linux_dsm_epyc7002/arch/arm/include/asm/cp15.h
Russell King f5fe12b1ea ARM: spectre-v2: harden user aborts in kernel space
In order to prevent aliasing attacks on the branch predictor,
invalidate the BTB or instruction cache on CPUs that are known to be
affected when taking an abort on a address that is outside of a user
task limit:

Cortex A8, A9, A12, A17, A73, A75: flush BTB.
Cortex A15, Brahma B15: invalidate icache.

If the IBE bit is not set, then there is little point to enabling the
workaround.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Boot-tested-by: Tony Lindgren <tony@atomide.com>
Reviewed-by: Tony Lindgren <tony@atomide.com>
2018-05-31 10:40:32 +01:00

139 lines
3.8 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef __ASM_ARM_CP15_H
#define __ASM_ARM_CP15_H
#include <asm/barrier.h>
/*
* CR1 bits (CP#15 CR1)
*/
#define CR_M (1 << 0) /* MMU enable */
#define CR_A (1 << 1) /* Alignment abort enable */
#define CR_C (1 << 2) /* Dcache enable */
#define CR_W (1 << 3) /* Write buffer enable */
#define CR_P (1 << 4) /* 32-bit exception handler */
#define CR_D (1 << 5) /* 32-bit data address range */
#define CR_L (1 << 6) /* Implementation defined */
#define CR_B (1 << 7) /* Big endian */
#define CR_S (1 << 8) /* System MMU protection */
#define CR_R (1 << 9) /* ROM MMU protection */
#define CR_F (1 << 10) /* Implementation defined */
#define CR_Z (1 << 11) /* Implementation defined */
#define CR_I (1 << 12) /* Icache enable */
#define CR_V (1 << 13) /* Vectors relocated to 0xffff0000 */
#define CR_RR (1 << 14) /* Round Robin cache replacement */
#define CR_L4 (1 << 15) /* LDR pc can set T bit */
#define CR_DT (1 << 16)
#ifdef CONFIG_MMU
#define CR_HA (1 << 17) /* Hardware management of Access Flag */
#else
#define CR_BR (1 << 17) /* MPU Background region enable (PMSA) */
#endif
#define CR_IT (1 << 18)
#define CR_ST (1 << 19)
#define CR_FI (1 << 21) /* Fast interrupt (lower latency mode) */
#define CR_U (1 << 22) /* Unaligned access operation */
#define CR_XP (1 << 23) /* Extended page tables */
#define CR_VE (1 << 24) /* Vectored interrupts */
#define CR_EE (1 << 25) /* Exception (Big) Endian */
#define CR_TRE (1 << 28) /* TEX remap enable */
#define CR_AFE (1 << 29) /* Access flag enable */
#define CR_TE (1 << 30) /* Thumb exception enable */
#ifndef __ASSEMBLY__
#if __LINUX_ARM_ARCH__ >= 4
#define vectors_high() (get_cr() & CR_V)
#else
#define vectors_high() (0)
#endif
#ifdef CONFIG_CPU_CP15
#define __ACCESS_CP15(CRn, Op1, CRm, Op2) \
"mrc", "mcr", __stringify(p15, Op1, %0, CRn, CRm, Op2), u32
#define __ACCESS_CP15_64(Op1, CRm) \
"mrrc", "mcrr", __stringify(p15, Op1, %Q0, %R0, CRm), u64
#define __read_sysreg(r, w, c, t) ({ \
t __val; \
asm volatile(r " " c : "=r" (__val)); \
__val; \
})
#define read_sysreg(...) __read_sysreg(__VA_ARGS__)
#define __write_sysreg(v, r, w, c, t) asm volatile(w " " c : : "r" ((t)(v)))
#define write_sysreg(v, ...) __write_sysreg(v, __VA_ARGS__)
#define BPIALL __ACCESS_CP15(c7, 0, c5, 6)
#define ICIALLU __ACCESS_CP15(c7, 0, c5, 0)
extern unsigned long cr_alignment; /* defined in entry-armv.S */
static inline unsigned long get_cr(void)
{
unsigned long val;
asm("mrc p15, 0, %0, c1, c0, 0 @ get CR" : "=r" (val) : : "cc");
return val;
}
static inline void set_cr(unsigned long val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 0 @ set CR"
: : "r" (val) : "cc");
isb();
}
static inline unsigned int get_auxcr(void)
{
unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 1 @ get AUXCR" : "=r" (val));
return val;
}
static inline void set_auxcr(unsigned int val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 1 @ set AUXCR"
: : "r" (val));
isb();
}
#define CPACC_FULL(n) (3 << (n * 2))
#define CPACC_SVC(n) (1 << (n * 2))
#define CPACC_DISABLE(n) (0 << (n * 2))
static inline unsigned int get_copro_access(void)
{
unsigned int val;
asm("mrc p15, 0, %0, c1, c0, 2 @ get copro access"
: "=r" (val) : : "cc");
return val;
}
static inline void set_copro_access(unsigned int val)
{
asm volatile("mcr p15, 0, %0, c1, c0, 2 @ set copro access"
: : "r" (val) : "cc");
isb();
}
#else /* ifdef CONFIG_CPU_CP15 */
/*
* cr_alignment is tightly coupled to cp15 (at least in the minds of the
* developers). Yielding 0 for machines without a cp15 (and making it
* read-only) is fine for most cases and saves quite some #ifdeffery.
*/
#define cr_alignment UL(0)
static inline unsigned long get_cr(void)
{
return 0;
}
#endif /* ifdef CONFIG_CPU_CP15 / else */
#endif /* ifndef __ASSEMBLY__ */
#endif