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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/mtd/devices/phram.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/mtd/devices/phram.c')
| -rw-r--r-- | drivers/mtd/devices/phram.c | 445 |
1 files changed, 445 insertions, 0 deletions
diff --git a/drivers/mtd/devices/phram.c b/drivers/mtd/devices/phram.c new file mode 100644 index 000000000..b42cadcd7 --- /dev/null +++ b/drivers/mtd/devices/phram.c @@ -0,0 +1,445 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (c) ???? Jochen Schäuble <psionic@psionic.de> + * Copyright (c) 2003-2004 Joern Engel <joern@wh.fh-wedel.de> + * + * Usage: + * + * one commend line parameter per device, each in the form: + * phram=<name>,<start>,<len>[,<erasesize>] + * <name> may be up to 63 characters. + * <start>, <len>, and <erasesize> can be octal, decimal or hexadecimal. If followed + * by "ki", "Mi" or "Gi", the numbers will be interpreted as kilo, mega or + * gigabytes. <erasesize> is optional and defaults to PAGE_SIZE. + * + * Example: + * phram=swap,64Mi,128Mi phram=test,900Mi,1Mi,64Ki + */ + +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + +#include <linux/io.h> +#include <linux/init.h> +#include <linux/kernel.h> +#include <linux/list.h> +#include <linux/module.h> +#include <linux/moduleparam.h> +#include <linux/slab.h> +#include <linux/mtd/mtd.h> +#include <asm/div64.h> +#include <linux/platform_device.h> +#include <linux/of_address.h> +#include <linux/of.h> +#include <linux/security.h> + +struct phram_mtd_list { + struct mtd_info mtd; + struct list_head list; + bool cached; +}; + +static LIST_HEAD(phram_list); + +static int phram_erase(struct mtd_info *mtd, struct erase_info *instr) +{ + u_char *start = mtd->priv; + + memset(start + instr->addr, 0xff, instr->len); + + return 0; +} + +static int phram_point(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, void **virt, resource_size_t *phys) +{ + *virt = mtd->priv + from; + *retlen = len; + return 0; +} + +static int phram_unpoint(struct mtd_info *mtd, loff_t from, size_t len) +{ + return 0; +} + +static int phram_read(struct mtd_info *mtd, loff_t from, size_t len, + size_t *retlen, u_char *buf) +{ + u_char *start = mtd->priv; + + memcpy(buf, start + from, len); + *retlen = len; + return 0; +} + +static int phram_write(struct mtd_info *mtd, loff_t to, size_t len, + size_t *retlen, const u_char *buf) +{ + u_char *start = mtd->priv; + + memcpy(start + to, buf, len); + *retlen = len; + return 0; +} + +static int phram_map(struct phram_mtd_list *phram, phys_addr_t start, size_t len) +{ + void *addr = NULL; + + if (phram->cached) + addr = memremap(start, len, MEMREMAP_WB); + else + addr = (void __force *)ioremap(start, len); + if (!addr) + return -EIO; + + phram->mtd.priv = addr; + + return 0; +} + +static void phram_unmap(struct phram_mtd_list *phram) +{ + void *addr = phram->mtd.priv; + + if (phram->cached) { + memunmap(addr); + return; + } + + iounmap((void __iomem *)addr); +} + +static void unregister_devices(void) +{ + struct phram_mtd_list *this, *safe; + + list_for_each_entry_safe(this, safe, &phram_list, list) { + mtd_device_unregister(&this->mtd); + phram_unmap(this); + kfree(this->mtd.name); + kfree(this); + } +} + +static int register_device(struct platform_device *pdev, const char *name, + phys_addr_t start, size_t len, uint32_t erasesize) +{ + struct device_node *np = pdev ? pdev->dev.of_node : NULL; + bool cached = np ? !of_property_read_bool(np, "no-map") : false; + struct phram_mtd_list *new; + int ret = -ENOMEM; + + new = kzalloc_obj(*new); + if (!new) + goto out0; + + new->cached = cached; + + ret = phram_map(new, start, len); + if (ret) { + pr_err("ioremap failed\n"); + goto out1; + } + + + new->mtd.name = name; + new->mtd.size = len; + new->mtd.flags = MTD_CAP_RAM; + new->mtd._erase = phram_erase; + new->mtd._point = phram_point; + new->mtd._unpoint = phram_unpoint; + new->mtd._read = phram_read; + new->mtd._write = phram_write; + new->mtd.owner = THIS_MODULE; + new->mtd.type = MTD_RAM; + new->mtd.erasesize = erasesize; + new->mtd.writesize = 1; + + mtd_set_of_node(&new->mtd, np); + + ret = -EAGAIN; + if (mtd_device_register(&new->mtd, NULL, 0)) { + pr_err("Failed to register new device\n"); + goto out2; + } + + if (pdev) + platform_set_drvdata(pdev, new); + else + list_add_tail(&new->list, &phram_list); + + return 0; + +out2: + phram_unmap(new); +out1: + kfree(new); +out0: + return ret; +} + +static int parse_num64(uint64_t *num64, char *token) +{ + size_t len; + int shift = 0; + int ret; + + len = strlen(token); + /* By dwmw2 editorial decree, "ki", "Mi" or "Gi" are to be used. */ + if (len > 2) { + if (token[len - 1] == 'i') { + switch (token[len - 2]) { + case 'G': + shift += 10; + fallthrough; + case 'M': + shift += 10; + fallthrough; + case 'k': + shift += 10; + token[len - 2] = 0; + break; + default: + return -EINVAL; + } + } + } + + ret = kstrtou64(token, 0, num64); + *num64 <<= shift; + + return ret; +} + +static int