This is a note to let you know that I've just added the patch titled
powerpc/6xx: set High BAT Enable flag on G2_LE cores
to the 6.6-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
powerpc-6xx-set-high-bat-enable-flag-on-g2_le-cores.patch
and it can be found in the queue-6.6 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit ed78b4a4d36b2f5b9ccca16012141e1b85230046
Author: Matthias Schiffer <matthias.schiffer@xxxxxxxxxxxxxxx>
Date: Wed Jan 24 11:38:38 2024 +0100
powerpc/6xx: set High BAT Enable flag on G2_LE cores
[ 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@xxxxxxxxxxxxxxx>
Reviewed-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
Signed-off-by: Michael Ellerman <mpe@xxxxxxxxxxxxxx>
Link: https://msgid.link/20240124103838.43675-1-matthias.schiffer@xxxxxxxxxxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/arch/powerpc/include/asm/reg.h b/arch/powerpc/include/asm/reg.h
index 4ae4ab9090a2..ade5f094dbd2 100644
--- a/arch/powerpc/include/asm/reg.h
+++ b/arch/powerpc/include/asm/reg.h
@@ -617,6 +617,8 @@
#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 f29ce3dd6140..bfd3f442e5eb 100644
--- a/arch/powerpc/kernel/cpu_setup_6xx.S
+++ b/arch/powerpc/kernel/cpu_setup_6xx.S
@@ -26,6 +26,15 @@ 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)
@@ -115,6 +124,16 @@ SYM_FUNC_START_LOCAL(setup_604_hid0)
blr
SYM_FUNC_END(setup_604_hid0)
+/* 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
@@ -495,4 +514,3 @@ _GLOBAL(__restore_cpu_setup)
mtcr r7
blr
_ASM_NOKPROBE_SYMBOL(__restore_cpu_setup)
-
