Hexagon: add support for ARCH_PFN_OFFSET

Add support for loading the kernel at a physical offset.  The
offset should still be 4M aligned.

Signed-off-by: Richard Kuo <rkuo@codeaurora.org>

8 files changed, 91 insertions, 55 deletions

diff --git a/arch/hexagon/Kconfig b/arch/hexagon/Kconfig
index e4decc6b8947..dd89a7245ac4 100644
--- a/arch/hexagon/Kconfig
+++ b/arch/hexagon/Kconfig
@@ -33,6 +33,7 @@ config HEXAGON
           Qualcomm Hexagon is a processor architecture designed for high
           performance and low power across a wide variety of applications.
 
+
 config HEXAGON_ARCH_V1
         bool
 
@@ -45,6 +46,11 @@ config HEXAGON_ARCH_V3
 config HEXAGON_ARCH_V4
         bool
 
+config HEXAGON_PHYS_OFFSET
+        def_bool y
+        ---help---
+          Platforms that don't load the kernel at zero set this.
+
 config FRAME_POINTER
         def_bool y
 
diff --git a/arch/hexagon/include/asm/hexagon_vm.h b/arch/hexagon/include/asm/hexagon_vm.h
index c144bee6cabe..6b81e4d5ecb1 100644
--- a/arch/hexagon/include/asm/hexagon_vm.h
+++ b/arch/hexagon/include/asm/hexagon_vm.h
@@ -31,10 +31,26 @@
  * for tracing/debugging.
  */
 
-/*
- * Lets make this stuff visible only if configured,
- * so we can unconditionally include the file.
- */
+#define HVM_TRAP1_VMVERSION             0
+#define HVM_TRAP1_VMRTE                 1
+#define HVM_TRAP1_VMSETVEC              2
+#define HVM_TRAP1_VMSETIE               3
+#define HVM_TRAP1_VMGETIE               4
+#define HVM_TRAP1_VMINTOP               5
+#define HVM_TRAP1_VMCLRMAP              10
+#define HVM_TRAP1_VMNEWMAP              11
+#define HVM_TRAP1_FORMERLY_VMWIRE       12
+#define HVM_TRAP1_VMCACHE               13
+#define HVM_TRAP1_VMGETTIME             14
+#define HVM_TRAP1_VMSETTIME             15
+#define HVM_TRAP1_VMWAIT                16
+#define HVM_TRAP1_VMYIELD               17
+#define HVM_TRAP1_VMSTART               18
+#define HVM_TRAP1_VMSTOP                19
+#define HVM_TRAP1_VMVPID                20
+#define HVM_TRAP1_VMSETREGS             21
+#define HVM_TRAP1_VMGETREGS             22
+#define HVM_TRAP1_VMTIMEROP             24
 
 #ifndef __ASSEMBLY__
 
@@ -175,25 +191,6 @@ static inline long __vmintop_clear(long i)
 
 #else /* Only assembly code should reference these */
 
-#define HVM_TRAP1_VMRTE                 1
-#define HVM_TRAP1_VMSETVEC              2
-#define HVM_TRAP1_VMSETIE               3
-#define HVM_TRAP1_VMGETIE               4
-#define HVM_TRAP1_VMINTOP               5
-#define HVM_TRAP1_VMCLRMAP              10
-#define HVM_TRAP1_VMNEWMAP              11
-#define HVM_TRAP1_FORMERLY_VMWIRE       12
-#define HVM_TRAP1_VMCACHE               13
-#define HVM_TRAP1_VMGETTIME             14
-#define HVM_TRAP1_VMSETTIME             15
-#define HVM_TRAP1_VMWAIT                16
-#define HVM_TRAP1_VMYIELD               17
-#define HVM_TRAP1_VMSTART               18
-#define HVM_TRAP1_VMSTOP                19
-#define HVM_TRAP1_VMVPID                20
-#define HVM_TRAP1_VMSETREGS             21
-#define HVM_TRAP1_VMGETREGS             22
-
 #endif /* __ASSEMBLY__ */
 
