From 39acbc12affcaa23ef1d887ba3d197baca8e6e47 Mon Sep 17 00:00:00 2001 From: Stas Sergeev Date: Sun, 18 Oct 2009 00:31:38 +0400 Subject: Driver core: fix driver_register() return value In this patch: http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=16dc42e018c2868211b4928f20a957c0c216126c the check was added for another driver to already claim the same device on the same bus. But the returned error code was wrong: to modprobe, the -EEXIST means that _this_ driver is already installed. It therefore doesn't produce the needed error message when _another_ driver is trying to register for the same device. Returning -EBUSY fixes the problem. Signed-off-by: Stas Sergeev Cc: stable Signed-off-by: Greg Kroah-Hartman --- drivers/base/driver.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/base/driver.c b/drivers/base/driver.c index ed2ebd3c287d..f367885a7646 100644 --- a/drivers/base/driver.c +++ b/drivers/base/driver.c @@ -236,7 +236,7 @@ int driver_register(struct device_driver *drv) put_driver(other); printk(KERN_ERR "Error: Driver '%s' is already registered, " "aborting...\n", drv->name); - return -EEXIST; + return -EBUSY; } ret = bus_add_driver(drv); -- cgit v1.2.2 From 1a6f2a7512021ceae3c4201c7aab07f032e9ce91 Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Mon, 12 Oct 2009 20:17:41 -0700 Subject: Driver core: allow certain drivers prohibit bind/unbind via sysfs MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Platform drivers registered via platform_driver_probe() can be bound to devices only once, upon registration, because discard their probe() routines to save memory. Unbinding the driver through sysfs 'unbind' leaves the device stranded and confuses users so let's not create bind and unbind attributes for such drivers. Signed-off-by: Dmitry Torokhov Cc: Éric Piel Signed-off-by: Greg Kroah-Hartman --- drivers/base/bus.c | 17 +++++++++++------ drivers/base/platform.c | 6 +++++- include/linux/device.h | 4 +++- 3 files changed, 19 insertions(+), 8 deletions(-) diff --git a/drivers/base/bus.c b/drivers/base/bus.c index 973bf2ad4e0d..63c143e54a57 100644 --- a/drivers/base/bus.c +++ b/drivers/base/bus.c @@ -689,15 +689,19 @@ int bus_add_driver(struct device_driver *drv) printk(KERN_ERR "%s: driver_add_attrs(%s) failed\n", __func__, drv->name); } - error = add_bind_files(drv); - if (error) { - /* Ditto */ - printk(KERN_ERR "%s: add_bind_files(%s) failed\n", - __func__, drv->name); + + if (!drv->suppress_bind_attrs) { + error = add_bind_files(drv); + if (error) { + /* Ditto */ + printk(KERN_ERR "%s: add_bind_files(%s) failed\n", + __func__, drv->name); + } } kobject_uevent(&priv->kobj, KOBJ_ADD); return 0; + out_unregister: kfree(drv->p); drv->p = NULL; @@ -720,7 +724,8 @@ void bus_remove_driver(struct device_driver *drv) if (!drv->bus) return; - remove_bind_files(drv); + if (!drv->suppress_bind_attrs) + remove_bind_files(drv); driver_remove_attrs(drv->bus, drv); driver_remove_file(drv, &driver_attr_uevent); klist_remove(&drv->p->knode_bus); diff --git a/drivers/base/platform.c b/drivers/base/platform.c index ed156a13aa40..4fa954b07ac4 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -521,11 +521,15 @@ int __init_or_module platform_driver_probe(struct platform_driver *drv, { int retval, code; + /* make sure driver won't have bind/unbind attributes */ + drv->driver.suppress_bind_attrs = true; + /* temporary section violation during probe() */ drv->probe = probe; retval = code = platform_driver_register(drv); - /* Fixup that section violation, being paranoid about code scanning + /* + * Fixup that section violation, being paranoid about code scanning * the list of drivers in order to probe new devices. Check to see * if the probe was successful, and make sure any forced probes of * new devices fail. diff --git a/include/linux/device.h b/include/linux/device.h index aca31bf7d8ed..2ea3e4921812 100644 --- a/include/linux/device.h +++ b/include/linux/device.h @@ -124,7 +124,9 @@ struct device_driver { struct bus_type *bus; struct module *owner; - const char *mod_name; /* used for built-in modules */ + const char *mod_name; /* used for built-in modules */ + + bool suppress_bind_attrs; /* disables bind/unbind via sysfs */ int (*probe) (struct device *dev); int (*remove) (struct device *dev); -- cgit