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bh=TqXpp0mGR6pbQr82UrkZafoUwwcLEWn2SwPyhW5ccH4=; b=X5xdE8rLMlmIhymO9yURWuCRx9 w1LgYZs4/coLMo59/hY71k4+rqnnXzqaLc5HYdKHqVHeoeTjhEf7wUc+AnskcobUNmGIMxBiv8Nn8 4fequI0umG+GJm1tyfsebfRL+VKkmKOxEwafCKr8gSWS1hpUZbDjeFqnf5ue3DwhmTAMrdbOYR7Vs 1us/UOeklOrrDnWWlQ0mwgKBLyIuyRsaCVXegU/FjJbxeXni04d40TF9X1ydJQypCAQlOZPMknDfW luZOgQOsCu0wq15gDwNE23B8ohPubiurmXTgY3jEVQMDaFCaX4lsgzS0gc8tNvC4H8mXH5q3iqLZM 4fHLE72w==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.96 #2 (Red Hat Linux)) id 1pk9qT-005dWa-2g; Wed, 05 Apr 2023 20:35:05 +0000 From: Luis Chamberlain To: david@redhat.com, patches@lists.linux.dev, linux-modules@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, pmladek@suse.com, petr.pavlu@suse.com, prarit@redhat.com, torvalds@linux-foundation.org, gregkh@linuxfoundation.org, rafael@kernel.org Cc: christophe.leroy@csgroup.eu, tglx@linutronix.de, peterz@infradead.org, song@kernel.org, rppt@kernel.org, dave@stgolabs.net, willy@infradead.org, vbabka@suse.cz, mhocko@suse.com, dave.hansen@linux.intel.com, colin.i.king@gmail.com, jim.cromie@gmail.com, catalin.marinas@arm.com, jbaron@akamai.com, rick.p.edgecombe@intel.com, mcgrof@kernel.org Subject: [PATCH v2 1/2] Change DEFINE_SEMAPHORE() to take a number argument Date: Wed, 5 Apr 2023 13:35:04 -0700 Message-Id: <20230405203505.1343562-2-mcgrof@kernel.org> X-Mailer: git-send-email 2.38.1 In-Reply-To: <20230405203505.1343562-1-mcgrof@kernel.org> References: <20230405203505.1343562-1-mcgrof@kernel.org> MIME-Version: 1.0 X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 78E551C0009 X-Stat-Signature: 696knn89dwjek41x3ifuqfn31w9njsk6 X-Rspam-User: X-HE-Tag: 1680726912-807431 X-HE-Meta: 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 RqFBI4qC 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: From: Peter Zijlstra Fundamentally semaphores are a counted primitive, but DEFINE_SEMAPHORE() does not expose this and explicitly creates a binary semaphore. Change DEFINE_SEMAPHORE() to take a number argument and use that in the few places that open-coded it using __SEMAPHORE_INITIALIZER(). Signed-off-by: Peter Zijlstra (Intel) [mcgrof: add some tribal knowledge about why some folks prefer binary sempahores over mutexes] Signed-off-by: Luis Chamberlain Reviewed-by: Davidlohr Bueso Reviewed-by: Sergey Senozhatsky # printk --- arch/mips/cavium-octeon/setup.c | 2 +- arch/x86/kernel/cpu/intel.c | 2 +- drivers/firmware/efi/runtime-wrappers.c | 2 +- drivers/firmware/efi/vars.c | 2 +- drivers/macintosh/adb.c | 2 +- drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c | 2 +- drivers/platform/x86/intel/ifs/sysfs.c | 2 +- drivers/scsi/esas2r/esas2r_ioctl.c | 2 +- .../vc04_services/interface/vchiq_arm/vchiq_arm.c | 2 +- include/linux/semaphore.h | 11 +++++++++-- kernel/printk/printk.c | 2 +- net/rxrpc/call_object.c | 6 ++---- 12 files changed, 21 insertions(+), 16 deletions(-) diff --git a/arch/mips/cavium-octeon/setup.c b/arch/mips/cavium-octeon/setup.c index a71727f7a608..c5561016f577 100644 --- a/arch/mips/cavium-octeon/setup.c +++ b/arch/mips/cavium-octeon/setup.c @@ -72,7 +72,7 @@ extern void pci_console_init(const char *arg); static unsigned long long max_memory = ULLONG_MAX; static unsigned long long reserve_low_mem; -DEFINE_SEMAPHORE(octeon_bootbus_sem); +DEFINE_SEMAPHORE(octeon_bootbus_sem, 1); EXPORT_SYMBOL(octeon_bootbus_sem); static struct octeon_boot_descriptor *octeon_boot_desc_ptr; diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c index 291d4167fab8..12bad63822f0 100644 --- a/arch/x86/kernel/cpu/intel.c +++ b/arch/x86/kernel/cpu/intel.c @@ -1177,7 +1177,7 @@ static const struct { static struct ratelimit_state bld_ratelimit; static unsigned int sysctl_sld_mitigate = 1; -static DEFINE_SEMAPHORE(buslock_sem); +static DEFINE_SEMAPHORE(buslock_sem, 1); #ifdef CONFIG_PROC_SYSCTL static struct ctl_table sld_sysctls[] = { diff --git a/drivers/firmware/efi/runtime-wrappers.c b/drivers/firmware/efi/runtime-wrappers.c index 1fba4e09cdcf..a400c4312c82 100644 --- a/drivers/firmware/efi/runtime-wrappers.c +++ b/drivers/firmware/efi/runtime-wrappers.c @@ -158,7 +158,7 @@ void efi_call_virt_check_flags(unsigned long flags, const char *call) * none of the remaining functions are actually ever called at runtime. * So let's just use a single lock to serialize all Runtime Services calls. */ -static DEFINE_SEMAPHORE(efi_runtime_lock); +static DEFINE_SEMAPHORE(efi_runtime_lock, 1); /* * Expose the EFI runtime lock to the UV platform diff --git a/drivers/firmware/efi/vars.c b/drivers/firmware/efi/vars.c index bd75b87f5fc1..bfc5fa6aa47b 100644 --- a/drivers/firmware/efi/vars.c +++ b/drivers/firmware/efi/vars.c @@ -21,7 +21,7 @@ /* Private pointer to registered efivars */ static struct efivars *__efivars; -static DEFINE_SEMAPHORE(efivars_lock); +static DEFINE_SEMAPHORE(efivars_lock, 1); static efi_status_t check_var_size(bool nonblocking, u32 attributes, unsigned long size) diff --git a/drivers/macintosh/adb.c b/drivers/macintosh/adb.c index 23bd0c77ac1a..56599515d51a 100644 --- a/drivers/macintosh/adb.c +++ b/drivers/macintosh/adb.c @@ -80,7 +80,7 @@ static struct adb_driver *adb_controller; BLOCKING_NOTIFIER_HEAD(adb_client_list); static int adb_got_sleep; static int adb_inited; -static DEFINE_SEMAPHORE(adb_probe_mutex); +static DEFINE_SEMAPHORE(adb_probe_mutex, 1); static int sleepy_trackpad; static int autopoll_devs; int __adb_probe_sync; diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c index 5d1e4fe335aa..5a105bab4387 100644 --- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c +++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c @@ -298,7 +298,7 @@ const u32 dmae_reg_go_c[] = { /* Global resources for unloading a previously loaded device */ #define BNX2X_PREV_WAIT_NEEDED 1 -static DEFINE_SEMAPHORE(bnx2x_prev_sem); +static DEFINE_SEMAPHORE(bnx2x_prev_sem, 1); static LIST_HEAD(bnx2x_prev_list); /* Forward declaration */ diff --git a/drivers/platform/x86/intel/ifs/sysfs.c b/drivers/platform/x86/intel/ifs/sysfs.c index ee636a76b083..4c3c642ee19a 100644 --- a/drivers/platform/x86/intel/ifs/sysfs.c +++ b/drivers/platform/x86/intel/ifs/sysfs.c @@ -13,7 +13,7 @@ * Protects against simultaneous tests on multiple cores, or * reloading can file while a test is in progress */ -static DEFINE_SEMAPHORE(ifs_sem); +static DEFINE_SEMAPHORE(ifs_sem, 1); /* * The sysfs interface to check additional details