powerpc/64e: Move virtual memory closer to linear memory

Today nohash/64 have linear memory based at 0xc000000000000000 and
virtual memory based at 0x8000000000000000.

In order to implement KASAN, we need to regroup both areas.

Move virtual memmory at 0xc000100000000000.

This complicates a bit TLB miss handlers. Until now, memory region
was easily identified with the 4 higher bits of address:
- 0 ==> User
- c ==> Linear Memory
- 8 ==> Virtual Memory

Now we need to rely on the 20 higher bits, with:
- 0xxxx ==> User
- c0000 ==> Linear Memory
- c0001 ==> Virtual Memory

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/4b225168031449fc34fc7132f3923cc8dc54af60.1656427701.git.christophe.leroy@csgroup.eu

diff --git a/arch/powerpc/include/asm/nohash/64/pgtable.h b/arch/powerpc/include/asm/nohash/64/pgtable.h
index d29f1d6..9104cc4 100644 (file)
--- a/arch/powerpc/include/asm/nohash/64/pgtable.h
+++ b/arch/powerpc/include/asm/nohash/64/pgtable.h
@@ -25,7 +25,7 @@
 /*
  * Define the address range of the kernel non-linear virtual area
  */
-#define KERN_VIRT_START ASM_CONST(0x8000000000000000)
+#define KERN_VIRT_START ASM_CONST(0xc000100000000000)
 #define KERN_VIRT_SIZE ASM_CONST(0x0000100000000000)
 
 /*

diff --git a/arch/powerpc/mm/nohash/tlb_low_64e.S b/arch/powerpc/mm/nohash/tlb_low_64e.S
index a59485c..68ffbfd 100644 (file)
--- a/arch/powerpc/mm/nohash/tlb_low_64e.S
+++ b/arch/powerpc/mm/nohash/tlb_low_64e.S
@@ -213,10 +213,11 @@ itlb_miss_kernel_bolted:
 tlb_miss_kernel_bolted:
        mfspr   r10,SPRN_MAS1
        ld      r14,PACA_KERNELPGD(r13)
-       cmpldi  cr0,r15,8               /* Check for vmalloc region */
+       srdi    r15,r16,44              /* get kernel region */
+       andi.   r15,r15,1               /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1          /* Clear TID */
        mtspr   SPRN_MAS1,r10
-       beq+    tlb_miss_common_bolted
+       bne+    tlb_miss_common_bolted
 
 tlb_miss_fault_bolted:
        /* We need to check if it was an instruction miss */
@@ -498,7 +499,9 @@ tlb_miss_huge_e6500:
 
 tlb_miss_kernel_e6500:
        ld      r14,PACA_KERNELPGD(r13)
-       cmpldi  cr1,r15,8               /* Check for vmalloc region */
+       srdi    r15,r16,44              /* get kernel region */
+       xoris   r15,r15,0xc             /* Check for vmalloc region */
+       cmplwi  cr1,r15,1
        beq+    cr1,tlb_miss_common_e6500
 
 tlb_miss_fault_e6500:
@@ -532,16 +535,18 @@ itlb_miss_fault_e6500:
         */
        mfspr   r14,SPRN_ESR
        mfspr   r16,SPRN_DEAR           /* get faulting address */
-       srdi    r15,r16,60              /* get region */
-       cmpldi  cr0,r15,0xc             /* linear mapping ? */
+       srdi    r15,r16,44              /* get region */
+       xoris   r15,r15,0xc
+       cmpldi  cr0,r15,0               /* linear mapping ? */
        beq     tlb_load_linear         /* yes -> go to linear map load */
+       cmpldi  cr1,r15,1               /* vmalloc mapping ? */
 
        /* The page tables are mapped virtually linear. At this point, though,
         * we don't know whether we are trying to fault in a first level
         * virtual address or a virtual page table address. We can get that
         * from bit 0x1 of the region ID which we have set for a page table
         */
-       andi.   r10,r15,0x1
+       andis.  r10,r15,0x1
        bne-    virt_page_table_tlb_miss
 
        std     r14,EX_TLB_ESR(r12);    /* save ESR */
@@ -553,7 +558,7 @@ itlb_miss_fault_e6500:
 
        /* We do the user/kernel test for the PID here along with the RW test
         */
-       cmpldi  cr0,r15,0               /* Check for user region */
+       srdi.   r15,r16,60              /* Check for user region */
 
        /* We pre-test some combination of permissions to avoid double
         * faults:
@@ -577,10 +582,9 @@ itlb_miss_fault_e6500:
        beq     normal_tlb_miss_user
        /* XXX replace the RMW cycles with immediate loads + writes */
 1:     mfspr   r10,SPRN_MAS1
-       cmpldi  cr0,r15,8               /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1          /* Clear TID */
        mtspr   SPRN_MAS1,r10
-       beq+    normal_tlb_miss
+       beq+    cr1,normal_tlb_miss
 
        /* We got a crappy address, just fault with whatever DEAR and ESR
         * are here
@@ -606,16 +610,18 @@ itlb_miss_fault_e6500:
         *
         * Faulting address is SRR0 which is already in r16
         */
-       srdi    r15,r16,60              /* get region */
-       cmpldi  cr0,r15,0xc             /* linear mapping ? */
+       srdi    r15,r16,44              /* get region */
+       xoris   r15,r15,0xc
+       cmpldi  cr0,r15,0               /* linear mapping ? */
        beq     tlb_load_linear         /* yes -> go to linear map load */
+       cmpldi  cr1,r15,1               /* vmalloc mapping ? */
 