v1.2.2 From 468727ab1273a0f95562befa611a3ce39778599c Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 21 Oct 2009 21:45:15 -0600 Subject: Documentation: ABI: rename sysfs-devices-cache_disable properly Rename sysfs-devices-cache_disable to sysfs-devices-system-cpu, in order to keep a stricter correlation between a sysfs directory and its documentation. Reported-by: David Rientjes Signed-off-by: Alex Chiang Acked-by: David Rientjes Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-devices-cache_disable | 18 ------------------ Documentation/ABI/testing/sysfs-devices-system-cpu | 18 ++++++++++++++++++ 2 files changed, 18 insertions(+), 18 deletions(-) delete mode 100644 Documentation/ABI/testing/sysfs-devices-cache_disable create mode 100644 Documentation/ABI/testing/sysfs-devices-system-cpu diff --git a/Documentation/ABI/testing/sysfs-devices-cache_disable b/Documentation/ABI/testing/sysfs-devices-cache_disable deleted file mode 100644 index 175bb4f70512..000000000000 --- a/Documentation/ABI/testing/sysfs-devices-cache_disable +++ /dev/null @@ -1,18 +0,0 @@ -What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X -Date: August 2008 -KernelVersion: 2.6.27 -Contact: mark.langsdorf@amd.com -Description: These files exist in every cpu's cache index directories. - There are currently 2 cache_disable_# files in each - directory. Reading from these files on a supported - processor will return that cache disable index value - for that processor and node. Writing to one of these - files will cause the specificed cache index to be disabled. - - Currently, only AMD Family 10h Processors support cache index - disable, and only for their L3 caches. See the BIOS and - Kernel Developer's Guide at - http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf - for formatting information and other details on the - cache index disable. -Users: joachim.deguara@amd.com diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu new file mode 100644 index 000000000000..175bb4f70512 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -0,0 +1,18 @@ +What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X +Date: August 2008 +KernelVersion: 2.6.27 +Contact: mark.langsdorf@amd.com +Description: These files exist in every cpu's cache index directories. + There are currently 2 cache_disable_# files in each + directory. Reading from these files on a supported + processor will return that cache disable index value + for that processor and node. Writing to one of these + files will cause the specificed cache index to be disabled. + + Currently, only AMD Family 10h Processors support cache index + disable, and only for their L3 caches. See the BIOS and + Kernel Developer's Guide at + http://www.amd.com/us-en/assets/content_type/white_papers_and_tech_docs/31116-Public-GH-BKDG_3.20_2-4-09.pdf + for formatting information and other details on the + cache index disable. +Users: joachim.deguara@amd.com -- cgit v1.2.2 From 2ceb3fb0a78c671892b01319ac8e3baede33a78c Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 21 Oct 2009 21:45:20 -0600 Subject: Documentation: ABI: document /sys/devices/system/cpu/ This interface has been around for a long time, but hasn't been officially documented. Document the top level sysfs directory for CPU attributes. Signed-off-by: Alex Chiang Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-devices-system-cpu | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 175bb4f70512..86126b187ae6 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -1,3 +1,15 @@ +What: /sys/devices/system/cpu/ +Date: pre-git history +Contact: Linux kernel mailing list +Description: + A collection of both global and individual CPU attributes + + Individual CPU attributes are contained in subdirectories + named by the kernel's logical CPU number, e.g.: + + /sys/devices/system/cpu/cpu#/ + + What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X Date: August 2008 KernelVersion: 2.6.27 -- cgit v1.2.2 From d93fc863d2d2cea1057996c39cef368f41741448 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 21 Oct 2009 21:45:25 -0600 Subject: Documentation: ABI: /sys/devices/system/cpu/ topology files Add brief descriptions for the following sysfs files: /sys/devices/system/cpu/kernel_max /sys/devices/system/cpu/offline /sys/devices/system/cpu/online /sys/devices/system/cpu/possible /sys/devices/system/cpu/present Excerpted the relevant information from Documentation/cputopology.txt and pointed back to cputopology.txt as the authoritative source of information. Cc: Mike Travis Cc: Rusty Russell Signed-off-by: Alex Chiang Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-devices-system-cpu | 28 ++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 86126b187ae6..871acdbeed1a 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -10,6 +10,34 @@ Description: /sys/devices/system/cpu/cpu#/ +What: /sys/devices/system/cpu/kernel_max + /sys/devices/system/cpu/offline + /sys/devices/system/cpu/online + /sys/devices/system/cpu/possible + /sys/devices/system/cpu/present +Date: December 2008 +Contact: Linux kernel mailing list +Description: CPU topology files that describe kernel limits related to + hotplug. Briefly: + + kernel_max: the maximum cpu index allowed by the kernel + configuration. + + offline: cpus that are not online because they have been + HOTPLUGGED off or exceed the limit of cpus allowed by the + kernel configuration (kernel_max above). + + online: cpus that are online and being scheduled. + + possible: cpus that have been allocated resources and can be + brought online if they are present. + + present: cpus that have been identified as being present in + the system. + + See Documentation/cputopology.txt for more information. + + What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X Date: August 2008 KernelVersion: 2.6.27 -- cgit v1.2.2 From 663fb2fc733006f685400fb44551303b72b61a88 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 21 Oct 2009 21:45:31 -0600 Subject: Documentation: ABI: /sys/devices/system/cpu/cpu#/ topology files Add brief descriptions for the following sysfs files: /sys/devices/system/cpu/cpu#/topology/core_id /sys/devices/system/cpu/cpu#/topology/core_siblings /sys/devices/system/cpu/cpu#/topology/core_siblings_list /sys/devices/system/cpu/cpu#/topology/physical_package_id /sys/devices/system/cpu/cpu#/topology/thread_siblings /sys/devices/system/cpu/cpu#/topology/thread_siblings_list The descriptions in Documentation/cputopology.txt weren't very informative, so I attempted a better description based on code reading and hopeful guessing. Updated Documentation/cputopology.txt with the better descriptions and fixed some style issues. Cc: Mike Travis Cc: Rusty Russell Signed-off-by: Alex Chiang Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-devices-system-cpu | 39 ++++++++++++++++++ Documentation/cputopology.txt | 47 ++++++++++++++-------- 2 files changed, 69 insertions(+), 17 deletions(-) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 871acdbeed1a..2ade5c0809a0 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -38,6 +38,45 @@ Description: CPU topology files that describe kernel limits related to See Documentation/cputopology.txt for more information. +What: /sys/devices/system/cpu/cpu#/topology/core_id + /sys/devices/system/cpu/cpu#/topology/core_siblings + /sys/devices/system/cpu/cpu#/topology/core_siblings_list + /sys/devices/system/cpu/cpu#/topology/physical_package_id + /sys/devices/system/cpu/cpu#/topology/thread_siblings + /sys/devices/system/cpu/cpu#/topology/thread_siblings_list +Date: December 2008 +Contact: Linux kernel mailing list +Description: CPU topology files that describe a logical CPU's relationship + to other cores and threads in the same physical package. + + One cpu# directory is created per logical CPU in the system, + e.g. /sys/devices/system/cpu/cpu42/. + + Briefly, the files above are: + + core_id: the CPU core ID of cpu#. Typically it is the + hardware platform's identifier (rather than the kernel's). + The actual value is architecture and platform dependent. + + core_siblings: internal kernel map of cpu#'s hardware threads + within the same physical_package_id. + + core_siblings_list: human-readable list of the logical CPU + numbers within the same physical_package_id as cpu#. + + physical_package_id: physical package id of cpu#. Typically + corresponds to a physical socket number, but the actual value + is architecture and platform dependent. + + thread_siblings: internel kernel map of cpu#'s hardware + threads within the same core as cpu# + + thread_siblings_list: human-readable list of cpu#'s hardware + threads within the same core as cpu# + + See Documentation/cputopology.txt for more information. + + What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X Date: August 2008 KernelVersion: 2.6.27 diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index b41f3e58aefa..f1c5c4bccd3e 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -1,15 +1,28 @@ -Export cpu topology info via sysfs. Items (attributes) are similar +Export CPU topology info via sysfs. Items (attributes) are similar to /proc/cpuinfo. 