[BOOT-WRAPPER 11/11] Boot CPUs sequentially
Mark Rutland
mark.rutland at arm.com
Mon Jul 29 09:15:01 PDT 2024
Currently the boot-wrapper initializes all CPUs in parallel. This means
that we cannot log errors as they happen, as this would mean multiple
CPUs concurrently writing to the UART, producing garbled output. To
produce meaningful output we have to special-case errors on the boot CPU
and hope CPUs have been configured consistently.
To make it easier to handle errors, boot CPUs sequentially so that errors
can be logged as they happen. With this change it's pretty clear that
the cpu_init_bootmethod() abstraction isn't helpful, and so this is
removed with cpu_init_arch() directly initializing PSCI where necessary.
When things go well this looks like:
| Boot-wrapper v0.2
| Entered at EL3
| Memory layout:
| [0000000080000000..0000000080001f90] => boot-wrapper
| [000000008000fff8..0000000080010000] => mbox
| [0000000080200000..0000000082cbaa00] => kernel
| [0000000088000000..0000000088002df1] => dtb
| CPU0: (MPIDR 0000000000000000) initializing...
| CPU0: Done
| CPU1: (MPIDR 0000000000000100) initializing...
| CPU1: Done
| CPU2: (MPIDR 0000000000000200) initializing...
| CPU2: Done
| CPU3: (MPIDR 0000000000000300) initializing...
| CPU3: Done
| CPU4: (MPIDR 0000000000010000) initializing...
| CPU4: Done
| CPU5: (MPIDR 0000000000010100) initializing...
| CPU5: Done
| CPU6: (MPIDR 0000000000010200) initializing...
| CPU6: Done
| CPU7: (MPIDR 0000000000010300) initializing...
| CPU7: Done
| All CPUs initialized. Entering kernel...
|
| [ 0.000000] Booting Linux on physical CPU 0x0000000000 [0x410fd0f0]
Signed-off-by: Mark Rutland <mark.rutland at arm.com>
Cc: Akos Denke <akos.denke at arm.com>
Cc: Andre Przywara <andre.przywara at arm.com>
Cc: Luca Fancellu <luca.fancellu at arm.com>
Cc: Marc Zyngier <maz at kernel.org>
---
arch/aarch32/boot.S | 2 --
arch/aarch32/init.c | 17 +++++++++------
arch/aarch64/boot.S | 2 --
arch/aarch64/init.c | 17 +++++++++------
arch/aarch64/spin.S | 3 ---
common/init.c | 50 +++++++++++++++++++++++++++++++++++++--------
common/psci.c | 14 -------------
include/boot.h | 6 +-----
8 files changed, 64 insertions(+), 47 deletions(-)
diff --git a/arch/aarch32/boot.S b/arch/aarch32/boot.S
index 3a51cb0..679e28a 100644
--- a/arch/aarch32/boot.S
+++ b/arch/aarch32/boot.S
@@ -70,8 +70,6 @@ reset_common:
bl cpu_init_bootwrapper
- bl cpu_init_arch
-
b start_bootmethod
err_invalid_id:
diff --git a/arch/aarch32/init.c b/arch/aarch32/init.c
index cb67bf6..d08ac83 100644
--- a/arch/aarch32/init.c
+++ b/arch/aarch32/init.c
@@ -6,6 +6,7 @@
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE.txt file.
*/
+#include <boot.h>
#include <cpu.h>
#include <gic.h>
#include <platform.h>
@@ -43,24 +44,28 @@ static void cpu_init_monitor(void)
#ifdef PSCI
extern char psci_vectors[];
-bool cpu_init_psci_arch(void)
+static void cpu_init_psci_arch(unsigned int cpu)
{
- if (read_cpsr_mode() != PSR_MON)
- return false;
+ if (read_cpsr_mode() != PSR_MON) {
+ print_cpu_warn(cpu, "PSCI could not be initialized (not booted at PL1).\r\n");
+ return;
+ }
mcr(MVBAR, (unsigned long)psci_vectors);
isb();
-
- return true;
}
+#else
+static static void cpu_init_psci_arch(unsigned int cpu) { }
#endif
-void cpu_init_arch(void)
+void cpu_init_arch(unsigned int cpu)
{
if (read_cpsr_mode() == PSR_MON) {
cpu_init_monitor();
gic_secure_init();
}
+ cpu_init_psci_arch(cpu);
+
mcr(CNTFRQ, COUNTER_FREQ);
}
diff --git a/arch/aarch64/boot.S b/arch/aarch64/boot.S
index 4cc41bb..f8fc808 100644
--- a/arch/aarch64/boot.S
+++ b/arch/aarch64/boot.S
@@ -69,8 +69,6 @@ reset_common:
bl cpu_init_bootwrapper
- bl cpu_init_arch
-
b start_bootmethod
err_invalid_id:
diff --git a/arch/aarch64/init.c b/arch/aarch64/init.c
index 68c220b..81fe33a 100644
--- a/arch/aarch64/init.c
+++ b/arch/aarch64/init.c
@@ -6,6 +6,7 @@
* Use of this source code is governed by a BSD-style license that can be
* found in the LICENSE.txt file.
