include/bl31/ehf.h

   1 /*
   2  * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
   3  *
   4  * SPDX-License-Identifier: BSD-3-Clause
   5  */
   6
   7 #ifndef EHF_H
   8 #define EHF_H
   9
  10 #ifndef __ASSEMBLY__
  11
  12 #include <cdefs.h>
  13 #include <stdint.h>
  14
  15 #include <lib/utils_def.h>
  16
  17 /* Valid priorities set bit 0 of the priority handler. */
  18 #define EHF_PRI_VALID_  BIT(0)
  19
  20 /* Marker for no handler registered for a valid priority */
  21 #define EHF_NO_HANDLER_ (0U | EHF_PRI_VALID_)
  22
  23 /* Extract the specified number of top bits from 7 lower bits of priority */
  24 #define EHF_PRI_TO_IDX(pri, plat_bits) \
  25         ((((unsigned) (pri)) & 0x7fu) >> (7u - (plat_bits)))
  26
  27 /* Install exception priority descriptor at a suitable index */
  28 #define EHF_PRI_DESC(plat_bits, priority) \
  29         [EHF_PRI_TO_IDX(priority, plat_bits)] = { \
  30                 .ehf_handler = EHF_NO_HANDLER_, \
  31         }
  32
  33 /* Macro for platforms to regiter its exception priorities */
  34 #define EHF_REGISTER_PRIORITIES(priorities, num, bits) \
  35         const ehf_priorities_t exception_data = { \
  36                 .num_priorities = (num), \
  37                 .ehf_priorities = (priorities), \
  38                 .pri_bits = (bits), \
  39         }
  40
  41 /*
  42  * Priority stack, managed as a bitmap.
  43  *
  44  * Currently only supports 32 priority levels, allowing platforms to use up to 5
  45  * top bits of priority. But the type can be changed to uint64_t should need
  46  * arise to support 64 priority levels, allowing platforms to use up to 6 top
  47  * bits of priority.
  48  */
  49 typedef uint32_t ehf_pri_bits_t;
  50
  51 /*
  52  * Per-PE exception data. The data for each PE is kept as a per-CPU data field.
  53  * See cpu_data.h.
  54  */
  55 typedef struct {
  56         ehf_pri_bits_t active_pri_bits;
  57
  58         /* Priority mask value before any priority levels were active */
  59         uint8_t init_pri_mask;
  60
  61         /* Non-secure priority mask value stashed during Secure execution */
  62         uint8_t ns_pri_mask;
  63 } __aligned(sizeof(uint64_t)) pe_exc_data_t;
  64
  65 typedef int (*ehf_handler_t)(uint32_t intr_raw, uint32_t flags, void *handle,
  66                 void *cookie);
  67
  68 typedef struct ehf_pri_desc {
  69         /*
  70          * 4-byte-aligned exception handler. Bit 0 indicates the corresponding
  71          * priority level is valid. This is effectively of ehf_handler_t type,
  72          * but left as uintptr_t in order to make pointer arithmetic convenient.
  73          */
  74         uintptr_t ehf_handler;
  75 } ehf_pri_desc_t;
  76
  77 typedef struct ehf_priority_type {
  78         ehf_pri_desc_t *ehf_priorities;
  79         unsigned int num_priorities;
  80         unsigned int pri_bits;
  81 } ehf_priorities_t;
  82
  83 void ehf_init(void);
  84 void ehf_activate_priority(unsigned int priority);
  85 void ehf_deactivate_priority(unsigned int priority);
  86 void ehf_register_priority_handler(unsigned int pri, ehf_handler_t handler);
  87 void ehf_allow_ns_preemption(uint64_t preempt_ret_code);
  88 unsigned int ehf_is_ns_preemption_allowed(void);
  89
  90 #endif /* __ASSEMBLY__ */
  91
  92 #endif /* EHF_H */