 /*
@@ -224,6 +221,8 @@ static inline long __vmintop_clear(long i)
 #define HVM_VMEST_UM_MSK        1
 #define HVM_VMEST_IE_SFT        30
 #define HVM_VMEST_IE_MSK        1
+#define HVM_VMEST_SS_SFT        29
+#define HVM_VMEST_SS_MSK        1
 #define HVM_VMEST_EVENTNUM_SFT  16
 #define HVM_VMEST_EVENTNUM_MSK  0xff
 #define HVM_VMEST_CAUSE_SFT     0
@@ -260,6 +259,8 @@ static inline long __vmintop_clear(long i)
 #define HVM_GE_C_INVI   0x15
 #define HVM_GE_C_PRIVI  0x1B
 #define HVM_GE_C_XMAL   0x1C
+#define HVM_GE_C_WREG   0x1D
+#define HVM_GE_C_PCAL   0x1E
 #define HVM_GE_C_RMAL   0x20
 #define HVM_GE_C_WMAL   0x21
 #define HVM_GE_C_RPROT  0x22
diff --git a/arch/hexagon/include/asm/mem-layout.h b/arch/hexagon/include/asm/mem-layout.h
index af16e977c55e..1426cd71a1d3 100644
--- a/arch/hexagon/include/asm/mem-layout.h
+++ b/arch/hexagon/include/asm/mem-layout.h
@@ -32,16 +32,25 @@
 #define PAGE_OFFSET                     _AC(0xc0000000, UL)
 
 /*
- * LOAD_ADDRESS is the physical/linear address of where in memory
- * the kernel gets loaded. The 12 least significant bits must be zero (0)
- * due to limitations on setting the EVB
- *
+ * Compiling for a platform that needs a crazy physical offset
+ * (like if the memory starts at 1GB and up) means we need
+ * an actual PHYS_OFFSET.  Should be set up in head.S.
  */
 
-#ifndef LOAD_ADDRESS
-#define LOAD_ADDRESS                    0x00000000
+#ifdef CONFIG_HEXAGON_PHYS_OFFSET
+#ifndef __ASSEMBLY__
+extern unsigned long    __phys_offset;
+#endif
+#define PHYS_OFFSET     __phys_offset
+#endif
+
+#ifndef PHYS_OFFSET
+#define PHYS_OFFSET     0
 #endif
 
+#define PHYS_PFN_OFFSET (PHYS_OFFSET >> PAGE_SHIFT)
+#define ARCH_PFN_OFFSET PHYS_PFN_OFFSET
+
 #define TASK_SIZE                       (PAGE_OFFSET)
 
 /*  not sure how these are used yet  */
diff --git a/arch/hexagon/include/asm/page.h b/arch/hexagon/include/asm/page.h
index 692adc213429..de1b2871d09c 100644
--- a/arch/hexagon/include/asm/page.h
+++ b/arch/hexagon/include/asm/page.h
@@ -96,8 +96,8 @@ typedef struct page *pgtable_t;
  * MIPS says they're only used during mem_init.
  * also, check if we need a PHYS_OFFSET.
  */
-#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET)
-#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET))
+#define __pa(x) ((unsigned long)(x) - PAGE_OFFSET + PHYS_OFFSET)
+#define __va(x) ((void *)((unsigned long)(x) - PHYS_OFFSET + PAGE_OFFSET))
 
 /* The "page frame" descriptor is defined in linux/mm.h */
 struct page;
@@ -147,6 +147,7 @@ static inline void clear_page(void *page)
  */
 #define kern_addr_valid(addr)   (1)
 
+#include <asm/mem-layout.h>
 #include <asm-generic/memory_model.h>
 /* XXX Todo: implement assembly-optimized version of getorder. */
 #include <asm-generic/getorder.h>
diff --git a/arch/hexagon/kernel/head.S b/arch/hexagon/kernel/head.S
index d859402c73ba..477320c455f7 100644
--- a/arch/hexagon/kernel/head.S
+++ b/arch/hexagon/kernel/head.S
@@ -43,14 +43,21 @@ ENTRY(stext)
          * Symbol is kernel segment address, but we need
          * the logical/physical address.
          */
-        r24 = asl(r24, #2)
-        r24 = lsr(r24, #2)
+        r25 = pc;
+        r2.h = #0xffc0;
+        r2.l = #0x0000;
+        r25 = and(r2,r25);      /*  R25 holds PHYS_OFFSET now  */
+        r1.h = #HI(PAGE_OFFSET);
+        r1.l = #LO(PAGE_OFFSET);
+        r24 = sub(r24,r1);      /* swapper_pg_dir - PAGE_OFFSET */
+        r24 = add(r24,r25);     /* + PHYS_OFFSET */
 