parse_name(char **pname, const char *token) +{ + size_t len; + char *name; + + len = strlen(token) + 1; + if (len > 64) + return -ENOSPC; + + name = kstrdup(token, GFP_KERNEL); + if (!name) + return -ENOMEM; + + *pname = name; + return 0; +} + + +static inline void kill_final_newline(char *str) +{ + char *newline = strrchr(str, '\n'); + + if (newline && !newline[1]) + *newline = 0; +} + + +#define parse_err(fmt, args...) do { \ + pr_err(fmt , ## args); \ + return 1; \ +} while (0) + +#ifndef MODULE +static int phram_init_called; +/* + * This shall contain the module parameter if any. It is of the form: + * - phram=<device>,<address>,<size>[,<erasesize>] for module case + * - phram.phram=<device>,<address>,<size>[,<erasesize>] for built-in case + * We leave 64 bytes for the device name, 20 for the address , 20 for the + * size and 20 for the erasesize. + * Example: phram.phram=rootfs,0xa0000000,512Mi,65536 + */ +static char phram_paramline[64 + 20 + 20 + 20]; +#endif + +static int phram_setup(const char *val) +{ + char buf[64 + 20 + 20 + 20], *str = buf; + char *token[4]; + char *name; + uint64_t start; + uint64_t len; + uint64_t erasesize = PAGE_SIZE; + uint32_t rem; + int i, ret; + + if (strnlen(val, sizeof(buf)) >= sizeof(buf)) + parse_err("parameter too long\n"); + + strcpy(str, val); + kill_final_newline(str); + + for (i = 0; i < 4; i++) + token[i] = strsep(&str, ","); + + if (str) + parse_err("too many arguments\n"); + + if (!token[2]) + parse_err("not enough arguments\n"); + + ret = parse_name(&name, token[0]); + if (ret) + return ret; + + ret = parse_num64(&start, token[1]); + if (ret) { + parse_err("illegal start address\n"); + goto error; + } + + ret = parse_num64(&len, token[2]); + if (ret) { + parse_err("illegal device length\n"); + goto error; + } + + if (token[3]) { + ret = parse_num64(&erasesize, token[3]); + if (ret) { + parse_err("illegal erasesize\n"); + goto error; + } + } + + if (len == 0 || erasesize == 0 || erasesize > len + || erasesize > UINT_MAX) { + parse_err("illegal erasesize or len\n"); + ret = -EINVAL; + goto error; + } + + div_u64_rem(len, (uint32_t)erasesize, &rem); + if (rem) { + parse_err("len is not multiple of erasesize\n"); + ret = -EINVAL; + goto error; + } + + ret = register_device(NULL, name, start, len, (uint32_t)erasesize); + if (ret) + goto error; + + pr_info("%s device: %#llx at %#llx for erasesize %#llx\n", name, len, start, erasesize); + return 0; + +error: + kfree(name); + return ret; +} + +static int phram_param_call(const char *val, const struct kernel_param *kp) +{ +#ifdef MODULE + return phram_setup(val); +#else + /* + * If more parameters are later passed in via + * /sys/module/phram/parameters/phram + * and init_phram() has already been called, + * we can parse the argument now. + */ + + if (phram_init_called) + return phram_setup(val); + + /* + * During early boot stage, we only save the parameters + * here. We must parse them later: if the param passed + * from kernel boot command line, phram_param_call() is + * called so early that it is not possible to resolve + * the device (even kmalloc() fails). Defer that work to + * phram_setup(). + */ + + if (strlen(val) >= sizeof(phram_paramline)) + return -ENOSPC; + strcpy(phram_paramline, val); + + return 0; +#endif +} + +module_param_call(phram, phram_param_call, NULL, NULL, 0200); +MODULE_PARM_DESC(phram, "Memory region to map. \"phram=<name>,<start>,<length>[,<erasesize>]\""); + +#ifdef CONFIG_OF +static const struct of_device_id phram_of_match[] = { + { .compatible = "phram" }, + {} +}; +MODULE_DEVICE_TABLE(of, phram_of_match); +#endif + +static int phram_probe(struct platform_device *pdev) +{ + struct resource *res; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (!res) + return -ENOMEM; + + /* mtd_set_of_node() reads name from "label" */ + return register_device(pdev, NULL, res->start, resource_size(res), + PAGE_SIZE); +} + +static void phram_remove(struct platform_device *pdev) +{ + struct phram_mtd_list *phram = platform_get_drvdata(pdev); + + mtd_device_unregister(&phram->mtd); + phram_unmap(phram); + kfree(phram); +} + +static struct platform_driver phram_driver = { + .probe = phram_probe, + .remove = phram_remove, + .driver = { + .name = "phram", + .of_match_table = of_match_ptr(phram_of_match), + }, +}; + +static int __init init_phram(void) +{ + int ret; + + ret = security_locked_down(LOCKDOWN_DEV_MEM); + if (ret) + return ret; + + ret = platform_driver_register(&phram_driver); + if (ret) + return ret; + +#ifndef MODULE + if (phram_paramline[0]) { + ret = phram_setup(phram_paramline); + if (ret) + platform_driver_unregister(&phram_driver); + } + phram_init_called = 1; +#endif + + return ret; +} + +static void __exit cleanup_phram(void) +{ + unregister_devices(); + platform_driver_unregister(&phram_driver); +} + +module_init(init_phram); +module_exit(cleanup_phram); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Joern Engel <joern@wh.fh-wedel.de>"); +MODULE_DESCRIPTION("MTD driver for physical RAM"); |
