mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-24 11:36:44 +07:00
f226650494
The GICv3 architecture specification is incredibly misleading when it comes to PMR and the requirement for a DSB. It turns out that this DSB is only required if the CPU interface sends an Upstream Control message to the redistributor in order to update the RD's view of PMR. This message is only sent when ICC_CTLR_EL1.PMHE is set, which isn't the case in Linux. It can still be set from EL3, so some special care is required. But the upshot is that in the (hopefuly large) majority of the cases, we can drop the DSB altogether. This relies on a new static key being set if the boot CPU has PMHE set. The drawback is that this static key has to be exported to modules. Cc: Will Deacon <will@kernel.org> Cc: James Morse <james.morse@arm.com> Cc: Julien Thierry <julien.thierry.kdev@gmail.com> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
173 lines
4.1 KiB
C
173 lines
4.1 KiB
C
/* SPDX-License-Identifier: GPL-2.0-only */
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/*
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* Based on arch/arm/include/asm/barrier.h
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*
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* Copyright (C) 2012 ARM Ltd.
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*/
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#ifndef __ASM_BARRIER_H
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#define __ASM_BARRIER_H
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#ifndef __ASSEMBLY__
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#include <linux/kasan-checks.h>
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#define __nops(n) ".rept " #n "\nnop\n.endr\n"
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#define nops(n) asm volatile(__nops(n))
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#define sev() asm volatile("sev" : : : "memory")
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#define wfe() asm volatile("wfe" : : : "memory")
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#define wfi() asm volatile("wfi" : : : "memory")
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#define isb() asm volatile("isb" : : : "memory")
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#define dmb(opt) asm volatile("dmb " #opt : : : "memory")
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#define dsb(opt) asm volatile("dsb " #opt : : : "memory")
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#define psb_csync() asm volatile("hint #17" : : : "memory")
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#define csdb() asm volatile("hint #20" : : : "memory")
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#define spec_bar() asm volatile(ALTERNATIVE("dsb nsh\nisb\n", \
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SB_BARRIER_INSN"nop\n", \
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ARM64_HAS_SB))
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#ifdef CONFIG_ARM64_PSEUDO_NMI
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#define pmr_sync() \
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do { \
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extern struct static_key_false gic_pmr_sync; \
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\
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if (static_branch_unlikely(&gic_pmr_sync)) \
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dsb(sy); \
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} while(0)
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#else
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#define pmr_sync() do {} while (0)
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#endif
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#define mb() dsb(sy)
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#define rmb() dsb(ld)
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#define wmb() dsb(st)
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#define dma_rmb() dmb(oshld)
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#define dma_wmb() dmb(oshst)
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/*
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* Generate a mask for array_index__nospec() that is ~0UL when 0 <= idx < sz
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* and 0 otherwise.
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*/
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#define array_index_mask_nospec array_index_mask_nospec
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static inline unsigned long array_index_mask_nospec(unsigned long idx,
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unsigned long sz)
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{
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unsigned long mask;
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asm volatile(
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" cmp %1, %2\n"
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" sbc %0, xzr, xzr\n"
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: "=r" (mask)
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: "r" (idx), "Ir" (sz)
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: "cc");
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csdb();
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return mask;
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}
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#define __smp_mb() dmb(ish)
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#define __smp_rmb() dmb(ishld)
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#define __smp_wmb() dmb(ishst)
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#define __smp_store_release(p, v) \
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do { \
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typeof(p) __p = (p); \
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union { typeof(*p) __val; char __c[1]; } __u = \
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{ .__val = (__force typeof(*p)) (v) }; \
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compiletime_assert_atomic_type(*p); \
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kasan_check_write(__p, sizeof(*p)); \
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switch (sizeof(*p)) { \
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case 1: \
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asm volatile ("stlrb %w1, %0" \
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: "=Q" (*__p) \
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: "r" (*(__u8 *)__u.__c) \
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: "memory"); \
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break; \
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case 2: \
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asm volatile ("stlrh %w1, %0" \
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: "=Q" (*__p) \
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: "r" (*(__u16 *)__u.__c) \
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: "memory"); \
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break; \
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case 4: \
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asm volatile ("stlr %w1, %0" \
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: "=Q" (*__p) \
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: "r" (*(__u32 *)__u.__c) \
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: "memory"); \
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break; \
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case 8: \
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asm volatile ("stlr %1, %0" \
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: "=Q" (*__p) \
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: "r" (*(__u64 *)__u.__c) \
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: "memory"); \
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break; \
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} \
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} while (0)
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#define __smp_load_acquire(p) \
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({ \
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union { typeof(*p) __val; char __c[1]; } __u; \
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typeof(p) __p = (p); \
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compiletime_assert_atomic_type(*p); \
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kasan_check_read(__p, sizeof(*p)); \
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switch (sizeof(*p)) { \
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case 1: \
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asm volatile ("ldarb %w0, %1" \
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: "=r" (*(__u8 *)__u.__c) \
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: "Q" (*__p) : "memory"); \
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break; \
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case 2: \
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asm volatile ("ldarh %w0, %1" \
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: "=r" (*(__u16 *)__u.__c) \
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: "Q" (*__p) : "memory"); \
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break; \
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case 4: \
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asm volatile ("ldar %w0, %1" \
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: "=r" (*(__u32 *)__u.__c) \
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: "Q" (*__p) : "memory"); \
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break; \
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case 8: \
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asm volatile ("ldar %0, %1" \
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: "=r" (*(__u64 *)__u.__c) \
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: "Q" (*__p) : "memory"); \
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break; \
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} \
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__u.__val; \
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})
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#define smp_cond_load_relaxed(ptr, cond_expr) \
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({ \
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typeof(ptr) __PTR = (ptr); \
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typeof(*ptr) VAL; \
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for (;;) { \
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VAL = READ_ONCE(*__PTR); \
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if (cond_expr) \
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break; \
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__cmpwait_relaxed(__PTR, VAL); \
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} \
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VAL; \
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})
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#define smp_cond_load_acquire(ptr, cond_expr) \
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({ \
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typeof(ptr) __PTR = (ptr); \
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typeof(*ptr) VAL; \
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for (;;) { \
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VAL = smp_load_acquire(__PTR); \
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if (cond_expr) \
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break; \
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__cmpwait_relaxed(__PTR, VAL); \
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} \
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VAL; \
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})
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#include <asm-generic/barrier.h>
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#endif /* __ASSEMBLY__ */
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#endif /* __ASM_BARRIER_H */
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