[POWERPC] 85xx: Cleanup TLB initialization

* Determine the RPN we are running the kernel at runtime rather
  than using compile time constant for initial TLB

* Cleanup adjust_total_lowmem() to respect memstart_addr and
  be a bit more clear on variables that are sizes vs addresses.

Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>

2 files changed, 43 insertions, 28 deletions

diff --git a/arch/powerpc/kernel/head_fsl_booke.S b/arch/powerpc/kernel/head_fsl_booke.S
index d9cc2c288d9e..9f40b3e77100 100644
--- a/arch/powerpc/kernel/head_fsl_booke.S
+++ b/arch/powerpc/kernel/head_fsl_booke.S
@@ -68,7 +68,9 @@ _ENTRY(_start);
         mr      r29,r5
         mr      r28,r6
         mr      r27,r7
+        li      r25,0           /* phys kernel start (low) */
         li      r24,0           /* CPU number */
+        li      r23,0           /* phys kernel start (high) */
 
 /* We try to not make any assumptions about how the boot loader
  * setup or used the TLBs.  We invalidate all mappings from the
@@ -167,7 +169,28 @@ skpinv:	addi	r6,r6,1				/* Increment */
         mtspr   SPRN_MAS0,r7
         tlbre
 
-        /* Just modify the entry ID, EPN and RPN for the temp mapping */
+        /* grab and fixup the RPN */
+        mfspr   r6,SPRN_MAS1    /* extract MAS1[SIZE] */
+        rlwinm  r6,r6,25,27,30
+        li      r8,-1
+        addi    r6,r6,10
+        slw     r6,r8,r6        /* convert to mask */
+
+        bl      1f              /* Find our address */
+1:      mflr    r7
+
+        mfspr   r8,SPRN_MAS3
+#ifdef CONFIG_PHYS_64BIT
+        mfspr   r23,SPRN_MAS7
+#endif
+        and     r8,r6,r8
+        subfic  r9,r6,-4096
+        and     r9,r9,r7
+
+        or      r25,r8,r9
+        ori     r8,r25,(MAS3_SX|MAS3_SW|MAS3_SR)
+
+        /* Just modify the entry ID and EPN for the temp mapping */
         lis     r7,0x1000       /* Set MAS0(TLBSEL) = 1 */
         rlwimi  r7,r5,16,4,15   /* Setup MAS0 = TLBSEL | ESEL(r5) */
         mtspr   SPRN_MAS0,r7
@@ -177,12 +200,10 @@ skpinv:	addi	r6,r6,1				/* Increment */
         ori     r6,r6,(MAS1_TSIZE(BOOKE_PAGESZ_4K))@l
         mtspr   SPRN_MAS1,r6
         mfspr   r6,SPRN_MAS2
-        lis     r7,PHYSICAL_START@h
+        li      r7,0            /* temp EPN = 0 */
         rlwimi  r7,r6,0,20,31
         mtspr   SPRN_MAS2,r7
-        mfspr   r6,SPRN_MAS3
-        rlwimi  r7,r6,0,20,31
-        mtspr   SPRN_MAS3,r7
+        mtspr   SPRN_MAS3,r8
         tlbwe
 
         xori    r6,r4,1
@@ -232,8 +253,7 @@ skpinv:	addi	r6,r6,1				/* Increment */
         ori     r6,r6,PAGE_OFFSET@l
         rlwimi  r6,r7,0,20,31
         mtspr   SPRN_MAS2,r6
-        li      r7,(MAS3_SX|MAS3_SW|MAS3_SR)
-        mtspr   SPRN_MAS3,r7
+        mtspr   SPRN_MAS3,r8
         tlbwe
 
 /* 7. Jump to KERNELBASE mapping */
diff --git a/arch/powerpc/mm/fsl_booke_mmu.c b/arch/powerpc/mm/fsl_booke_mmu.c
index 3dd0c8189bae..59f6649ae42a 100644
--- a/arch/powerpc/mm/fsl_booke_mmu.c
+++ b/arch/powerpc/mm/fsl_booke_mmu.c
@@ -49,7 +49,6 @@
 #include <asm/mmu.h>
 #include <asm/uaccess.h>
 #include <asm/smp.h>
-#include <asm/bootx.h>
 #include <asm/machdep.h>
 #include <asm/setup.h>
 
@@ -59,7 +58,6 @@ extern void loadcam_entry(unsigned int index);
 unsigned int tlbcam_index;
 unsigned int num_tlbcam_entries;
 static unsigned long __cam0, __cam1, __cam2;
-#define MAX_LOW_MEM     CONFIG_LOWMEM_SIZE
 
 #define NUM_TLBCAMS     (16)
 
@@ -195,35 +193,32 @@ unsigned long __init mmu_mapin_ram(void)
 void __init
 adjust_total_lowmem(void)
 {
-        unsigned long max_low_mem = MAX_LOW_MEM;
-        unsigned long cam_max = 0x10000000;
-        unsigned long ram;
+        phys_addr_t max_lowmem_size = __max_low_memory;
+        phys_addr_t cam_max_size = 0x10000000;
+        phys_addr_t ram;
 
-        /* adjust CAM size to max_low_mem */
-        if (max_low_mem < cam_max)
-                cam_max = max_low_mem;
+        /* adjust CAM size to max_lowmem_size */
+        if (max_lowmem_size < cam_max_size)
+                cam_max_size = max_lowmem_size;
 
-        /* adjust lowmem size to max_low_mem */
-        if (max_low_mem < total_lowmem)
-                ram = max_low_mem;
-        else
-                ram = total_lowmem;
+        /* adjust lowmem size to max_lowmem_size */
+        ram = min(max_lowmem_size, total_lowmem);
 
         /* Calculate CAM values */
         __cam0 = 1UL << 2 * (__ilog2(ram) / 2);
-        if (__cam0 > cam_max)
-                __cam0 = cam_max;
+        if (__cam0 > cam_max_size)
+                __cam0 = cam_max_size;
         ram -= __cam0;
         if (ram) {
                 __cam1 = 1UL << 2 * (__ilog2(ram) / 2);
-                if (__cam1 > cam_max)
-                        __cam1 = cam_max;
+                if (__cam1 > cam_max_size)
+                        __cam1 = cam_max_size;
                 ram -= __cam1;
         }
         if (ram) {
                 __cam2 = 1UL << 2 * (__ilog2(ram) / 2);
-                if (__cam2 > cam_max)
-                        __cam2 = cam_max;
+                if (__cam2 > cam_max_size)
+                        __cam2 = cam_max_size;
                 ram -= __cam2;
         }
 
@@ -231,6 +226,6 @@ adjust_total_lowmem(void)
                         " CAM2=%ldMb residual: %ldMb\n",
                         __cam0 >> 20, __cam1 >> 20, __cam2 >> 20,
                         (total_lowmem - __cam0 - __cam1 - __cam2) >> 20);
-        __max_low_memory = max_low_mem = __cam0 + __cam1 + __cam2;
-        __initial_memory_limit = __max_low_memory;
+        __max_low_memory = __cam0 + __cam1 + __cam2;
+        __initial_memory_limit = memstart_addr + __max_low_memory;
 }