-        r0 = r24
+        r0 = r24;  /* aka __pa(swapper_pg_dir)  */
 
         /*
-         * Initialize a 16MB PTE to make the virtual and physical
+         * Initialize page dir to make the virtual and physical
          * addresses where the kernel was loaded be identical.
+         * Done in 4MB chunks.
          */
 #define PTE_BITS ( __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X      \
                   | __HEXAGON_C_WB_L2 << 6                      \
@@ -143,6 +150,13 @@ __head_s_vaddr_target:
         r2 = sub(r2,r0);
         call memset;
 
+        /*  Set PHYS_OFFSET; should still be in R25 */
+#ifdef CONFIG_HEXAGON_PHYS_OFFSET
+        r0.l = #LO(__phys_offset);
+        r0.h = #HI(__phys_offset);
+        memw(r0) = r25;
+#endif
+
         /* Time to make the doughnuts.   */
         call start_kernel
 
diff --git a/arch/hexagon/kernel/setup.c b/arch/hexagon/kernel/setup.c
index 94a387835008..2e2304f7b7ee 100644
--- a/arch/hexagon/kernel/setup.c
+++ b/arch/hexagon/kernel/setup.c
@@ -68,6 +68,8 @@ void __init setup_arch(char **cmdline_p)
          */
         __vmsetvec(_K_VM_event_vector);
 
+        printk(KERN_INFO "PHYS_OFFSET=0x%08x\n", PHYS_OFFSET);
+
         /*
          * Simulator has a few differences from the hardware.
          * For now, check uninitialized-but-mapped memory
diff --git a/arch/hexagon/kernel/vmlinux.lds.S b/arch/hexagon/kernel/vmlinux.lds.S
index 14e793f6abbf..fafb886511e3 100644
--- a/arch/hexagon/kernel/vmlinux.lds.S
+++ b/arch/hexagon/kernel/vmlinux.lds.S
@@ -18,8 +18,6 @@
  * 02110-1301, USA.
  */
 
-#define LOAD_OFFSET PAGE_OFFSET
-
 #include <asm-generic/vmlinux.lds.h>
 #include <asm/asm-offsets.h>    /*  Most of the kernel defines are here  */
 #include <asm/mem-layout.h>     /*  except for page_offset  */
@@ -36,13 +34,9 @@ See asm-generic/sections.h for seemingly required labels.
 
 #define PAGE_SIZE _PAGE_SIZE
 
-/*  This LOAD_OFFSET is temporary for debugging on the simulator; it may change
-    for hypervisor pseudo-physical memory.  */
-
-
 SECTIONS
 {
-        . = PAGE_OFFSET + LOAD_ADDRESS;
+        . = PAGE_OFFSET;
 
         __init_begin = .;
         HEAD_TEXT_SECTION
@@ -52,7 +46,7 @@ SECTIONS
 
         . = ALIGN(_PAGE_SIZE);
         _stext = .;
-        .text : AT(ADDR(.text) - LOAD_OFFSET) {
+        .text : AT(ADDR(.text)) {
                 _text = .;
                 TEXT_TEXT
                 SCHED_TEXT
diff --git a/arch/hexagon/mm/init.c b/arch/hexagon/mm/init.c
index 69ffcfd28794..8e803a6e3402 100644
--- a/arch/hexagon/mm/init.c
+++ b/arch/hexagon/mm/init.c
@@ -31,9 +31,10 @@
  * Define a startpg just past the end of the kernel image and a lastpg
  * that corresponds to the end of real or simulated platform memory.
  */
-#define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET))
+#define bootmem_startpg (PFN_UP(((unsigned long) _end) - PAGE_OFFSET + PHYS_OFFSET))
 
-unsigned long bootmem_lastpg;  /*  Should be set by platform code  */
+unsigned long bootmem_lastpg;   /*  Should be set by platform code  */
+unsigned long __phys_offset;    /*  physical kernel offset >> 12  */
 
