arm-trusted-firmware/include/lib/cpus/aarch64/cpu_macros.S
Arvind Ram Prakash bbff267b6f fix(errata-abi): add support for handling split workarounds
Certain erratum workarounds like Neoverse N1 1542419, need a part
of their mitigation done in EL3 and the rest in lower EL. But currently
such workarounds return HIGHER_EL_MITIGATION which indicates that the
erratum has already been mitigated by a higher EL(EL3 in this case)
which causes the lower EL to not apply it's part of the mitigation.

This patch fixes this issue by adding support for split workarounds
so that on certain errata we return AFFECTED even though EL3 has
applied it's workaround. This is done by reusing the chosen field of
erratum_entry structure into a bitfield that has two bitfields -
Bit 0 indicates that the erratum has been enabled in build,
Bit 1 indicates that the erratum is a split workaround and should
return AFFECTED instead of HIGHER_EL_MITIGATION.

SDEN documentation:
https://developer.arm.com/documentation/SDEN885747/latest

Signed-off-by: Arvind Ram Prakash <arvind.ramprakash@arm.com>
Change-Id: Iec94d665b5f55609507a219a7d1771eb75e7f4a7
2025-03-07 17:02:25 +01:00

659 lines
17 KiB
ArmAsm

/*
* Copyright (c) 2014-2025, Arm Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#ifndef CPU_MACROS_S
#define CPU_MACROS_S
#include <assert_macros.S>
#include <lib/cpus/cpu_ops.h>
#include <lib/cpus/errata.h>
/*
* Write given expressions as quad words
*
* _count:
* Write at least _count quad words. If the given number of
* expressions is less than _count, repeat the last expression to
* fill _count quad words in total
* _rest:
* Optional list of expressions. _this is for parameter extraction
* only, and has no significance to the caller
*
* Invoked as:
* fill_constants 2, foo, bar, blah, ...
*/
.macro fill_constants _count:req, _this, _rest:vararg
.ifgt \_count
/* Write the current expression */
.ifb \_this
.error "Nothing to fill"
.endif
.quad \_this
/* Invoke recursively for remaining expressions */
.ifnb \_rest
fill_constants \_count-1, \_rest
.else
fill_constants \_count-1, \_this
.endif
.endif
.endm
/*
* Declare CPU operations
*
* _name:
* Name of the CPU for which operations are being specified
* _midr:
* Numeric value expected to read from CPU's MIDR
* _resetfunc:
* Reset function for the CPU.
* _extra1:
* This is a placeholder for future per CPU operations. Currently,
* some CPUs use this entry to set a test function to determine if
* the workaround for CVE-2017-5715 needs to be applied or not.
* _extra2:
* This is a placeholder for future per CPU operations. Currently
* some CPUs use this entry to set a function to disable the
* workaround for CVE-2018-3639.
* _extra3:
* This is a placeholder for future per CPU operations. Currently,
* some CPUs use this entry to set a test function to determine if
* the workaround for CVE-2022-23960 needs to be applied or not.
* _extra4:
* This is a placeholder for future per CPU operations. Currently,
* some CPUs use this entry to set a test function to determine if
* the workaround for CVE-2024-7881 needs to be applied or not.
* _e_handler:
* This is a placeholder for future per CPU exception handlers.
* _power_down_ops:
* Comma-separated list of functions to perform power-down
* operatios on the CPU. At least one, and up to
* CPU_MAX_PWR_DWN_OPS number of functions may be specified.
* Starting at power level 0, these functions shall handle power
* down at subsequent power levels. If there aren't exactly
* CPU_MAX_PWR_DWN_OPS functions, the last specified one will be
* used to handle power down at subsequent levels
*/
.macro declare_cpu_ops_base _name:req, _midr:req, _resetfunc:req, \
_extra1:req, _extra2:req, _extra3:req, _extra4:req, \
_e_handler:req, _power_down_ops:vararg
.section .cpu_ops, "a"
.align 3
.type cpu_ops_\_name, %object
.quad \_midr
#if defined(IMAGE_AT_EL3)
.quad \_resetfunc
#endif
.quad \_extra1
.quad \_extra2
.quad \_extra3
.quad \_extra4
.quad \_e_handler
#ifdef IMAGE_BL31
/* Insert list of functions */
fill_constants CPU_MAX_PWR_DWN_OPS, \_power_down_ops
#endif
/*
* It is possible (although unlikely) that a cpu may have no errata in
* code. In that case the start label will not be defined. The list is
* intended to be used in a loop, so define it as zero-length for
* predictable behaviour. Since this macro is always called at the end
* of the cpu file (after all errata have been parsed) we can be sure
* that we are at the end of the list. Some cpus call declare_cpu_ops
* twice, so only do this once.
