linux_dsm_epyc7002/arch/arm64/include/asm/cache.h
Catalin Marinas ebc7e21e0f arm64: Increase ARCH_DMA_MINALIGN to 128
This patch increases the ARCH_DMA_MINALIGN to 128 so that it covers the
currently known Cache Writeback Granule (CTR_EL0.CWG) on arm64 and moves
the fallback in cache_line_size() from L1_CACHE_BYTES to this constant.
In addition, it warns (and taints) if the CWG is larger than
ARCH_DMA_MINALIGN as this is not safe with non-coherent DMA.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-05-15 13:29:55 +01:00

86 lines
2.2 KiB
C

/*
* Copyright (C) 2012 ARM Ltd.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#ifndef __ASM_CACHE_H
#define __ASM_CACHE_H
#include <asm/cputype.h>
#define CTR_L1IP_SHIFT 14
#define CTR_L1IP_MASK 3
#define CTR_DMINLINE_SHIFT 16
#define CTR_ERG_SHIFT 20
#define CTR_CWG_SHIFT 24
#define CTR_CWG_MASK 15
#define CTR_IDC_SHIFT 28
#define CTR_DIC_SHIFT 29
#define CTR_L1IP(ctr) (((ctr) >> CTR_L1IP_SHIFT) & CTR_L1IP_MASK)
#define ICACHE_POLICY_VPIPT 0
#define ICACHE_POLICY_VIPT 2
#define ICACHE_POLICY_PIPT 3
#define L1_CACHE_SHIFT (6)
#define L1_CACHE_BYTES (1 << L1_CACHE_SHIFT)
/*
* Memory returned by kmalloc() may be used for DMA, so we must make
* sure that all such allocations are cache aligned. Otherwise,
* unrelated code may cause parts of the buffer to be read into the
* cache before the transfer is done, causing old data to be seen by
* the CPU.
*/
#define ARCH_DMA_MINALIGN (128)
#ifndef __ASSEMBLY__
#include <linux/bitops.h>
#define ICACHEF_ALIASING 0
#define ICACHEF_VPIPT 1
extern unsigned long __icache_flags;
/*
* Whilst the D-side always behaves as PIPT on AArch64, aliasing is
* permitted in the I-cache.
*/
static inline int icache_is_aliasing(void)
{
return test_bit(ICACHEF_ALIASING, &__icache_flags);
}
static inline int icache_is_vpipt(void)
{
return test_bit(ICACHEF_VPIPT, &__icache_flags);
}
static inline u32 cache_type_cwg(void)
{
return (read_cpuid_cachetype() >> CTR_CWG_SHIFT) & CTR_CWG_MASK;
}
#define __read_mostly __attribute__((__section__(".data..read_mostly")))
static inline int cache_line_size(void)
{
u32 cwg = cache_type_cwg();
return cwg ? 4 << cwg : ARCH_DMA_MINALIGN;
}
#endif /* __ASSEMBLY__ */
#endif