xref: /linux/drivers/staging/octeon/ethernet-mem.c (revision 422d97b8)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * This file is based on code from OCTEON SDK by Cavium Networks.
4  *
5  * Copyright (c) 2003-2010 Cavium Networks
6  */
7 
8 #include <linux/kernel.h>
9 #include <linux/netdevice.h>
10 #include <linux/slab.h>
11 
12 #include "octeon-ethernet.h"
13 #include "ethernet-mem.h"
14 #include "ethernet-defines.h"
15 
16 /**
17  * cvm_oct_fill_hw_skbuff - fill the supplied hardware pool with skbuffs
18  * @pool:     Pool to allocate an skbuff for
19  * @size:     Size of the buffer needed for the pool
20  * @elements: Number of buffers to allocate
21  *
22  * Returns the actual number of buffers allocated.
23  */
cvm_oct_fill_hw_skbuff(int pool,int size,int elements)24 static int cvm_oct_fill_hw_skbuff(int pool, int size, int elements)
25 {
26 	int freed = elements;
27 
28 	while (freed) {
29 		struct sk_buff *skb = dev_alloc_skb(size + 256);
30 
31 		if (unlikely(!skb))
32 			break;
33 		skb_reserve(skb, 256 - (((unsigned long)skb->data) & 0x7f));
34 		*(struct sk_buff **)(skb->data - sizeof(void *)) = skb;
35 		cvmx_fpa_free(skb->data, pool, size / 128);
36 		freed--;
37 	}
38 	return elements - freed;
39 }
40 
41 /**
42  * cvm_oct_free_hw_skbuff- free hardware pool skbuffs
43  * @pool:     Pool to allocate an skbuff for
44  * @size:     Size of the buffer needed for the pool
45  * @elements: Number of buffers to allocate
46  */
cvm_oct_free_hw_skbuff(int pool,int size,int elements)47 static void cvm_oct_free_hw_skbuff(int pool, int size, int elements)
48 {
49 	char *memory;
50 
51 	do {
52 		memory = cvmx_fpa_alloc(pool);
53 		if (memory) {
54 			struct sk_buff *skb =
55 			    *(struct sk_buff **)(memory - sizeof(void *));
56 			elements--;
57 			dev_kfree_skb(skb);
58 		}
59 	} while (memory);
60 
61 	if (elements < 0)
62 		pr_warn("Freeing of pool %u had too many skbuffs (%d)\n",
63 			pool, elements);
64 	else if (elements > 0)
65 		pr_warn("Freeing of pool %u is missing %d skbuffs\n",
66 			pool, elements);
67 }
68 
69 /**
70  * cvm_oct_fill_hw_memory - fill a hardware pool with memory.
71  * @pool:     Pool to populate
72  * @size:     Size of each buffer in the pool
73  * @elements: Number of buffers to allocate
74  *
75  * Returns the actual number of buffers allocated.
76  */
cvm_oct_fill_hw_memory(int pool,int size,int elements)77 static int cvm_oct_fill_hw_memory(int pool, int size, int elements)
78 {
79 	char *memory;
80 	char *fpa;
81 	int freed = elements;
82 
83 	while (freed) {
84 		/*
85 		 * FPA memory must be 128 byte aligned.  Since we are
86 		 * aligning we need to save the original pointer so we
87 		 * can feed it to kfree when the memory is returned to
88 		 * the kernel.
89 		 *
90 		 * We allocate an extra 256 bytes to allow for
91 		 * alignment and space for the original pointer saved
92 		 * just before the block.
93 		 */
94 		memory = kmalloc(size + 256, GFP_ATOMIC);
95 		if (unlikely(!memory)) {
96 			pr_warn("Unable to allocate %u bytes for FPA pool %d\n",
97 				elements * size, pool);
98 			break;
99 		}
100 		fpa = (char *)(((unsigned long)memory + 256) & ~0x7fUL);
101 		*((char **)fpa - 1) = memory;
102 		cvmx_fpa_free(fpa, pool, 0);
103 		freed--;
104 	}
105 	return elements - freed;
106 }
107 
108 /**
109  * cvm_oct_free_hw_memory - Free memory allocated by cvm_oct_fill_hw_memory
110  * @pool:     FPA pool to free
111  * @size:     Size of each buffer in the pool
112  * @elements: Number of buffers that should be in the pool
113  */
cvm_oct_free_hw_memory(int pool,int size,int elements)114 static void cvm_oct_free_hw_memory(int pool, int size, int elements)
115 {
116 	char *memory;
117 	char *fpa;
118 
119 	do {
120 		fpa = cvmx_fpa_alloc(pool);
121 		if (fpa) {
122 			elements--;
123 			fpa = (char *)phys_to_virt(cvmx_ptr_to_phys(fpa));
124 			memory = *((char **)fpa - 1);
125 			kfree(memory);
126 		}
127 	} while (fpa);
128 
129 	if (elements < 0)
130 		pr_warn("Freeing of pool %u had too many buffers (%d)\n",
131 			pool, elements);
132 	else if (elements > 0)
133 		pr_warn("Warning: Freeing of pool %u is missing %d buffers\n",
134 			pool, elements);
135 }
136 
cvm_oct_mem_fill_fpa(int pool,int size,int elements)137 int cvm_oct_mem_fill_fpa(int pool, int size, int elements)
138 {
139 	int freed;
140 
141 	if (pool == CVMX_FPA_PACKET_POOL)
142 		freed = cvm_oct_fill_hw_skbuff(pool, size, elements);
143 	else
144 		freed = cvm_oct_fill_hw_memory(pool, size, elements);
145 	return freed;
146 }
147 
cvm_oct_mem_empty_fpa(int pool,int size,int elements)148 void cvm_oct_mem_empty_fpa(int pool, int size, int elements)
149 {
150 	if (pool == CVMX_FPA_PACKET_POOL)
151 		cvm_oct_free_hw_skbuff(pool, size, elements);
152 	else
153 		cvm_oct_free_hw_memory(pool, size, elements);
154 }
155