 /*  Set as variable to limit PMD copies  */
 int max_kernel_seg = 0x303;
@@ -44,7 +45,6 @@ unsigned long zero_page_mask;
 /*  indicate pfn's of high memory  */
 unsigned long highstart_pfn, highend_pfn;
 
-/* struct mmu_gather defined in asm-generic.h;  */
 DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
 
 /* Default cache attribute for newly created page tables */
@@ -71,7 +71,7 @@ void __init mem_init(void)
 {
         /*  No idea where this is actually declared.  Seems to evade LXR.  */
         totalram_pages += free_all_bootmem();
-        num_physpages = bootmem_lastpg; /*  seriously, what?  */
+        num_physpages = bootmem_lastpg-ARCH_PFN_OFFSET;
 
         printk(KERN_INFO "totalram_pages = %ld\n", totalram_pages);
 
@@ -193,6 +193,9 @@ void __init setup_arch_memory(void)
          * This needs to change for highmem setups.
          */
 
+        /*  Prior to this, bootmem_lastpg is actually mem size  */
+        bootmem_lastpg += ARCH_PFN_OFFSET;
+
         /* Memory size needs to be a multiple of 16M */
         bootmem_lastpg = PFN_DOWN((bootmem_lastpg << PAGE_SHIFT) &
                 ~((BIG_KERNEL_PAGE_SIZE) - 1));
@@ -201,12 +204,15 @@ void __init setup_arch_memory(void)
          * Reserve the top DMA_RESERVE bytes of RAM for DMA (uncached)
          * memory allocation
          */
-        bootmap_size = init_bootmem(bootmem_startpg, bootmem_lastpg -
-                                    PFN_DOWN(DMA_RESERVED_BYTES));
+
+        max_low_pfn = bootmem_lastpg - PFN_DOWN(DMA_RESERVED_BYTES);
+        min_low_pfn = ARCH_PFN_OFFSET;
+        bootmap_size =  init_bootmem_node(NODE_DATA(0), bootmem_startpg, min_low_pfn, max_low_pfn);
 
         printk(KERN_INFO "bootmem_startpg:  0x%08lx\n", bootmem_startpg);
         printk(KERN_INFO "bootmem_lastpg:  0x%08lx\n", bootmem_lastpg);
         printk(KERN_INFO "bootmap_size:  %d\n", bootmap_size);
+        printk(KERN_INFO "min_low_pfn:  0x%08lx\n", min_low_pfn);
         printk(KERN_INFO "max_low_pfn:  0x%08lx\n", max_low_pfn);
 
         /*
@@ -221,14 +227,17 @@ void __init setup_arch_memory(void)
         /*  this actually only goes to the end of the first gig  */
         segtable_end = segtable + (1<<(30-22));
 
-        /*  Move forward to the start of empty pages  */
-        segtable += bootmem_lastpg >> (22-PAGE_SHIFT);
+        /*
+         * Move forward to the start of empty pages; take into account
+         * phys_offset shift.
+         */
 
+        segtable += (bootmem_lastpg-ARCH_PFN_OFFSET)>>(22-PAGE_SHIFT);
         {
-            int i;
+                int i;
 
-            for (i = 1 ; i <= DMA_RESERVE ; i++)
-                segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB)
+                for (i = 1 ; i <= DMA_RESERVE ; i++)
+                        segtable[-i] = ((segtable[-i] & __HVM_PTE_PGMASK_4MB)
                                 | __HVM_PTE_R | __HVM_PTE_W | __HVM_PTE_X
                                 | __HEXAGON_C_UNC << 6
                                 | __HVM_PDE_S_4MB);
@@ -256,7 +265,7 @@ void __init setup_arch_memory(void)
          * Free all the memory that wasn't taken up by the bootmap, the DMA
          * reserve, or kernel itself.
          */
-        free_bootmem(PFN_PHYS(bootmem_startpg)+bootmap_size,
+        free_bootmem(PFN_PHYS(bootmem_startpg) + bootmap_size,
                      PFN_PHYS(bootmem_lastpg - bootmem_startpg) - bootmap_size -
                      DMA_RESERVED_BYTES);