From 2bc6b218717b9d08f466f88209251d54bc09b207 Mon Sep 17 00:00:00 2001 From: Fuad Tabba Date: Tue, 22 Sep 2026 19:14:30 +0100 Subject: arm64/boot: Disable trapping of PMZR_EL0 writes to EL2 __init_el2_fgt2() writes one mask to both HDFGRTR2_EL2 and HDFGWTR2_EL2. PMZR_EL0 is write-only, so its trap bit, nPMZR_EL0, exists only in HDFGWTR2_EL2 and is therefore never set: a PMZR_EL0 write from the host traps to EL2, where the nVHE hypervisor has no handler and BUG()s. The kernel never writes PMZR_EL0, but kernel.perf_user_access=1 has the PMU driver set PMUSERENR_EL0.UEN for a task with a user-read event, so a write from EL0 reaches the trap and takes the host down without a panic message. Accumulate the HDFGWTR2_EL2 bits separately, as __init_el2_fgt() already does for HDFGWTR_EL2, and set nPMZR_EL0 with the other FEAT_PMUv3p9 bits. Fixes: 858c7bfcb35e1 ("arm64/boot: Enable EL2 requirements for FEAT_PMUv3p9") Cc: stable@vger.kernel.org Signed-off-by: Fuad Tabba Reviewed-by: Anshuman Khandual Reviewed-by: Oliver Upton Signed-off-by: Will Deacon --- drivers/mfd/atmel-flexcom.c | 123 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 123 insertions(+) create mode 100644 drivers/mfd/atmel-flexcom.c (limited to 'drivers/mfd/atmel-flexcom.c') diff --git a/drivers/mfd/atmel-flexcom.c b/drivers/mfd/atmel-flexcom.c new file mode 100644 index 000000000..d5df5466e --- /dev/null +++ b/drivers/mfd/atmel-flexcom.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Driver for Atmel Flexcom + * + * Copyright (C) 2015 Atmel Corporation + * + * Author: Cyrille Pitchen + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/* I/O register offsets */ +#define FLEX_MR 0x0 /* Mode Register */ +#define FLEX_VERSION 0xfc /* Version Register */ + +/* Mode Register bit fields */ +#define FLEX_MR_OPMODE_OFFSET (0) /* Operating Mode */ +#define FLEX_MR_OPMODE_MASK (0x3 << FLEX_MR_OPMODE_OFFSET) +#define FLEX_MR_OPMODE(opmode) (((opmode) << FLEX_MR_OPMODE_OFFSET) & \ + FLEX_MR_OPMODE_MASK) + +struct atmel_flexcom { + void __iomem *base; + u32 opmode; + struct clk *clk; +}; + +static int atmel_flexcom_probe(struct platform_device *pdev) +{ + struct device_node *np = pdev->dev.of_node; + struct atmel_flexcom *ddata; + int err; + + ddata = devm_kzalloc(&pdev->dev, sizeof(*ddata), GFP_KERNEL); + if (!ddata) + return -ENOMEM; + + platform_set_drvdata(pdev, ddata); + + err = of_property_read_u32(np, "atmel,flexcom-mode", &ddata->opmode); + if (err) + return err; + + if (ddata->opmode < ATMEL_FLEXCOM_MODE_USART || + ddata->opmode > ATMEL_FLEXCOM_MODE_TWI) + return -EINVAL; + + ddata->base = devm_platform_get_and_ioremap_resource(pdev, 0, NULL); + if (IS_ERR(ddata->base)) + return PTR_ERR(ddata->base); + + ddata->clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(ddata->clk)) + return PTR_ERR(ddata->clk); + + err = clk_prepare_enable(ddata->clk); + if (err) + return err; + + /* + * Set the Operating Mode in the Mode Register: only the selected device + * is clocked. Hence, registers of the other serial devices remain + * inaccessible and are read as zero. Also the external I/O lines of the + * Flexcom are muxed to reach the selected device. + */ + writel(FLEX_MR_OPMODE(ddata->opmode), ddata->base + FLEX_MR); + + clk_disable_unprepare(ddata->clk); + + return devm_of_platform_populate(&pdev->dev); +} + +static const struct of_device_id atmel_flexcom_of_match[] = { + { .compatible = "atmel,sama5d2-flexcom" }, + { /* sentinel */ } +}; +MODULE_DEVICE_TABLE(of, atmel_flexcom_of_match); + +static int __maybe_unused atmel_flexcom_resume_noirq(struct device *dev) +{ + struct atmel_flexcom *ddata = dev_get_drvdata(dev); + int err; + u32 val; + + err = clk_prepare_enable(ddata->clk); + if (err) + return err; + + val = FLEX_MR_OPMODE(ddata->opmode); + writel(val, ddata->base + FLEX_MR); + + clk_disable_unprepare(ddata->clk); + + return 0; +} + +static const struct dev_pm_ops __maybe_unused atmel_flexcom_pm_ops = { + .resume_noirq = atmel_flexcom_resume_noirq, +}; + +static struct platform_driver atmel_flexcom_driver = { + .probe = atmel_flexcom_probe, + .driver = { + .name = "atmel_flexcom", + .pm = pm_ptr(&atmel_flexcom_pm_ops), + .of_match_table = atmel_flexcom_of_match, + }, +}; + +module_platform_driver(atmel_flexcom_driver); + +MODULE_AUTHOR("Cyrille Pitchen "); +MODULE_DESCRIPTION("Atmel Flexcom MFD driver"); +MODULE_LICENSE("GPL v2"); -- cgit v1.3.1