*/
+#include <boot.h>
#include <cpu.h>
#include <gic.h>
#include <platform.h>
@@ -159,24 +160,28 @@ static void cpu_init_el3(void)
#ifdef PSCI
extern char psci_vectors[];
-bool cpu_init_psci_arch(void)
+static void cpu_init_psci_arch(unsigned int cpu)
{
- if (mrs(CurrentEL) != CURRENTEL_EL3)
- return false;
+ if (mrs(CurrentEL) != CURRENTEL_EL3) {
+ print_cpu_warn(cpu, "PSCI could not be initialized (not booted at EL3).\r\n");
+ return;
+ }
msr(VBAR_EL3, (unsigned long)psci_vectors);
isb();
-
- return true;
}
+#else
+static void cpu_init_psci_arch(unsigned int cpu);
#endif
-void cpu_init_arch(void)
+void cpu_init_arch(unsigned int cpu)
{
if (mrs(CurrentEL) == CURRENTEL_EL3) {
cpu_init_el3();
gic_secure_init();
}
+ cpu_init_psci_arch(cpu);
+
msr(CNTFRQ_EL0, COUNTER_FREQ);
}
diff --git a/arch/aarch64/spin.S b/arch/aarch64/spin.S
index a7879d4..81d7ee4 100644
--- a/arch/aarch64/spin.S
+++ b/arch/aarch64/spin.S
@@ -12,9 +12,6 @@
.text
-ASM_FUNC(cpu_init_bootmethod)
- ret
-
ASM_FUNC(start_bootmethod)
cpuid x0, x1
bl find_logical_id
diff --git a/common/init.c b/common/init.c
index 3c05ac3..6197ead 100644
--- a/common/init.c
+++ b/common/init.c
@@ -43,18 +43,50 @@ static void announce_objects(void)
void announce_arch(void);
+static void init_bootwrapper(void)
+{
+ init_uart();
+ announce_bootwrapper();
+ announce_arch();
+ announce_objects();
+ init_platform();
+}
+
+static void cpu_init_self(unsigned int cpu)
+{
+ print_string("CPU");
+ print_uint_dec(cpu);
+ print_string(": (MPIDR ");
+ print_ulong_hex(read_mpidr());
+ print_string(") initializing...\r\n");
+
+ cpu_init_arch(cpu);
+
+ print_cpu_msg(cpu, "Done\r\n");
+}
+
void cpu_init_bootwrapper(void)
{
+ static volatile unsigned int cpu_next = 0;
unsigned int cpu = this_cpu_logical_id();
- if (cpu == 0) {
- init_uart();
- announce_bootwrapper();
- announce_arch();
- announce_objects();
- print_string("\r\n");
- init_platform();
- }
+ if (cpu == 0)
+ init_bootwrapper();
+
+ while (cpu_next != cpu)
+ wfe();
+
+ cpu_init_self(cpu);
+
+ cpu_next = cpu + 1;
+ dsb(sy);
+ sev();
+
+ if (cpu != 0)
+ return;
+
+ while (cpu_next != NR_CPUS)
+ wfe();
- cpu_init_bootmethod(cpu);
+ print_string("All CPUs initialized. Entering kernel...\r\n\r\n");
}
diff --git a/common/psci.c b/common/psci.c
index 19cc315..5fe8999 100644
--- a/common/psci.c
+++ b/common/psci.c
@@ -87,17 +87,3 @@ void __noreturn psci_first_spin(void)
unreachable();
}
-
-void cpu_init_bootmethod(unsigned int cpu)
-{
- if (cpu_init_psci_arch())
- return;
-
- if (cpu == 0) {
- print_string("WARNING: PSCI could not be initialized. Boot may fail\r\n\r\n");
- return;
- }
-
- while (1)
- wfe();
-}
diff --git a/include/boot.h b/include/boot.h
index 18b805d..12c9c5c 100644
--- a/include/boot.h
+++ b/include/boot.h
@@ -17,10 +17,6 @@ void __noreturn spin(unsigned long *mbox, unsigned long invalid);
void __noreturn first_spin(unsigned int cpu, unsigned long *mbox,
unsigned long invalid_addr);
-void cpu_init_bootmethod(unsigned int cpu);
-
-#ifdef PSCI
-bool cpu_init_psci_arch(void);
-#endif
+void cpu_init_arch(unsigned int cpu);
#endif
--
2.30.2
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