*/
.pushsection .rodata.errata_entries
.ifndef \_name\()_errata_list_start
\_name\()_errata_list_start:
.endif
.ifndef \_name\()_errata_list_end
\_name\()_errata_list_end:
.endif
.popsection
/* and now put them in cpu_ops */
.quad \_name\()_errata_list_start
.quad \_name\()_errata_list_end
#if REPORT_ERRATA
.ifndef \_name\()_cpu_str
/*
* Place errata reported flag, and the spinlock to arbitrate access to
* it in the data section.
*/
.pushsection .data
define_asm_spinlock \_name\()_errata_lock
\_name\()_errata_reported:
.word 0
.popsection
/* Place CPU string in rodata */
.pushsection .rodata
\_name\()_cpu_str:
.asciz "\_name"
.popsection
.endif
.quad \_name\()_cpu_str
#ifdef IMAGE_BL31
/* Pointers to errata lock and reported flag */
.quad \_name\()_errata_lock
.quad \_name\()_errata_reported
#endif /* IMAGE_BL31 */
#endif /* REPORT_ERRATA */
#if defined(IMAGE_BL31) && CRASH_REPORTING
.quad \_name\()_cpu_reg_dump
#endif
.endm
.macro declare_cpu_ops _name:req, _midr:req, _resetfunc:req, \
_power_down_ops:vararg
declare_cpu_ops_base \_name, \_midr, \_resetfunc, 0, 0, 0, 0, 0, \
\_power_down_ops
.endm
.macro declare_cpu_ops_eh _name:req, _midr:req, _resetfunc:req, \
_e_handler:req, _power_down_ops:vararg
declare_cpu_ops_base \_name, \_midr, \_resetfunc, \
0, 0, 0, 0, \_e_handler, \_power_down_ops
.endm
.macro declare_cpu_ops_wa _name:req, _midr:req, \
_resetfunc:req, _extra1:req, _extra2:req, \
_extra3:req, _power_down_ops:vararg
declare_cpu_ops_base \_name, \_midr, \_resetfunc, \
\_extra1, \_extra2, \_extra3, 0, 0, \_power_down_ops
.endm
.macro declare_cpu_ops_wa_4 _name:req, _midr:req, \
_resetfunc:req, _extra1:req, _extra2:req, \
_extra3:req, _extra4:req, _power_down_ops:vararg
declare_cpu_ops_base \_name, \_midr, \_resetfunc, \
\_extra1, \_extra2, \_extra3, \_extra4, 0, \_power_down_ops
.endm
/*
* This macro is used on some CPUs to detect if they are vulnerable
* to CVE-2017-5715.
*/
.macro cpu_check_csv2 _reg _label
mrs \_reg, id_aa64pfr0_el1
ubfx \_reg, \_reg, #ID_AA64PFR0_CSV2_SHIFT, #ID_AA64PFR0_CSV2_LENGTH
/*
* If the field equals 1, branch targets trained in one context cannot
* affect speculative execution in a different context.
*
* If the field equals 2, it means that the system is also aware of
* SCXTNUM_ELx register contexts. We aren't using them in the TF, so we
* expect users of the registers to do the right thing.
*
* Only apply mitigations if the value of this field is 0.
*/
#if ENABLE_ASSERTIONS
cmp \_reg, #3 /* Only values 0 to 2 are expected */
ASM_ASSERT(lo)
#endif
cmp \_reg, #0
bne \_label
.endm
/*
* Helper macro that reads the part number of the current
* CPU and jumps to the given label if it matches the CPU
* MIDR provided.
*
* Clobbers x0.
*/
.macro jump_if_cpu_midr _cpu_midr, _label
mrs x0, midr_el1
ubfx x0, x0, MIDR_PN_SHIFT, #12
cmp w0, #((\_cpu_midr >> MIDR_PN_SHIFT) & MIDR_PN_MASK)
b.eq \_label
.endm
/*
* Workaround wrappers for errata that apply at reset or runtime. Reset errata
* will be applied automatically
*
* _cpu:
* Name of cpu as given to declare_cpu_ops
*
* _cve:
* Whether erratum is a CVE. CVE year if yes, 0 otherwise
*
* _id:
* Erratum or CVE number. Please combine with previous field with ERRATUM
* or CVE macros
*
* _chosen:
* Compile time flag on whether the erratum is included
*
* _split_wa:
* Flag that indicates whether an erratum has split workaround or not.
