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rapidio: remove global irq spinlocks from the subsystem

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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>
This commit is contained in:
Ioan Nicu
2017-10-03 16:15:13 -07:00
committed by Linus Torvalds
parent 57148a64e8
commit 31d1e130f4
4 changed files with 35 additions and 37 deletions
Download Patch File Download Diff File Expand all files Collapse all files

8
arch/powerpc/sysdev/fsl_rmu.c
View File

@@ -104,6 +104,8 @@
#define DOORBELL_MESSAGE_SIZE 0x08
static DEFINE_SPINLOCK(fsl_rio_doorbell_lock);
struct rio_msg_regs {
u32 omr;
u32 osr;
@@ -626,9 +628,13 @@ err_out:
int fsl_rio_doorbell_send(struct rio_mport *mport,
int index, u16 destid, u16 data)
{
unsigned long flags;
pr_debug("fsl_doorbell_send: index %d destid %4.4x data %4.4x\n",
index, destid, data);
spin_lock_irqsave(&fsl_rio_doorbell_lock, flags);
/* In the serial version silicons, such as MPC8548, MPC8641,
* below operations is must be.
*/
@@ -638,6 +644,8 @@ int fsl_rio_doorbell_send(struct rio_mport *mport,
out_be32(&dbell->dbell_regs->oddatr, (index << 20) | data);
out_be32(&dbell->dbell_regs->odmr, 0x00000001);
spin_unlock_irqrestore(&fsl_rio_doorbell_lock, flags);
return 0;
}