* [PATCH v2 00/13] Introduce seqnum_ops @ 2020-11-13 17:46 Shuah Khan 2020-11-13 17:46 ` [PATCH v2 07/13] drivers/edac: convert pci counters to seqnum_ops Shuah Khan 0 siblings, 1 reply; 2+ messages in thread From: Shuah Khan @ 2020-11-13 17:46 UTC (permalink / raw) To: corbet, keescook, gregkh, peterz, rafael, lenb, james.morse, tony.luck, bp, minyard, arnd, mchehab, rric, valentina.manea.m, shuah, zohar, dmitry.kasatkin, jmorris, serge Cc: Shuah Khan, linux-doc, linux-kernel, linux-kselftest, linux-acpi, openipmi-developer, linux-edac, linux-usb, linux-integrity, linux-security-module Sequence Number api provides interfaces for unsigned atomic up counters leveraging atomic_t and atomic64_t ops underneath. There are a number of atomic_t usages in the kernel where atomic_t api is used for counting sequence numbers and other statistical counters. Several of these usages, convert atomic_read() and atomic_inc_return() return values to unsigned. Introducing sequence number ops supports these use-cases with a standard core-api. The atomic_t api provides a wide range of atomic operations as a base api to implement atomic counters, bitops, spinlock interfaces. The usages also evolved into being used for resource lifetimes and state management. The refcount_t api was introduced to address resource lifetime problems related to atomic_t wrapping. There is a large overlap between the atomic_t api used for resource lifetimes and just counters, stats, and sequence numbers. It has become difficult to differentiate between the atomic_t usages that should be converted to refcount_t and the ones that can be left alone. Introducing seqnum_ops to wrap the usages that are stats, counters, sequence numbers makes it easier for tools that scan for underflow and overflow on atomic_t usages to detect overflow and underflows to scan just the cases that are prone to errors. In addition, to supporting sequence number use-cases, Sequence Number Ops helps differentiate atomic_t counter usages from atomic_t usages that guard object lifetimes, hence prone to overflow and underflow errors from up counting use-cases. It becomes easier for tools that scan for underflow and overflow on atomic_t usages to detect overflow and underflows to scan just the cases that are prone to errors. Changes since v1: - Removed dec based on Greg KH's comments - Removed read/set/inc based on the discussion with Peter Zijlstra - Interfaces are restricted to init, increment and return new value, and fetch current value. - Interfaces return u32 and u64 - a few reviewers suggested unsigned. After reviewing a few use-cases, I determined this is a good path forward. It adds unsigned atomic support that doesn't exist now, and simplifies code in drivers that currently convert atomic_t return values to unsigned. All the drivers changes included in this series used to convert atomic_t returns to unsigned. Patch v1 thread: https://lore.kernel.org/lkml/cover.1605027593.git.skhan@linuxfoundation.org/ Counters thread: lore.kernel.org/lkml/cover.1602209970.git.skhan@linuxfoundation.org Shuah Khan (13): seqnum_ops: Introduce Sequence Number Ops selftests: lib:test_seqnum_ops: add new test for seqnum_ops drivers/acpi: convert seqno seqnum_ops drivers/acpi/apei: convert seqno to seqnum_ops drivers/base/test/test_async_driver_probe: convert to use seqnum_ops drivers/char/ipmi: convert stats to use seqnum_ops drivers/edac: convert pci counters to seqnum_ops drivers/oprofile: convert stats to use seqnum_ops drivers/staging/rtl8723bs: convert stats to use seqnum_ops usb: usbip/vhci: convert seqno to seqnum_ops drivers/staging/rtl8188eu: convert stats to use seqnum_ops drivers/staging/unisys/visorhba: convert stats to use seqnum_ops security/integrity/ima: converts stats to seqnum_ops Documentation/core-api/atomic_ops.rst | 4 + Documentation/core-api/index.rst | 1 + Documentation/core-api/seqnum_ops.rst | 89 +++++++++++++ MAINTAINERS | 8 ++ drivers/acpi/acpi_extlog.c | 8 +- drivers/acpi/apei/ghes.c | 8 +- drivers/base/test/test_async_driver_probe.c | 28 +++-- drivers/char/ipmi/ipmi_msghandler.c | 9 +- drivers/char/ipmi/ipmi_si_intf.c | 9 +- drivers/char/ipmi/ipmi_ssif.c | 9 +- drivers/edac/edac_pci.h | 5 +- drivers/edac/edac_pci_sysfs.c | 30 ++--- drivers/oprofile/buffer_sync.c | 9 +- drivers/oprofile/event_buffer.c | 3 +- drivers/oprofile/oprof.c | 3 +- drivers/oprofile/oprofile_stats.c | 11 +- drivers/oprofile/oprofile_stats.h | 11 +- drivers/oprofile/oprofilefs.c | 3 +- drivers/staging/rtl8188eu/core/rtw_mlme_ext.c | 23 +++- .../staging/rtl8188eu/include/rtw_mlme_ext.h | 3 +- drivers/staging/rtl8723bs/core/rtw_cmd.c | 3 +- drivers/staging/rtl8723bs/core/rtw_mlme_ext.c | 33 +++-- drivers/staging/rtl8723bs/include/rtw_cmd.h | 3 +- .../staging/rtl8723bs/include/rtw_mlme_ext.h | 3 +- .../staging/unisys/visorhba/visorhba_main.c | 21 ++-- drivers/usb/usbip/vhci.h | 3 +- drivers/usb/usbip/vhci_hcd.c | 7 +- drivers/usb/usbip/vhci_rx.c | 5 +- include/linux/oprofile.h | 3 +- include/linux/seqnum_ops.h | 118 +++++++++++++++++ lib/Kconfig | 9 ++ lib/Makefile | 1 + lib/test_seqnum_ops.c | 119 ++++++++++++++++++ security/integrity/ima/ima.h | 5 +- security/integrity/ima/ima_api.c | 3 +- security/integrity/ima/ima_fs.c | 5 +- security/integrity/ima/ima_queue.c | 7 +- tools/testing/selftests/lib/Makefile | 1 + tools/testing/selftests/lib/config | 1 + .../testing/selftests/lib/test_seqnum_ops.sh | 10 ++ 40 files changed, 524 insertions(+), 110 deletions(-) create mode 100644 Documentation/core-api/seqnum_ops.rst create mode 100644 include/linux/seqnum_ops.h create mode 100644 lib/test_seqnum_ops.c create mode 100755 tools/testing/selftests/lib/test_seqnum_ops.sh -- 2.27.0 ^ permalink raw reply [flat|nested] 2+ messages in thread
* [PATCH v2 07/13] drivers/edac: convert pci counters to seqnum_ops 2020-11-13 17:46 [PATCH v2 00/13] Introduce seqnum_ops Shuah Khan @ 2020-11-13 17:46 ` Shuah Khan 0 siblings, 0 replies; 2+ messages in thread From: Shuah Khan @ 2020-11-13 17:46 UTC (permalink / raw) To: bp, mchehab, tony.luck, james.morse, rric, gregkh, keescook, peterz Cc: Shuah Khan, linux-edac, linux-kernel Sequence Number api provides interfaces for unsigned atomic up counters leveraging atomic_t and atomic64_t ops underneath. atomic_t variables used for pci counters keep track of pci parity and non-parity errors. Convert them to use seqnum_ops. Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> --- drivers/edac/edac_pci.h | 5 +++-- drivers/edac/edac_pci_sysfs.c | 30 +++++++++++++++--------------- 2 files changed, 18 insertions(+), 17 deletions(-) diff --git a/drivers/edac/edac_pci.h b/drivers/edac/edac_pci.h index 5175f5724cfa..33b33e62c37f 100644 --- a/drivers/edac/edac_pci.h +++ b/drivers/edac/edac_pci.h @@ -30,12 +30,13 @@ #include <linux/pci.h> #include <linux/types.h> #include <linux/workqueue.h> +#include <linux/seqnum_ops.h> #ifdef CONFIG_PCI struct edac_pci_counter { - atomic_t pe_count; - atomic_t npe_count; + struct seqnum32 pe_count; + struct seqnum32 npe_count; }; /* diff --git a/drivers/edac/edac_pci_sysfs.c b/drivers/edac/edac_pci_sysfs.c index 53042af7262e..08a34ecd2fb7 100644 --- a/drivers/edac/edac_pci_sysfs.c +++ b/drivers/edac/edac_pci_sysfs.c @@ -23,8 +23,8 @@ static int edac_pci_log_pe = 1; /* log PCI parity errors */ static int edac_pci_log_npe = 1; /* log PCI non-parity error errors */ static int edac_pci_poll_msec = 1000; /* one second workq period */ -static atomic_t pci_parity_count = ATOMIC_INIT(0); -static atomic_t pci_nonparity_count = ATOMIC_INIT(0); +static struct seqnum32 pci_parity_count = SEQNUM_INIT(0); +static struct seqnum32 pci_nonparity_count = SEQNUM_INIT(0); static struct kobject *edac_pci_top_main_kobj; static atomic_t edac_pci_sysfs_refcount = ATOMIC_INIT(0); @@ -58,13 +58,13 @@ int