linux/arch/arm64/include/asm/arch_gicv3.h
Alexandru Elisei 3367805909 irqchip/gic-v3: Support pseudo-NMIs when SCR_EL3.FIQ == 0
The GIC's internal view of the priority mask register and the assigned
interrupt priorities are based on whether GIC security is enabled and
whether firmware routes Group 0 interrupts to EL3. At the moment, we
support priority masking when ICC_PMR_EL1 and interrupt priorities are
either both modified by the GIC, or both left unchanged.

Trusted Firmware-A's default interrupt routing model allows Group 0
interrupts to be delivered to the non-secure world (SCR_EL3.FIQ == 0).
Unfortunately, this is precisely the case that the GIC driver doesn't
support: ICC_PMR_EL1 remains unchanged, but the GIC's view of interrupt
priorities is different from the software programmed values.

Support pseudo-NMIs when SCR_EL3.FIQ == 0 by using a different value to
mask regular interrupts. All the other values remain the same.

Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20200912153707.667731-3-alexandru.elisei@arm.com
2020-09-13 17:52:04 +01:00

181 lines
4.0 KiB
C

/* SPDX-License-Identifier: GPL-2.0-only */
/*
* arch/arm64/include/asm/arch_gicv3.h
*
* Copyright (C) 2015 ARM Ltd.
*/
#ifndef __ASM_ARCH_GICV3_H
#define __ASM_ARCH_GICV3_H
#include <asm/sysreg.h>
#ifndef __ASSEMBLY__
#include <linux/irqchip/arm-gic-common.h>
#include <linux/stringify.h>
#include <asm/barrier.h>
#include <asm/cacheflush.h>
#define read_gicreg(r) read_sysreg_s(SYS_ ## r)
#define write_gicreg(v, r) write_sysreg_s(v, SYS_ ## r)
/*
* Low-level accessors
*
* These system registers are 32 bits, but we make sure that the compiler
* sets the GP register's most significant bits to 0 with an explicit cast.
*/
static inline void gic_write_eoir(u32 irq)
{
write_sysreg_s(irq, SYS_ICC_EOIR1_EL1);
isb();
}
static __always_inline void gic_write_dir(u32 irq)
{
write_sysreg_s(irq, SYS_ICC_DIR_EL1);
isb();
}
static inline u64 gic_read_iar_common(void)
{
u64 irqstat;
irqstat = read_sysreg_s(SYS_ICC_IAR1_EL1);
dsb(sy);
return irqstat;
}
/*
* Cavium ThunderX erratum 23154
*
* The gicv3 of ThunderX requires a modified version for reading the
* IAR status to ensure data synchronization (access to icc_iar1_el1
* is not sync'ed before and after).
*/
static inline u64 gic_read_iar_cavium_thunderx(void)
{
u64 irqstat;
nops(8);
irqstat = read_sysreg_s(SYS_ICC_IAR1_EL1);
nops(4);
mb();
return irqstat;
}
static inline void gic_write_ctlr(u32 val)
{
write_sysreg_s(val, SYS_ICC_CTLR_EL1);
isb();
}
static inline u32 gic_read_ctlr(void)
{
return read_sysreg_s(SYS_ICC_CTLR_EL1);
}
static inline void gic_write_grpen1(u32 val)
{
write_sysreg_s(val, SYS_ICC_IGRPEN1_EL1);
isb();
}
static inline void gic_write_sgi1r(u64 val)
{
write_sysreg_s(val, SYS_ICC_SGI1R_EL1);
}
static inline u32 gic_read_sre(void)
{
return read_sysreg_s(SYS_ICC_SRE_EL1);
}
static inline void gic_write_sre(u32 val)
{
write_sysreg_s(val, SYS_ICC_SRE_EL1);
isb();
}
static inline void gic_write_bpr1(u32 val)
{
write_sysreg_s(val, SYS_ICC_BPR1_EL1);
}
static inline u32 gic_read_pmr(void)
{
return read_sysreg_s(SYS_ICC_PMR_EL1);
}
static __always_inline void gic_write_pmr(u32 val)
{
write_sysreg_s(val, SYS_ICC_PMR_EL1);
}
static inline u32 gic_read_rpr(void)
{
return read_sysreg_s(SYS_ICC_RPR_EL1);
}
#define gic_read_typer(c) readq_relaxed(c)
#define gic_write_irouter(v, c) writeq_relaxed(v, c)
#define gic_read_lpir(c) readq_relaxed(c)
#define gic_write_lpir(v, c) writeq_relaxed(v, c)
#define gic_flush_dcache_to_poc(a,l) __flush_dcache_area((a), (l))
#define gits_read_baser(c) readq_relaxed(c)
#define gits_write_baser(v, c) writeq_relaxed(v, c)
#define gits_read_cbaser(c) readq_relaxed(c)
#define gits_write_cbaser(v, c) writeq_relaxed(v, c)
#define gits_write_cwriter(v, c) writeq_relaxed(v, c)
#define gicr_read_propbaser(c) readq_relaxed(c)
#define gicr_write_propbaser(v, c) writeq_relaxed(v, c)
#define gicr_write_pendbaser(v, c) writeq_relaxed(v, c)
#define gicr_read_pendbaser(c) readq_relaxed(c)
#define gicr_write_vpropbaser(v, c) writeq_relaxed(v, c)
#define gicr_read_vpropbaser(c) readq_relaxed(c)
#define gicr_write_vpendbaser(v, c) writeq_relaxed(v, c)
#define gicr_read_vpendbaser(c) readq_relaxed(c)
static inline bool gic_prio_masking_enabled(void)
{
return system_uses_irq_prio_masking();
}
static inline void gic_pmr_mask_irqs(void)
{
BUILD_BUG_ON(GICD_INT_DEF_PRI < (__GIC_PRIO_IRQOFF |
GIC_PRIO_PSR_I_SET));
BUILD_BUG_ON(GICD_INT_DEF_PRI >= GIC_PRIO_IRQON);
/*
* Need to make sure IRQON allows IRQs when SCR_EL3.FIQ is cleared
* and non-secure PMR accesses are not subject to the shifts that
* are applied to IRQ priorities
*/
BUILD_BUG_ON((0x80 | (GICD_INT_DEF_PRI >> 1)) >= GIC_PRIO_IRQON);
/*
* Same situation as above, but now we make sure that we can mask
* regular interrupts.
*/
BUILD_BUG_ON((0x80 | (GICD_INT_DEF_PRI >> 1)) < (__GIC_PRIO_IRQOFF_NS |
GIC_PRIO_PSR_I_SET));
gic_write_pmr(GIC_PRIO_IRQOFF);
}
static inline void gic_arch_enable_irqs(void)
{
asm volatile ("msr daifclr, #2" : : : "memory");
}
#endif /* __ASSEMBLY__ */
#endif /* __ASM_ARCH_GICV3_H */