Commit ec3c1003 authored by Achin Gupta's avatar Achin Gupta
Browse files

Simplify management of SCTLR_EL3 and SCTLR_EL1

This patch reworks the manner in which the M,A, C, SA, I, WXN & EE bits of
SCTLR_EL3 & SCTLR_EL1 are managed. The EE bit is cleared immediately after reset
in EL3. The I, A and SA bits are set next in EL3 and immediately upon entry in
S-EL1. These bits are no longer managed in the blX_arch_setup() functions. They
do not have to be saved and restored either. The M, WXN and optionally the C
bit are set in the enable_mmu_elX() function. This is done during both the warm
and cold boot paths.

Fixes ARM-software/tf-issues#226

Change-Id: Ie894d1a07b8697c116960d858cd138c50bc7a069
parent 539a7b38
......@@ -37,20 +37,11 @@
******************************************************************************/
void bl1_arch_setup(void)
{
unsigned long tmp_reg = 0;
/* Enable alignment checks */
tmp_reg = read_sctlr_el3();
tmp_reg |= (SCTLR_A_BIT | SCTLR_SA_BIT);
write_sctlr_el3(tmp_reg);
isb();
/*
* Set the next EL to be AArch64, route external abort and SError
* interrupts to EL3
*/
tmp_reg = SCR_RES1_BITS | SCR_RW_BIT | SCR_EA_BIT;
write_scr(tmp_reg);
write_scr_el3(SCR_RES1_BITS | SCR_RW_BIT | SCR_EA_BIT);
/*
* Enable SError and Debug exceptions
......
......@@ -44,7 +44,7 @@
func bl1_entrypoint
/* ---------------------------------------------
* Set the CPU endianness before doing anything
* that might involve memory reads or writes
* that might involve memory reads or writes.
* ---------------------------------------------
*/
mrs x0, sctlr_el3
......@@ -59,12 +59,14 @@ func bl1_entrypoint
*/
bl cpu_reset_handler
/* -------------------------------
* Enable the instruction cache.
* -------------------------------
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
* and data access alignment checks
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el3
orr x0, x0, #SCTLR_I_BIT
orr x0, x0, x1
msr sctlr_el3, x0
isb
......
......@@ -65,11 +65,13 @@ func bl2_entrypoint
msr vbar_el1, x0
/* ---------------------------------------------
* Enable the instruction cache.
* Enable the instruction cache, stack pointer
* and data access alignment checks
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, #SCTLR_I_BIT
orr x0, x0, x1
msr sctlr_el1, x0
isb
......
......@@ -42,21 +42,12 @@
******************************************************************************/
void bl31_arch_setup(void)
{
unsigned long tmp_reg = 0;
uint64_t counter_freq;
/* Enable alignment checks */
tmp_reg = read_sctlr_el3();
tmp_reg |= (SCTLR_A_BIT | SCTLR_SA_BIT);
write_sctlr_el3(tmp_reg);
/*
* Route external abort and SError interrupts to EL3
* other SCR bits will be configured before exiting to a lower exception
* level
*/
tmp_reg = SCR_RES1_BITS | SCR_EA_BIT;
write_scr(tmp_reg);
write_scr_el3(SCR_RES1_BITS | SCR_EA_BIT);
/*
* Enable SError and Debug exceptions
......@@ -65,6 +56,5 @@ void bl31_arch_setup(void)
enable_debug_exceptions();
/* Program the counter frequency */
counter_freq = plat_get_syscnt_freq();
write_cntfrq_el0(counter_freq);
write_cntfrq_el0(plat_get_syscnt_freq());
}
......@@ -52,6 +52,15 @@ func bl31_entrypoint
mov x20, x0
mov x21, x1
#else
/* ---------------------------------------------
* Set the CPU endianness before doing anything
* that might involve memory reads or writes.
* ---------------------------------------------
*/
mrs x0, sctlr_el3
bic x0, x0, #SCTLR_EE_BIT
msr sctlr_el3, x0
isb
/* -----------------------------------------------------
* Perform any processor specific actions upon reset
......@@ -61,14 +70,15 @@ func bl31_entrypoint
*/
bl cpu_reset_handler
#endif
/* ---------------------------------------------
* Enable the instruction cache.
* Enable the instruction cache, stack pointer
* and data access alignment checks
* ---------------------------------------------
*/
mrs x1, sctlr_el3
orr x1, x1, #SCTLR_I_BIT
msr sctlr_el3, x1
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el3
orr x0, x0, x1
msr sctlr_el3, x0
isb
/* ---------------------------------------------
......
......@@ -89,11 +89,13 @@ func tsp_entrypoint
msr vbar_el1, x0
/* ---------------------------------------------
* Enable the instruction cache.
* Enable the instruction cache, stack pointer
* and data access alignment checks
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, #SCTLR_I_BIT
orr x0, x0, x1
msr sctlr_el1, x0
isb
......@@ -196,11 +198,13 @@ func tsp_cpu_on_entry
msr vbar_el1, x0
/* ---------------------------------------------
* Enable the instruction cache.
* Enable the instruction cache, stack pointer
* and data access alignment checks
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el1
orr x0, x0, #SCTLR_I_BIT
orr x0, x0, x1
msr sctlr_el1, x0
isb
......
......@@ -129,11 +129,8 @@
#define SCTLR_A_BIT (1 << 1)
#define SCTLR_C_BIT (1 << 2)
#define SCTLR_SA_BIT (1 << 3)
#define SCTLR_B_BIT (1 << 7)
#define SCTLR_Z_BIT (1 << 11)
#define SCTLR_I_BIT (1 << 12)
#define SCTLR_WXN_BIT (1 << 19)
#define SCTLR_EXCEPTION_BITS (0x3 << 6)
#define SCTLR_EE_BIT (1 << 25)
/* CPUECTLR definitions */
......
......@@ -329,8 +329,7 @@ void init_xlat_tables(void)
isb(); \
\
sctlr = read_sctlr_el##_el(); \
sctlr |= SCTLR_WXN_BIT | SCTLR_M_BIT | SCTLR_I_BIT; \
sctlr |= SCTLR_A_BIT; \
sctlr |= SCTLR_WXN_BIT | SCTLR_M_BIT; \
\
if (flags & DISABLE_DCACHE) \
sctlr &= ~SCTLR_C_BIT; \
......
......@@ -54,6 +54,25 @@ psci_aff_suspend_finish_entry:
adr x23, psci_afflvl_suspend_finishers
psci_aff_common_finish_entry:
#if !RESET_TO_BL31
/* ---------------------------------------------
* Enable the instruction cache, stack pointer
* and data access alignment checks. Also, set
* the EL3 exception endianess to little-endian.
* It can be assumed that BL3-1 entrypoint code
* will do this when RESET_TO_BL31 is set. The
* same assumption cannot be made when another
* boot loader executes before BL3-1 in the warm
* boot path e.g. BL1.
* ---------------------------------------------
*/
mov x1, #(SCTLR_I_BIT | SCTLR_A_BIT | SCTLR_SA_BIT)
mrs x0, sctlr_el3
orr x0, x0, x1
msr sctlr_el3, x0
isb
#endif
/* ---------------------------------------------
* Initialise the pcpu cache pointer for the CPU
* ---------------------------------------------
......
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