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/misc/smpro-misc.c | 144 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 144 insertions(+) create mode 100644 drivers/misc/smpro-misc.c (limited to 'drivers/misc/smpro-misc.c') diff --git a/drivers/misc/smpro-misc.c b/drivers/misc/smpro-misc.c new file mode 100644 index 000000000..2ca5e3bcc --- /dev/null +++ b/drivers/misc/smpro-misc.c @@ -0,0 +1,144 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Ampere Computing SoC's SMpro Misc Driver + * + * Copyright (c) 2022, Ampere Computing LLC + */ +#include +#include +#include + +/* Boot Stage/Progress Registers */ +#define BOOTSTAGE 0xB0 +#define BOOTSTAGE_LO 0xB1 +#define CUR_BOOTSTAGE 0xB2 +#define BOOTSTAGE_HI 0xB3 + +/* SOC State Registers */ +#define SOC_POWER_LIMIT 0xE5 + +struct smpro_misc { + struct regmap *regmap; +}; + +static ssize_t boot_progress_show(struct device *dev, struct device_attribute *da, char *buf) +{ + struct smpro_misc *misc = dev_get_drvdata(dev); + u16 boot_progress[3] = { 0 }; + u32 bootstage; + u8 boot_stage; + u8 cur_stage; + u32 reg_lo; + u32 reg; + int ret; + + /* Read current boot stage */ + ret = regmap_read(misc->regmap, CUR_BOOTSTAGE, ®); + if (ret) + return ret; + + cur_stage = reg & 0xff; + + ret = regmap_read(misc->regmap, BOOTSTAGE, &bootstage); + if (ret) + return ret; + + boot_stage = (bootstage >> 8) & 0xff; + + if (boot_stage > cur_stage) + return -EINVAL; + + ret = regmap_read(misc->regmap, BOOTSTAGE_LO, ®_lo); + if (!ret) + ret = regmap_read(misc->regmap, BOOTSTAGE_HI, ®); + if (ret) + return ret; + + /* Firmware to report new boot stage next time */ + if (boot_stage < cur_stage) { + ret = regmap_write(misc->regmap, BOOTSTAGE, ((bootstage & 0xff00) | 0x1)); + if (ret) + return ret; + } + + boot_progress[0] = bootstage; + boot_progress[1] = swab16(reg); + boot_progress[2] = swab16(reg_lo); + + return sysfs_emit(buf, "%*phN\n", (int)sizeof(boot_progress), boot_progress); +} + +static DEVICE_ATTR_RO(boot_progress); + +static ssize_t soc_power_limit_show(struct device *dev, struct device_attribute *da, char *buf) +{ + struct smpro_misc *misc = dev_get_drvdata(dev); + unsigned int value; + int ret; + + ret = regmap_read(misc->regmap, SOC_POWER_LIMIT, &value); + if (ret) + return ret; + + return sysfs_emit(buf, "%d\n", value); +} + +static ssize_t soc_power_limit_store(struct device *dev, struct device_attribute *da, + const char *buf, size_t count) +{ + struct smpro_misc *misc = dev_get_drvdata(dev); + unsigned long val; + s32 ret; + + ret = kstrtoul(buf, 0, &val); + if (ret) + return ret; + + ret = regmap_write(misc->regmap, SOC_POWER_LIMIT, (unsigned int)val); + if (ret) + return -EPROTO; + + return count; +} + +static DEVICE_ATTR_RW(soc_power_limit); + +static struct attribute *smpro_misc_attrs[] = { + &dev_attr_boot_progress.attr, + &dev_attr_soc_power_limit.attr, + NULL +}; + +ATTRIBUTE_GROUPS(smpro_misc); + +static int smpro_misc_probe(struct platform_device *pdev) +{ + struct smpro_misc *misc; + + misc = devm_kzalloc(&pdev->dev, sizeof(struct smpro_misc), GFP_KERNEL); + if (!misc) + return -ENOMEM; + + platform_set_drvdata(pdev, misc); + + misc->regmap = dev_get_regmap(pdev->dev.parent, NULL); + if (!misc->regmap) + return -ENODEV; + + return 0; +} + +static struct platform_driver smpro_misc_driver = { + .probe = smpro_misc_probe, + .driver = { + .name = "smpro-misc", + .dev_groups = smpro_misc_groups, + }, +}; + +module_platform_driver(smpro_misc_driver); + +MODULE_AUTHOR("Tung Nguyen "); +MODULE_AUTHOR("Quan Nguyen "); +MODULE_DESCRIPTION("Ampere Altra SMpro Misc driver"); +MODULE_LICENSE("GPL"); -- cgit v1.3.1