[PATCH 5.10 009/142] parisc: Enable -mlong-calls gcc option by default when !CONFIG_MODULES

Greg Kroah-Hartman
2021-02-02T13:50:30Z

From: Helge Deller <deller@gmx.de>

commit 00e35f2b0e8acb88d4e1aa96ff0490e3bfe46580 upstream.

When building a kernel without module support, the CONFIG_MLONGCALL option
needs to be enabled in order to reach symbols which are outside of a 22-bit
branch.

This patch changes the autodetection in the Kconfig script to always enable
CONFIG_MLONGCALL when modules are disabled and uses a far call to
preempt_schedule_irq() in intr_do_preempt() to reach the symbol in all cases.

Signed-off-by: Helge Deller <deller@gmx.de>
Reported-by: kernel test robot <lkp@intel.com>
Cc: stable@vger.kernel.org # v5.6+
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
arch/parisc/Kconfig | 5 ++---
arch/parisc/kernel/entry.S | 13 ++++++++++---
2 files changed, 12 insertions(+), 6 deletions(-)

--- a/arch/parisc/Kconfig
+++ b/arch/parisc/Kconfig
@@ -202,9 +202,8 @@ config PREFETCH
depends on PA8X00 || PA7200

config MLONGCALLS
- bool "Enable the -mlong-calls compiler option for big kernels"
- default y if !MODULES || UBSAN || FTRACE
- default n
+ def_bool y if !MODULES || UBSAN || FTRACE
+ bool "Enable the -mlong-calls compiler option for big kernels" if MODULES && !UBSAN && !FTRACE
depends on PA8X00
help
If you configure the kernel to include many drivers built-in instead
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -997,10 +997,17 @@ intr_do_preempt:
bb,<,n %r20, 31 - PSW_SM_I, intr_restore
nop

+ /* ssm PSW_SM_I done later in intr_restore */
+#ifdef CONFIG_MLONGCALLS
+ ldil L%intr_restore, %r2
+ load32 preempt_schedule_irq, %r1
+ bv %r0(%r1)
+ ldo R%intr_restore(%r2), %r2
+#else
+ ldil L%intr_restore, %r1
BL preempt_schedule_irq, %r2
- nop
-
- b,n intr_restore /* ssm PSW_SM_I done by intr_restore */
+ ldo R%intr_restore(%r1), %r2
+#endif
#endif /* CONFIG_PREEMPTION */

/*