linux/arch/arm64/include/asm/cache.h
Suzuki K Poulose 4c4a39dd5f arm64: Fix mismatched cache line size detection
If there is a mismatch in the I/D min line size, we must
always use the system wide safe value both in applications
and in the kernel, while performing cache operations. However,
we have been checking more bits than just the min line sizes,
which triggers false negatives. We may need to trap the user
accesses in such cases, but not necessarily patch the kernel.

This patch fixes the check to do the right thing as advertised.
A new capability will be added to check mismatches in other
fields and ensure we trap the CTR accesses.

Fixes: be68a8aaf9 ("arm64: cpufeature: Fix CTR_EL0 field definitions")
Cc: <stable@vger.kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
2018-07-05 10:19:57 +01:00

90 lines
2.3 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_IMINLINE_SHIFT 0
#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_CACHE_MINLINE_MASK \
(0xf << CTR_DMINLINE_SHIFT | 0xf << CTR_IMINLINE_SHIFT)
#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