// Copyright 2013, ARM Limited
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright notice,
// this list of conditions and the following disclaimer in the documentation
// and/or other materials provided with the distribution.
// * Neither the name of ARM Limited nor the names of its contributors may be
// used to endorse or promote products derived from this software without
// specific prior written permission.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS CONTRIBUTORS "AS IS" AND
// ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
// WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
// DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
// FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
// DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
// SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
// OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
#include "utils-vixl.h"
#include "a64/cpu-a64.h"
namespace vixl {
// Initialise to smallest possible cache size.
unsigned CPU::dcache_line_size_ = 1;
unsigned CPU::icache_line_size_ = 1;
// Currently computes I and D cache line size.
void CPU::SetUp() {
uint32_t cache_type_register = GetCacheType();
// The cache type register holds information about the caches, including I
// D caches line size.
static const int kDCacheLineSizeShift = 16;
static const int kICacheLineSizeShift = 0;
static const uint32_t kDCacheLineSizeMask = 0xf << kDCacheLineSizeShift;
static const uint32_t kICacheLineSizeMask = 0xf << kICacheLineSizeShift;
// The cache type register holds the size of the I and D caches as a power of
// two.
uint32_t dcache_line_size_power_of_two =
(cache_type_register & kDCacheLineSizeMask) >> kDCacheLineSizeShift;
uint32_t icache_line_size_power_of_two =
(cache_type_register & kICacheLineSizeMask) >> kICacheLineSizeShift;
dcache_line_size_ = 1 << dcache_line_size_power_of_two;
icache_line_size_ = 1 << icache_line_size_power_of_two;
}
uint32_t CPU::GetCacheType() {
#ifdef USE_SIMULATOR
// This will lead to a cache with 1 byte long lines, which is fine since the
// simulator will not need this information.
return 0;
#else
uint32_t cache_type_register;
// Copy the content of the cache type register to a core register.
__asm__ __volatile__ ("mrs %[ctr], ctr_el0" // NOLINT
: [ctr] "=r" (cache_type_register));
return cache_type_register;
#endif
}
void CPU::EnsureIAndDCacheCoherency(void *address, size_t length) {
#ifdef USE_SIMULATOR
USE(address);
USE(length);
// TODO: consider adding cache simulation to ensure every address run has been
// synchronised.
#else
// The code below assumes user space cache operations are allowed.
uintptr_t start = reinterpret_cast<uintptr_t>(address);
// Sizes will be used to generate a mask big enough to cover a pointer.
uintptr_t dsize = static_cast<uintptr_t>(dcache_line_size_);
uintptr_t isize = static_cast<uintptr_t>(icache_line_size_);
// Cache line sizes are always a power of 2.
VIXL_ASSERT(CountSetBits(dsize, 64) == 1);
VIXL_ASSERT(CountSetBits(isize, 64) == 1);
uintptr_t dstart = start & ~(dsize - 1);
uintptr_t istart = start & ~(isize - 1);
uintptr_t end = start + length;
__asm__ __volatile__ ( // NOLINT
// Clean every line of the D cache containing the target data.
"0: \n\t"
// dc : Data Cache maintenance
// c : Clean
// va : by (Virtual) Address
// u : to the point of Unification
// The point of unification for a processor is the point by which the
// instruction and data caches are guaranteed to see the same copy of a
// memory location. See ARM DDI 0406B page B2-12 for more information.
"dc cvau, %[dline] \n\t"
"add %[dline], %[dline], %[dsize] \n\t"
"cmp %[dline], %[end] \n\t"
"b.lt 0b \n\t"
// Barrier to make sure the effect of the code above is visible to the rest
// of the world.
// dsb : Data Synchronisation Barrier
// ish : Inner SHareable domain
// The point of unification for an Inner Shareable shareability domain is
// the point by which the instruction and data caches of all the processors
// in that Inner Shareable shareability domain are guaranteed to see the
// same copy of a memory location. See ARM DDI 0406B page B2-12 for more
// information.
"dsb ish \n\t"
// Invalidate every line of the I cache containing the target data.
"1: \n\t"
// ic : instruction cache maintenance
// i : invalidate
// va : by address
// u : to the point of unification
"ic ivau, %[iline] \n\t"
"add %[iline], %[iline], %[isize] \n\t"
"cmp %[iline], %[end] \n\t"
"b.lt 1b \n\t"
// Barrier to make sure the effect of the code above is visible to the rest
// of the world.
"dsb ish \n\t"
// Barrier to ensure any prefetching which happened before this code is
// discarded.
// isb : Instruction Synchronisation Barrier
"isb \n\t"
: [dline] "+r" (dstart),
[iline] "+r" (istart)
: [dsize] "r" (dsize),
[isize] "r" (isize),
[end] "r" (end)
// This code does not write to memory but without the dependency gcc might
// move this code before the code is generated.
: "cc", "memory"
); // NOLINT
#endif
}
} // namespace vixl