From 3b306f6f3a03c285a7044350d263cb9251def49d Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Fri, 26 Oct 2018 12:37:43 -0700 Subject: [PATCH 1/4] Revert "RISC-V: Select GENERIC_LIB_UMODDI3 on RV32" I'm removing the generic 64-bit divide support, which means this will no longer work. This reverts commit 757331db921428295948fed5e7377a436e66d34e. Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 1 - 1 file changed, 1 deletion(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index fe451348ae57..4198759f6798 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -109,7 +109,6 @@ config ARCH_RV32I select GENERIC_LIB_ASHRDI3 select GENERIC_LIB_LSHRDI3 select GENERIC_LIB_UCMPDI2 - select GENERIC_LIB_UMODDI3 config ARCH_RV64I bool "RV64I" From 0ef08ca36a3aafbf0dcce7b3c2c4b6b664ce56bd Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Fri, 26 Oct 2018 12:38:11 -0700 Subject: [PATCH 2/4] Revert "lib: Add umoddi3 and udivmoddi4 of GCC library routines" We don't want 64-bit divide in the kernel. This reverts commit 6315730e9eab7de5fa9864bb13a352713f48aef1. Signed-off-by: Palmer Dabbelt --- lib/Kconfig | 3 - lib/Makefile | 1 - lib/udivmoddi4.c | 310 ----------------------------------------------- lib/umoddi3.c | 32 ----- 4 files changed, 346 deletions(-) delete mode 100644 lib/udivmoddi4.c delete mode 100644 lib/umoddi3.c diff --git a/lib/Kconfig b/lib/Kconfig index d82f20609939..a3928d4438b5 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -621,6 +621,3 @@ config GENERIC_LIB_CMPDI2 config GENERIC_LIB_UCMPDI2 bool - -config GENERIC_LIB_UMODDI3 - bool diff --git a/lib/Makefile b/lib/Makefile index 56a8d9c23ef3..423876446810 100644 --- a/lib/Makefile +++ b/lib/Makefile @@ -270,4 +270,3 @@ obj-$(CONFIG_GENERIC_LIB_LSHRDI3) += lshrdi3.o obj-$(CONFIG_GENERIC_LIB_MULDI3) += muldi3.o obj-$(CONFIG_GENERIC_LIB_CMPDI2) += cmpdi2.o obj-$(CONFIG_GENERIC_LIB_UCMPDI2) += ucmpdi2.o -obj-$(CONFIG_GENERIC_LIB_UMODDI3) += umoddi3.o udivmoddi4.o diff --git a/lib/udivmoddi4.c b/lib/udivmoddi4.c deleted file mode 100644 index c08bc8a5f1cf..000000000000 --- a/lib/udivmoddi4.c +++ /dev/null @@ -1,310 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -/* - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see the file COPYING, or write - * to the Free Software Foundation, Inc. - */ - -#include - -#define count_leading_zeros(COUNT, X) ((COUNT) = __builtin_clz(X)) - -#define W_TYPE_SIZE 32 - -#define __ll_B ((unsigned long) 1 << (W_TYPE_SIZE / 2)) -#define __ll_lowpart(t) ((unsigned long) (t) & (__ll_B - 1)) -#define __ll_highpart(t) ((unsigned long) (t) >> (W_TYPE_SIZE / 2)) - -/* If we still don't have umul_ppmm, define it using plain C. */ -#if !defined(umul_ppmm) -#define umul_ppmm(w1, w0, u, v) \ - do { \ - unsigned long __x0, __x1, __x2, __x3; \ - unsigned short __ul, __vl, __uh, __vh; \ - \ - __ul = __ll_lowpart(u); \ - __uh = __ll_highpart(u); \ - __vl = __ll_lowpart(v); \ - __vh = __ll_highpart(v); \ - \ - __x0 = (unsigned long) __ul * __vl; \ - __x1 = (unsigned long) __ul * __vh; \ - __x2 = (unsigned long) __uh * __vl; \ - __x3 = (unsigned long) __uh * __vh; \ - \ - __x1 += __ll_highpart(__x0); \ - __x1 += __x2; \ - if (__x1 < __x2) \ - __x3 += __ll_B; \ - \ - (w1) = __x3 + __ll_highpart(__x1); \ - (w0) = __ll_lowpart(__x1) * __ll_B + __ll_lowpart(__x0);\ - } while (0) -#endif - -#if !defined(sub_ddmmss) -#define sub_ddmmss(sh, sl, ah, al, bh, bl) \ - do { \ - unsigned long __x; \ - __x = (al) - (bl); \ - (sh) = (ah) - (bh) - (__x > (al)); \ - (sl) = __x; \ - } while (0) -#endif - -/* Define this unconditionally, so it can be used for debugging. */ -#define __udiv_qrnnd_c(q, r, n1, n0, d) \ - do { \ - unsigned long __d1, __d0, __q1, __q0; \ - unsigned long __r1, __r0, __m; \ - __d1 = __ll_highpart(d); \ - __d0 = __ll_lowpart(d); \ - \ - __r1 = (n1) % __d1; \ - __q1 = (n1) / __d1; \ - __m = (unsigned long) __q1 * __d0; \ - __r1 = __r1 * __ll_B | __ll_highpart(n0); \ - if (__r1 < __m) { \ - __q1--, __r1 += (d); \ - if (__r1 >= (d)) \ - if (__r1 < __m) \ - __q1--, __r1 += (d); \ - } \ - __r1 -= __m; \ - \ - __r0 = __r1 % __d1; \ - __q0 = __r1 / __d1; \ - __m = (unsigned long) __q0 * __d0; \ - __r0 = __r0 * __ll_B | __ll_lowpart(n0); \ - if (__r0 < __m) { \ - __q0--, __r0 += (d); \ - if (__r0 >= (d)) \ - if (__r0 < __m) \ - __q0--, __r0 += (d); \ - } \ - __r0 -= __m; \ - \ - (q) = (unsigned long) __q1 * __ll_B | __q0; \ - (r) = __r0; \ - } while (0) - -/* If udiv_qrnnd was not defined for this processor, use __udiv_qrnnd_c. */ -#if !defined(udiv_qrnnd) -#define UDIV_NEEDS_NORMALIZATION 1 -#define udiv_qrnnd __udiv_qrnnd_c -#endif - -unsigned long long __udivmoddi4(unsigned long long u, unsigned long long v, - unsigned long long *rp) -{ - const DWunion nn = {.ll = u }; - const DWunion dd = {.ll = v }; - DWunion rr, ww; - unsigned long d0, d1, n0, n1, n2; - unsigned long q0 = 0, q1 = 0; - unsigned long b, bm; - - d0 = dd.s.low; - d1 = dd.s.high; - n0 = nn.s.low; - n1 = nn.s.high; - -#if !UDIV_NEEDS_NORMALIZATION - - if (d1 == 0) { - if (d0 > n1) { - /* 0q = nn / 0D */ - - udiv_qrnnd(q0, n0, n1, n0, d0); - q1 = 0; - - /* Remainder in n0. */ - } else { - /* qq = NN / 0d */ - - if (d0 == 0) - /* Divide intentionally by zero. */ - d0 = 1 / d0; - - udiv_qrnnd(q1, n1, 0, n1, d0); - udiv_qrnnd(q0, n0, n1, n0, d0); - - /* Remainder in n0. */ - } - - if (rp != 0) { - rr.s.low = n0; - rr.s.high = 0; - *rp = rr.ll; - } - -#else /* UDIV_NEEDS_NORMALIZATION */ - - if (d1 == 0) { - if (d0 > n1) { - /* 0q = nn / 0D */ - - count_leading_zeros(bm, d0); - - if (bm != 0) { - /* - * Normalize, i.e. make the most significant bit - * of the denominator set. - */ - - d0 = d0 << bm; - n1 = (n1 << bm) | (n0 >> (W_TYPE_SIZE - bm)); - n0 = n0 << bm; - } - - udiv_qrnnd(q0, n0, n1, n0, d0); - q1 = 0; - - /* Remainder in n0 >> bm. */ - } else { - /* qq = NN / 0d */ - - if (d0 == 0) - /* Divide intentionally by zero. */ - d0 = 1 / d0; - - count_leading_zeros(bm, d0); - - if (bm == 0) { - /* - * From (n1 >= d0) /\ (the most significant bit - * of d0 is set), conclude (the most significant - * bit of n1 is set) /\ (theleading quotient - * digit q1 = 1). - * - * This special case is necessary, not an - * optimization. (Shifts counts of W_TYPE_SIZE - * are undefined.) - */ - - n1 -= d0; - q1 = 1; - } else { - /* Normalize. */ - - b = W_TYPE_SIZE - bm; - - d0 = d0 << bm; - n2 = n1 >> b; - n1 = (n1 << bm) | (n0 >> b); - n0 = n0 << bm; - - udiv_qrnnd(q1, n1, n2, n1, d0); - } - - /* n1 != d0... */ - - udiv_qrnnd(q0, n0, n1, n0, d0); - - /* Remainder in n0 >> bm. */ - } - - if (rp != 0) { - rr.s.low = n0 >> bm; - rr.s.high = 0; - *rp = rr.ll; - } - -#endif /* UDIV_NEEDS_NORMALIZATION */ - - } else { - if (d1 > n1) { - /* 00 = nn / DD */ - - q0 = 0; - q1 = 0; - - /* Remainder in n1n0. */ - if (rp != 0) { - rr.s.low = n0; - rr.s.high = n1; - *rp = rr.ll; - } - } else { - /* 0q = NN / dd */ - - count_leading_zeros(bm, d1); - if (bm == 0) { - /* - * From (n1 >= d1) /\ (the most significant bit - * of d1 is set), conclude (the most significant - * bit of n1 is set) /\ (the quotient digit q0 = - * 0 or 1). - * - * This special case is necessary, not an - * optimization. - */ - - /* - * The condition on the next line takes - * advantage of that n1 >= d1 (true due to - * program flow). - */ - if (n1 > d1 || n0 >= d0) { - q0 = 1; - sub_ddmmss(n1, n0, n1, n0, d1, d0); - } else { - q0 = 0; - } - - q1 = 0; - - if (rp != 0) { - rr.s.low = n0; - rr.s.high = n1; - *rp = rr.ll; - } - } else { - unsigned long m1, m0; - /* Normalize. */ - - b = W_TYPE_SIZE - bm; - - d1 = (d1 << bm) | (d0 >> b); - d0 = d0 << bm; - n2 = n1 >> b; - n1 = (n1 << bm) | (n0 >> b); - n0 = n0 << bm; - - udiv_qrnnd(q0, n1, n2, n1, d1); - umul_ppmm(m1, m0, q0, d0); - - if (m1 > n1 || (m1 == n1 && m0 > n0)) { - q0--; - sub_ddmmss(m1, m0, m1, m0, d1, d0); - } - - q1 = 0; - - /* Remainder in (n1n0 - m1m0) >> bm. */ - if (rp != 0) { - sub_ddmmss(n1, n0, n1, n0, m1, m0); - rr.s.low = (n1 << b) | (n0 >> bm); - rr.s.high = n1 >> bm; - *rp = rr.ll; - } - } - } - } - - ww.s.low = q0; - ww.s.high = q1; - - return ww.ll; -} diff --git a/lib/umoddi3.c b/lib/umoddi3.c deleted file mode 100644 index d7bbf0f85197..000000000000 --- a/lib/umoddi3.c +++ /dev/null @@ -1,32 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 - -/* - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, see the file COPYING, or write - * to the Free Software Foundation, Inc. - */ - -#include -#include - -extern unsigned long long __udivmoddi4(unsigned long long u, - unsigned long long v, - unsigned long long *rp); - -unsigned long long __umoddi3(unsigned long long u, unsigned long long v) -{ - unsigned long long w; - (void)__udivmoddi4(u, v, &w); - return w; -} -EXPORT_SYMBOL(__umoddi3); From 732e8e4130ffccb618390e0f80a884543e61fd61 Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Tue, 23 Oct 2018 09:33:47 +0200 Subject: [PATCH 3/4] RISC-V: properly determine hardware caps On the Hifive-U platform, cpu 0 is a masked cpu with less capabilities than the other cpus. Ignore it for the purpose of determining the hardware capabilities of the system. Signed-off-by: Andreas Schwab Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/cpufeature.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c index 5493f3228704..0339087aa652 100644 --- a/arch/riscv/kernel/cpufeature.c +++ b/arch/riscv/kernel/cpufeature.c @@ -28,7 +28,7 @@ bool has_fpu __read_mostly; void riscv_fill_hwcap(void) { - struct device_node *node; + struct device_node *node = NULL; const char *isa; size_t i; static unsigned long isa2hwcap[256] = {0}; @@ -44,9 +44,11 @@ void riscv_fill_hwcap(void) /* * We don't support running Linux on hertergenous ISA systems. For - * now, we just check the ISA of the first processor. + * now, we just check the ISA of the first "okay" processor. */ - node = of_find_node_by_type(NULL, "cpu"); + while ((node = of_find_node_by_type(node, "cpu"))) + if (riscv_of_processor_hartid(node) >= 0) + break; if (!node) { pr_warning("Unable to find \"cpu\" devicetree entry"); return; From 9b4789eacb654b7bbc806c831bcebd799ae0e2f5 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Mon, 25 Jun 2018 13:23:12 -0700 Subject: [PATCH 4/4] Move EM_RISCV into elf-em.h This should never have been inside our arch port to begin with, it's just a relic from when we were maintaining out of tree patches. Reviewed-by: Kees Cook Reviewed-by: Paul Walmsley Reviewed-by: Christoph Hellwig Tested-by: David Abdurachmanov Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/elf.h | 3 --- include/uapi/linux/elf-em.h | 1 + 2 files changed, 1 insertion(+), 3 deletions(-) diff --git a/arch/riscv/include/asm/elf.h b/arch/riscv/include/asm/elf.h index a1ef503d616e..697fc23b0d5a 100644 --- a/arch/riscv/include/asm/elf.h +++ b/arch/riscv/include/asm/elf.h @@ -16,9 +16,6 @@ #include #include -/* TODO: Move definition into include/uapi/linux/elf-em.h */ -#define EM_RISCV 0xF3 - /* * These are used to set parameters in the core dumps. */ diff --git a/include/uapi/linux/elf-em.h b/include/uapi/linux/elf-em.h index 31aa10178335..93722e60204c 100644 --- a/include/uapi/linux/elf-em.h +++ b/include/uapi/linux/elf-em.h @@ -41,6 +41,7 @@ #define EM_TILEPRO 188 /* Tilera TILEPro */ #define EM_MICROBLAZE 189 /* Xilinx MicroBlaze */ #define EM_TILEGX 191 /* Tilera TILE-Gx */ +#define EM_RISCV 243 /* RISC-V */ #define EM_BPF 247 /* Linux BPF - in-kernel virtual machine */ #define EM_FRV 0x5441 /* Fujitsu FR-V */