edac_pci_get_poll_msec(void) /**************************** EDAC PCI sysfs instance *******************/ static ssize_t instance_pe_count_show(struct edac_pci_ctl_info *pci, char *data) { - return sprintf(data, "%u\n", atomic_read(&pci->counters.pe_count)); + return sprintf(data, "%u\n", seqnum32_fetch(&pci->counters.pe_count)); } static ssize_t instance_npe_count_show(struct edac_pci_ctl_info *pci, char *data) { - return sprintf(data, "%u\n", atomic_read(&pci->counters.npe_count)); + return sprintf(data, "%u\n", seqnum32_fetch(&pci->counters.npe_count)); } #define to_instance(k) container_of(k, struct edac_pci_ctl_info, kobj) @@ -553,7 +553,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) edac_printk(KERN_CRIT, EDAC_PCI, "Signaled System Error on %s\n", pci_name(dev)); - atomic_inc(&pci_nonparity_count); + seqnum32_inc_return(&pci_nonparity_count); } if (status & (PCI_STATUS_PARITY)) { @@ -561,7 +561,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) "Master Data Parity Error on %s\n", pci_name(dev)); - atomic_inc(&pci_parity_count); + seqnum32_inc_return(&pci_parity_count); } if (status & (PCI_STATUS_DETECTED_PARITY)) { @@ -569,7 +569,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) "Detected Parity Error on %s\n", pci_name(dev)); - atomic_inc(&pci_parity_count); + seqnum32_inc_return(&pci_parity_count); } } @@ -592,7 +592,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) edac_printk(KERN_CRIT, EDAC_PCI, "Bridge " "Signaled System Error on %s\n", pci_name(dev)); - atomic_inc(&pci_nonparity_count); + seqnum32_inc_return(&pci_nonparity_count); } if (status & (PCI_STATUS_PARITY)) { @@ -600,7 +600,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) "Master Data Parity Error on " "%s\n", pci_name(dev)); - atomic_inc(&pci_parity_count); + seqnum32_inc_return(&pci_parity_count); } if (status & (PCI_STATUS_DETECTED_PARITY)) { @@ -608,7 +608,7 @@ static void edac_pci_dev_parity_test(struct pci_dev *dev) "Detected Parity Error on %s\n", pci_name(dev)); - atomic_inc(&pci_parity_count); + seqnum32_inc_return(&pci_parity_count); } } } @@ -638,7 +638,7 @@ static inline void edac_pci_dev_parity_iterator(pci_parity_check_fn_t fn) */ void edac_pci_do_parity_check(void) { - int before_count; + u32 before_count; edac_dbg(3, "\n"); @@ -646,7 +646,7 @@ void edac_pci_do_parity_check(void) if (!check_pci_errors) return; - before_count = atomic_read(&pci_parity_count); + before_count = seqnum32_fetch(&pci_parity_count); /* scan all PCI devices looking for a Parity Error on devices and * bridges. @@ -658,7 +658,7 @@ void edac_pci_do_parity_check(void) /* Only if operator has selected panic on PCI Error */ if (edac_pci_get_panic_on_pe()) { /* If the count is different 'after' from 'before' */ - if (before_count != atomic_read(&pci_parity_count)) + if (before_count != seqnum32_fetch(&pci_parity_count)) panic("EDAC: PCI Parity Error"); } } @@ -686,7 +686,7 @@ void edac_pci_handle_pe(struct edac_pci_ctl_info *pci, const char *msg) { /* global PE counter incremented by edac_pci_do_parity_check() */ - atomic_inc(&pci->counters.pe_count); + seqnum32_inc_return(&pci->counters.pe_count); if (edac_pci_get_log_pe()) edac_pci_printk(pci, KERN_WARNING, @@ -711,7 +711,7 @@ void edac_pci_handle_npe(struct edac_pci_ctl_info *pci, const char *msg) { /* global NPE counter incremented by edac_pci_do_parity_check() */ - atomic_inc(&pci->counters.npe_count); + seqnum32_inc_return(&pci->counters.npe_count); if (edac_pci_get_log_npe()) edac_pci_printk(pci, KERN_WARNING, -- 2.27.0 ^ permalink raw reply related [flat|nested] 2+ messages in thread
end of thread, other threads:[~2020-11-13 17:47 UTC | newest] Thread overview: 2+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-11-13 17:46 [PATCH v2 00/13] Introduce seqnum_ops Shuah Khan 2020-11-13 17:46 ` [PATCH v2 07/13] drivers/edac: convert pci counters to seqnum_ops Shuah Khan
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