From 63ade96711c7a0bb7226f3b029e800fafccd4b0b Mon Sep 17 00:00:00 2001 From: Dmitry Torokhov Date: Tue, 3 Sep 2024 21:31:00 -0700 Subject: [PATCH] Input: iforce - use guard notation when acquiring mutex and spinlock Using guard notation makes the code more compact and error handling more robust by ensuring that locks are released in all code paths when control leaves critical section. Link: https://lore.kernel.org/r/20240904043104.1030257-4-dmitry.torokhov@gmail.com Signed-off-by: Dmitry Torokhov --- drivers/input/joystick/iforce/iforce-ff.c | 48 +++++++--------- .../input/joystick/iforce/iforce-packets.c | 57 ++++++++----------- drivers/input/joystick/iforce/iforce-serio.c | 36 +++++------- drivers/input/joystick/iforce/iforce-usb.c | 13 ++--- 4 files changed, 68 insertions(+), 86 deletions(-) diff --git a/drivers/input/joystick/iforce/iforce-ff.c b/drivers/input/joystick/iforce/iforce-ff.c index 95c0348843e6b..8c78cbe553c8c 100644 --- a/drivers/input/joystick/iforce/iforce-ff.c +++ b/drivers/input/joystick/iforce/iforce-ff.c @@ -21,14 +21,13 @@ static int make_magnitude_modifier(struct iforce* iforce, unsigned char data[3]; if (!no_alloc) { - mutex_lock(&iforce->mem_mutex); - if (allocate_resource(&(iforce->device_memory), mod_chunk, 2, - iforce->device_memory.start, iforce->device_memory.end, 2L, - NULL, NULL)) { - mutex_unlock(&iforce->mem_mutex); + guard(mutex)(&iforce->mem_mutex); + + if (allocate_resource(&iforce->device_memory, mod_chunk, 2, + iforce->device_memory.start, + iforce->device_memory.end, + 2L, NULL, NULL)) return -ENOSPC; - } - mutex_unlock(&iforce->mem_mutex); } data[0] = LO(mod_chunk->start); @@ -54,14 +53,13 @@ static int make_period_modifier(struct iforce* iforce, period = TIME_SCALE(period); if (!no_alloc) { - mutex_lock(&iforce->mem_mutex); - if (allocate_resource(&(iforce->device_memory), mod_chunk, 0x0c, - iforce->device_memory.start, iforce->device_memory.end, 2L, - NULL, NULL)) { - mutex_unlock(&iforce->mem_mutex); + guard(mutex)(&iforce->mem_mutex); + + if (allocate_resource(&iforce->device_memory, mod_chunk, 0x0c, + iforce->device_memory.start, + iforce->device_memory.end, + 2L, NULL, NULL)) return -ENOSPC; - } - mutex_unlock(&iforce->mem_mutex); } data[0] = LO(mod_chunk->start); @@ -94,14 +92,13 @@ static int make_envelope_modifier(struct iforce* iforce, fade_duration = TIME_SCALE(fade_duration); if (!no_alloc) { - mutex_lock(&iforce->mem_mutex); + guard(mutex)(&iforce->mem_mutex); + if (allocate_resource(&(iforce->device_memory), mod_chunk, 0x0e, - iforce->device_memory.start, iforce->device_memory.end, 2L, - NULL, NULL)) { - mutex_unlock(&iforce->mem_mutex); + iforce->device_memory.start, + iforce->device_memory.end, + 2L, NULL, NULL)) return -ENOSPC; - } - mutex_unlock(&iforce->mem_mutex); } data[0] = LO(mod_chunk->start); @@ -131,14 +128,13 @@ static int make_condition_modifier(struct iforce* iforce, unsigned char data[10]; if (!no_alloc) { - mutex_lock(&iforce->mem_mutex); + guard(mutex)(&iforce->mem_mutex); + if (allocate_resource(&(iforce->device_memory), mod_chunk, 8, - iforce->device_memory.start, iforce->device_memory.end, 2L, - NULL, NULL)) { - mutex_unlock(&iforce->mem_mutex); + iforce->device_memory.start, + iforce->device_memory.end, + 2L, NULL, NULL)) return -ENOSPC; - } - mutex_unlock(&iforce->mem_mutex); } data[0] = LO(mod_chunk->start); diff --git a/drivers/input/joystick/iforce/iforce-packets.c b/drivers/input/joystick/iforce/iforce-packets.c index 763642c8cee9f..8c2531e2977c1 100644 --- a/drivers/input/joystick/iforce/iforce-packets.c +++ b/drivers/input/joystick/iforce/iforce-packets.c @@ -31,49 +31,42 @@ int iforce_send_packet(struct iforce *iforce, u16 cmd, unsigned char* data) int c; int empty; int head, tail; - unsigned long flags; /* * Update head and tail of xmit buffer */ - spin_lock_irqsave(&iforce->xmit_lock, flags); - - head = iforce->xmit.head; - tail = iforce->xmit.tail; - - - if (CIRC_SPACE(head, tail, XMIT_SIZE) < n+2) { - dev_warn(&iforce->dev->dev, - "not enough space in xmit buffer to send new packet\n"); - spin_unlock_irqrestore(&iforce->xmit_lock, flags); - return -1; - } + scoped_guard(spinlock_irqsave, &iforce->xmit_lock) { + head = iforce->xmit.head; + tail = iforce->xmit.tail; + + if (CIRC_SPACE(head, tail, XMIT_SIZE) < n + 2) { + dev_warn(&iforce->dev->dev, + "not enough space in xmit buffer to send new packet\n"); + return -1; + } - empty = head == tail; - XMIT_INC(iforce->xmit.head, n+2); + empty = head == tail; + XMIT_INC(iforce->xmit.head, n + 2); /* * Store packet in xmit buffer */ - iforce->xmit.buf[head] = HI(cmd); - XMIT_INC(head, 1); - iforce->xmit.buf[head] = LO(cmd); - XMIT_INC(head, 1); - - c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE); - if (n < c) c=n; - - memcpy(&iforce->xmit.buf[head], - data, - c); - if (n != c) { - memcpy(&iforce->xmit.buf[0], - data + c, - n - c); + iforce->xmit.buf[head] = HI(cmd); + XMIT_INC(head, 1); + iforce->xmit.buf[head] = LO(cmd); + XMIT_INC(head, 1); + + c = CIRC_SPACE_TO_END(head, tail, XMIT_SIZE); + if (n < c) + c = n; + + memcpy(&iforce->xmit.buf[head], data, c); + if (n != c) + memcpy(&iforce->xmit.buf[0], data + c, n - c); + + XMIT_INC(head, n); } - XMIT_INC(head, n); - spin_unlock_irqrestore(&iforce->xmit_lock, flags); /* * If necessary, start the transmission */ diff --git a/drivers/input/joystick/iforce/iforce-serio.c b/drivers/input/joystick/iforce/iforce-serio.c index 2380546d79782..75b85c46dfa41 100644 --- a/drivers/input/joystick/iforce/iforce-serio.c +++ b/drivers/input/joystick/iforce/iforce-serio.c @@ -28,45 +28,39 @@ static void iforce_serio_xmit(struct iforce *iforce) iforce); unsigned char cs; int i; - unsigned long flags; if (test_and_set_bit(IFORCE_XMIT_RUNNING, iforce->xmit_flags)) { set_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags); return; } - spin_lock_irqsave(&iforce->xmit_lock, flags); + guard(spinlock_irqsave)(&iforce->xmit_lock); -again: - if (iforce->xmit.head == iforce->xmit.tail) { - iforce_clear_xmit_and_wake(iforce); - spin_unlock_irqrestore(&iforce->xmit_lock, flags); - return; - } + do { + if (iforce->xmit.head == iforce->xmit.tail) + break; - cs = 0x2b; + cs = 0x2b; - serio_write(iforce_serio->serio, 0x2b); + serio_write(iforce_serio->serio, 0x2b); - serio_write(iforce_serio->serio, iforce->xmit.buf[iforce->xmit.tail]); - cs ^= iforce->xmit.buf[iforce->xmit.tail]; - XMIT_INC(iforce->xmit.tail, 1); - - for (i=iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) { serio_write(iforce_serio->serio, iforce->xmit.buf[iforce->xmit.tail]); cs ^= iforce->xmit.buf[iforce->xmit.tail]; XMIT_INC(iforce->xmit.tail, 1); - } - serio_write(iforce_serio->serio, cs); + for (i = iforce->xmit.buf[iforce->xmit.tail]; i >= 0; --i) { + serio_write(iforce_serio->serio, + iforce->xmit.buf[iforce->xmit.tail]); + cs ^= iforce->xmit.buf[iforce->xmit.tail]; + XMIT_INC(iforce->xmit.tail, 1); + } - if (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags)) - goto again; + serio_write(iforce_serio->serio, cs); - iforce_clear_xmit_and_wake(iforce); + } while (test_and_clear_bit(IFORCE_XMIT_AGAIN, iforce->xmit_flags)); - spin_unlock_irqrestore(&iforce->xmit_lock, flags); + iforce_clear_xmit_and_wake(iforce); } static int iforce_serio_get_id(struct iforce *iforce, u8 id, diff --git a/drivers/input/joystick/iforce/iforce-usb.c b/drivers/input/joystick/iforce/iforce-usb.c index cba92bd590a8d..1f00f76b01745 100644 --- a/drivers/input/joystick/iforce/iforce-usb.c +++ b/drivers/input/joystick/iforce/iforce-usb.c @@ -25,13 +25,11 @@ static void __iforce_usb_xmit(struct iforce *iforce) struct iforce_usb *iforce_usb = container_of(iforce, struct iforce_usb, iforce); int n, c; - unsigned long flags; - spin_lock_irqsave(&iforce->xmit_lock, flags); + guard(spinlock_irqsave)(&iforce->xmit_lock); if (iforce->xmit.head == iforce->xmit.tail) { iforce_clear_xmit_and_wake(iforce); - spin_unlock_irqrestore(&iforce->xmit_lock, flags); return; } @@ -45,7 +43,8 @@ static void __iforce_usb_xmit(struct iforce *iforce) /* Copy rest of data then */ c = CIRC_CNT_TO_END(iforce->xmit.head, iforce->xmit.tail, XMIT_SIZE); - if (n < c) c=n; + if (n < c) + c = n; memcpy(iforce_usb->out->transfer_buffer + 1, &iforce->xmit.buf[iforce->xmit.tail], @@ -53,11 +52,12 @@ static void __iforce_usb_xmit(struct iforce *iforce) if (n != c) { memcpy(iforce_usb->out->transfer_buffer + 1 + c, &iforce->xmit.buf[0], - n-c); + n - c); } XMIT_INC(iforce->xmit.tail, n); - if ( (n=usb_submit_urb(iforce_usb->out, GFP_ATOMIC)) ) { + n=usb_submit_urb(iforce_usb->out, GFP_ATOMIC); + if (n) { dev_warn(&iforce_usb->intf->dev, "usb_submit_urb failed %d\n", n); iforce_clear_xmit_and_wake(iforce); @@ -66,7 +66,6 @@ static void __iforce_usb_xmit(struct iforce *iforce) /* The IFORCE_XMIT_RUNNING bit is not cleared here. That's intended. * As long as the urb completion handler is not called, the transmiting * is considered to be running */ - spin_unlock_irqrestore(&iforce->xmit_lock, flags); } static void iforce_usb_xmit(struct iforce *iforce) -- 2.39.5