powerpc/44x: Support 16K/64K base page sizes on 44x

This adds support for 16k and 64k page sizes on PowerPC 44x processors.

The PGDIR table is much smaller than a page when using 16k or 64k
pages (512 and 32 bytes respectively) so we allocate the PGDIR with
kzalloc() instead of __get_free_pages().

One PTE table covers rather a large memory area when using 16k or 64k
pages (32MB or 512MB respectively), so we can easily put FIXMAP and
PKMAP in the area covered by one PTE table.

Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Vladimir Panfilov <pvr@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

3 files changed, 24 insertions, 15 deletions

diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index c05ab1d3e620..661d07d2146b 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -380,6 +380,10 @@ int main(void)
         DEFINE(VCPU_FAULT_DEAR, offsetof(struct kvm_vcpu, arch.fault_dear));
         DEFINE(VCPU_FAULT_ESR, offsetof(struct kvm_vcpu, arch.fault_esr));
 #endif
+#ifdef CONFIG_44x
+        DEFINE(PGD_T_LOG2, PGD_T_LOG2);
+        DEFINE(PTE_T_LOG2, PTE_T_LOG2);
+#endif
 
         return 0;
 }
diff --git a/arch/powerpc/kernel/head_44x.S b/arch/powerpc/kernel/head_44x.S
index bd4fe9e7278b..b56fecc93a16 100644
--- a/arch/powerpc/kernel/head_44x.S
+++ b/arch/powerpc/kernel/head_44x.S
@@ -402,12 +402,14 @@ interrupt_base:
         rlwimi  r13,r12,10,30,30
 
         /* Load the PTE */
-        rlwinm  r12, r10, 13, 19, 29    /* Compute pgdir/pmd offset */
+        /* Compute pgdir/pmd offset */
+        rlwinm  r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
         lwzx    r11, r12, r11           /* Get pgd/pmd entry */
         rlwinm. r12, r11, 0, 0, 20      /* Extract pt base address */
         beq     2f                      /* Bail if no table */
 
-        rlwimi  r12, r10, 23, 20, 28    /* Compute pte address */
+        /* Compute pte address */
+        rlwimi  r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
         lwz     r11, 0(r12)             /* Get high word of pte entry */
         lwz     r12, 4(r12)             /* Get low word of pte entry */
 
@@ -496,12 +498,14 @@ tlb_44x_patch_hwater_D:
         /* Make up the required permissions */
         li      r13,_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_HWEXEC
 
-        rlwinm  r12, r10, 13, 19, 29    /* Compute pgdir/pmd offset */
+        /* Compute pgdir/pmd offset */
+        rlwinm  r12, r10, PPC44x_PGD_OFF_SHIFT, PPC44x_PGD_OFF_MASK_BIT, 29
         lwzx    r11, r12, r11           /* Get pgd/pmd entry */
         rlwinm. r12, r11, 0, 0, 20      /* Extract pt base address */
         beq     2f                      /* Bail if no table */
 
-        rlwimi  r12, r10, 23, 20, 28    /* Compute pte address */
+        /* Compute pte address */
+        rlwimi  r12, r10, PPC44x_PTE_ADD_SHIFT, PPC44x_PTE_ADD_MASK_BIT, 28
         lwz     r11, 0(r12)             /* Get high word of pte entry */
         lwz     r12, 4(r12)             /* Get low word of pte entry */
 
@@ -565,15 +569,16 @@ tlb_44x_patch_hwater_I:
  */
 finish_tlb_load:
         /* Combine RPN & ERPN an write WS 0 */
-        rlwimi  r11,r12,0,0,19
+        rlwimi  r11,r12,0,0,31-PAGE_SHIFT
         tlbwe   r11,r13,PPC44x_TLB_XLAT
 
         /*
          * Create WS1. This is the faulting address (EPN),
          * page size, and valid flag.
          */
-        li      r11,PPC44x_TLB_VALID | PPC44x_TLB_4K
-        rlwimi  r10,r11,0,20,31                 /* Insert valid and page size*/
+        li      r11,PPC44x_TLB_VALID | PPC44x_TLBE_SIZE
+        /* Insert valid and page size */
+        rlwimi  r10,r11,0,PPC44x_PTE_ADD_MASK_BIT,31
         tlbwe   r10,r13,PPC44x_TLB_PAGEID       /* Write PAGEID */
 
         /* And WS 2 */
@@ -645,12 +650,12 @@ _GLOBAL(set_context)
  * goes at the beginning of the data segment, which is page-aligned.
  */
         .data
-        .align  12
+        .align  PAGE_SHIFT
         .globl  sdata
 sdata:
         .globl  empty_zero_page
 empty_zero_page:
-        .space  4096
+        .space  PAGE_SIZE
 
 /*
  * To support >32-bit physical addresses, we use an 8KB pgdir.
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S
index ae0d084b6a24..15f28e0de78d 100644
--- a/arch/powerpc/kernel/misc_32.S
+++ b/arch/powerpc/kernel/misc_32.S
@@ -426,8 +426,8 @@ _GLOBAL(__flush_dcache_icache)
 BEGIN_FTR_SECTION
         blr
 END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
-        rlwinm  r3,r3,0,0,19                    /* Get page base address */
-        li      r4,4096/L1_CACHE_BYTES  /* Number of lines in a page */
+        rlwinm  r3,r3,0,0,31-PAGE_SHIFT         /* Get page base address */
+        li      r4,PAGE_SIZE/L1_CACHE_BYTES     /* Number of lines in a page */
         mtctr   r4
         mr      r6,r3
 0:      dcbst   0,r3                            /* Write line to ram */
@@ -467,8 +467,8 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
         rlwinm  r0,r10,0,28,26                  /* clear DR */
         mtmsr   r0
         isync
-        rlwinm  r3,r3,0,0,19                    /* Get page base address */
-        li      r4,4096/L1_CACHE_BYTES  /* Number of lines in a page */
+        rlwinm  r3,r3,0,0,31-PAGE_SHIFT         /* Get page base address */
+        li      r4,PAGE_SIZE/L1_CACHE_BYTES     /* Number of lines in a page */
         mtctr   r4
         mr      r6,r3
 0:      dcbst   0,r3                            /* Write line to ram */
@@ -492,7 +492,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_COHERENT_ICACHE)
  * void clear_pages(void *page, int order) ;
  */
 _GLOBAL(clear_pages)
-        li      r0,4096/L1_CACHE_BYTES
+        li      r0,PAGE_SIZE/L1_CACHE_BYTES
         slw     r0,r0,r4
         mtctr   r0
 #ifdef CONFIG_8xx
@@ -550,7 +550,7 @@ _GLOBAL(copy_page)
         dcbt    r5,r4
         li      r11,L1_CACHE_BYTES+4
 #endif /* MAX_COPY_PREFETCH */
-        li      r0,4096/L1_CACHE_BYTES - MAX_COPY_PREFETCH
+        li      r0,PAGE_SIZE/L1_CACHE_BYTES - MAX_COPY_PREFETCH
         crclr   4*cr0+eq
 2:
         mtctr   r0