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[2a01:c22:76de:5100:1131:aa83:adfe:51dd]) by smtp.googlemail.com with ESMTPSA id a640c23a62f3a-a868f220d2bsm9544166b.43.2024.08.21.13.47.43 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 21 Aug 2024 13:47:43 -0700 (PDT) Message-ID: Date: Wed, 21 Aug 2024 22:47:42 +0200 Precedence: bulk X-Mailing-List: linux-i2c@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: [PATCH 2/3] i2c: Replace list-based mechanism for handling userspace-created clients From: Heiner Kallweit To: Wolfram Sang Cc: "linux-i2c@vger.kernel.org" References: <9fabf29f-2b45-461e-ae6e-4391a40bcaca@gmail.com> Content-Language: en-US Autocrypt: addr=hkallweit1@gmail.com; keydata= xsFNBF/0ZFUBEAC0eZyktSE7ZNO1SFXL6cQ4i4g6Ah3mOUIXSB4pCY5kQ6OLKHh0FlOD5/5/ sY7IoIouzOjyFdFPnz4Bl3927ClT567hUJJ+SNaFEiJ9vadI6vZm2gcY4ExdIevYHWe1msJF MVE4yNwdS+UsPeCF/6CQQTzHc+n7DomE7fjJD5J1hOJjqz2XWe71fTvYXzxCFLwXXbBiqDC9 dNqOe5odPsa4TsWZ09T33g5n2nzTJs4Zw8fCy8rLqix/raVsqr8fw5qM66MVtdmEljFaJ9N8 /W56qGCp+H8Igk/F7CjlbWXiOlKHA25mPTmbVp7VlFsvsmMokr/imQr+0nXtmvYVaKEUwY2g 86IU6RAOuA8E0J5bD/BeyZdMyVEtX1kT404UJZekFytJZrDZetwxM/cAH+1fMx4z751WJmxQ J7mIXSPuDfeJhRDt9sGM6aRVfXbZt+wBogxyXepmnlv9K4A13z9DVLdKLrYUiu9/5QEl6fgI kPaXlAZmJsQfoKbmPqCHVRYj1lpQtDM/2/BO6gHASflWUHzwmBVZbS/XRs64uJO8CB3+V3fa cIivllReueGCMsHh6/8wgPAyopXOWOxbLsZ291fmZqIR0L5Y6b2HvdFN1Xhc+YrQ8TKK+Z4R mJRDh0wNQ8Gm89g92/YkHji4jIWlp2fwzCcx5+lZCQ1XdqAiHQARAQABzSZIZWluZXIgS2Fs bHdlaXQgPGhrYWxsd2VpdDFAZ21haWwuY29tPsLBjgQTAQgAOBYhBGxfqY/yOyXjyjJehXLe ig9U8DoMBQJf9GRVAhsDBQsJCAcCBhUKCQgLAgQWAgMBAh4BAheAAAoJEHLeig9U8DoMSycQ AJbfg8HZEK0ljV4M8nvdaiNixWAufrcZ+SD8zhbxl8GispK4F3Yo+20Y3UoZ7FcIidJWUUJL axAOkpI/70YNhlqAPMsuudlAieeYZKjIv1WV5ucNZ3VJ7dC+dlVqQdAr1iD869FZXvy91KhJ wYulyCf+s4T9YgmLC6jLMBZghKIf1uhSd0NzjyCqYWbk2ZxByZHgunEShOhHPHswu3Am0ftt ePaYIHgZs+Vzwfjs8I7EuW/5/f5G9w1vibXxtGY/GXwgGGHRDjFM7RSprGOv4F5eMGh+NFUJ TU9N96PQYMwXVxnQfRXl8O6ffSVmFx4H9rovxWPKobLmqQL0WKLLVvA/aOHCcMKgfyKRcLah 57vGC50Ga8oT2K1g0AhKGkyJo7lGXkMu5yEs0m9O+btqAB261/E3DRxfI1P/tvDZpLJKtq35 dXsj6sjvhgX7VxXhY1wE54uqLLHY3UZQlmH3QF5t80MS7/KhxB1pO1Cpcmkt9hgyzH8+5org +9wWxGUtJWNP7CppY+qvv3SZtKJMKsxqk5coBGwNkMms56z4qfJm2PUtJQGjA65XWdzQACib 2iaDQoBqGZfXRdPT0tC1H5kUJuOX4ll1hI/HBMEFCcO8++Bl2wcrUsAxLzGvhINVJX2DAQaF aNetToazkCnzubKfBOyiTqFJ0b63c5dqziAgzsFNBF/0ZFUBEADF8UEZmKDl1w/UxvjeyAeX kghYkY3bkK6gcIYXdLRfJw12GbvMioSguvVzASVHG8h7NbNjk1yur6AONfbUpXKSNZ0skV8V fG+ppbaY+zQofsSMoj5gP0amwbwvPzVqZCYJai81VobefTX2MZM2Mg/ThBVtGyzV3NeCpnBa 8AX3s9rrX2XUoCibYotbbxx9afZYUFyflOc7kEpc9uJXIdaxS2Z6MnYLHsyVjiU6tzKCiVOU KJevqvzPXJmy0xaOVf7mhFSNQyJTrZpLa+tvB1DQRS08CqYtIMxRrVtC0t0LFeQGly6bOngr ircurWJiJKbSXVstLHgWYiq3/GmCSx/82ObeLO3PftklpRj8d+kFbrvrqBgjWtMH4WtK5uN5 1WJ71hWJfNchKRlaJ3GWy8KolCAoGsQMovn/ZEXxrGs1ndafu47yXOpuDAozoHTBGvuSXSZo