powerpc/kuap: Wire-up KUAP on book3e/64

This adds KUAP support to book3e/64.
This is done by reading the content of SPRN_MAS1 and checking
the TID at the time user pgtable is loaded.

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/e2c2c9375afd4bbc06aa904d0103a5f5102a2b1a.1634627931.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S
index 9235e72..8b97c4a 100644 (file)
--- a/arch/powerpc/mm/nohash/tlb_low_64e.S
+++ b/arch/powerpc/mm/nohash/tlb_low_64e.S
@@ -128,6 +128,13 @@ END_BTB_FLUSH_SECTION
 
        bne     tlb_miss_kernel_bolted
 
+tlb_miss_user_bolted:
+#ifdef CONFIG_PPC_KUAP
+       mfspr   r10,SPRN_MAS1
+       rlwinm. r10,r10,0,0x3fff0000
+       beq-    tlb_miss_fault_bolted /* KUAP fault */
+#endif
+
 tlb_miss_common_bolted:
 /*
  * This is the guts of the TLB miss handler for bolted-linear.
@@ -246,7 +253,7 @@ itlb_miss_fault_bolted:
 
        cmpldi  cr0,r15,0                       /* Check for user region */
        oris    r11,r11,_PAGE_ACCESSED@h
-       beq     tlb_miss_common_bolted
+       beq     tlb_miss_user_bolted
        b       itlb_miss_kernel_bolted
 
 #ifdef CONFIG_PPC_FSL_BOOK3E
@@ -676,6 +683,11 @@ finish_normal_tlb_miss:
        /* Check if required permissions are met */
        andc.   r15,r11,r14
        bne-    normal_tlb_miss_access_fault
+#ifdef CONFIG_PPC_KUAP
+       mfspr   r11,SPRN_MAS1
+       rlwinm. r10,r11,0,0x3fff0000
+       beq-    normal_tlb_miss_access_fault /* KUAP fault */
+#endif
 
        /* Now we build the MAS:
         *
@@ -689,15 +701,17 @@ finish_normal_tlb_miss:
         *
         * TODO: mix up code below for better scheduling
         */
-       clrrdi  r11,r16,12              /* Clear low crap in EA */
-       rlwimi  r11,r14,32-19,27,31     /* Insert WIMGE */
-       mtspr   SPRN_MAS2,r11
+       clrrdi  r10,r16,12              /* Clear low crap in EA */
+       rlwimi  r10,r14,32-19,27,31     /* Insert WIMGE */
+       mtspr   SPRN_MAS2,r10
 
        /* Check page size, if not standard, update MAS1 */
-       rldicl  r11,r14,64-8,64-8
-       cmpldi  cr0,r11,BOOK3E_PAGESZ_4K
+       rldicl  r10,r14,64-8,64-8
+       cmpldi  cr0,r10,BOOK3E_PAGESZ_4K
        beq-    1f
+#ifndef CONFIG_PPC_KUAP
        mfspr   r11,SPRN_MAS1
+#endif
        rlwimi  r11,r14,31,21,24
        rlwinm  r11,r11,0,21,19
        mtspr   SPRN_MAS1,r11
@@ -786,7 +800,16 @@ virt_page_table_tlb_miss:
        mfspr   r10,SPRN_MAS1
        rlwinm  r10,r10,0,16,1                  /* Clear TID */
        mtspr   SPRN_MAS1,r10
+#ifdef CONFIG_PPC_KUAP
+       b       2f
+1:
+       mfspr   r10,SPRN_MAS1
+       rlwinm. r10,r10,0,0x3fff0000
+       beq-    virt_page_table_tlb_miss_fault /* KUAP fault */
+2:
+#else
 1:
+#endif
 BEGIN_MMU_FTR_SECTION
        /* Search if we already have a TLB entry for that virtual address, and
         * if we do, bail out.
@@ -1027,6 +1050,11 @@ virt_page_table_tlb_miss_whacko_fault:
  * avoid too much complication, it will save/restore things for us
  */
 htw_tlb_miss:
+#ifdef CONFIG_PPC_KUAP
+       mfspr   r10,SPRN_MAS1
+       rlwinm. r10,r10,0,0x3fff0000
+       beq-    htw_tlb_miss_fault /* KUAP fault */
+#endif
        /* Search if we already have a TLB entry for that virtual address, and
         * if we do, bail out.
         *

diff --git a/arch/powerpc/platforms/Kconfig.cputype b/arch/powerpc/platforms/Kconfig.cputype
index 3ad2f3f..172f28e 100644 (file)
--- a/arch/powerpc/platforms/Kconfig.cputype
+++ b/arch/powerpc/platforms/Kconfig.cputype
@@ -122,6 +122,7 @@ config PPC_BOOK3E_64
        select PPC_SMP_MUXED_IPI
        select PPC_DOORBELL
        select ZONE_DMA
+       select PPC_HAVE_KUAP
 
 endchoice