE */ + unsigned int start; /* inclusive */ + unsigned int end; /* exclusive */ +}; + +static int rcar_fuse_reg_read(void *priv, unsigned int offset, void *val, + size_t bytes) +{ + struct rcar_fuse *fuse = priv; + int ret; + + ret = pm_runtime_resume_and_get(fuse->dev); + if (ret < 0) + return ret; + + __ioread32_copy(val, fuse->base + offset, bytes / 4); + + pm_runtime_put(fuse->dev); + + return 0; +} + +static int rcar_fuse_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + const struct rcar_fuse_data *data = device_get_match_data(dev); + struct nvmem_config config = { + .dev = dev, + .name = "rcar-fuse", + .id = NVMEM_DEVID_NONE, + .owner = THIS_MODULE, + .type = NVMEM_TYPE_OTP, + .read_only = true, + .root_only = true, + .reg_read = rcar_fuse_reg_read, + .word_size = 4, + .stride = 4, + }; + struct rcar_fuse *fuse; + struct resource *res; + int ret; + + ret = devm_pm_runtime_enable(dev); + if (ret < 0) + return ret; + + fuse = devm_kzalloc(dev, sizeof(*fuse), GFP_KERNEL); + if (!fuse) + return -ENOMEM; + + fuse->base = devm_platform_get_and_ioremap_resource(pdev, data->bank, + &res); + if (IS_ERR(fuse->base)) + return PTR_ERR(fuse->base); + + fuse->dev = dev; + fuse->keepouts[0].start = 0; + fuse->keepouts[0].end = data->start; + fuse->keepouts[1].start = data->end; + fuse->keepouts[1].end = resource_size(res); + + config.keepout = fuse->keepouts; + config.nkeepout = ARRAY_SIZE(fuse->keepouts); + config.size = resource_size(res); + config.priv = fuse; + + fuse->nvmem = devm_nvmem_register(dev, &config); + if (IS_ERR(fuse->nvmem)) + return dev_err_probe(dev, PTR_ERR(fuse->nvmem), + "Failed to register NVMEM device\n"); + + return 0; +} + +static const struct rcar_fuse_data rcar_fuse_v3u = { + .bank = 0, + .start = 0x0c0, + .end = 0x0e8, +}; + +static const struct rcar_fuse_data rcar_fuse_s4 = { + .bank = 0, + .start = 0x0c0, + .end = 0x14c, +}; + +static const struct rcar_fuse_data rcar_fuse_v4h = { + .bank = 1, + .start = 0x100, + .end = 0x1a0, +}; + +static const struct rcar_fuse_data rcar_fuse_v4m = { + .bank = 1, + .start = 0x100, + .end = 0x110, +}; + +static const struct of_device_id rcar_fuse_match[] = { + { .compatible = "renesas,r8a779a0-efuse", .data = &rcar_fuse_v3u }, + { .compatible = "renesas,r8a779f0-efuse", .data = &rcar_fuse_s4 }, + { .compatible = "renesas,r8a779g0-otp", .data = &rcar_fuse_v4h }, + { .compatible = "renesas,r8a779h0-otp", .data = &rcar_fuse_v4m }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, rcar_fuse_match); + +static struct platform_driver rcar_fuse_driver = { + .probe = rcar_fuse_probe, + .driver = { + .name = "rcar_fuse", + .of_match_table = rcar_fuse_match, + }, +}; +module_platform_driver(rcar_fuse_driver); + +MODULE_DESCRIPTION("Renesas R-Car E-FUSE/OTP driver"); +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Geert Uytterhoeven"); -- cgit v1.3.1