* Default value is 0.
*/
.macro add_erratum_entry _cpu:req, _cve:req, _id:req, _chosen:req, _split_wa=0
#if REPORT_ERRATA || ERRATA_ABI_SUPPORT
.pushsection .rodata.errata_entries
.align 3
.ifndef \_cpu\()_errata_list_start
\_cpu\()_errata_list_start:
.endif
.quad check_erratum_\_cpu\()_\_id
/* Will fit CVEs with up to 10 character in the ID field */
.word \_id
.hword \_cve
/* bit magic that appends chosen field based on _split_wa */
.byte ((\_chosen * 0b11) & ((\_split_wa << 1) | \_chosen))
.byte 0x0 /* alignment */
.popsection
#endif
.endm
/*******************************************************************************
* Errata workaround wrappers
******************************************************************************/
/*
* Workaround wrappers for errata that apply at reset or runtime. Reset errata
* will be applied automatically
*
* _cpu:
* Name of cpu as given to declare_cpu_ops
*
* _cve:
* Whether erratum is a CVE. CVE year if yes, 0 otherwise
*
* _id:
* Erratum or CVE number. Please combine with previous field with ERRATUM
* or CVE macros
*
* _chosen:
* Compile time flag on whether the erratum is included
*
* _split_wa:
* Flag that indicates whether an erratum has split workaround or not.
* Default value is 0.
*
* in body:
* clobber x0 to x7 (please only use those)
* argument x7 - cpu_rev_var
*
* _wa clobbers: x0-x8 (PCS compliant)
*/
.macro workaround_reset_start _cpu:req, _cve:req, _id:req, \
_chosen:req, _split_wa=0
add_erratum_entry \_cpu, \_cve, \_id, \_chosen, \_split_wa
.if \_chosen
/* put errata directly into the reset function */
.pushsection .text.asm.\_cpu\()_reset_func, "ax"
.else
/* or something else that will get garbage collected by the
* linker */
.pushsection .text.asm.erratum_\_cpu\()_\_id\()_wa, "ax"
.endif
/* revision is stored in x14, get it */
mov x0, x14
bl check_erratum_\_cpu\()_\_id
/* save rev_var for workarounds that might need it */
mov x7, x14
cbz x0, erratum_\_cpu\()_\_id\()_skip_reset
.endm
/*
* See `workaround_reset_start` for usage info. Additional arguments:
*
* _midr:
* Check if CPU's MIDR matches the CPU it's meant for. Must be specified
* for errata applied in generic code
*/
.macro workaround_runtime_start _cpu:req, _cve:req, _id:req, _chosen:req, _midr
add_erratum_entry \_cpu, \_cve, \_id, \_chosen
func erratum_\_cpu\()_\_id\()_wa
mov x8, x30
/*
* Let errata specify if they need MIDR checking. Sadly, storing the
* MIDR in an .equ to retrieve automatically blows up as it stores some
* brackets in the symbol
*/
.ifnb \_midr
jump_if_cpu_midr \_midr, 1f
b erratum_\_cpu\()_\_id\()_skip_runtime
1:
.endif
/* save rev_var for workarounds that might need it but don't
* restore to x0 because few will care */
mov x7, x0
bl check_erratum_\_cpu\()_\_id
cbz x0, erratum_\_cpu\()_\_id\()_skip_runtime
.endm
/*
* Usage and arguments identical to `workaround_reset_start`. The _cve argument
* is kept here so the same #define can be used as that macro
*/
.macro workaround_reset_end _cpu:req, _cve:req, _id:req
erratum_\_cpu\()_\_id\()_skip_reset:
.popsection
.endm
/*
* See `workaround_reset_start` for usage info. The _cve argument is kept here
* so the same #define can be used as that macro. Additional arguments:
*
* _no_isb:
* Optionally do not include the trailing isb. Please disable with the
* NO_ISB macro
*/
.macro workaround_runtime_end _cpu:req, _cve:req, _id:req, _no_isb
/*
* Runtime errata do not have a reset function to call the isb for them
* and missing the isb could be very problematic. It is also likely as
* they tend to be scattered in generic code.
