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wvoec3: add membarriers to complete cache flush am: cbfc3c7193

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Original change: https://googleplex-android-review.googlesource.com/c/platform/vendor/widevine/+/13719187

MUST ONLY BE SUBMITTED BY AUTOMERGER

Change-Id: I6f57d5bacfef47e2ebed665cb540e29a1fd44fe6
This commit is contained in:
Robert Shih
2021-03-02 05:34:28 +00:00
committed by Automerger Merge Worker
parent 475ea683d9 cbfc3c7193
commit 48ca2c099c
1 changed files with 60 additions and 2 deletions
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62
libwvdrmengine/level3/include/clear_cache_function.h
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@@ -1,13 +1,65 @@
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#if __mips__
#include <linux/membarrier.h>
#include <sys/syscall.h>
#include <asm/cachectl.h>
#include <sys/utsname.h>
#if __mips__
# include <asm/cachectl.h>
#endif
#include "log.h"
namespace wvoec3 {
bool supports_membarier_syscall() {
// Check kernel version supports membarrier(2); version 4.16 is required.
static constexpr int kRequiredMajor = 4;
static constexpr int kRequiredMinor = 16;
struct utsname uts;
int major = 0, minor = 0;
if (uname(&uts) != 0 || strcmp(uts.sysname, "Linux") != 0 ||
sscanf(uts.release, "%d.%d", &major, &minor) != 2) {
LOGE("Failed to get kernel version");
return false;
}
if (major < kRequiredMajor ||
(major == kRequiredMajor && minor < kRequiredMinor)) {
LOGE("Kernel version %d, %d < required %d, %d", major, minor,
kRequiredMajor, kRequiredMinor);
return false;
}
return true;
}
#if defined(__NR_membarrier)
// membarrier function is used to complete flush of CPU instruction pipelines.
// Reference:
// * membarrier(2)
// * art::jit::JitMemoryRegion::CommitCode
int membarrier_function(int command) {
static bool supports_membarier = supports_membarier_syscall();
if (supports_membarier) {
return syscall(__NR_membarrier, command, 0);
}
errno = ENOSYS;
return -1;
}
#else // __NR_membarrier
# pragma message \
"(info): __NR_membarrier unavailable; membarrier_function will be no-op."
int membarrier_function(int) {
errno = ENOSYS;
return -1;
}
#endif // __NR_membarrier
// The Cache Flush function is very processor dependent, and is used by the
// Level3 code using platform-specific flags.
// Linked in separately from the rest of the build, since this code isn't
@@ -58,6 +110,12 @@ void clear_cache_function(void *page, size_t len) {
// TODO(fredgc): silence warning about unused variables.
#endif
#endif
#if defined(__arm__) || defined(__aarch64__)
# pragma message "(info): inserting membarrier_function calls."
membarrier_function(MEMBARRIER_CMD_REGISTER_PRIVATE_EXPEDITED_SYNC_CORE);
membarrier_function(MEMBARRIER_CMD_PRIVATE_EXPEDITED_SYNC_CORE);
#endif // defined(__arm__) || defined(__aarch64__)
}
} // namespace wvoec3