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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/misc/sram.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/misc/sram.c')
| -rw-r--r-- | drivers/misc/sram.c | 464 |
1 files changed, 464 insertions, 0 deletions
diff --git a/drivers/misc/sram.c b/drivers/misc/sram.c new file mode 100644 index 000000000..1919d24c8 --- /dev/null +++ b/drivers/misc/sram.c @@ -0,0 +1,464 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Generic on-chip SRAM allocation driver + * + * Copyright (C) 2012 Philipp Zabel, Pengutronix + */ + +#include <linux/clk.h> +#include <linux/delay.h> +#include <linux/genalloc.h> +#include <linux/io.h> +#include <linux/list_sort.h> +#include <linux/of.h> +#include <linux/of_address.h> +#include <linux/platform_device.h> +#include <linux/regmap.h> +#include <linux/slab.h> +#include <linux/mfd/syscon.h> +#include <soc/at91/atmel-secumod.h> + +#include "sram.h" + +#define SRAM_GRANULARITY 32 + +static ssize_t sram_read(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + char *buf, loff_t pos, size_t count) +{ + struct sram_partition *part; + + /* Cast away the const as the attribute is part of a larger structure */ + part = (struct sram_partition *)container_of(attr, struct sram_partition, battr); + + mutex_lock(&part->lock); + memcpy_fromio(buf, part->base + pos, count); + mutex_unlock(&part->lock); + + return count; +} + +static ssize_t sram_write(struct file *filp, struct kobject *kobj, + const struct bin_attribute *attr, + char *buf, loff_t pos, size_t count) +{ + struct sram_partition *part; + + /* Cast away the const as the attribute is part of a larger structure */ + part = (struct sram_partition *)container_of(attr, struct sram_partition, battr); + + mutex_lock(&part->lock); + memcpy_toio(part->base + pos, buf, count); + mutex_unlock(&part->lock); + + return count; +} + +static int sram_add_pool(struct sram_dev *sram, struct sram_reserve *block, + phys_addr_t start, struct sram_partition *part) +{ + int ret; + + part->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), + NUMA_NO_NODE, block->label); + if (IS_ERR(part->pool)) + return PTR_ERR(part->pool); + + ret = gen_pool_add_virt(part->pool, (unsigned long)part->base, start, + block->size, NUMA_NO_NODE); + if (ret < 0) { + dev_err(sram->dev, "failed to register subpool: %d\n", ret); + return ret; + } + + return 0; +} + +static int sram_add_export(struct sram_dev *sram, struct sram_reserve *block, + phys_addr_t start, struct sram_partition *part) +{ + sysfs_bin_attr_init(&part->battr); + part->battr.attr.name = devm_kasprintf(sram->dev, GFP_KERNEL, + "%llx.sram", + (unsigned long long)start); + if (!part->battr.attr.name) + return -ENOMEM; + + part->battr.attr.mode = S_IRUSR | S_IWUSR; + part->battr.read = sram_read; + part->battr.write = sram_write; + part->battr.size = block->size; + + return device_create_bin_file(sram->dev, &part->battr); +} + +static int sram_add_partition(struct sram_dev *sram, struct sram_reserve *block, + phys_addr_t start) +{ + int ret; + struct sram_partition *part = &sram->partition[sram->partitions]; + + mutex_init(&part->lock); + + if (sram->config && sram->config->map_only_reserved) { + void __iomem *virt_base; + + if (sram->no_memory_wc) + virt_base = devm_ioremap_resource(sram->dev, &block->res); + else + virt_base = devm_ioremap_resource_wc(sram->dev, &block->res); + + if (IS_ERR(virt_base)) { + dev_err(sram->dev, "could not map SRAM at %pr\n", &block->res); + return PTR_ERR(virt_base); + } + + part->base = virt_base; + } else { + part->base = sram->virt_base + block->start; + } + + if (block->pool) { + ret = sram_add_pool(sram, block, start, part); + if (ret) + return ret; + } + if (block->export) { + ret = sram_add_export(sram, block, start, part); + if (ret) + return ret; + } + if (block->protect_exec) { + ret = sram_check_protect_exec(sram, block, part); + if (ret) + return ret; + + ret = sram_add_pool(sram, block, start, part); + if (ret) + return ret; + + sram_add_protect_exec(part); + } + + sram->partitions++; + + return 0; +} + +static