diff options
Diffstat (limited to 'lib/cpus/aarch32/cpu_helpers.S')
| -rw-r--r-- | lib/cpus/aarch32/cpu_helpers.S | 246 |
1 files changed, 246 insertions, 0 deletions
diff --git a/lib/cpus/aarch32/cpu_helpers.S b/lib/cpus/aarch32/cpu_helpers.S new file mode 100644 index 00000000..bfdc1e4f --- /dev/null +++ b/lib/cpus/aarch32/cpu_helpers.S @@ -0,0 +1,246 @@ +/* + * Copyright (c) 2016-2017, ARM Limited and Contributors. All rights reserved. + * + * SPDX-License-Identifier: BSD-3-Clause + */ + +#include <arch.h> +#include <asm_macros.S> +#include <assert_macros.S> +#include <cpu_data.h> +#include <cpu_macros.S> + +#if defined(IMAGE_BL1) || defined(IMAGE_BL32) + /* + * The reset handler common to all platforms. After a matching + * cpu_ops structure entry is found, the correponding reset_handler + * in the cpu_ops is invoked. The reset handler is invoked very early + * in the boot sequence and it is assumed that we can clobber r0 - r10 + * without the need to follow AAPCS. + * Clobbers: r0 - r10 + */ + .globl reset_handler +func reset_handler + mov r10, lr + + /* The plat_reset_handler can clobber r0 - r9 */ + bl plat_reset_handler + + /* Get the matching cpu_ops pointer (clobbers: r0 - r5) */ + bl get_cpu_ops_ptr + +#if ENABLE_ASSERTIONS + cmp r0, #0 + ASM_ASSERT(ne) +#endif + + /* Get the cpu_ops reset handler */ + ldr r1, [r0, #CPU_RESET_FUNC] + cmp r1, #0 + mov lr, r10 + bxne r1 + bx lr +endfunc reset_handler + +#endif /* IMAGE_BL1 || IMAGE_BL32 */ + +#ifdef IMAGE_BL32 /* The power down core and cluster is needed only in BL32 */ + /* + * void prepare_cpu_pwr_dwn(unsigned int power_level) + * + * Prepare CPU power down function for all platforms. The function takes + * a domain level to be powered down as its parameter. After the cpu_ops + * pointer is retrieved from cpu_data, the handler for requested power + * level is called. + */ + .globl prepare_cpu_pwr_dwn +func prepare_cpu_pwr_dwn + /* + * If the given power level exceeds CPU_MAX_PWR_DWN_OPS, we call the + * power down handler for the last power level + */ + mov r2, #(CPU_MAX_PWR_DWN_OPS - 1) + cmp r0, r2 + movhi r0, r2 + + push {r0, lr} + bl _cpu_data + pop {r2, lr} + + ldr r0, [r0, #CPU_DATA_CPU_OPS_PTR] +#if ENABLE_ASSERTIONS + cmp r0, #0 + ASM_ASSERT(ne) +#endif + + /* Get the appropriate power down handler */ + mov r1, #CPU_PWR_DWN_OPS + add r1, r1, r2, lsl #2 + ldr r1, [r0, r1] + bx r1 +endfunc prepare_cpu_pwr_dwn + + /* + * Initializes the cpu_ops_ptr if not already initialized + * in cpu_data. This must only be called after the data cache + * is enabled. AAPCS is followed. + */ + .globl init_cpu_ops +func init_cpu_ops + push {r4 - r6, lr} + bl _cpu_data + mov r6, r0 + ldr r1, [r0, #CPU_DATA_CPU_OPS_PTR] + cmp r1, #0 + bne 1f + bl get_cpu_ops_ptr +#if ENABLE_ASSERTIONS + cmp r0, #0 + ASM_ASSERT(ne) +#endif + str r0, [r6, #CPU_DATA_CPU_OPS_PTR]! +1: + pop {r4 - r6, pc} +endfunc init_cpu_ops + +#endif /* IMAGE_BL32 */ + + /* + * The below function returns the cpu_ops structure matching the + * midr of the core. It reads the MIDR and finds the matching + * entry in cpu_ops entries. Only the implementation and part number + * are used to match the entries. + * Return : + * r0 - The matching cpu_ops pointer on Success + * r0 - 0 on failure. + * Clobbers: r0 - r5 + */ + .globl