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palmer-dabbeltpalmer-dabbelt
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RISC-V: Fix some RV32 bugs and build failures
This patch set fixes up various failures in the RV32I port. The fixes are all nominally independent, but are really only testable together because the RV32I port fails to build without all of them. The patch set includes: * The removal of tishift on RV32I targets, as 128-bit integers are not supported by the toolchain. * The removal of swiotlb from RV32I targets, since all physical addresses can be mapped by all hardware on all existing RV32I targets. * The addition of ummodi3 and udivmoddi4 from an old version of GCC that was licensed under GPLv2 as generic code, along with their use on RV32I targets. * A fix to our page alignment logic within ioremap for RV32I targets. Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
2 parents 4e4101c + 827a438 commit a6de21b

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8 files changed

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8 files changed

+353
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‎arch/riscv/Kconfig

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -109,6 +109,7 @@ config ARCH_RV32I
109109
select GENERIC_LIB_ASHRDI3
110110
select GENERIC_LIB_LSHRDI3
111111
select GENERIC_LIB_UCMPDI2
112+
select GENERIC_LIB_UMODDI3
112113

113114
config ARCH_RV64I
114115
bool "RV64I"

‎arch/riscv/kernel/setup.c

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Original file line numberDiff line numberDiff line change
@@ -227,7 +227,10 @@ void __init setup_arch(char **cmdline_p)
227227
setup_bootmem();
228228
paging_init();
229229
unflatten_device_tree();
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231+
#ifdef CONFIG_SWIOTLB
230232
swiotlb_init(1);
233+
#endif
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232235
#ifdef CONFIG_SMP
233236
setup_smp();

‎arch/riscv/lib/Makefile

Lines changed: 2 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -2,6 +2,7 @@ lib-y += delay.o
22
lib-y += memcpy.o
33
lib-y += memset.o
44
lib-y += uaccess.o
5-
lib-y += tishift.o
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lib-(CONFIG_64BIT) += tishift.o
67

78
lib-$(CONFIG_32BIT) += udivdi3.o

‎arch/riscv/mm/ioremap.c

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -42,7 +42,7 @@ static void __iomem *__ioremap_caller(phys_addr_t addr, size_t size,
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4343
/* Page-align mappings */
4444
offset = addr & (~PAGE_MASK);
45-
addr &= PAGE_MASK;
45+
addr -= offset;
4646
size = PAGE_ALIGN(size + offset);
4747

4848
area = get_vm_area_caller(size, VM_IOREMAP, caller);

‎lib/Kconfig

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Original file line numberDiff line numberDiff line change
@@ -621,3 +621,6 @@ config GENERIC_LIB_CMPDI2
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622622
config GENERIC_LIB_UCMPDI2
623623
bool
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config GENERIC_LIB_UMODDI3
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bool

‎lib/Makefile

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Original file line numberDiff line numberDiff line change
@@ -270,3 +270,4 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o
270270
obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o
271271
obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o
272272
obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o
273+
obj-$(CONFIG_GENERIC_LIB_UMODDI3) += umoddi3.o udivmoddi4.o

