xref: /openbmc/qemu/hw/ppc/spapr_ovec.c (revision 709395f8) 
1 /*
2  * QEMU SPAPR Architecture Option Vector Helper Functions
3  *
4  * Copyright IBM Corp. 2016
5  *
6  * Authors:
7  *  Bharata B Rao     <bharata@linux.vnet.ibm.com>
8  *  Michael Roth      <mdroth@linux.vnet.ibm.com>
9  *
10  * This work is licensed under the terms of the GNU GPL, version 2 or later.
11  * See the COPYING file in the top-level directory.
12  */
13 
14 #include "qemu/osdep.h"
15 #include "hw/ppc/spapr_ovec.h"
16 #include "qemu/bitmap.h"
17 #include "exec/address-spaces.h"
18 #include "qemu/error-report.h"
19 #include "sysemu/qtest.h"
20 #include "trace.h"
21 #include <libfdt.h>
22 
23 #define OV_MAXBYTES 256 /* not including length byte */
24 #define OV_MAXBITS (OV_MAXBYTES * BITS_PER_BYTE)
25 
26 /* we *could* work with bitmaps directly, but handling the bitmap privately
27  * allows us to more safely make assumptions about the bitmap size and
28  * simplify the calling code somewhat
29  */
30 struct sPAPROptionVector {
31     unsigned long *bitmap;
32     int32_t bitmap_size; /* only used for migration */
33 };
34 
35 const VMStateDescription vmstate_spapr_ovec = {
36     .name = "spapr_option_vector",
37     .version_id = 1,
38     .minimum_version_id = 1,
39     .fields = (VMStateField[]) {
40         VMSTATE_BITMAP(bitmap, sPAPROptionVector, 1, bitmap_size),
41         VMSTATE_END_OF_LIST()
42     }
43 };
44 
45 sPAPROptionVector *spapr_ovec_new(void)
46 {
47     sPAPROptionVector *ov;
48 
49     ov = g_new0(sPAPROptionVector, 1);
50     ov->bitmap = bitmap_new(OV_MAXBITS);
51     ov->bitmap_size = OV_MAXBITS;
52 
53     return ov;
54 }
55 
56 sPAPROptionVector *spapr_ovec_clone(sPAPROptionVector *ov_orig)
57 {
58     sPAPROptionVector *ov;
59 
60     g_assert(ov_orig);
61 
62     ov = spapr_ovec_new();
63     bitmap_copy(ov->bitmap, ov_orig->bitmap, OV_MAXBITS);
64 
65     return ov;
66 }
67 
68 void spapr_ovec_intersect(sPAPROptionVector *ov,
69                           sPAPROptionVector *ov1,
70                           sPAPROptionVector *ov2)
71 {
72     g_assert(ov);
73     g_assert(ov1);
74     g_assert(ov2);
75 
76     bitmap_and(ov->bitmap, ov1->bitmap, ov2->bitmap, OV_MAXBITS);
77 }
78 
79 /* returns true if options bits were removed, false otherwise */
80 bool spapr_ovec_diff(sPAPROptionVector *ov,
81                      sPAPROptionVector *ov_old,
82                      sPAPROptionVector *ov_new)
83 {
84     unsigned long *change_mask = bitmap_new(OV_MAXBITS);
85     unsigned long *removed_bits = bitmap_new(OV_MAXBITS);
86     bool bits_were_removed = false;
87 
88     g_assert(ov);
89     g_assert(ov_old);
90     g_assert(ov_new);
91 
92     bitmap_xor(change_mask, ov_old->bitmap, ov_new->bitmap, OV_MAXBITS);
93     bitmap_and(ov->bitmap, ov_new->bitmap, change_mask, OV_MAXBITS);
94     bitmap_and(removed_bits, ov_old->bitmap, change_mask, OV_MAXBITS);
95 
96     if (!bitmap_empty(removed_bits, OV_MAXBITS)) {
97         bits_were_removed = true;
98     }
99 
100     g_free(change_mask);
101     g_free(removed_bits);
102 
103     return bits_were_removed;
104 }
105 
106 void spapr_ovec_cleanup(sPAPROptionVector *ov)
107 {
108     if (ov) {
109         g_free(ov->bitmap);
110         g_free(ov);
111     }
112 }
113 
114 void spapr_ovec_set(sPAPROptionVector *ov, long bitnr)
115 {
116     g_assert(ov);
117     g_assert(bitnr < OV_MAXBITS);
118 
119     set_bit(bitnr, ov->bitmap);
120 }
121 
122 void spapr_ovec_clear(sPAPROptionVector *ov, long bitnr)
123 {
124     g_assert(ov);
125     g_assert(bitnr < OV_MAXBITS);
126 
127     clear_bit(bitnr, ov->bitmap);
128 }
129 
130 bool spapr_ovec_test(sPAPROptionVector *ov, long bitnr)
131 {
132     g_assert(ov);
