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| author | Ioan Nicu <ioan.nicu.ext@nokia.com> | 2017-10-04 02:15:13 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-10-04 03:54:24 +0300 |
| commit | 31d1e130f4a0f8f629a460167569577cac9b17c1 (patch) | |
| tree | ea592c410053b35919ddbd5b116480598e6d957b /drivers/rapidio/devices | |
| parent | 57148a64e823bb1f49112fa52a92a7f372cda892 (diff) | |
| download | linux-31d1e130f4a0f8f629a460167569577cac9b17c1.tar.xz | |
rapidio: remove global irq spinlocks from the subsystem
Locking of config and doorbell operations should be done only if the
underlying hardware requires it.
This patch removes the global spinlocks from the rapidio subsystem and
moves them to the mport drivers (fsl_rio and tsi721), only to the
necessary places. For example, local config space read and write
operations (lcread/lcwrite) are atomic in all existing drivers, so there
should be no need for locking, while the cread/cwrite operations which
generate maintenance transactions need to be synchronized with a lock.
Later, each driver could chose to use a per-port lock instead of a
global one, or even more granular locking.
Link: http://lkml.kernel.org/r/20170824113023.GD50104@nokia.com
Signed-off-by: Ioan Nicu <ioan.nicu.ext@nokia.com>
Signed-off-by: Frank Kunz <frank.kunz@nokia.com>
Acked-by: Alexandre Bounine <alexandre.bounine@idt.com>
Cc: Matt Porter <mporter@kernel.crashing.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'drivers/rapidio/devices')
| -rw-r--r-- | drivers/rapidio/devices/tsi721.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/rapidio/devices/tsi721.c b/drivers/rapidio/devices/tsi721.c index 315a4be8dc1e..9a68914100ad 100644 --- a/drivers/rapidio/devices/tsi721.c +++ b/drivers/rapidio/devices/tsi721.c @@ -51,6 +51,8 @@ module_param(mbox_sel, byte, S_IRUGO); MODULE_PARM_DESC(mbox_sel, "RIO Messaging MBOX Selection Mask (default: 0x0f = all)"); +static DEFINE_SPINLOCK(tsi721_maint_lock); + static void tsi721_omsg_handler(struct tsi721_device *priv, int ch); static void tsi721_imsg_handler(struct tsi721_device *priv, int ch); @@ -124,12 +126,15 @@ static int tsi721_maint_dma(struct tsi721_device *priv, u32 sys_size, void __iomem *regs = priv->regs + TSI721_DMAC_BASE(priv->mdma.ch_id); struct tsi721_dma_desc *bd_ptr; u32 rd_count, swr_ptr, ch_stat; + unsigned long flags; int i, err = 0; u32 op = do_wr ? MAINT_WR : MAINT_RD; if (offset > (RIO_MAINT_SPACE_SZ - len) || (len != sizeof(u32))) return -EINVAL; + spin_lock_irqsave(&tsi721_maint_lock, flags); + bd_ptr = priv->mdma.bd_base; rd_count = ioread32(regs + TSI721_DMAC_DRDCNT); @@ -197,7 +202,9 @@ static int tsi721_maint_dma(struct tsi721_device *priv, u32 sys_size, */ swr_ptr = ioread32(regs + TSI721_DMAC_DSWP); iowrite32(swr_ptr, regs + TSI721_DMAC_DSRP); + err_out: + spin_unlock_irqrestore(&tsi721_maint_lock, flags); return err; } |