‎lib/udivmoddi4.c

Lines changed: 310 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,310 @@
1+
// SPDX-License-Identifier: GPL-2.0
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/*
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* This program is free software; you can redistribute it and/or modify
5+
* it under the terms of the GNU General Public License as published by
6+
* the Free Software Foundation; either version 2 of the License, or
7+
* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
10+
* but WITHOUT ANY WARRANTY; without even the implied warranty of
11+
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12+
* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
15+
* along with this program; if not, see the file COPYING, or write
16+
* to the Free Software Foundation, Inc.
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*/
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#include <linux/libgcc.h>
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#define count_leading_zeros(COUNT, X) ((COUNT) = __builtin_clz(X))
22+
23+
#define W_TYPE_SIZE 32
24+
25+
#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2))
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#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1))
27+
#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2))
28+
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/* If we still don't have umul_ppmm, define it using plain C. */
30+
#if !defined(umul_ppmm)
31+
#define umul_ppmm(w1, w0, u, v) \
32+
do { \
33+
unsigned long __x0, __x1, __x2, __x3; \
34+
unsigned short __ul, __vl, __uh, __vh; \
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\
36+
__ul = __ll_lowpart(u); \
37+
__uh = __ll_highpart(u); \
38+
__vl = __ll_lowpart(v); \
39+
__vh = __ll_highpart(v); \
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\
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__x0 = (unsigned long) __ul * __vl; \
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__x1 = (unsigned long) __ul * __vh; \
43+
__x2 = (unsigned long) __uh * __vl; \
44+
__x3 = (unsigned long) __uh * __vh; \
45+
\
46+
__x1 += __ll_highpart(__x0); \
47+
__x1 += __x2; \
48+
if (__x1 < __x2) \
49+
__x3 += __ll_B; \
50+
\
51+
(w1) = __x3 + __ll_highpart(__x1); \
52+
(w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\
53+
} while (0)
54+
#endif
55+
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#if !defined(sub_ddmmss)
57+
#define sub_ddmmss(sh, sl, ah, al, bh, bl) \
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do { \
59+
unsigned long __x; \
60+
__x = (al) - (bl); \
61+
(sh) = (ah) - (bh) - (__x > (al)); \
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(sl) = __x; \
63+
} while (0)
64+
#endif
65+
66+
/* Define this unconditionally, so it can be used for debugging. */
67+
#define __udiv_qrnnd_c(q, r, n1, n0, d) \
68+
do { \
69+
unsigned long __d1, __d0, __q1, __q0; \
70+
unsigned long __r1, __r0, __m; \
71+
__d1 = __ll_highpart(d); \
72+
__d0 = __ll_lowpart(d); \
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\
74+
__r1 = (n1) % __d1; \
75+
__q1 = (n1) / __d1; \
76+
__m = (unsigned long) __q1 * __d0; \
77+
__r1 = __r1 * __ll_B | __ll_highpart(n0); \
78+
if (__r1 < __m) { \
79+
__q1--, __r1 += (d); \
80+
if (__r1 >= (d)) \
81+
if (__r1 < __m) \
82+
__q1--, __r1 += (d); \
83+
} \
84+
__r1 -= __m; \
85+
\
86+
__r0 = __r1 % __d1; \
87+
__q0 = __r1 / __d1; \
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__m = (unsigned long) __q0 * __d0; \
89+
__r0 = __r0 * __ll_B | __ll_lowpart(n0); \
90+
if (__r0 < __m) { \
91+
__q0--, __r0 += (d); \
92+
if (__r0 >= (d)) \
93+
if (__r0 < __m) \
94+
__q0--, __r0 += (d); \
95+
} \
96+
__r0 -= __m; \
97+
\
98+
(q) = (unsigned long) __q1 * __ll_B | __q0; \
99+
(r) = __r0; \
100+
} while (0)
101+
102+
/* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c. */
103+
#if !defined(udiv_qrnnd)
104+
#define UDIV_NEEDS_NORMALIZATION 1
105+
#define udiv_qrnnd __udiv_qrnnd_c
106+
#endif
107+
108+
unsigned long long __udivmoddi4(unsigned long long u, unsigned long long v,
109+
unsigned long long *rp)
110+
{
111+
const DWunion nn = {.ll = u };
112+
const DWunion dd = {.ll = v };
113+
DWunion rr, ww;
114+
unsigned long d0, d1, n0, n1, n2;
115+
unsigned long q0 = 0, q1 = 0;
116+
unsigned long b, bm;
117+
118+
d0 = dd.s.low;
119+
d1 = dd.s.high;
120+
n0 = nn.s.low;
121+
n1 = nn.s.high;
122+
123+
#if !UDIV_NEEDS_NORMALIZATION
124+
125+
if (d1 == 0) {
126+
if (d0 > n1) {
127+
/* 0q = nn / 0D */
128+
129+
udiv_qrnnd(q0, n0, n1, n0, d0);
130+
q1 = 0;
131+
132+
/* Remainder in n0. */
133+
} else {
134+
/* qq = NN / 0d */
135+
136+
if (d0 == 0)
137+
/* Divide intentionally by zero. */
