linux/arch/arm64/include/asm/arch_gicv3.h
Marc Zyngier 33625282ad irqchip/gic-v3: Probe for SCR_EL3 being clear before resetting AP0Rn
We would like to reset the Group-0 Active Priority Registers
at boot time if they are available to us. They would be available
if SCR_EL3.FIQ was not set, but we cannot directly probe this bit,
and short of checking, we may end-up trapping to EL3, and the
firmware may not be please to get such an exception. Yes, this
is dumb.

Instead, let's use PMR to find out if its value gets affected by
SCR_EL3.FIQ being set. We use the fact that when SCR_EL3.FIQ is
set, the LSB of the priority is lost due to the shifting back and
forth of the actual priority. If we read back a 0, we know that
Group0 is unavailable. In case we read a non-zero value, we can
safely reset the AP0Rn register.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-22 13:46:18 +00:00

145 lines
3.4 KiB
C

/*
* arch/arm64/include/asm/arch_gicv3.h
*
* Copyright (C) 2015 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_ARCH_GICV3_H
#define __ASM_ARCH_GICV3_H
#include <asm/sysreg.h>
#ifndef __ASSEMBLY__
#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 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);
}
#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 gits_write_vpropbaser(v, c) writeq_relaxed(v, c)
#define gits_write_vpendbaser(v, c) writeq_relaxed(v, c)
#define gits_read_vpendbaser(c) readq_relaxed(c)
#endif /* __ASSEMBLY__ */
#endif /* __ASM_ARCH_GICV3_H */