[PATCH 6.1 057/197] powerpc/6xx: set High BAT Enable flag on G2_LE cores

Greg Kroah-Hartman
2024-02-20T21:00:54Z

From: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>

[ Upstream commit a038a3ff8c6582404834852c043dadc73a5b68b4 ]

MMU_FTR_USE_HIGH_BATS is set for G2_LE cores and derivatives like e300cX,
but the high BATs need to be enabled in HID2 to work. Add register
definitions and add the needed setup to __setup_cpu_603.

This fixes boot on CPUs like the MPC5200B with STRICT_KERNEL_RWX enabled
on systems where the flag has not been set by the bootloader already.

Fixes: e4d6654ebe6e ("powerpc/mm/32s: rework mmu_mapin_ram()")
Signed-off-by: Matthias Schiffer <matthias.schiffer@ew.tq-group.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://msgid.link/20240124103838.43675-1-matthias.schiffer@ew.tq-group.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
arch/powerpc/include/asm/reg.h | 2 ++
arch/powerpc/kernel/cpu_setup_6xx.S | 20 +++++++++++++++++++-
2 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 8fda87af2fa5..6c0ab745f0c8 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -608,6 +608,8 @@
#endif
#define SPRN_HID2 0x3F8 /* Hardware Implementation Register 2 */
#define SPRN_HID2_GEKKO 0x398 /* Gekko HID2 Register */
+#define SPRN_HID2_G2_LE 0x3F3 /* G2_LE HID2 Register */
+#define HID2_G2_LE_HBE (1<<18) /* High BAT Enable (G2_LE) */
#define SPRN_IABR 0x3F2 /* Instruction Address Breakpoint Register */
#define SPRN_IABR2 0x3FA /* 83xx */
#define SPRN_IBCR 0x135 /* 83xx Insn Breakpoint Control Reg */
diff --git a/arch/powerpc/kernel/cpu_setup_6xx.S b/arch/powerpc/kernel/cpu_setup_6xx.S
index f8b5ff64b604..6cbad50c71f6 100644
--- a/arch/powerpc/kernel/cpu_setup_6xx.S
+++ b/arch/powerpc/kernel/cpu_setup_6xx.S
@@ -24,6 +24,15 @@ BEGIN_FTR_SECTION
bl __init_fpu_registers
END_FTR_SECTION_IFCLR(CPU_FTR_FPU_UNAVAILABLE)
bl setup_common_caches
+
+ /*
+ * This assumes that all cores using __setup_cpu_603 with
+ * MMU_FTR_USE_HIGH_BATS are G2_LE compatible
+ */
+BEGIN_MMU_FTR_SECTION
+ bl setup_g2_le_hid2
+END_MMU_FTR_SECTION_IFSET(MMU_FTR_USE_HIGH_BATS)
+
mtlr r5
blr
_GLOBAL(__setup_cpu_604)
@@ -111,6 +120,16 @@ setup_604_hid0:
isync
blr

+/* Enable high BATs for G2_LE and derivatives like e300cX */
+SYM_FUNC_START_LOCAL(setup_g2_le_hid2)
+ mfspr r11,SPRN_HID2_G2_LE
+ oris r11,r11,HID2_G2_LE_HBE@h
+ mtspr SPRN_HID2_G2_LE,r11
+ sync
+ isync
+ blr
+SYM_FUNC_END(setup_g2_le_hid2)
+
/* 7400 <= rev 2.7 and 7410 rev = 1.0 suffer from some
* erratas we work around here.
* Moto MPC710CE.pdf describes them, those are errata
@@ -485,4 +504,3 @@ _GLOBAL(__restore_cpu_setup)
mtcr r7
blr
_ASM_NOKPROBE_SYMBOL(__restore_cpu_setup)
-
--
2.43.0