ythk/0EAuz5IkwkhYBT1MGIAvNSn9ivE5aRnBazugy0rTRkVggHvt3/7flFHlGVGpBHxFUwb /a4UjJBPtIwa4tWR8B1Ma36S8Jk456k2n1id7M0LQ+eqstmp6Y+UB+pt9NX6t0Slw1NCdYTW gJezWTVKF7pmTdXszXGxlc9kTrVUz04PqPjnYbv5UWuDd2eyzGjrrFOsJEi8OK2d2j4FfF++ AzOMdW09JVqejQARAQABwsF2BBgBCAAgFiEEbF+pj/I7JePKMl6Fct6KD1TwOgwFAl/0ZFUC GwwACgkQct6KD1TwOgxUfg//eAoYc0Vm4NrxymfcY30UjHVD0LgSvU8kUmXxil3qhFPS7KA+ y7tgcKLHOkZkXMX5MLFcS9+SmrAjSBBV8omKoHNo+kfFx/dUAtz0lot8wNGmWb+NcHeKM1eb nwUMOEa1uDdfZeKef/U/2uHBceY7Gc6zPZPWgXghEyQMTH2UhLgeam8yglyO+A6RXCh+s6ak Wje7Vo1wGK4eYxp6pwMPJXLMsI0ii/2k3YPEJPv+yJf90MbYyQSbkTwZhrsokjQEaIfjrIk3 rQRjTve/J62WIO28IbY/mENuGgWehRlTAbhC4BLTZ5uYS0YMQCR7v9UGMWdNWXFyrOB6PjSu Trn9MsPoUc8qI72mVpxEXQDLlrd2ijEWm7Nrf52YMD7hL6rXXuis7R6zY8WnnBhW0uCfhajx q+KuARXC0sDLztcjaS3ayXonpoCPZep2Bd5xqE4Ln8/COCslP7E92W1uf1EcdXXIrx1acg21 H/0Z53okMykVs3a8tECPHIxnre2UxKdTbCEkjkR4V6JyplTS47oWMw3zyI7zkaadfzVFBxk2 lo/Tny+FX1Azea3Ce7oOnRUEZtWSsUidtIjmL8YUQFZYm+JUIgfRmSpMFq8JP4VH43GXpB/S OCrl+/xujzvoUBFV/cHKjEQYBxo+MaiQa1U54ykM2W4DnHb1UiEf5xDkFd4= In-Reply-To: <9fabf29f-2b45-461e-ae6e-4391a40bcaca@gmail.com> Similarly to the list of auto-detected clients, we can also replace the list of userspace-created clients with flagging such client devices. Signed-off-by: Heiner Kallweit --- drivers/i2c/i2c-core-base.c | 58 ++++++++++++++----------------------- include/linux/i2c.h | 1 + 2 files changed, 22 insertions(+), 37 deletions(-) diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c index 549bb76b7..b9f1b1a1b 100644 --- a/drivers/i2c/i2c-core-base.c +++ b/drivers/i2c/i2c-core-base.c @@ -1265,14 +1265,12 @@ new_device_store(struct device *dev, struct device_attribute *attr, info.flags |= I2C_CLIENT_SLAVE; } + info.flags |= I2C_CLIENT_USER; + client = i2c_new_client_device(adap, &info); if (IS_ERR(client)) return PTR_ERR(client); - /* Keep track of the added device */ - mutex_lock(&adap->userspace_clients_lock); - list_add_tail(&client->detected, &adap->userspace_clients); - mutex_unlock(&adap->userspace_clients_lock); dev_info(dev, "%s: Instantiated device %s at 0x%02hx\n", "new_device", info.type, info.addr); @@ -1280,6 +1278,15 @@ new_device_store(struct device *dev, struct device_attribute *attr, } static DEVICE_ATTR_WO(new_device); +static int __i2c_find_user_addr(struct device *dev, void *addrp) +{ + struct i2c_client *client = i2c_verify_client(dev); + unsigned short addr = *(unsigned short *)addrp; + + return client && client->flags & I2C_CLIENT_USER && + i2c_encode_flags_to_addr(client) == addr; +} + /* * And of course let the users delete the devices they instantiated, if * they got it wrong. This interface can only be used to delete devices @@ -1294,7 +1301,8 @@ delete_device_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct i2c_adapter *adap = to_i2c_adapter(dev); - struct