void sram_free_partitions(struct sram_dev *sram) +{ + struct sram_partition *part; + + if (!sram->partitions) + return; + + part = &sram->partition[sram->partitions - 1]; + for (; sram->partitions; sram->partitions--, part--) { + if (part->battr.size) + device_remove_bin_file(sram->dev, &part->battr); + + if (part->pool && + gen_pool_avail(part->pool) < gen_pool_size(part->pool)) + dev_err(sram->dev, "removed pool while SRAM allocated\n"); + } +} + +static int sram_reserve_cmp(void *priv, const struct list_head *a, + const struct list_head *b) +{ + const struct sram_reserve *ra = list_entry(a, struct sram_reserve, list); + const struct sram_reserve *rb = list_entry(b, struct sram_reserve, list); + + return ra->start - rb->start; +} + +static int sram_reserve_regions(struct sram_dev *sram, struct resource *res) +{ + struct device_node *np = sram->dev->of_node, *child; + unsigned long size, cur_start, cur_size; + struct sram_reserve *rblocks, *block; + struct list_head reserve_list; + unsigned int nblocks, exports = 0; + const char *label; + int ret = 0; + + INIT_LIST_HEAD(&reserve_list); + + size = resource_size(res); + + /* + * We need an additional block to mark the end of the memory region + * after the reserved blocks from the dt are processed. + */ + nblocks = (np) ? of_get_available_child_count(np) + 1 : 1; + rblocks = kzalloc_objs(*rblocks, nblocks); + if (!rblocks) + return -ENOMEM; + + block = &rblocks[0]; + for_each_available_child_of_node(np, child) { + struct resource child_res; + + ret = of_address_to_resource(child, 0, &child_res); + if (ret < 0) { + dev_err(sram->dev, + "could not get address for node %pOF\n", + child); + goto err_chunks; + } + + if (child_res.start < res->start || child_res.end > res->end) { + dev_err(sram->dev, + "reserved block %pOF outside the sram area\n", + child); + ret = -EINVAL; + goto err_chunks; + } + + block->start = child_res.start - res->start; + block->size = resource_size(&child_res); + block->res = child_res; + list_add_tail(&block->list, &reserve_list); + + block->export = of_property_read_bool(child, "export"); + block->pool = of_property_read_bool(child, "pool"); + block->protect_exec = of_property_read_bool(child, "protect-exec"); + + if ((block->export || block->pool || block->protect_exec) && + block->size) { + exports++; + + label = NULL; + ret = of_property_read_string(child, "label", &label); + if (ret && ret != -EINVAL) { + dev_err(sram->dev, + "%pOF has invalid label name\n", + child); + goto err_chunks; + } + if (!label) + block->label = devm_kasprintf(sram->dev, GFP_KERNEL, + "%s", of_node_full_name(child)); + else + block->label = devm_kstrdup(sram->dev, + label, GFP_KERNEL); + if (!block->label) { + ret = -ENOMEM; + goto err_chunks; + } + + dev_dbg(sram->dev, "found %sblock '%s' 0x%x-0x%x\n", + block->export ? "exported " : "", block->label, + block->start, block->start + block->size); + } else { + dev_dbg(sram->dev, "found reserved block 0x%x-0x%x\n", + block->start, block->start + block->size); + } + + block++; + } + child = NULL; + + /* the last chunk marks the end of the region */ + rblocks[nblocks - 1].start = size; + rblocks[nblocks - 1].size = 0; + list_add_tail(&rblocks[nblocks - 1].list, &reserve_list); + + list_sort(NULL, &reserve_list, sram_reserve_cmp); + + if (exports) { + sram->partition = devm_kcalloc(sram->dev, + exports, sizeof(*sram->partition), + GFP_KERNEL); + if (!sram->partition) { + ret = -ENOMEM; + goto err_chunks; + } + } + + cur_start = 0; + list_for_each_entry(block, &reserve_list, list) { + /* can only happen if sections overlap */ + if (block->start < cur_start) { + dev_err(sram->dev, + "block at 0x%x starts after current offset 0x%lx\n", + block->start, cur_start); + ret = -EINVAL; + sram_free_partitions(sram); + goto err_chunks; + } + + if ((block->export || block->pool || block->protect_exec) && + block->size) { + ret = sram_add_partition(sram, block, + res->start + block->start); + if (ret) { + sram_free_partitions(sram); + goto err_chunks; + } + } + + /* current start is in a reserved block, so continue after it */ + if (block->start == cur_start) { + cur_start = block->start + block->size; + continue; + } + + /* + * allocate the space between the current starting + * address and the following reserved block, or the + * end of the region. + */ + cur_size = block->start - cur_start; + + if (sram->pool) { + dev_dbg(sram->dev, "adding chunk 0x%lx-0x%lx\n", + cur_start, cur_start + cur_size); + + ret = gen_pool_add_virt(sram->pool, + (unsigned long)sram->virt_base + cur_start, + res->start + cur_start, cur_size, -1); + if (ret < 0) { + sram_free_partitions(sram); + goto err_chunks; + } + } + + /* next allocation after this reserved block */ + cur_start = block->start + block->size; + } + +err_chunks: + of_node_put(child); + kfree(rblocks); + + return ret; +} + +static int atmel_securam_wait(void) +{ + struct regmap *regmap; + u32 val; + + regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-secumod"); + if (IS_ERR(regmap)) + return -ENODEV; + + return regmap_read_poll_timeout(regmap, AT91_SECUMOD_RAMRDY, val, + val & AT91_SECUMOD_RAMRDY_READY, + 10000, 500000); +} + +static const struct sram_config atmel_securam_config = { + .init = atmel_securam_wait, +}; + +/* + * SYSRAM contains areas that are not accessible by the + * kernel, such as the first 256K that is reserved for TZ. + * Accesses to those areas (including speculative accesses) + * trigger SErrors. As such we must map only the areas of + * SYSRAM specified in the device tree. + */ +static const struct sram_config tegra_sysram_config = { + .map_only_reserved = true, +}; + +static const struct of_device_id sram_dt_ids[] = { + { .compatible = "mmio-sram" }, + { .compatible = "atmel,sama5d2-securam", .data = &atmel_securam_config }, + { .compatible = "nvidia,tegra186-sysram", .data = &tegra_sysram_config }, + { .compatible = "nvidia,tegra194-sysram", .data = &tegra_sysram_config }, + { .compatible = "nvidia,tegra234-sysram", .data = &tegra_sysram_config }, + {} +}; + +static int sram_probe(struct platform_device *pdev) +{ + const struct sram_config *config; + struct sram_dev *sram; + int ret; + struct resource *res; + struct clk *clk; + + config = of_device_get_match_data(&pdev->dev); + + sram = devm_kzalloc(&pdev->dev, sizeof(*sram), GFP_KERNEL); + if (!sram) + return -ENOMEM; + + sram->dev = &pdev->dev; + sram->no_memory_wc = of_property_read_bool(pdev->dev.of_node, "no-memory-wc"); + sram->config = config; + + if (!config || !config->map_only_reserved) { + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + if (sram->no_memory_wc) + sram->virt_base = devm_ioremap_resource(&pdev->dev, res); + else + sram->virt_base = devm_ioremap_resource_wc(&pdev->dev, res); + if (IS_ERR(sram->virt_base)) { + dev_err(&pdev->dev, "could not map SRAM registers\n"); + return PTR_ERR(sram->virt_base); + } + + sram->pool = devm_gen_pool_create(sram->dev, ilog2(SRAM_GRANULARITY), + NUMA_NO_NODE, NULL); + if (IS_ERR(sram->pool)) + return PTR_ERR(sram->pool); + } + + clk = devm_clk_get_optional_enabled(sram->dev, NULL); + if (IS_ERR(clk)) + return PTR_ERR(clk); + + ret = sram_reserve_regions(sram, + platform_get_resource(pdev, IORESOURCE_MEM, 0)); + if (ret) + return ret; + + platform_set_drvdata(pdev, sram); + + if (config && config->init) { + ret = config->init(); + if (ret) + goto err_free_partitions; + } + + if (sram->pool) + dev_dbg(sram->dev, "SRAM pool: %zu KiB @ 0x%p\n", + gen_pool_size(sram->pool) / 1024, sram->virt_base); + + return 0; + +err_free_partitions: + sram_free_partitions(sram); + + return ret; +} + +static void sram_remove(struct platform_device *pdev) +{ + struct sram_dev *sram = platform_get_drvdata(pdev); + + sram_free_partitions(sram); + + if (sram->pool && gen_pool_avail(sram->pool) < gen_pool_size(sram->pool)) + dev_err(sram->dev, "removed while SRAM allocated\n"); +} + +static struct platform_driver sram_driver = { + .driver = { + .name = "sram", + .of_match_table = sram_dt_ids, + }, + .probe = sram_probe, + .remove = sram_remove, +}; + +static int __init sram_init(void) +{ + return platform_driver_register(&sram_driver); +} + +postcore_initcall(sram_init); |
