[PATCH v1 11/15] powerpc/kuap: Wire-up KUAP on 44x

From: Christophe Leroy
Date: Wed Oct 06 2021 - 08:48:53 EST


This adds KUAP support to 44x. This is done by checking
the content of SPRN_PID at the time it is read and written
into SPRN_MMUCR.

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxxxxxx>
---
arch/powerpc/kernel/head_44x.S | 16 ++++++++++++++++
arch/powerpc/platforms/Kconfig.cputype | 1 +
2 files changed, 17 insertions(+)

diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index 02d2928d1e01..cf92a3434acd 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -334,6 +334,10 @@ interrupt_base:
mfspr r12,SPRN_MMUCR
mfspr r13,SPRN_PID /* Get PID */
rlwimi r12,r13,0,24,31 /* Set TID */
+#ifdef CONFIG_PPC_KUAP
+ cmpwi r13,0
+ beq 2f /* KUAP Fault */
+#endif

4:
mtspr SPRN_MMUCR,r12
@@ -444,6 +448,10 @@ interrupt_base:
mfspr r12,SPRN_MMUCR
mfspr r13,SPRN_PID /* Get PID */
rlwimi r12,r13,0,24,31 /* Set TID */
+#ifdef CONFIG_PPC_KUAP
+ cmpwi r13,0
+ beq 2f /* KUAP Fault */
+#endif

4:
mtspr SPRN_MMUCR,r12
@@ -575,6 +583,10 @@ finish_tlb_load_44x:
3: mfspr r11,SPRN_SPRG3
lwz r11,PGDIR(r11)
mfspr r12,SPRN_PID /* Get PID */
+#ifdef CONFIG_PPC_KUAP
+ cmpwi r12,0
+ beq 2f /* KUAP Fault */
+#endif
4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */

/* Mask of required permission bits. Note that while we
@@ -672,6 +684,10 @@ finish_tlb_load_44x:
3: mfspr r11,SPRN_SPRG_THREAD
lwz r11,PGDIR(r11)
mfspr r12,SPRN_PID /* Get PID */
+#ifdef CONFIG_PPC_KUAP
+ cmpwi r12,0
+ beq 2f /* KUAP Fault */
+#endif
4: mtspr SPRN_MMUCR,r12 /* Set MMUCR */

/* Make up the required permissions */
diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index dce1cf31047b..74e5887abbce 100644
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -62,6 +62,7 @@ config 44x
select HAVE_PCI
select PHYS_64BIT
select PPC_HAVE_KUEP
+ select PPC_HAVE_KUAP

endchoice

--
2.31.1