133     g_assert(bitnr < OV_MAXBITS);
134 
135     /* support memory unplug for qtest */
136     if (qtest_enabled() && bitnr == OV5_HP_EVT) {
137         return true;
138     }
139 
140     return test_bit(bitnr, ov->bitmap) ? true : false;
141 }
142 
143 static void guest_byte_to_bitmap(uint8_t entry, unsigned long *bitmap,
144                                  long bitmap_offset)
145 {
146     int i;
147 
148     for (i = 0; i < BITS_PER_BYTE; i++) {
149         if (entry & (1 << (BITS_PER_BYTE - 1 - i))) {
150             bitmap_set(bitmap, bitmap_offset + i, 1);
151         }
152     }
153 }
154 
155 static uint8_t guest_byte_from_bitmap(unsigned long *bitmap, long bitmap_offset)
156 {
157     uint8_t entry = 0;
158     int i;
159 
160     for (i = 0; i < BITS_PER_BYTE; i++) {
161         if (test_bit(bitmap_offset + i, bitmap)) {
162             entry |= (1 << (BITS_PER_BYTE - 1 - i));
163         }
164     }
165 
166     return entry;
167 }
168 
169 static target_ulong vector_addr(target_ulong table_addr, int vector)
170 {
171     uint16_t vector_count, vector_len;
172     int i;
173 
174     vector_count = ldub_phys(&address_space_memory, table_addr) + 1;
175     if (vector > vector_count) {
176         return 0;
177     }
178     table_addr++; /* skip nr option vectors */
179 
180     for (i = 0; i < vector - 1; i++) {
181         vector_len = ldub_phys(&address_space_memory, table_addr) + 1;
182         table_addr += vector_len + 1; /* bit-vector + length byte */
183     }
184     return table_addr;
185 }
186 
187 sPAPROptionVector *spapr_ovec_parse_vector(target_ulong table_addr, int vector)
188 {
189     sPAPROptionVector *ov;
190     target_ulong addr;
191     uint16_t vector_len;
192     int i;
193 
194     g_assert(table_addr);
195     g_assert(vector >= 1);      /* vector numbering starts at 1 */
196 
197     addr = vector_addr(table_addr, vector);
198     if (!addr) {
199         /* specified vector isn't present */
200         return NULL;
201     }
202 
203     vector_len = ldub_phys(&address_space_memory, addr++) + 1;
204     g_assert(vector_len <= OV_MAXBYTES);
205     ov = spapr_ovec_new();
206 
207     for (i = 0; i < vector_len; i++) {
208         uint8_t entry = ldub_phys(&address_space_memory, addr + i);
209         if (entry) {
210             trace_spapr_ovec_parse_vector(vector, i + 1, vector_len, entry);
211             guest_byte_to_bitmap(entry, ov->bitmap, i * BITS_PER_BYTE);
212         }
213     }
214 
215     return ov;
216 }
217 
218 int spapr_ovec_populate_dt(void *fdt, int fdt_offset,
219                            sPAPROptionVector *ov, const char *name)
220 {
221     uint8_t vec[OV_MAXBYTES + 1];
222     uint16_t vec_len;
223     unsigned long lastbit;
224     int i;
225 
226     g_assert(ov);
227 
228     lastbit = find_last_bit(ov->bitmap, OV_MAXBITS);
229     /* if no bits are set, include at least 1 byte of the vector so we can
230      * still encoded this in the device tree while abiding by the same
231      * encoding/sizing expected in ibm,client-architecture-support
232      */
233     vec_len = (lastbit == OV_MAXBITS) ? 1 : lastbit / BITS_PER_BYTE + 1;
234     g_assert(vec_len <= OV_MAXBYTES);
235     /* guest expects vector len encoded as vec_len - 1, since the length byte
236      * is assumed and not included, and the first byte of the vector
237      * is assumed as well
238      */
239     vec[0] = vec_len - 1;
240 
241     for (i = 1; i < vec_len + 1; i++) {
242         vec[i] = guest_byte_from_bitmap(ov->bitmap, (i - 1) * BITS_PER_BYTE);
243         if (vec[i]) {
244             trace_spapr_ovec_populate_dt(i, vec_len, vec[i]);
245         }
246     }
247 
248     return fdt_setprop(fdt, fdt_offset, name, vec, vec_len + 1);
249 }
250