of last test diff --git a/drivers/scsi/esas2r/esas2r_ioctl.c b/drivers/scsi/esas2r/esas2r_ioctl.c index e003d923acbf..055d2e87a2c8 100644 --- a/drivers/scsi/esas2r/esas2r_ioctl.c +++ b/drivers/scsi/esas2r/esas2r_ioctl.c @@ -56,7 +56,7 @@ dma_addr_t esas2r_buffered_ioctl_addr; u32 esas2r_buffered_ioctl_size; struct pci_dev *esas2r_buffered_ioctl_pcid; -static DEFINE_SEMAPHORE(buffered_ioctl_semaphore); +static DEFINE_SEMAPHORE(buffered_ioctl_semaphore, 1); typedef int (*BUFFERED_IOCTL_CALLBACK)(struct esas2r_adapter *, struct esas2r_request *, struct esas2r_sg_context *, diff --git a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c index cddcd3c596c9..1a656fdc9445 100644 --- a/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c +++ b/drivers/staging/vc04_services/interface/vchiq_arm/vchiq_arm.c @@ -149,7 +149,7 @@ static char *g_fragments_base; static char *g_free_fragments; static struct semaphore g_free_fragments_sema; -static DEFINE_SEMAPHORE(g_free_fragments_mutex); +static DEFINE_SEMAPHORE(g_free_fragments_mutex, 1); static int vchiq_blocking_bulk_transfer(struct vchiq_instance *instance, unsigned int handle, void *data, diff --git a/include/linux/semaphore.h b/include/linux/semaphore.h index 6694d0019a68..2d6aa3fd7861 100644 --- a/include/linux/semaphore.h +++ b/include/linux/semaphore.h @@ -25,8 +25,15 @@ struct semaphore { .wait_list = LIST_HEAD_INIT((name).wait_list), \ } -#define DEFINE_SEMAPHORE(name) \ - struct semaphore name = __SEMAPHORE_INITIALIZER(name, 1) +/* + * There is a big difference between a binary semaphore and a mutex. + * You cannot call mutex_unlock() from IRQ context because it takes an + * internal mutex spin_lock in a non-IRQ-safe manner. Both try_lock() + * and unlock() can be called from IRQ context. A mutex must also be + * released in the same context that locked it. + */ +#define DEFINE_SEMAPHORE(_name, _n) \ + struct semaphore _name = __SEMAPHORE_INITIALIZER(_name, _n) static inline void sema_init(struct semaphore *sem, int val) { diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c index fd0c9f913940..76987aaa5a45 100644 --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -89,7 +89,7 @@ static DEFINE_MUTEX(console_mutex); * console_sem protects updates to console->seq and console_suspended, * and also provides serialization for console printing. */ -static DEFINE_SEMAPHORE(console_sem); +static DEFINE_SEMAPHORE(console_sem, 1); HLIST_HEAD(console_list); EXPORT_SYMBOL_GPL(console_list); DEFINE_STATIC_SRCU(console_srcu); diff --git a/net/rxrpc/call_object.c b/net/rxrpc/call_object.c index e9f1f49d18c2..3e5cc70884dd 100644 --- a/net/rxrpc/call_object.c +++ b/net/rxrpc/call_object.c @@ -40,10 +40,8 @@ const char *const rxrpc_call_completions[NR__RXRPC_CALL_COMPLETIONS] = { struct kmem_cache *rxrpc_call_jar; -static struct semaphore rxrpc_call_limiter = - __SEMAPHORE_INITIALIZER(rxrpc_call_limiter, 1000); -static struct semaphore rxrpc_kernel_call_limiter = - __SEMAPHORE_INITIALIZER(rxrpc_kernel_call_limiter, 1000); +static DEFINE_SEMAPHORE(rxrpc_call_limiter, 1000); +static DEFINE_SEMAPHORE(rxrpc_kernel_call_limiter, 1000); void rxrpc_poke_call(struct rxrpc_call *call, enum rxrpc_call_poke_trace what) {