[Xen-devel] [PATCH v2 02/18] mini-os: remove unused alloc_contig_pages() function

[Juergen Gross <jgross@xxxxxxxx>]

alloc_contig_pages() is never used anywhere in mini-os. Remove it.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
 arch/x86/mm.c | 142 ----------------------------------------------------------
 include/mm.h  |   1 -
 2 files changed, 143 deletions(-)

diff --git a/arch/x86/mm.c b/arch/x86/mm.c
index ae1036e..c59a5d3 100644
--- a/arch/x86/mm.c
+++ b/arch/x86/mm.c
@@ -652,148 +652,6 @@ int unmap_frames(unsigned long va, unsigned long 
num_frames)
 }
 
 /*
- * Allocate pages which are contiguous in machine memory.
- * Returns a VA to where they are mapped or 0 on failure.
- * 
- * addr_bits indicates if the region has restrictions on where it is
- * located. Typical values are 32 (if for example PCI devices can't access
- * 64bit memory) or 0 for no restrictions.
- *
- * Allocated pages can be freed using the page allocators free_pages() 
- * function.
- *
- * based on Linux function xen_create_contiguous_region()
- */
-#define MAX_CONTIG_ORDER 9 /* 2MB */
-unsigned long alloc_contig_pages(int order, unsigned int addr_bits)
-{
-    unsigned long in_va, va;
-    unsigned long in_frames[1UL << order], out_frames, mfn;
-    multicall_entry_t call[1UL << order];
-    unsigned int i, num_pages = 1UL << order;
-    int ret, exch_success;
-
-    /* pass in num_pages 'extends' of size 1 and
-     * request 1 extend of size 'order */
-    struct xen_memory_exchange exchange = {
-        .in = {
-            .nr_extents   = num_pages,
-            .extent_order = 0,
-            .domid        = DOMID_SELF
-        },
-        .out = {
-            .nr_extents   = 1,
-            .extent_order = order,
-            .address_bits = addr_bits,
-            .domid        = DOMID_SELF
-        },
-        .nr_exchanged = 0
-    };
-
-    if ( order > MAX_CONTIG_ORDER )
-    {
-        printk("alloc_contig_pages: order too large 0x%x > 0x%x\n",
-               order, MAX_CONTIG_ORDER);
-        return 0;
-    }
-
-    /* Allocate some potentially discontiguous pages */
-    in_va = alloc_pages(order);
-    if ( !in_va )
-    {
-        printk("alloc_contig_pages: could not get enough pages (order=0x%x\n",
-               order);
-        return 0;
-    }
-
-    /* set up arguments for exchange hyper call */
-    set_xen_guest_handle(exchange.in.extent_start, in_frames);
-    set_xen_guest_handle(exchange.out.extent_start, &out_frames);
-
-    /* unmap current frames, keep a list of MFNs */
-    for ( i = 0; i < num_pages; i++ )
-    {
-        int arg = 0;
-
-        va = in_va + (PAGE_SIZE * i);
-        in_frames[i] = virt_to_mfn(va);
-
-        /* update P2M mapping */
-        phys_to_machine_mapping[virt_to_pfn(va)] = INVALID_P2M_ENTRY;
-
-        /* build multi call */
-        call[i].op = __HYPERVISOR_update_va_mapping;
-        call[i].args[arg++] = va;
-        call[i].args[arg++] = 0;
-#ifdef __i386__
-        call[i].args[arg++] = 0;
-#endif  
-        call[i].args[arg++] = UVMF_INVLPG;
-    }
-
-    ret = HYPERVISOR_multicall(call, i);
-    if ( ret )
-    {
-        printk("Odd, update_va_mapping hypercall failed with rc=%d.\n", ret);
-        return 0;
-    }
-
-    /* try getting a contig range of MFNs */
-    out_frames = virt_to_pfn(in_va); /* PFNs to populate */
-    ret = HYPERVISOR_memory_op(XENMEM_exchange, &exchange);
-    if ( ret ) {
-        printk("mem exchanged order=0x%x failed with rc=%d, 
nr_exchanged=%lu\n",
-               order, ret, exchange.nr_exchanged);
-        /* we still need to return the allocated pages above to the pool
-         * ie. map them back into the 1:1 mapping etc. so we continue but 
-         * in the end return the pages to the page allocator and return 0. */
-        exch_success = 0;
-    }
-    else
-        exch_success = 1;
-
-    /* map frames into 1:1 and update p2m */
-    for ( i = 0; i < num_pages; i++ )
-    {
-        int arg = 0;
-        pte_t pte;
-
-        va = in_va + (PAGE_SIZE * i);
-        mfn = i < exchange.nr_exchanged ? (out_frames + i) : in_frames[i];
-        pte = __pte(mfn << PAGE_SHIFT | L1_PROT);
-
-        /* update P2M mapping */
-        phys_to_machine_mapping[virt_to_pfn(va)] = mfn;
-
-        /* build multi call */
-        call[i].op = __HYPERVISOR_update_va_mapping;
-        call[i].args[arg++] = va;
-#ifdef __x86_64__
-        call[i].args[arg++] = (pgentry_t)pte.pte;
-#else
-        call[i].args[arg++] = pte.pte_low;
-        call[i].args[arg++] = pte.pte_high;
-#endif  
-        call[i].args[arg++] = UVMF_INVLPG;
-    }
-    ret = HYPERVISOR_multicall(call, i);
-    if ( ret )
-    {
-        printk("update_va_mapping hypercall no. 2 failed with rc=%d.\n", ret);
-        return 0;
-    }
-
-    if ( !exch_success )
-    {
-        /* since the exchanged failed we just free the pages as well */
-        free_pages((void *) in_va, order);
-        return 0;
-    }
-    
-    return in_va;
-}
-
-/*
  * Clear some of the bootstrap memory
  */
 static void clear_bootstrap(void)
diff --git a/include/mm.h b/include/mm.h
index f57d8ab..a48f485 100644
--- a/include/mm.h
+++ b/include/mm.h
@@ -71,7 +71,6 @@ void do_map_frames(unsigned long addr,
         const unsigned long *f, unsigned long n, unsigned long stride,
        unsigned long increment, domid_t id, int *err, unsigned long prot);
 int unmap_frames(unsigned long va, unsigned long num_frames);
-unsigned long alloc_contig_pages(int order, unsigned int addr_bits);
 #ifdef HAVE_LIBC
 extern unsigned long heap, brk, heap_mapped, heap_end;
 #endif
-- 
2.6.6


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