*/
.ifb \_no_isb
isb
.endif
erratum_\_cpu\()_\_id\()_skip_runtime:
ret x8
endfunc erratum_\_cpu\()_\_id\()_wa
.endm
/*******************************************************************************
* Errata workaround helpers
******************************************************************************/
/*
* Set a bit in a system register. Can set multiple bits but is limited by the
* way the ORR instruction encodes them.
*
* _reg:
* Register to write to
*
* _bit:
* Bit to set. Please use a descriptive #define
*
* _assert:
* Optionally whether to read back and assert that the bit has been
* written. Please disable with NO_ASSERT macro
*
* clobbers: x1
*/
.macro sysreg_bit_set _reg:req, _bit:req, _assert=1
mrs x1, \_reg
orr x1, x1, #\_bit
msr \_reg, x1
.endm
/*
* Clear a bit in a system register. Can clear multiple bits but is limited by
* the way the BIC instrucion encodes them.
*
* see sysreg_bit_set for usage
*/
.macro sysreg_bit_clear _reg:req, _bit:req
mrs x1, \_reg
bic x1, x1, #\_bit
msr \_reg, x1
.endm
/*
* Toggle a bit in a system register. Can toggle multiple bits but is limited by
* the way the EOR instrucion encodes them.
*
* see sysreg_bit_set for usage
*/
.macro sysreg_bit_toggle _reg:req, _bit:req, _assert=1
mrs x1, \_reg
eor x1, x1, #\_bit
msr \_reg, x1
.endm
.macro override_vector_table _table:req
adr x1, \_table
msr vbar_el3, x1
.endm
/*
* BFI : Inserts bitfield into a system register.
*
* BFI{cond} Rd, Rn, #lsb, #width
*/
.macro sysreg_bitfield_insert _reg:req, _src:req, _lsb:req, _width:req
/* Source value for BFI */
mov x1, #\_src
mrs x0, \_reg
bfi x0, x1, #\_lsb, #\_width
msr \_reg, x0
.endm
.macro sysreg_bitfield_insert_from_gpr _reg:req, _gpr:req, _lsb:req, _width:req
/* Source value in register for BFI */
mov x1, \_gpr
mrs x0, \_reg
bfi x0, x1, #\_lsb, #\_width
msr \_reg, x0
.endm
/*
* Extract CPU revision and variant, and combine them into a single numeric for
* easier comparison.
*
* _res:
* register where the result will be placed
* _tmp:
* register to clobber for temporaries
*/
.macro get_rev_var _res:req, _tmp:req
mrs \_tmp, midr_el1
/*
* Extract the variant[23:20] and revision[3:0] from MIDR, and pack them
* as variant[7:4] and revision[3:0] of x0.
*
* First extract x1[23:16] to x0[7:0] and zero fill the rest. Then
* extract x1[3:0] into x0[3:0] retaining other bits.
*/
ubfx \_res, \_tmp, #(MIDR_VAR_SHIFT - MIDR_REV_BITS), #(MIDR_REV_BITS + MIDR_VAR_BITS)
bfxil \_res, \_tmp, #MIDR_REV_SHIFT, #MIDR_REV_BITS
.endm
/*
* Apply erratum
*
* _cpu:
* Name of cpu as given to declare_cpu_ops
*
* _cve:
* Whether erratum is a CVE. CVE year if yes, 0 otherwise
*
* _id:
* Erratum or CVE number. Please combine with previous field with ERRATUM
* or CVE macros
*
* _chosen:
* Compile time flag on whether the erratum is included
*
* _get_rev:
* Optional parameter that determines whether to insert a call to the CPU revision fetching
* procedure. Stores the result of this in the temporary register x10 to allow for chaining
*
* clobbers: x0-x10 (PCS compliant)
*/
.macro apply_erratum _cpu:req, _cve:req, _id:req, _chosen:req, _get_rev=GET_CPU_REV
.if (\_chosen && \_get_rev)
mov x9, x30
bl cpu_get_rev_var
mov x10, x0
.elseif (\_chosen)
mov x9, x30
mov x0, x10
.endif
.if \_chosen
bl erratum_\_cpu\()_\_id\()_wa
mov x30, x9
.endif
.endm
/*
* Helpers to report if an erratum applies. Compares the given revision variant
* to the given value. Return ERRATA_APPLIES or ERRATA_NOT_APPLIES accordingly.
