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/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2012 Regents of the University of California
*/
#ifndef _ASM_RISCV_PROCESSOR_H
#define _ASM_RISCV_PROCESSOR_H
#include <linux/const.h>
#include <linux/cache.h>
#include <linux/prctl.h>
#include <vdso/processor.h>
#include <asm/ptrace.h>
/*
* addr is a hint to the maximum userspace address that mmap should provide, so
* this macro needs to return the largest address space available so that
* mmap_end < addr, being mmap_end the top of that address space.
* See Documentation/arch/riscv/vm-layout.rst for more details.
*/
#define arch_get_mmap_end(addr, len, flags) \
({ \
unsigned long mmap_end; \
typeof(addr) _addr = (addr); \
if ((_addr) == 0 || is_compat_task() || \
((_addr + len) > BIT(VA_BITS - 1))) \
mmap_end = STACK_TOP_MAX; \
else \
mmap_end = (_addr + len); \
mmap_end; \
})
#define arch_get_mmap_base(addr, base) \
({ \
unsigned long mmap_base; \
typeof(addr) _addr = (addr); \
typeof(base) _base = (base); \
unsigned long rnd_gap = DEFAULT_MAP_WINDOW - (_base); \
if ((_addr) == 0 || is_compat_task() || \
((_addr + len) > BIT(VA_BITS - 1))) \
mmap_base = (_base); \
else \
mmap_base = (_addr + len) - rnd_gap; \
mmap_base; \
})
#ifdef CONFIG_64BIT
#define DEFAULT_MAP_WINDOW (UL(1) << (MMAP_VA_BITS - 1))
#define STACK_TOP_MAX TASK_SIZE_64
#else
#define DEFAULT_MAP_WINDOW TASK_SIZE
#define STACK_TOP_MAX TASK_SIZE
#endif
#define STACK_ALIGN 16
#define STACK_TOP DEFAULT_MAP_WINDOW
/*
* This decides where the kernel will search for a free chunk of vm
* space during mmap's.
*/
#ifdef CONFIG_64BIT
#define TASK_UNMAPPED_BASE PAGE_ALIGN((UL(1) << MMAP_MIN_VA_BITS) / 3)
#else
#define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
#endif
#ifndef __ASSEMBLY__
struct task_struct;
struct pt_regs;
/*
* We use a flag to track in-kernel Vector context. Currently the flag has the
* following meaning:
*
* - bit 0: indicates whether the in-kernel Vector context is active. The
* activation of this state disables the preemption. On a non-RT kernel, it
* also disable bh.
* - bits 8: is used for tracking preemptible kernel-mode Vector, when
* RISCV_ISA_V_PREEMPTIVE is enabled. Calling kernel_vector_begin() does not
* disable the preemption if the thread's kernel_vstate.datap is allocated.
* Instead, the kernel set this bit field. Then the trap entry/exit code
* knows if we are entering/exiting the context that owns preempt_v.
* - 0: the task is not using preempt_v
* - 1: the task is actively using preempt_v. But whether does the task own
* the preempt_v context is decided by bits in RISCV_V_CTX_DEPTH_MASK.
* - bit 16-23 are RISCV_V_CTX_DEPTH_MASK, used by context tracking routine
* when preempt_v starts:
* - 0: the task is actively using, and own preempt_v context.
* - non-zero: the task was using preempt_v, but then took a trap within.
* Thus, the task does not own preempt_v. Any use of Vector will have to
* save preempt_v, if dirty, and fallback to non-preemptible kernel-mode
* Vector.
* - bit 30: The in-kernel preempt_v context is saved, and requries to be
* restored when returning to the context that owns the preempt_v.
* - bit 31: The in-kernel preempt_v context is dirty, as signaled by the
* trap entry code. Any context switches out-of current task need to save
* it to the task's in-kernel V context. Also, any traps nesting on-top-of
* preempt_v requesting to use V needs a save.
*/
#define RISCV_V_CTX_DEPTH_MASK 0x00ff0000
#define RISCV_V_CTX_UNIT_DEPTH 0x00010000
#define RISCV_KERNEL_MODE_V 0x00000001
#define RISCV_PREEMPT_V 0x00000100
#define RISCV_PREEMPT_V_DIRTY 0x80000000
#define RISCV_PREEMPT_V_NEED_RESTORE 0x40000000
/* CPU-specific state of a task */
struct thread_struct {
/* Callee-saved registers */
unsigned long ra;
unsigned long sp; /* Kernel mode stack */
unsigned long s[12]; /* s[0]: frame pointer */
struct __riscv_d_ext_state fstate;
unsigned long bad_cause;
u32 riscv_v_flags;
u32 vstate_ctrl;
struct __riscv_v_ext_state vstate;
unsigned long align_ctl;
struct __riscv_v_ext_state kernel_vstate;
};
/* Whitelist the fstate from the task_struct for hardened usercopy */
static inline void arch_thread_struct_whitelist(unsigned long *offset,
unsigned long *size)
{
*offset = offsetof(struct thread_struct, fstate);
*size = sizeof_field(struct thread_struct, fstate);
}
#define INIT_THREAD { \
.sp = sizeof(init_stack) + (long)&init_stack, \
.align_ctl = PR_UNALIGN_NOPRINT, \
}
#define task_pt_regs(tsk) \
((struct pt_regs *)(task_stack_page(tsk) + THREAD_SIZE \
- ALIGN(sizeof(struct pt_regs), STACK_ALIGN)))
#define KSTK_EIP(tsk) (task_pt_regs(tsk)->epc)
#define KSTK_ESP(tsk) (task_pt_regs(tsk)->sp)
/* Do necessary setup to start up a newly executed thread. */
extern void start_thread(struct pt_regs *regs,
unsigned long pc, unsigned long sp);
extern unsigned long __get_wchan(struct task_struct *p);
static inline void wait_for_interrupt(void)
{
__asm__ __volatile__ ("wfi");
}
extern phys_addr_t dma32_phys_limit;
struct device_node;
int riscv_of_processor_hartid(struct device_node *node, unsigned long *hartid);
int riscv_early_of_processor_hartid(struct device_node *node, unsigned long *hartid);
int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid);
extern void riscv_fill_hwcap(void);
extern int arch_dup_task_struct(struct task_struct *dst, struct task_struct *src);
extern unsigned long signal_minsigstksz __ro_after_init;
#ifdef CONFIG_RISCV_ISA_V
/* Userspace interface for PR_RISCV_V_{SET,GET}_VS prctl()s: */
#define RISCV_V_SET_CONTROL(arg) riscv_v_vstate_ctrl_set_current(arg)
#define RISCV_V_GET_CONTROL() riscv_v_vstate_ctrl_get_current()
extern long riscv_v_vstate_ctrl_set_current(unsigned long arg);
extern long riscv_v_vstate_ctrl_get_current(void);
#endif /* CONFIG_RISCV_ISA_V */
extern int get_unalign_ctl(struct task_struct *tsk, unsigned long addr);
extern int set_unalign_ctl(struct task_struct *tsk, unsigned int val);
#define GET_UNALIGN_CTL(tsk, addr) get_unalign_ctl((tsk), (addr))
#define SET_UNALIGN_CTL(tsk, val) set_unalign_ctl((tsk), (val))
#endif /* __ASSEMBLY__ */
#endif /* _ASM_RISCV_PROCESSOR_H */
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