From 9f0346dcbea363787186c94ef94dd01aaa215afa Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 5 Sep 2026 11:59:05 -0700 Subject: Merge tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core Pull driver core fixes from Danilo Krummrich: - Fix kernfs listxattr() not returning security xattr names (e.g. SELinux labels) when the kernfs node has no allocated kernfs_iattrs - Fix silent truncation of IRQ vector indices in the Rust PCI abstractions - Don't select OF from DRIVER_PE_KUNIT_TEST; skip the test when OF is disabled instead of silently enabling extra kernel functionality - Russ Weight is retiring from kernel development; update the Firmware Loader sysfs contact to the driver-core mailing list, add a CREDITS entry for Firmware Upload, and update MAINTAINERS accordingly * tag 'driver-core-7.3-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/driver-core/driver-core: MAINTAINERS: Remove Russ Weight from Firmware Loader CREDITS: Add CREDITS entry for Firmware Upload firmware_loader: Change contact for sysfs nodes rust: pci: reject IRQ vector indices that do not fit in u32 kernfs: preserve security xattrs without allocating iattrs drivers: base: test: DRIVER_PE_KUNIT_TEST should not select OF --- drivers/soc/apple/tunable.c | 80 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 80 insertions(+) create mode 100644 drivers/soc/apple/tunable.c (limited to 'drivers/soc/apple/tunable.c') diff --git a/drivers/soc/apple/tunable.c b/drivers/soc/apple/tunable.c new file mode 100644 index 000000000..659323839 --- /dev/null +++ b/drivers/soc/apple/tunable.c @@ -0,0 +1,80 @@ +// SPDX-License-Identifier: GPL-2.0-only OR MIT +/* + * Apple Silicon hardware tunable support + * + * Each tunable is a list with each entry containing a offset into the MMIO + * region, a mask of bits to be cleared and a set of bits to be set. These + * tunables are passed along by the previous boot stages and vary from device + * to device such that they cannot be hardcoded in the individual drivers. + * + * Copyright (C) The Asahi Linux Contributors + */ + +#include +#include +#include +#include +#include + +struct apple_tunable *devm_apple_tunable_parse(struct device *dev, + struct device_node *np, + const char *name, + struct resource *res) +{ + struct apple_tunable *tunable; + struct property *prop; + const __be32 *p; + size_t sz; + int i; + + if (resource_size(res) < 4) + return ERR_PTR(-EINVAL); + + prop = of_find_property(np, name, NULL); + if (!prop) + return ERR_PTR(-ENOENT); + + if (prop->length % (3 * sizeof(u32))) + return ERR_PTR(-EINVAL); + sz = prop->length / (3 * sizeof(u32)); + + tunable = devm_kzalloc(dev, struct_size(tunable, values, sz), GFP_KERNEL); + if (!tunable) + return ERR_PTR(-ENOMEM); + tunable->sz = sz; + + for (i = 0, p = NULL; i < tunable->sz; ++i) { + p = of_prop_next_u32(prop, p, &tunable->values[i].offset); + p = of_prop_next_u32(prop, p, &tunable->values[i].mask); + p = of_prop_next_u32(prop, p, &tunable->values[i].value); + + /* Sanity checks to catch bugs in our bootloader */ + if (tunable->values[i].offset % 4) + return ERR_PTR(-EINVAL); + if (tunable->values[i].offset > (resource_size(res) - 4)) + return ERR_PTR(-EINVAL); + } + + return tunable; +} +EXPORT_SYMBOL(devm_apple_tunable_parse); + +void apple_tunable_apply(void __iomem *regs, struct apple_tunable *tunable) +{ + size_t i; + + for (i = 0; i < tunable->sz; ++i) { + u32 val, old_val; + + old_val = readl(regs + tunable->values[i].offset); + val = old_val & ~tunable->values[i].mask; + val |= tunable->values[i].value; + if (val != old_val) + writel(val, regs + tunable->values[i].offset); + } +} +EXPORT_SYMBOL(apple_tunable_apply); + +MODULE_LICENSE("Dual MIT/GPL"); +MODULE_AUTHOR("Sven Peter "); +MODULE_DESCRIPTION("Apple Silicon hardware tunable support"); -- cgit v1.3.1