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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2026-08-23 13:28:57 -0700 |
| commit | 4352b8aee98005853aa63f57d6377282de17a33f (patch) | |
| tree | 27614d7a9ef05c32d089004e104364ce42324837 /drivers/acpi/nvs.c | |
| download | linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.tar.gz linux-stable-4352b8aee98005853aa63f57d6377282de17a33f.zip | |
Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted
Pull I3C updates from Alexandre Belloni:
"A new driver this cycle, for the AMD AXI I3C controller.
There are also new features such as IBI wakeup support, SETAASA device
discovery and ACPI support for the the DAA methods, meaning we can now
communicate with the SPD devices on DDR5 modules.
New driver:
- AMD AXI I3C master controller
Subsystem:
- I3C Common Command Code (CCC) handling improvements, especially
around GET CCCs
- SETAASA device discovery support
- ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
well as I2C devices on I3C bus
- IBI-based wakeup support
Drivers:
- dw: SETAASA support
- mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
controller support, PIO queue management support for HCI v1.2
- renesas: improve suspend to RAM support, add runtime PM support"
* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
i3c: dw: reduce do_daa time if there's no client
i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
i3c: dw: rename "pclk" to "apb" to match dt-binding
i3c: dw: make struct dw_i3c_cmd smaller
i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
i3c: renesas: Don't register devices when ENTDAA times out
i3c: master: dw-i3c-master: fix OD timing for first broadcast
i3c: mipi-i3c-hci: Advertise IBI wakeup capability
i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
i3c: master: Reject IBI requests from non-IBI-capable devices
i3c: master: Add helper to query bus wakeup requirements
i3c: master: Report wakeup events for IBIs
i3c: master: Support IBI-based wakeup capability
i3c: master: Fix potential UAF in i3c_device_match()
i3c: master: Fix potential UAF in i3c_device_uevent()
i3c: Make dev->desc locking assumptions explicit
i3c: master: Fix use-after-free of master->this
...
Diffstat (limited to 'drivers/acpi/nvs.c')
| -rw-r--r-- | drivers/acpi/nvs.c | 213 |
1 files changed, 213 insertions, 0 deletions
diff --git a/drivers/acpi/nvs.c b/drivers/acpi/nvs.c new file mode 100644 index 000000000..12aee4102 --- /dev/null +++ b/drivers/acpi/nvs.c @@ -0,0 +1,213 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * nvs.c - Routines for saving and restoring ACPI NVS memory region + * + * Copyright (C) 2008-2011 Rafael J. Wysocki <rjw@sisk.pl>, Novell Inc. + */ + +#define pr_fmt(fmt) "ACPI: PM: " fmt + +#include <linux/io.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/mm.h> +#include <linux/slab.h> +#include <linux/acpi.h> + +#include "internal.h" + +/* ACPI NVS regions, APEI may use it */ + +struct nvs_region { + __u64 phys_start; + __u64 size; + struct list_head node; +}; + +static LIST_HEAD(nvs_region_list); + +#ifdef CONFIG_ACPI_SLEEP +static int suspend_nvs_register(unsigned long start, unsigned long size); +#else +static inline int suspend_nvs_register(unsigned long a, unsigned long b) +{ + return 0; +} +#endif + +int acpi_nvs_register(__u64 start, __u64 size) +{ + struct nvs_region *region; + + region = kmalloc_obj(*region); + if (!region) + return -ENOMEM; + region->phys_start = start; + region->size = size; + list_add_tail(®ion->node, &nvs_region_list); + + return suspend_nvs_register(start, size); +} + +int acpi_nvs_for_each_region(int (*func)(__u64 start, __u64 size, void *data), + void *data) +{ + int rc; + struct nvs_region *region; + + list_for_each_entry(region, &nvs_region_list, node) { + rc = func(region->phys_start, region->size, data); + if (rc) + return rc; + } + + return 0; +} + + +#ifdef CONFIG_ACPI_SLEEP +/* + * Platforms, like ACPI, may want us to save some memory used by them during + * suspend and to restore the contents of this memory during the subsequent + * resume. The code below implements a mechanism allowing us to do that. + */ + +struct nvs_page { + unsigned long phys_start; + unsigned int size; + void *kaddr; + void *data; + bool unmap; + struct list_head node; +}; + +static LIST_HEAD(nvs_list); + +/** + * suspend_nvs_register - register platform NVS memory region to save + * @start: Physical address of the region. + * @size: Size of the region. + * + * The NVS region need not be page-aligned (both ends) and we arrange + * things so that the data from page-aligned addresses in this region will + * be copied into separate RAM pages. + */ +static int suspend_nvs_register(unsigned long start, unsigned long size) +{ + struct nvs_page *entry, *next; + + pr_info("Registering ACPI NVS region [mem %#010lx-%#010lx] (%ld bytes)\n", + start, start + size - 1, size); + + while (size > 0) { + unsigned int nr_bytes; + + entry = kzalloc_obj(struct nvs_page); + if (!entry) + goto Error; + + list_add_tail(&entry->node, &nvs_list); + entry->phys_start = start; + nr_bytes = PAGE_SIZE - (start & ~PAGE_MASK); + entry->size = (size < nr_bytes) ? size : nr_bytes; + + start += entry->size; + size -= entry->size; + } + return 0; + + Error: + list_for_each_entry_safe(entry, next, &nvs_list, node) { + list_del(&entry->node); + kfree(entry); + } + return -ENOMEM; +} + +/** + * suspend_nvs_free - free data pages allocated for saving NVS regions + */ +void suspend_nvs_free(void) +{ + struct nvs_page *entry; + + list_for_each_entry(entry, &nvs_list, node) + if (entry->data) { + kfree(entry->data); + entry->data = NULL; + if (entry->kaddr) { + if (entry->unmap) { + iounmap(entry->kaddr); + entry->unmap = false; + } else { + acpi_os_unmap_iomem(entry->kaddr, + entry->size); + } + entry->kaddr = NULL; + } + } +} + +/** + * suspend_nvs_alloc - allocate memory necessary for saving NVS regions + */ +int suspend_nvs_alloc(void) +{ + struct nvs_page *entry; + + list_for_each_entry(entry, &nvs_list, node) { + entry->data = kmalloc(PAGE_SIZE, GFP_KERNEL); + if (!entry->data) { + suspend_nvs_free(); + return -ENOMEM; + } + } + return 0; +} + +/** + * suspend_nvs_save - save NVS memory regions + */ +int suspend_nvs_save(void) +{ + struct nvs_page *entry; + + pr_info("Saving platform NVS memory\n"); + + list_for_each_entry(entry, &nvs_list, node) + if (entry->data) { + unsigned long phys = entry->phys_start; + unsigned int size = entry->size; + + entry->kaddr = acpi_os_get_iomem(phys, size); + if (!entry->kaddr) { + entry->kaddr = acpi_os_ioremap(phys, size); + entry->unmap = !!entry->kaddr; + } + if (!entry->kaddr) { + suspend_nvs_free(); + return -ENOMEM; + } + memcpy(entry->data, entry->kaddr, entry->size); + } + + return 0; +} + +/** + * suspend_nvs_restore - restore NVS memory regions + * + * This function is going to be called with interrupts disabled, so it + * cannot iounmap the virtual addresses used to access the NVS region. + */ +void suspend_nvs_restore(void) +{ + struct nvs_page *entry; + + pr_info("Restoring platform NVS memory\n"); + + list_for_each_entry(entry, &nvs_list, node) + if (entry->data) + memcpy(entry->kaddr, entry->data, entry->size); +} +#endif |
