coreboot-kgpe-d16/payloads/libpayload/arch/arm64/cpu.S
Julius Werner bf33b03acf libpayload: arm64: Keep instruction cache enabled at all times
This patch makes libpayload enable the instruction cache as the very
first thing, which is similar to how we treat it in coreboot. It also
prevents the icache from being disabled again during mmu_disable() as
part of the two-stage page table setup in post_sysinfo_scan_mmu_setup().
It replaces the existing mmu_disable() implementation with the assembly
version from coreboot which handles certain edge cases better (see
CB:27238 for details).

The SCTLR flag definitions in libpayload seem to have still been
copy&pasted from arm32, so replace with the actual arm64 defintions from
coreboot.

Change-Id: Ifdbec34f0875ecc69fedcbea5c20e943379a3d2d
Signed-off-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38908
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
2020-02-17 15:42:34 +00:00

113 lines
3.9 KiB
ArmAsm

/*
* Optimized assembly for low-level CPU operations on ARM64 processors.
*
* Copyright (c) 2010 Per Odlund <per.odlund@armagedon.se>
* Copyright (c) 2014 Google Inc.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <arch/asm.h>
#include <arch/lib_helpers.h>
.macro dcache_apply_all crm
dsb sy
mrs x0, clidr_el1 // read CLIDR
and w3, w0, #0x07000000 // narrow to LoC
lsr w3, w3, #23 // left align LoC (low 4 bits)
cbz w3, 5f //done
mov w10, #0 // w10 = 2 * cache level
mov w8, #1 // w8 = constant 0b1
1: //next_level
add w2, w10, w10, lsr #1 // calculate 3 * cache level
lsr w1, w0, w2 // extract 3-bit cache type for this level
and w1, w1, #0x7 // w1 = cache type
cmp w1, #2 // is it data or i&d?
b.lt 4f //skip
msr csselr_el1, x10 // select current cache level
isb // sync change of csselr
mrs x1, ccsidr_el1 // w1 = read ccsidr
and w2, w1, #7 // w2 = log2(linelen_bytes) - 4
add w2, w2, #4 // w2 = log2(linelen_bytes)
ubfx w4, w1, #3, #10 // w4 = associativity - 1 (also
// max way number)
clz w5, w4 // w5 = 32 - log2(ways)
// (bit position of way in DC)
lsl w9, w4, w5 // w9 = max way number
// (aligned for DC)
lsl w16, w8, w5 // w16 = amount to decrement (way
// number per iteration)
2: //next_way
ubfx w7, w1, #13, #15 // w7 = max set #, right aligned
lsl w7, w7, w2 // w7 = max set #, DC aligned
lsl w17, w8, w2 // w17 = amount to decrement (set
// number per iteration)
3: //next_set
orr w11, w10, w9 // w11 = combine way # & cache #
orr w11, w11, w7 // ... and set #
dc \crm, x11 // clean and/or invalidate line
subs w7, w7, w17 // decrement set number
b.ge 3b //next_set
subs x9, x9, x16 // decrement way number
b.ge 2b //next_way
4: //skip
add w10, w10, #2 // increment 2 *cache level
cmp w3, w10 // Went beyond LoC?
b.gt 1b //next_level
5: //done
dsb sy
isb
ret
.endm
ENTRY(dcache_invalidate_all)
dcache_apply_all crm=isw
ENDPROC(dcache_invalidate_all)
ENTRY(dcache_clean_all)
dcache_apply_all crm=csw
ENDPROC(dcache_clean_all)
ENTRY(dcache_clean_invalidate_all)
dcache_apply_all crm=cisw
ENDPROC(dcache_clean_invalidate_all)
/* This must be implemented in assembly to ensure there are no accesses to
memory (e.g. the stack) in between disabling and flushing the cache. */
ENTRY(mmu_disable)
str x30, [sp, #-0x8]
mrs x0, sctlr_el2
mov x1, #~(SCTLR_C | SCTLR_M)
and x0, x0, x1
msr sctlr_el2, x0
isb
bl dcache_clean_invalidate_all
ldr x30, [sp, #-0x8]
ret
ENDPROC(mmu_disable)