Commit 1fe4d453 authored by Sandrine Bailleux's avatar Sandrine Bailleux
Browse files

Break down BL1 AArch64 synchronous exception handler

The AArch64 synchronous exception vector code in BL1 is almost
reaching its architectural limit of 32 instructions. This means
there is very little space for this code to grow.

This patch reduces the size of the exception vector code by
moving most of its code in a function to which we branch from
SynchronousExceptionA64.

Change-Id: Ib35351767a685fb2c2398029d32e54026194f7ed
parent a3a34899
Showing with 49 additions and 44 deletions
+49 -44
......@@ -115,51 +115,13 @@ SynchronousExceptionA64:
/* Enable the SError interrupt */
msr daifclr, #DAIF_ABT_BIT
/* ------------------------------------------------
* Only a single SMC exception from BL2 to ask
* BL1 to pass EL3 control to BL31 is expected
* here.
* It expects X0 with RUN_IMAGE SMC function id
* X1 with address of a entry_point_info_t structure
* describing the BL3-1 entrypoint
* ------------------------------------------------
*/
mov x19, x0
mov x20, x1
mrs x0, esr_el3
ubfx x1, x0, #ESR_EC_SHIFT, #ESR_EC_LENGTH
cmp x1, #EC_AARCH64_SMC
b.ne panic
/* Expect only SMC exceptions */
mrs x19, esr_el3
ubfx x20, x19, #ESR_EC_SHIFT, #ESR_EC_LENGTH
cmp x20, #EC_AARCH64_SMC
b.ne unexpected_sync_exception
mov x0, #RUN_IMAGE
cmp x19, x0
b.ne panic
mov x0, x20
bl display_boot_progress
ldp x0, x1, [x20, #ENTRY_POINT_INFO_PC_OFFSET]
msr elr_el3, x0
msr spsr_el3, x1
ubfx x0, x1, #MODE_EL_SHIFT, #2
cmp x0, #MODE_EL3
b.ne panic
bl disable_mmu_icache_el3
tlbi alle3
ldp x6, x7, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x30)]
ldp x4, x5, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x20)]
ldp x2, x3, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x10)]
ldp x0, x1, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x0)]
eret
panic:
mov x0, #SYNC_EXCEPTION_AARCH64
bl plat_report_exception
wfi
b panic
b smc_handler64
check_vector_size SynchronousExceptionA64
.align 7
......@@ -214,3 +176,46 @@ SErrorA32:
bl plat_report_exception
b SErrorA32
check_vector_size SErrorA32
func smc_handler64
/* ---------------------------------------------------------------------
* Only a single SMC exception from BL2 to ask BL1 to pass EL3 control
* to BL31 is expected here. It expects:
* - X0 with RUN_IMAGE SMC function ID;
* - X1 with the address of a entry_point_info_t structure describing
* the BL31 entrypoint.
* ---------------------------------------------------------------------
*/
mov x19, x0
mov x20, x1
mov x0, #RUN_IMAGE
cmp x19, x0
b.ne unexpected_sync_exception
mov x0, x20
bl display_boot_progress
ldp x0, x1, [x20, #ENTRY_POINT_INFO_PC_OFFSET]
msr elr_el3, x0
msr spsr_el3, x1
ubfx x0, x1, #MODE_EL_SHIFT, #2
cmp x0, #MODE_EL3
b.ne unexpected_sync_exception
bl disable_mmu_icache_el3
tlbi alle3
ldp x6, x7, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x30)]
ldp x4, x5, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x20)]
ldp x2, x3, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x10)]
ldp x0, x1, [x20, #(ENTRY_POINT_INFO_ARGS_OFFSET + 0x0)]
eret
endfunc smc_handler64
unexpected_sync_exception:
mov x0, #SYNC_EXCEPTION_AARCH64
bl plat_report_exception
wfi
b unexpected_sync_exception
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