138+
d0 = 1 / d0;
139+
140+
udiv_qrnnd(q1, n1, 0, n1, d0);
141+
udiv_qrnnd(q0, n0, n1, n0, d0);
142+
143+
/* Remainder in n0. */
144+
}
145+
146+
if (rp != 0) {
147+
rr.s.low = n0;
148+
rr.s.high = 0;
149+
*rp = rr.ll;
150+
}
151+
152+
#else /* UDIV_NEEDS_NORMALIZATION */
153+
154+
if (d1 == 0) {
155+
if (d0 > n1) {
156+
/* 0q = nn / 0D */
157+
158+
count_leading_zeros(bm, d0);
159+
160+
if (bm != 0) {
161+
/*
162+
* Normalize, i.e. make the most significant bit
163+
* of the denominator set.
164+
*/
165+
166+
d0 = d0 << bm;
167+
n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm));
168+
n0 = n0 << bm;
169+
}
170+
171+
udiv_qrnnd(q0, n0, n1, n0, d0);
172+
q1 = 0;
173+
174+
/* Remainder in n0 >> bm. */
175+
} else {
176+
/* qq = NN / 0d */
177+
178+
if (d0 == 0)
179+
/* Divide intentionally by zero. */
180+
d0 = 1 / d0;
181+
182+
count_leading_zeros(bm, d0);
183+
184+
if (bm == 0) {
185+
/*
186+
* From (n1 >= d0) /\ (the most significant bit
187+
* of d0 is set), conclude (the most significant
188+
* bit of n1 is set) /\ (theleading quotient
189+
* digit q1 = 1).
190+
*
191+
* This special case is necessary, not an
192+
* optimization. (Shifts counts of W_TYPE_SIZE
193+
* are undefined.)
194+
*/
195+
196+
n1 -= d0;
197+
q1 = 1;
198+
} else {
199+
/* Normalize. */
200+
201+
b = W_TYPE_SIZE - bm;
202+
203+
d0 = d0 << bm;
204+
n2 = n1 >> b;
205+
n1 = (n1 << bm) | (n0 >> b);
206+
n0 = n0 << bm;
207+
208+
udiv_qrnnd(q1, n1, n2, n1, d0);
209+
}
210+
211+
/* n1 != d0... */
212+
213+
udiv_qrnnd(q0, n0, n1, n0, d0);
214+
215+
/* Remainder in n0 >> bm. */
216+
}
217+
218+
if (rp != 0) {
219+
rr.s.low = n0 >> bm;
220+
rr.s.high = 0;
221+
*rp = rr.ll;
222+
}
223+
224+
#endif /* UDIV_NEEDS_NORMALIZATION */
225+
226+
} else {
227+
if (d1 > n1) {
228+
/* 00 = nn / DD */
229+
230+
q0 = 0;
231+
q1 = 0;
232+
233+
/* Remainder in n1n0. */
234+
if (rp != 0) {
235+
rr.s.low = n0;
236+
rr.s.high = n1;
237+
*rp = rr.ll;
238+
}
239+
} else {
240+
/* 0q = NN / dd */
241+
242+
count_leading_zeros(bm, d1);
243+
if (bm == 0) {
244+
/*
245+
* From (n1 >= d1) /\ (the most significant bit
246+
* of d1 is set), conclude (the most significant
247+
* bit of n1 is set) /\ (the quotient digit q0 =
248+
* 0 or 1).
249+
*
250+
* This special case is necessary, not an
251+
* optimization.
252+
*/
253+
254+
/*
255+
* The condition on the next line takes
256+
* advantage of that n1 >= d1 (true due to
257+
* program flow).
258+
*/
259+
if (n1 > d1 || n0 >= d0) {
260+
q0 = 1;
261+
sub_ddmmss(n1, n0, n1, n0, d1, d0);
262+
} else {
263+
q0 = 0;
264+
}
265+
266+
q1 = 0;
267+
268+
if (rp != 0) {
269+
rr.s.low = n0;
270+
rr.s.high = n1;
271+
*rp = rr.ll;
272+
}
273+
} else {
274+
unsigned long m1, m0;
275+
/* Normalize. */
276+
277+
b = W_TYPE_SIZE - bm;
278+
279+
d1 = (d1 << bm) | (d0 >> b);
280+
d0 = d0 << bm;
281+
n2 = n1 >> b;
282+
n1 = (n1 << bm) | (n0 >> b);
283+
n0 = n0 << bm;
284+
285+
udiv_qrnnd(q0, n1, n2, n1, d1);
286+
umul_ppmm(m1, m0, q0, d0);
287+
288+
if (m1 > n1 || (m1 == n1 && m0 > n0)) {
289+
q0--;
290+
sub_ddmmss(m1, m0, m1, m0, d1, d0);
291+
}
292+
293+
q1 = 0;
294+
295+
/* Remainder in (n1n0 - m1m0) >> bm. */
296+
if (rp != 0) {
297+
sub_ddmmss(n1, n0, n1, n0, m1, m0);
298+
rr.s.low = (n1 << b) | (n0 >> bm);
299+
rr.s.high = n1 >> bm;
300+
*rp = rr.ll;
301+
}
302+
}
303+
}
304+
}
305+
306+
ww.s.low = q0;
307+
ww.s.high = q1;
308+
309+
return ww.ll;
310+
}

‎lib/umoddi3.c

Lines changed: 32 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,32 @@
1+
// SPDX-License-Identifier: GPL-2.0
2+
3+
/*
4+
* This program is free software; you can redistribute it and/or modify
5+
* it under the terms of the GNU General Public License as published by
6+
* the Free Software Foundation; either version 2 of the License, or
7+
* (at your option) any later version.
8+
*
9+
* This program is distributed in the hope that it will be useful,
10+
* but WITHOUT ANY WARRANTY; without even the implied warranty of
11+
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12+
* GNU General Public License for more details.
13+
*
14+
* You should have received a copy of the GNU General Public License
15+
* along with this program; if not, see the file COPYING, or write
16+
* to the Free Software Foundation, Inc.
17+
*/
18+
19+
#include <linux/module.h>
20+
#include <linux/libgcc.h>
21+
22+
extern unsigned long long __udivmoddi4(unsigned long long u,
23+
unsigned long long v,
24+
unsigned long long *rp);
25+
26+
unsigned long long __umoddi3(unsigned long long u, unsigned long long v)
27+
{
28+
unsigned long long w;
29+
(void)__udivmoddi4(u, v, &w);
30+
return w;
31+
}
32+
EXPORT_SYMBOL(__umoddi3);

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