1) /sys/devices/system/cpu/cpuX/topology/physical_package_id: -represent the physical package id of cpu X; + + physical package id of cpuX. Typically corresponds to a physical + socket number, but the actual value is architecture and platform + dependent. + 2) /sys/devices/system/cpu/cpuX/topology/core_id: -represent the cpu core id to cpu X; + + the CPU core ID of cpuX. Typically it is the hardware platform's + identifier (rather than the kernel's). The actual value is + architecture and platform dependent. + 3) /sys/devices/system/cpu/cpuX/topology/thread_siblings: -represent the thread siblings to cpu X in the same core; + + internel kernel map of cpuX's hardware threads within the same + core as cpuX + 4) /sys/devices/system/cpu/cpuX/topology/core_siblings: -represent the thread siblings to cpu X in the same physical package; + + internal kernel map of cpuX's hardware threads within the same + physical_package_id. To implement it in an architecture-neutral way, a new source file, drivers/base/topology.c, is to export the 4 attributes. @@ -32,32 +45,32 @@ not defined by include/asm-XXX/topology.h: 3) thread_siblings: just the given CPU 4) core_siblings: just the given CPU -Additionally, cpu topology information is provided under +Additionally, CPU topology information is provided under /sys/devices/system/cpu and includes these files. The internal source for the output is in brackets ("[]"). - kernel_max: the maximum cpu index allowed by the kernel configuration. + kernel_max: the maximum CPU index allowed by the kernel configuration. [NR_CPUS-1] - offline: cpus that are not online because they have been + offline: CPUs that are not online because they have been HOTPLUGGED off (see cpu-hotplug.txt) or exceed the limit - of cpus allowed by the kernel configuration (kernel_max + of CPUs allowed by the kernel configuration (kernel_max above). [~cpu_online_mask + cpus >= NR_CPUS] - online: cpus that are online and being scheduled [cpu_online_mask] + online: CPUs that are online and being scheduled [cpu_online_mask] - possible: cpus that have been allocated resources and can be + possible: CPUs that have been allocated resources and can be brought online if they are present. [cpu_possible_mask] - present: cpus that have been identified as being present in the + present: CPUs that have been identified as being present in the system. [cpu_present_mask] The format for the above output is compatible with cpulist_parse() [see ]. Some examples follow. -In this example, there are 64 cpus in the system but cpus 32-63 exceed +In this example, there are 64 CPUs in the system but cpus 32-63 exceed the kernel max which is limited to 0..31 by the NR_CPUS config option -being 32. Note also that cpus 2 and 4-31 are not online but could be +being 32. Note also that CPUs 2 and 4-31 are not online but could be brought online as they are both present and possible. kernel_max: 31 @@ -67,8 +80,8 @@ brought online as they are both present and possible. present: 0-31 In this example, the NR_CPUS config option is 128, but the kernel was -started with possible_cpus=144. There are 4 cpus in the system and cpu2 -was manually taken offline (and is the only cpu that can be brought +started with possible_cpus=144. There are 4 CPUs in the system and cpu2 +was manually taken offline (and is the only CPU that can be brought online.) kernel_max: 127 @@ -78,4 +91,4 @@ online.) present: 0-3 See cpu-hotplug.txt for the possible_cpus=NUM kernel start parameter -as well as more information on the various cpumask's. +as well as more information on the various cpumasks. -- cgit v1.2.2 From e6dcfa7c61c4d31797a12d738bfe0bdec0ca2be1 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 21 Oct 2009 21:45:36 -0600 Subject: Documentation: ABI: /sys/devices/system/cpu/sched_[mc|smt]_power_savings Document sched_[mc|smt]_power_savings by reading existing code and git logs. Cc: Suresh Siddha Cc: Ingo Molnar Signed-off-by: Alex Chiang Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-devices-system-cpu | 24 ++++++++++++++++++++++ 1 file changed, 24 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 2ade5c0809a0..8cdda1c56980 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -9,6 +9,30 @@ Description: /sys/devices/system/cpu/cpu#/ +What: /sys/devices/system/cpu/sched_mc_power_savings + /sys/devices/system/cpu/sched_smt_power_savings +Date: June 2006 +Contact: Linux kernel mailing list +Description: Discover and adjust the kernel's multi-core scheduler support. + + Possible values are: + + 0 - No power saving load balance (default value) + 1 - Fill one thread/core/package first for long running threads + 2 - Also bias task wakeups to semi-idle cpu package for power + savings + + sched_mc_power_savings is dependent upon SCHED_MC, which is + itself architecture dependent. + + sched_smt_power_savings is dependent upon SCHED_SMT, which + is itself architecture dependent. + + The two files are independent of each other. It is possible + that one file may be present without the other. + + Introduced by git commit 5c45bf27. + What: /sys/devices/system/cpu/kernel_max /sys/devices/system/cpu/offline -- cgit v1.2.2 From c1fb5c475126b77b47ba762f5b48535cd0420d24 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 21 Oct 2009 21:45:41 -0600 Subject: Documentation: ABI: /sys/devices/system/cpu/cpuidle/ Document cpuidle sysfs attributes by reading code, Documentation/cpuidle/, and git logs. Cc: Venki Pallipadi Cc: Len Brown Signed-off-by: Alex Chiang Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-devices-system-cpu | 20 ++++++++++++++++++++ 1 file changed, 20 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 8cdda1c56980..968d8bad3835 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -101,6 +101,26 @@ Description: CPU topology files that describe a logical CPU's relationship See Documentation/cputopology.txt for more information. +What: /sys/devices/system/cpu/cpuidle/current_driver + /sys/devices/system/cpu/cpuidle/current_governer_ro +Date: September 2007 +Contact: Linux kernel mailing list +Description: Discover cpuidle policy and mechanism + + Various CPUs today support multiple idle levels that are + differentiated by varying exit latencies and power + consumption during idle. + + Idle policy (governor) is differentiated from idle mechanism + (driver) + + current_driver: displays current idle mechanism + + current_governor_ro: displays current idle policy + + See files in Documentation/cpuidle/ for more information. + + What: /sys/devices/system/cpu/cpu*/cache/index*/cache_disable_X Date: August 2008 KernelVersion: 2.6.27 -- cgit v1.2.2 From 657348a056eea4a27be20cf8e22c98a252597447 Mon Sep 17 00:00:00 2001 From: Alex Chiang Date: Wed, 21 Oct 2009 22:15:30 -0600 Subject: Documentation: ABI: /sys/devices/system/cpu/cpu#/node Describe NUMA node symlink created for CPUs when CONFIG_NUMA is set. Cc: Randy Dunlap Signed-off-by: Alex Chiang Signed-off-by: Greg Kroah-Hartman --- Documentation/ABI/testing/sysfs-devices-system-cpu | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/Documentation/ABI/testing/sysfs-devices-system-cpu b/Documentation/ABI/testing/sysfs-devices-system-cpu index 968d8bad3835..a703b9e9aeb9 100644 --- a/Documentation/ABI/testing/sysfs-devices-system-cpu +++ b/Documentation/ABI/testing/sysfs-devices-system-cpu @@ -62,6 +62,21 @@ Description: CPU topology files that describe kernel limits related to See Documentation/cputopology.txt for more information. + +What: /sys/devices/system/cpu/cpu#/node +Date: October 2009 +Contact: Linux memory management mailing list +Description: Discover NUMA node a CPU belongs to + + When CONFIG_NUMA is enabled, a symbolic link that points + to the corresponding NUMA node directory. + + For example, the following symlink is created for cpu42 + in NUMA node 2: + + /sys/devices/system/cpu/cpu42/node2 -> ../../node/node2 + + What: /sys/devices/system/cpu/cpu#/topology/core_id /sys/devices/system/cpu/cpu#/topology/core_siblings /sys/devices/system/cpu/cpu#/topology/core_siblings_list -- cgit v1.2.2