Hi,
On 04/05/2022 12:28, Sai Prakash Ranjan wrote:
Per discussion in [1], it was decided to move to using architecture
independent/asm-generic IO memory barriers to have just one set of
them and deprecate use of arm64 specific IO memory barriers in driver
code. So replace current usage of __io_rmb()/__iowmb() in drivers to
__io_ar()/__io_bw().
[1] https://lore.kernel.org/lkml/CAK8P3a0L2tLeF1Q0+0ijUxhGNaw+Z0fyPC1oW6_ELQfn0=i4iw@xxxxxxxxxxxxxx/
Looking at the dis-assembly it looks like in effect they are slightly
different for arm64.
i.e., before this patch we had
"dmb osh{ld/st}"
and after the patch we have :
"dsb {ld/st}"
Is this really what we want ? I don't think this is desirable.
Suzuki
Cc: Mathieu Poirier <mathieu.poirier@xxxxxxxxxx>
Cc: Suzuki K Poulose <suzuki.poulose@xxxxxxx>
Signed-off-by: Sai Prakash Ranjan <quic_saipraka@xxxxxxxxxxx>
Reviewed-by: Arnd Bergmann <arnd@xxxxxxxx>
---
drivers/hwtracing/coresight/coresight-etm4x-core.c | 8 ++++----
drivers/hwtracing/coresight/coresight-etm4x.h | 8 ++++----
2 files changed, 8 insertions(+), 8 deletions(-)
diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
index 7f416a12000e..81c0faf45b28 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
+++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
@@ -98,7 +98,7 @@ u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
}
if (!_relaxed)
- __iormb(res); /* Imitate the !relaxed I/O helpers */
+ __io_ar(res); /* Imitate the !relaxed I/O helpers */
return res;
}
@@ -106,7 +106,7 @@ u64 etm4x_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
void etm4x_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit)
{
if (!_relaxed)
- __iowmb(); /* Imitate the !relaxed I/O helpers */
+ __io_bw(); /* Imitate the !relaxed I/O helpers */
if (!_64bit)
val &= GENMASK(31, 0);
@@ -130,7 +130,7 @@ static u64 ete_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
}
if (!_relaxed)
- __iormb(res); /* Imitate the !relaxed I/O helpers */
+ __io_ar(res); /* Imitate the !relaxed I/O helpers */
return res;
}
@@ -138,7 +138,7 @@ static u64 ete_sysreg_read(u32 offset, bool _relaxed, bool _64bit)
static void ete_sysreg_write(u64 val, u32 offset, bool _relaxed, bool _64bit)
{
if (!_relaxed)
- __iowmb(); /* Imitate the !relaxed I/O helpers */
+ __io_bw(); /* Imitate the !relaxed I/O helpers */
if (!_64bit)
val &= GENMASK(31, 0);
diff --git a/drivers/hwtracing/coresight/coresight-etm4x.h b/drivers/hwtracing/coresight/coresight-etm4x.h
index 3c4d69b096ca..f54698731582 100644
--- a/drivers/hwtracing/coresight/coresight-etm4x.h
+++ b/drivers/hwtracing/coresight/coresight-etm4x.h
@@ -448,14 +448,14 @@
#define etm4x_read32(csa, offset) \
({ \
u32 __val = etm4x_relaxed_read32((csa), (offset)); \
- __iormb(__val); \
+ __io_ar(__val); \
__val; \
})
#define etm4x_read64(csa, offset) \
({ \
u64 __val = etm4x_relaxed_read64((csa), (offset)); \
- __iormb(__val); \
+ __io_ar(__val); \
__val; \
})
@@ -479,13 +479,13 @@
#define etm4x_write32(csa, val, offset) \
do { \
- __iowmb(); \
+ __io_bw(); \
etm4x_relaxed_write32((csa), (val), (offset)); \
} while (0)
#define etm4x_write64(csa, val, offset) \
do { \
- __iowmb(); \
+ __io_bw(); \
etm4x_relaxed_write64((csa), (val), (offset)); \
} while (0)