        /* We do the user/kernel test for the PID here along with the RW test
         */
        li      r11,_PAGE_PRESENT|_PAGE_BAP_UX  /* Base perm */
        oris    r11,r11,_PAGE_ACCESSED@h
 
-       cmpldi  cr0,r15,0                       /* Check for user region */
+       srdi.   r15,r16,60                      /* Check for user region */
        std     r14,EX_TLB_ESR(r12)             /* write crazy -1 to frame */
        beq     normal_tlb_miss_user
 
@@ -623,10 +629,9 @@ itlb_miss_fault_e6500:
        oris    r11,r11,_PAGE_ACCESSED@h
        /* XXX replace the RMW cycles with immediate loads + writes */
        mfspr   r10,SPRN_MAS1
-       cmpldi  cr0,r15,8                       /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1                  /* Clear TID */
        mtspr   SPRN_MAS1,r10
-       beq+    normal_tlb_miss
+       beq+    cr1,normal_tlb_miss
 
        /* We got a crappy address, just fault */
        TLB_MISS_EPILOG_ERROR
@@ -659,10 +664,11 @@ normal_tlb_miss:
         * NOTE: For 64K pages, we do things slightly differently in
         * order to handle the weird page table format used by linux
         */
-       ori     r10,r15,0x1
+       srdi    r15,r16,44
+       oris    r10,r15,0x1
        rldicl  r14,r16,64-(PAGE_SHIFT-3),PAGE_SHIFT-3+4
-       sldi    r15,r10,60
-       clrrdi  r14,r14,3
+       sldi    r15,r10,44
+       clrrdi  r14,r14,19
        or      r10,r15,r14
 
        ld      r14,0(r10)
@@ -763,6 +769,7 @@ normal_tlb_miss_access_fault:
  */
 virt_page_table_tlb_miss:
        /* Are we hitting a kernel page table ? */
+       srdi    r15,r16,60
        andi.   r10,r15,0x8
 
        /* The cool thing now is that r10 contains 0 for user and 8 for kernel,
@@ -791,7 +798,8 @@ virt_page_table_tlb_miss:
        /* Now, we need to walk the page tables. First check if we are in
         * range.
         */
-       rldicl. r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4
+       rldicl  r10,r16,64-(VPTE_INDEX_SIZE+3),VPTE_INDEX_SIZE+3+4
+       cmpldi  r10,0x80
        bne-    virt_page_table_tlb_miss_fault
 
        /* Get the PGD pointer */
@@ -910,23 +918,24 @@ virt_page_table_tlb_miss_whacko_fault:
         */
        mfspr   r14,SPRN_ESR
        mfspr   r16,SPRN_DEAR           /* get faulting address */
-       srdi    r11,r16,60              /* get region */
-       cmpldi  cr0,r11,0xc             /* linear mapping ? */
+       srdi    r11,r16,44              /* get region */
+       xoris   r11,r11,0xc
+       cmpldi  cr0,r11,0               /* linear mapping ? */
        beq     tlb_load_linear         /* yes -> go to linear map load */
+       cmpldi  cr1,r11,1               /* vmalloc mapping ? */
 
        /* We do the user/kernel test for the PID here along with the RW test
         */
-       cmpldi  cr0,r11,0               /* Check for user region */
+       srdi.   r11,r16,60              /* Check for user region */
        ld      r15,PACAPGD(r13)        /* Load user pgdir */
        beq     htw_tlb_miss
 
        /* XXX replace the RMW cycles with immediate loads + writes */
 1:     mfspr   r10,SPRN_MAS1
-       cmpldi  cr0,r11,8               /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1          /* Clear TID */
        mtspr   SPRN_MAS1,r10
        ld      r15,PACA_KERNELPGD(r13) /* Load kernel pgdir */
-       beq+    htw_tlb_miss
+       beq+    cr1,htw_tlb_miss
 
        /* We got a crappy address, just fault with whatever DEAR and ESR
         * are here
@@ -952,19 +961,20 @@ virt_page_table_tlb_miss_whacko_fault:
         *
         * Faulting address is SRR0 which is already in r16
         */
-       srdi    r11,r16,60              /* get region */
-       cmpldi  cr0,r11,0xc             /* linear mapping ? */
+       srdi    r11,r16,44              /* get region */
+       xoris   r11,r11,0xc
+       cmpldi  cr0,r11,0               /* linear mapping ? */
        beq     tlb_load_linear         /* yes -> go to linear map load */
+       cmpldi  cr1,r11,1               /* vmalloc mapping ? */
 
        /* We do the user/kernel test for the PID here along with the RW test
         */
-       cmpldi  cr0,r11,0                       /* Check for user region */
+       srdi.   r11,r16,60              /* Check for user region */
        ld      r15,PACAPGD(r13)                /* Load user pgdir */
        beq     htw_tlb_miss
 
        /* XXX replace the RMW cycles with immediate loads + writes */
 1:     mfspr   r10,SPRN_MAS1
-       cmpldi  cr0,r11,8                       /* Check for vmalloc region */
        rlwinm  r10,r10,0,16,1                  /* Clear TID */
        mtspr   SPRN_MAS1,r10
        ld      r15,PACA_KERNELPGD(r13)         /* Load kernel pgdir */