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authorLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2026-10-02 12:17:24 -0700
commit3f1fe48a36b0b6722dc3fd421d93512bac138e9a (patch)
treeb767d7f6e26bc64334d3f14f8422d187239dc45d /drivers/nvmem/max77759-nvmem.c
downloadlinux-stable-3f1fe48a36b0b6722dc3fd421d93512bac138e9a.tar.gz
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Merge tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linuxgrafted
Pull io_uring fixes from Jens Axboe: - Fix a task_work add use-after-free with SQPOLL. The sqpoll thread could pop and complete the last request while io_req_normal_work_add() was still looking at them after the mpscq push. Use the same approach as DEFER_TASKRUN to protect from that, holding an RCU read lock across the add, and have exit wait for an RCU grace period for SQPOLL rings as well. - CQE32 ring fixes: correct the free entry check for 32b CQEs, zero the big_cqe for aux CQEs, and only post the dummy skip CQE on CQE_MIXED rings - Mark the source filter table as COW when cloning bpf filters, so registering another filter on the source doesn't modify the shared table in place - Initialize the task context before running the BPF loop - Requeue zcrx multishot receives stopped by a local resource - End a TX_TIMESTAMP multishot cmd when the CQ is full (lollipopkit) * tag 'io_uring-7.3-20261002' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: io_uring: fix task_work add use-after-free with SQPOLL io_uring/cmd_net: end TX_TIMESTAMP multishot when the CQ is full io_uring/zcrx: requeue multishot receives stopped by a local resource io_uring: initialize task context before running the BPF loop io_uring: zero big_cqe for aux CQEs on CQE32 rings io_uring: fix free entry check for 32b CQEs on CQE32 rings io_uring: only post the dummy skip CQE on CQE_MIXED rings io_uring/bpf_filter: mark source as COW when cloning filters
Diffstat (limited to 'drivers/nvmem/max77759-nvmem.c')
-rw-r--r--drivers/nvmem/max77759-nvmem.c144
1 files changed, 144 insertions, 0 deletions
diff --git a/drivers/nvmem/max77759-nvmem.c b/drivers/nvmem/max77759-nvmem.c
new file mode 100644
index 000000000..283000ec3
--- /dev/null
+++ b/drivers/nvmem/max77759-nvmem.c
@@ -0,0 +1,144 @@
+// SPDX-License-Identifier: GPL-2.0-only
+//
+// Copyright 2020 Google Inc
+// Copyright 2025 Linaro Ltd.
+//
+// NVMEM driver for Maxim MAX77759
+
+#include <linux/dev_printk.h>
+#include <linux/device.h>
+#include <linux/device/driver.h>
+#include <linux/err.h>
+#include <linux/mfd/max77759.h>
+#include <linux/module.h>
+#include <linux/nvmem-provider.h>
+#include <linux/overflow.h>
+#include <linux/platform_device.h>
+#include <linux/string.h>
+
+#define MAX77759_NVMEM_OPCODE_HEADER_LEN 3
+/*
+ * NVMEM commands have a three byte header (which becomes part of the command),
+ * so we need to subtract that.