get_cpu_ops_ptr +func get_cpu_ops_ptr + /* Get the cpu_ops start and end locations */ + ldr r4, =(__CPU_OPS_START__ + CPU_MIDR) + ldr r5, =(__CPU_OPS_END__ + CPU_MIDR) + + /* Initialize the return parameter */ + mov r0, #0 + + /* Read the MIDR_EL1 */ + ldcopr r2, MIDR + ldr r3, =CPU_IMPL_PN_MASK + + /* Retain only the implementation and part number using mask */ + and r2, r2, r3 +1: + /* Check if we have reached end of list */ + cmp r4, r5 + bhs error_exit + + /* load the midr from the cpu_ops */ + ldr r1, [r4], #CPU_OPS_SIZE + and r1, r1, r3 + + /* Check if midr matches to midr of this core */ + cmp r1, r2 + bne 1b + + /* Subtract the increment and offset to get the cpu-ops pointer */ + sub r0, r4, #(CPU_OPS_SIZE + CPU_MIDR) +error_exit: + bx lr +endfunc get_cpu_ops_ptr + +/* + * Extract CPU revision and variant, and combine them into a single numeric for + * easier comparison. + */ + .globl cpu_get_rev_var +func cpu_get_rev_var + ldcopr r1, MIDR + + /* + * Extract the variant[23:20] and revision[3:0] from r1 and pack it in + * r0[0:7] as variant[7:4] and revision[3:0]: + * + * First extract r1[23:16] to r0[7:0] and zero fill the rest. Then + * extract r1[3:0] into r0[3:0] retaining other bits. + */ + ubfx r0, r1, #(MIDR_VAR_SHIFT - MIDR_REV_BITS), #(MIDR_REV_BITS + MIDR_VAR_BITS) + bfi r0, r1, #MIDR_REV_SHIFT, #MIDR_REV_BITS + bx lr +endfunc cpu_get_rev_var + +/* + * Compare the CPU's revision-variant (r0) with a given value (r1), for errata + * application purposes. If the revision-variant is less than or same as a given + * value, indicates that errata applies; otherwise not. + */ + .globl cpu_rev_var_ls +func cpu_rev_var_ls + cmp r0, r1 + movls r0, #ERRATA_APPLIES + movhi r0, #ERRATA_NOT_APPLIES + bx lr +endfunc cpu_rev_var_ls + +/* + * Compare the CPU's revision-variant (r0) with a given value (r1), for errata + * application purposes. If the revision-variant is higher than or same as a + * given value, indicates that errata applies; otherwise not. + */ + .globl cpu_rev_var_hs +func cpu_rev_var_hs + cmp r0, r1 + movge r0, #ERRATA_APPLIES + movlt r0, #ERRATA_NOT_APPLIES + bx lr +endfunc cpu_rev_var_hs + +#if REPORT_ERRATA +/* + * void print_errata_status(void); + * + * Function to print errata status for CPUs of its class. Must be called only: + * + * - with MMU and data caches are enabled; + * - after cpu_ops have been initialized in per-CPU data. + */ + .globl print_errata_status +func print_errata_status + push {r4, lr} +#ifdef IMAGE_BL1 + /* + * BL1 doesn't have per-CPU data. So retrieve the CPU operations + * directly. + */ + bl get_cpu_ops_ptr + ldr r0, [r0, #CPU_ERRATA_FUNC] + cmp r0, #0 + blxne r0 +#else + /* + * Retrieve pointer to cpu_ops, and further, the errata printing + * function. If it's non-NULL, jump to the function in turn. + */ + bl _cpu_data + ldr r1, [r0, #CPU_DATA_CPU_OPS_PTR] + ldr r0, [r1, #CPU_ERRATA_FUNC] + cmp r0, #0 + beq 1f + + mov r4, r0 + + /* + * Load pointers to errata lock and printed flag. Call + * errata_needs_reporting to check whether this CPU needs to report + * errata status pertaining to its class. + */ + ldr r0, [r1, #CPU_ERRATA_LOCK] + ldr r1, [r1, #CPU_ERRATA_PRINTED] + bl errata_needs_reporting + cmp r0, #0 + blxne r4 +1: +#endif + pop {r4, pc} +endfunc print_errata_status +#endif |