i2c_client *client, *next; + struct i2c_client *client; + struct device *child_dev; unsigned short addr; char end; int res; @@ -1311,27 +1319,16 @@ delete_device_store(struct device *dev, struct device_attribute *attr, } /* Make sure the device was added through sysfs */ - res = -ENOENT; - mutex_lock_nested(&adap->userspace_clients_lock, - i2c_adapter_depth(adap)); - list_for_each_entry_safe(client, next, &adap->userspace_clients, - detected) { - if (i2c_encode_flags_to_addr(client) == addr) { - dev_info(dev, "%s: Deleting device %s at 0x%02hx\n", - "delete_device", client->name, client->addr); - - list_del(&client->detected); - i2c_unregister_device(client); - res = count; - break; - } + child_dev = device_find_child(&adap->dev, &addr, __i2c_find_user_addr); + if (!child_dev) { + dev_err(dev, "Can't find userspace-created device at %#x\n", addr); + return -ENOENT; } - mutex_unlock(&adap->userspace_clients_lock); + client = i2c_verify_client(child_dev); + i2c_unregister_device(client); + put_device(child_dev); - if (res < 0) - dev_err(dev, "%s: Can't find device in list\n", - "delete_device"); - return res; + return count; } static DEVICE_ATTR_IGNORE_LOCKDEP(delete_device, S_IWUSR, NULL, delete_device_store); @@ -1688,7 +1685,6 @@ static int __unregister_dummy(struct device *dev, void *dummy) void i2c_del_adapter(struct i2c_adapter *adap) { struct i2c_adapter *found; - struct i2c_client *client, *next; /* First make sure that this adapter was ever added */ mutex_lock(&core_lock); @@ -1701,18 +1697,6 @@ void i2c_del_adapter(struct i2c_adapter *adap) i2c_acpi_remove_space_handler(adap); - /* Remove devices instantiated from sysfs */ - mutex_lock_nested(&adap->userspace_clients_lock, - i2c_adapter_depth(adap)); - list_for_each_entry_safe(client, next, &adap->userspace_clients, - detected) { - dev_dbg(&adap->dev, "Removing %s at 0x%x\n", client->name, - client->addr); - list_del(&client->detected); - i2c_unregister_device(client); - } - mutex_unlock(&adap->userspace_clients_lock); - /* Detach any active clients. This can't fail, thus we do not * check the returned value. This is a two-pass process, because * we can't remove the dummy devices during the first pass: they diff --git a/include/linux/i2c.h b/include/linux/i2c.h index 910a9b259..ba2564fe4 100644 --- a/include/linux/i2c.h +++ b/include/linux/i2c.h @@ -333,6 +333,7 @@ struct i2c_client { #define I2C_CLIENT_HOST_NOTIFY 0x40 /* We want to use I2C host notify */ #define I2C_CLIENT_WAKE 0x80 /* for board_info; true iff can wake */ #define I2C_CLIENT_AUTO 0x100 /* for board_info; auto-detected */ +#define I2C_CLIENT_USER 0x200 /* for board_info; userspace-created */ #define I2C_CLIENT_SCCB 0x9000 /* Use Omnivision SCCB protocol */ /* Must match I2C_M_STOP|IGNORE_NAK */