+ */
+#define MAX77759_NVMEM_SIZE (MAX77759_MAXQ_OPCODE_MAXLENGTH \
+ - MAX77759_NVMEM_OPCODE_HEADER_LEN)
+
+struct max77759_nvmem {
+ struct device *dev;
+ struct max77759 *max77759;
+};
+
+static int max77759_nvmem_reg_read(void *priv, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct max77759_nvmem *nvmem = priv;
+ DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length,
+ MAX77759_NVMEM_OPCODE_HEADER_LEN);
+ DEFINE_FLEX(struct max77759_maxq_response, rsp, rsp, length,
+ MAX77759_MAXQ_OPCODE_MAXLENGTH);
+ int ret;
+
+ cmd->cmd[0] = MAX77759_MAXQ_OPCODE_USER_SPACE_READ;
+ cmd->cmd[1] = offset;
+ cmd->cmd[2] = bytes;
+ rsp->length = bytes + MAX77759_NVMEM_OPCODE_HEADER_LEN;
+
+ ret = max77759_maxq_command(nvmem->max77759, cmd, rsp);
+ if (ret < 0)
+ return ret;
+
+ if (memcmp(cmd->cmd, rsp->rsp, MAX77759_NVMEM_OPCODE_HEADER_LEN)) {
+ dev_warn(nvmem->dev, "protocol error (read)\n");
+ return -EIO;
+ }
+
+ memcpy(val, &rsp->rsp[MAX77759_NVMEM_OPCODE_HEADER_LEN], bytes);
+
+ return 0;
+}
+
+static int max77759_nvmem_reg_write(void *priv, unsigned int offset,
+ void *val, size_t bytes)
+{
+ struct max77759_nvmem *nvmem = priv;
+ DEFINE_FLEX(struct max77759_maxq_command, cmd, cmd, length,
+ MAX77759_MAXQ_OPCODE_MAXLENGTH);
+ DEFINE_FLEX(struct max77759_maxq_response, rsp, rsp, length,
+ MAX77759_MAXQ_OPCODE_MAXLENGTH);
+ int ret;
+
+ cmd->cmd[0] = MAX77759_MAXQ_OPCODE_USER_SPACE_WRITE;
+ cmd->cmd[1] = offset;
+ cmd->cmd[2] = bytes;
+ memcpy(&cmd->cmd[MAX77759_NVMEM_OPCODE_HEADER_LEN], val, bytes);
+ cmd->length = bytes + MAX77759_NVMEM_OPCODE_HEADER_LEN;
+ rsp->length = cmd->length;
+
+ ret = max77759_maxq_command(nvmem->max77759, cmd, rsp);
+ if (ret < 0)
+ return ret;
+
+ if (memcmp(cmd->cmd, rsp->rsp, cmd->length)) {
+ dev_warn(nvmem->dev, "protocol error (write)\n");
+ return -EIO;
+ }
+
+ return 0;
+}
+
+static int max77759_nvmem_probe(struct platform_device *pdev)
+{
+ struct nvmem_config config = {
+ .dev = &pdev->dev,
+ .name = dev_name(&pdev->dev),
+ .id = NVMEM_DEVID_NONE,
+ .type = NVMEM_TYPE_EEPROM,
+ .ignore_wp = true,
+ .size = MAX77759_NVMEM_SIZE,
+ .word_size = sizeof(u8),
+ .stride = sizeof(u8),
+ .reg_read = max77759_nvmem_reg_read,
+ .reg_write = max77759_nvmem_reg_write,
+ };
+ struct max77759_nvmem *nvmem;
+
+ nvmem = devm_kzalloc(&pdev->dev, sizeof(*nvmem), GFP_KERNEL);
+ if (!nvmem)
+ return -ENOMEM;
+
+ nvmem->dev = &pdev->dev;
+ nvmem->max77759 = dev_get_drvdata(pdev->dev.parent);
+
+ config.priv = nvmem;
+
+ return PTR_ERR_OR_ZERO(devm_nvmem_register(config.dev, &config));
+}
+
+static const struct of_device_id max77759_nvmem_of_id[] = {
+ { .compatible = "maxim,max77759-nvmem", },
+ { }
+};
+MODULE_DEVICE_TABLE(of, max77759_nvmem_of_id);
+
+static const struct platform_device_id max77759_nvmem_platform_id[] = {
+ { "max77759-nvmem", },
+ { }
+};
+MODULE_DEVICE_TABLE(platform, max77759_nvmem_platform_id);
+
+static struct platform_driver max77759_nvmem_driver = {
+ .driver = {
+ .name = "max77759-nvmem",
+ .probe_type = PROBE_PREFER_ASYNCHRONOUS,
+ .of_match_table = max77759_nvmem_of_id,
+ },
+ .probe = max77759_nvmem_probe,
+ .id_table = max77759_nvmem_platform_id,
+};
+
+module_platform_driver(max77759_nvmem_driver);
+
+MODULE_AUTHOR("André Draszik <andre.draszik@linaro.org>");
+MODULE_DESCRIPTION("NVMEM driver for Maxim MAX77759");
+MODULE_LICENSE("GPL");