*
* _rev_num: the given revision variant. Or
* _rev_num_lo,_rev_num_hi: the lower and upper bounds of the revision variant
*
* in body:
* clobber: x0
* argument: x0 - cpu_rev_var
*/
.macro cpu_rev_var_ls _rev_num:req
cmp x0, #\_rev_num
cset x0, ls
.endm
.macro cpu_rev_var_hs _rev_num:req
cmp x0, #\_rev_num
cset x0, hs
.endm
.macro cpu_rev_var_range _rev_num_lo:req, _rev_num_hi:req
cmp x0, #\_rev_num_lo
mov x1, #\_rev_num_hi
ccmp x0, x1, #2, hs
cset x0, ls
.endm
/*
* Helpers to select which revisions errata apply to.
*
* _cpu:
* Name of cpu as given to declare_cpu_ops
*
* _cve:
* Whether erratum is a CVE. CVE year if yes, 0 otherwise
*
* _id:
* Erratum or CVE number. Please combine with previous field with ERRATUM
* or CVE macros
*
* _rev_num:
* Revision to apply to
*
* in body:
* clobber: x0 to x1
* argument: x0 - cpu_rev_var
*/
.macro check_erratum_ls _cpu:req, _cve:req, _id:req, _rev_num:req
func check_erratum_\_cpu\()_\_id
cpu_rev_var_ls \_rev_num
ret
endfunc check_erratum_\_cpu\()_\_id
.endm
.macro check_erratum_hs _cpu:req, _cve:req, _id:req, _rev_num:req
func check_erratum_\_cpu\()_\_id
cpu_rev_var_hs \_rev_num
ret
endfunc check_erratum_\_cpu\()_\_id
.endm
.macro check_erratum_range _cpu:req, _cve:req, _id:req, _rev_num_lo:req, _rev_num_hi:req
func check_erratum_\_cpu\()_\_id
cpu_rev_var_range \_rev_num_lo, \_rev_num_hi
ret
endfunc check_erratum_\_cpu\()_\_id
.endm
.macro check_erratum_chosen _cpu:req, _cve:req, _id:req, _chosen:req
func check_erratum_\_cpu\()_\_id
.if \_chosen
mov x0, #ERRATA_APPLIES
.else
mov x0, #ERRATA_MISSING
.endif
ret
endfunc check_erratum_\_cpu\()_\_id
.endm
/*
* provide a shorthand for the name format for annoying errata
* body: clobber x0 to x4
*/
.macro check_erratum_custom_start _cpu:req, _cve:req, _id:req
func check_erratum_\_cpu\()_\_id
.endm
.macro check_erratum_custom_end _cpu:req, _cve:req, _id:req
endfunc check_erratum_\_cpu\()_\_id
.endm
/*******************************************************************************
* CPU reset function wrapper
******************************************************************************/
/*
* Helper to register a cpu with the errata framework. Begins the definition of
* the reset function.
*
* _cpu:
* Name of cpu as given to declare_cpu_ops
*/
.macro cpu_reset_prologue _cpu:req
func \_cpu\()_reset_func
mov x15, x30
get_rev_var x14, x0
.endm
/*
* Wrapper of the reset function to automatically apply all reset-time errata.
* Will end with an isb.
*
* _cpu:
* Name of cpu as given to declare_cpu_ops
*
* in body:
* clobber x8 to x14
* argument x14 - cpu_rev_var
*/
.macro cpu_reset_func_start _cpu:req
/* the func/endfunc macros will change sections. So change the section
* back to the reset function's */
.section .text.asm.\_cpu\()_reset_func, "ax"
.endm
.macro cpu_reset_func_end _cpu:req
isb
ret x15
endfunc \_cpu\()_reset_func
.endm
/*
* Helper macro that enables Maximum Power Mitigation Mechanism (MPMM) on
* compatible Arm cores.
*
* Clobbers x0.
*/
.macro enable_mpmm
#if ENABLE_MPMM
mrs x0, CPUPPMCR_EL3
/* if CPUPPMCR_EL3.MPMMPINCTL != 0, skip enabling MPMM */
ands x0, x0, CPUPPMCR_EL3_MPMMPINCTL_BIT
b.ne 1f
sysreg_bit_set CPUPPMCR_EL3, CPUMPMMCR_EL3_MPMM_EN_BIT
1:
#endif
.endm
#endif /* CPU_MACROS_S */