Commit 3a72c94e authored by Russell Currey's avatar Russell Currey Committed by Michael Ellerman

selftests/powerpc: Fix L1D flushing tests for Power10

The rfi_flush and entry_flush selftests work by using the PM_LD_MISS_L1
perf event to count L1D misses.  The value of this event has changed
over time:

- Power7 uses 0x400f0
- Power8 and Power9 use both 0x400f0 and 0x3e054
- Power10 uses only 0x3e054

Rather than relying on raw values, configure perf to count L1D read
misses in the most explicit way available.

This fixes the selftests to work on systems without 0x400f0 as
PM_LD_MISS_L1, and should change no behaviour for systems that the tests
already worked on.

The only potential downside is that referring to a specific perf event
requires PMU support implemented in the kernel for that platform.
Signed-off-by: default avatarRussell Currey <ruscur@russell.cc>
Acked-by: default avatarDaniel Axtens <dja@axtens.net>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20210223070227.2916871-1-ruscur@russell.cc
parent 5c4a4802
...@@ -53,7 +53,7 @@ int entry_flush_test(void) ...@@ -53,7 +53,7 @@ int entry_flush_test(void)
entry_flush = entry_flush_orig; entry_flush = entry_flush_orig;
fd = perf_event_open_counter(PERF_TYPE_RAW, /* L1d miss */ 0x400f0, -1); fd = perf_event_open_counter(PERF_TYPE_HW_CACHE, PERF_L1D_READ_MISS_CONFIG, -1);
FAIL_IF(fd < 0); FAIL_IF(fd < 0);
p = (char *)memalign(zero_size, CACHELINE_SIZE); p = (char *)memalign(zero_size, CACHELINE_SIZE);
......
...@@ -9,6 +9,10 @@ ...@@ -9,6 +9,10 @@
#define CACHELINE_SIZE 128 #define CACHELINE_SIZE 128
#define PERF_L1D_READ_MISS_CONFIG ((PERF_COUNT_HW_CACHE_L1D) | \
(PERF_COUNT_HW_CACHE_OP_READ << 8) | \
(PERF_COUNT_HW_CACHE_RESULT_MISS << 16))
void syscall_loop(char *p, unsigned long iterations, void syscall_loop(char *p, unsigned long iterations,
unsigned long zero_size); unsigned long zero_size);
......
...@@ -54,7 +54,7 @@ int rfi_flush_test(void) ...@@ -54,7 +54,7 @@ int rfi_flush_test(void)
rfi_flush = rfi_flush_orig; rfi_flush = rfi_flush_orig;
fd = perf_event_open_counter(PERF_TYPE_RAW, /* L1d miss */ 0x400f0, -1); fd = perf_event_open_counter(PERF_TYPE_HW_CACHE, PERF_L1D_READ_MISS_CONFIG, -1);
FAIL_IF(fd < 0); FAIL_IF(fd < 0);
p = (char *)memalign(zero_size, CACHELINE_SIZE); p = (char *)memalign(zero_size, CACHELINE_SIZE);
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment