arm_fpga: Add support for topology self-discovery
As secondary cores show up, they populate an array to
announce themselves so plat_core_pos_by_mpidr() can
return an invalid COREID code for any non-existing
MPIDR that it is queried about.
The Power Domain Tree Description is populated with
a topology based on the maximum harcoded values.
Signed-off-by: Javier Almansa Sobrino <javier.almansasobrino@arm.com>
Change-Id: I8fd64761a2296714ce0f37c46544f3e6f13b5f61
diff --git a/plat/arm/board/arm_fpga/aarch64/fpga_helpers.S b/plat/arm/board/arm_fpga/aarch64/fpga_helpers.S
index aeed310..20120c9 100644
--- a/plat/arm/board/arm_fpga/aarch64/fpga_helpers.S
+++ b/plat/arm/board/arm_fpga/aarch64/fpga_helpers.S
@@ -7,6 +7,8 @@
#include <arch.h>
#include <asm_macros.S>
#include <common/bl_common.h>
+#include "../fpga_private.h"
+
#include <platform_def.h>
.globl plat_get_my_entrypoint
@@ -14,10 +16,10 @@
.globl plat_is_my_cpu_primary
.globl platform_mem_init
.globl plat_my_core_pos
- .globl plat_fpga_calc_core_pos
.globl plat_crash_console_init
.globl plat_crash_console_putc
.globl plat_crash_console_flush
+ .globl plat_fpga_calc_core_pos
/* -----------------------------------------------------------------------
* Indicate a cold boot for every CPU - warm boot is unsupported for the
@@ -34,23 +36,59 @@
* -----------------------------------------------------------------------
*/
func plat_secondary_cold_boot_setup
+
+ /*
+ * Wait for the primary processor to initialise the .BSS segment
+ * to avoid a race condition that would erase fpga_valid_mpids
+ * if it is populated before the C runtime is ready.
+ *
+ * We cannot use the current spin-lock implementation until the
+ * runtime is up and we should not rely on sevl/wfe instructions as
+ * it is optional whether they are implemented or not, so we use
+ * a global variable as lock and wait for the primary processor to
+ * finish the C runtime bring-up.
+ */
+
+ ldr w0, =C_RUNTIME_READY_KEY
+ adrp x1, secondary_core_spinlock
+ add x1, x1, :lo12:secondary_core_spinlock
+1:
+ wfe
+ ldr w2, [x1]
+ cmp w2, w0
+ b.ne 1b
+ /* Prevent reordering of the store into fpga_valid_mpids below */
+ dmb ish
+
+ mov x10, x30
+ bl plat_my_core_pos
+ mov x30, x10
+
+ adrp x4, fpga_valid_mpids
+ add x4, x4, :lo12:fpga_valid_mpids
+ mov x5, #VALID_MPID
+ strb w5, [x4, x0]
+
/*
* Poll the CPU's hold entry until it indicates to jump
* to the entrypoint address.
*/
- bl plat_my_core_pos
- lsl x0, x0, #PLAT_FPGA_HOLD_ENTRY_SHIFT
- ldr x1, =hold_base
- ldr x2, =fpga_sec_entrypoint
+
+ adrp x1, hold_base
+ add x1, x1, :lo12:hold_base
poll_hold_entry:
- ldr x3, [x1, x0]
+ ldr x3, [x1, x0, LSL #PLAT_FPGA_HOLD_ENTRY_SHIFT]
cmp x3, #PLAT_FPGA_HOLD_STATE_GO
b.ne 1f
+
+ adrp x2, fpga_sec_entrypoint
+ add x2, x2, :lo12:fpga_sec_entrypoint
ldr x3, [x2]
br x3
1:
wfe
b poll_hold_entry
+
endfunc plat_secondary_cold_boot_setup
/* -----------------------------------------------------------------------
@@ -73,12 +111,16 @@
endfunc platform_mem_init
func plat_my_core_pos
+ ldr x1, =(MPID_MASK & ~(MPIDR_AFFLVL_MASK << MPIDR_AFF3_SHIFT))
mrs x0, mpidr_el1
+ and x0, x0, x1
b plat_fpga_calc_core_pos
+
endfunc plat_my_core_pos
/* -----------------------------------------------------------------------
- * unsigned int plat_fpga_calc_core_pos(u_register_t mpidr)
+ * unsigned int plat_fpga_calc_core_pos (uint32_t mpid)
+ * Clobber registers: x0 to x5
* -----------------------------------------------------------------------
*/
func plat_fpga_calc_core_pos
@@ -88,6 +130,7 @@
*
* If not set, shift MPIDR to left to make it look as if in a
* multi-threaded implementation.
+ *
*/
tst x0, #MPIDR_MT_MASK
lsl x3, x0, #MPIDR_AFFINITY_BITS
@@ -98,11 +141,13 @@
ubfx x1, x3, #MPIDR_AFF1_SHIFT, #MPIDR_AFFINITY_BITS
ubfx x2, x3, #MPIDR_AFF2_SHIFT, #MPIDR_AFFINITY_BITS
- /* Compute linear position */
mov x4, #FPGA_MAX_CPUS_PER_CLUSTER
- madd x1, x2, x4, x1
mov x5, #FPGA_MAX_PE_PER_CPU
+
+ /* Compute linear position */
+ madd x1, x2, x4, x1
madd x0, x1, x5, x0
+
ret
endfunc plat_fpga_calc_core_pos