drivers/staging/octeon/ethernet-mem.c

   1 /*
   2  * This file is based on code from OCTEON SDK by Cavium Networks.
   3  *
   4  * Copyright (c) 2003-2010 Cavium Networks
   5  *
   6  * This file is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, Version 2, as
   8  * published by the Free Software Foundation.
   9  */
  10
  11 #include <linux/kernel.h>
  12 #include <linux/netdevice.h>
  13 #include <linux/slab.h>
  14
  15 #include <asm/octeon/octeon.h>
  16
  17 #include "ethernet-mem.h"
  18 #include "ethernet-defines.h"
  19
  20 #include <asm/octeon/cvmx-fpa.h>
  21
  22 /**
  23  * cvm_oct_fill_hw_skbuff - fill the supplied hardware pool with skbuffs
  24  * @pool:     Pool to allocate an skbuff for
  25  * @size:     Size of the buffer needed for the pool
  26  * @elements: Number of buffers to allocate
  27  *
  28  * Returns the actual number of buffers allocated.
  29  */
  30 static int cvm_oct_fill_hw_skbuff(int pool, int size, int elements)
  31 {
  32         int freed = elements;
  33
  34         while (freed) {
  35                 struct sk_buff *skb = dev_alloc_skb(size + 256);
  36
  37                 if (unlikely(skb == NULL))
  38                         break;
  39                 skb_reserve(skb, 256 - (((unsigned long)skb->data) & 0x7f));
  40                 *(struct sk_buff **)(skb->data - sizeof(void *)) = skb;
  41                 cvmx_fpa_free(skb->data, pool, size / 128);
  42                 freed--;
  43         }
  44         return elements - freed;
  45 }
  46
  47 /**
  48  * cvm_oct_free_hw_skbuff- free hardware pool skbuffs
  49  * @pool:     Pool to allocate an skbuff for
  50  * @size:     Size of the buffer needed for the pool
  51  * @elements: Number of buffers to allocate
  52  */
  53 static void cvm_oct_free_hw_skbuff(int pool, int size, int elements)
  54 {
  55         char *memory;
  56
  57         do {
  58                 memory = cvmx_fpa_alloc(pool);
  59                 if (memory) {
  60                         struct sk_buff *skb =
  61                             *(struct sk_buff **)(memory - sizeof(void *));
  62                         elements--;
  63                         dev_kfree_skb(skb);
  64                 }
  65         } while (memory);
  66
  67         if (elements < 0)
  68                 pr_warn("Freeing of pool %u had too many skbuffs (%d)\n",
  69                         pool, elements);
  70         else if (elements > 0)
  71                 pr_warn("Freeing of pool %u is missing %d skbuffs\n",
  72                         pool, elements);
  73 }
  74
  75 /**
  76  * cvm_oct_fill_hw_memory - fill a hardware pool with memory.
  77  * @pool:     Pool to populate
  78  * @size:     Size of each buffer in the pool
  79  * @elements: Number of buffers to allocate
  80  *
  81  * Returns the actual number of buffers allocated.
  82  */
  83 static int cvm_oct_fill_hw_memory(int pool, int size, int elements)
  84 {
  85         char *memory;
  86         char *fpa;
  87         int freed = elements;
  88
  89         while (freed) {
  90                 /*
  91                  * FPA memory must be 128 byte aligned.  Since we are
  92                  * aligning we need to save the original pointer so we
  93                  * can feed it to kfree when the memory is returned to
  94                  * the kernel.
  95                  *
  96                  * We allocate an extra 256 bytes to allow for
  97                  * alignment and space for the original pointer saved
  98                  * just before the block.
  99                  */
 100                 memory = kmalloc(size + 256, GFP_ATOMIC);
 101                 if (unlikely(memory == NULL)) {
 102                         pr_warn("Unable to allocate %u bytes for FPA pool %d\n",
 103                                 elements * size, pool);
 104                         break;
 105                 }
 106                 fpa = (char *)(((unsigned long)memory + 256) & ~0x7fUL);
 107                 *((char **)fpa - 1) = memory;
 108                 cvmx_fpa_free(fpa, pool, 0);
 109                 freed--;
 110         }
 111         return elements - freed;
 112 }
 113
 114 /**
 115  * cvm_oct_free_hw_memory - Free memory allocated by cvm_oct_fill_hw_memory
 116  * @pool:     FPA pool to free
 117  * @size:     Size of each buffer in the pool
 118  * @elements: Number of buffers that should be in the pool
 119  */
 120 static void cvm_oct_free_hw_memory(int pool, int size, int elements)
 121 {
 122         char *memory;
 123         char *fpa;
 124
 125         do {
 126                 fpa = cvmx_fpa_alloc(pool);
 127                 if (fpa) {
 128                         elements--;
 129                         fpa = (char *)phys_to_virt(cvmx_ptr_to_phys(fpa));
 130                         memory = *((char **)fpa - 1);
 131                         kfree(memory);
 132                 }
 133         } while (fpa);
 134
 135         if (elements < 0)
 136                 pr_warn("Freeing of pool %u had too many buffers (%d)\n",
 137                         pool, elements);
 138         else if (elements > 0)
 139                 pr_warn("Warning: Freeing of pool %u is missing %d buffers\n",
 140                         pool, elements);
 141 }
 142
 143 int cvm_oct_mem_fill_fpa(int pool, int size, int elements)
 144 {
 145         int freed;
 146
 147         if (pool == CVMX_FPA_PACKET_POOL)
 148                 freed = cvm_oct_fill_hw_skbuff(pool, size, elements);
 149         else
 150                 freed = cvm_oct_fill_hw_memory(pool, size, elements);
 151         return freed;
 152 }
 153
 154 void cvm_oct_mem_empty_fpa(int pool, int size, int elements)
 155 {
 156         if (pool == CVMX_FPA_PACKET_POOL)
 157                 cvm_oct_free_hw_skbuff(pool, size, elements);
 158         else
 159                 cvm_oct_free_hw_memory(pool, size, elements);
 160 }