[RFC PATCH 15/25] kvx: Add misc common routines

Yann Sionneau
2023-01-03T17:01:20Z

Add some misc common routines for kvx, including: asm-offsets
routines, futex functions, i/o memory access functions.

CC: linux-kernel@vger.kernel.org
Co-developed-by: Clement Leger <clement.leger@bootlin.com>
Signed-off-by: Clement Leger <clement.leger@bootlin.com>
Co-developed-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
Signed-off-by: Guillaume Thouvenin <gthouvenin@kalray.eu>
Co-developed-by: Jonathan Borne <jborne@kalray.eu>
Signed-off-by: Jonathan Borne <jborne@kalray.eu>
Co-developed-by: Julian Vetter <jvetter@kalray.eu>
Signed-off-by: Julian Vetter <jvetter@kalray.eu>
Co-developed-by: Julien Villette <jvillette@kalray.eu>
Signed-off-by: Julien Villette <jvillette@kalray.eu>
Co-developed-by: Yann Sionneau <ysionneau@kalray.eu>
Signed-off-by: Yann Sionneau <ysionneau@kalray.eu>
---
arch/kvx/include/asm/futex.h | 141 ++++++++++++++++++++++++++++++
arch/kvx/include/asm/io.h | 34 ++++++++
arch/kvx/kernel/asm-offsets.c | 157 ++++++++++++++++++++++++++++++++++
arch/kvx/kernel/io.c | 96 +++++++++++++++++++++
4 files changed, 428 insertions(+)
create mode 100644 arch/kvx/include/asm/futex.h
create mode 100644 arch/kvx/include/asm/io.h
create mode 100644 arch/kvx/kernel/asm-offsets.c
create mode 100644 arch/kvx/kernel/io.c

diff --git a/arch/kvx/include/asm/futex.h b/arch/kvx/include/asm/futex.h
new file mode 100644
index 000000000000..b71b52339729
--- /dev/null
+++ b/arch/kvx/include/asm/futex.h
@@ -0,0 +1,141 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2018-2023 Kalray Inc.
+ * Authors:
+ * Clement Leger <cleger@kalray.eu>
+ * Yann Sionneau <ysionneau@kalray.eu>
+ * Jonathan Borne <jborne@kalray.eu>
+ *
+ * Part of code is taken from RiscV port
+ */
+
+#ifndef _ASM_KVX_FUTEX_H
+#define _ASM_KVX_FUTEX_H
+
+#ifdef __KERNEL__
+
+#include <linux/futex.h>
+#include <linux/uaccess.h>
+
+#define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
+{ \
+ __enable_user_access(); \
+ __asm__ __volatile__ ( \
+ " fence \n" \
+ " ;;\n " \
+ "1: lwz $r63 = 0[%[u]] \n" \
+ " ;;\n " \
+ " " insn " \n" \
+ " ;;\n " \
+ " acswapw 0[%[u]], $r62r63 \n" \
+ " ;;\n " \
+ " cb.deqz $r62? 1b \n" \
+ " ;;\n " \
+ " copyd %[ov] = $r63 \n" \
+ " ;;\n " \
+ "2: \n" \
+ " .section .fixup,\"ax\" \n" \
+ "3: make %[r] = 2b \n" \
+ " ;;\n " \
+ " make %[r] = %[e] \n" \
+ " igoto %[r] \n" \
+ " ;;\n " \
+ " .previous \n" \
+ " .section __ex_table,\"a\" \n" \
+ " .align 8 \n" \
+ " .dword 1b,3b \n" \
+ " .dword 2b,3b \n" \
+ " .previous \n" \
+ : [r] "+r" (ret), [ov] "+r" (oldval) \
+ : [u] "r" (uaddr), \
+ [op] "r" (oparg), [e] "i" (-EFAULT) \
+ : "r62", "r63", "memory"); \
+ __disable_user_access(); \
+}
+
+
+static inline int
+arch_futex_atomic_op_inuser(int op, u32 oparg, int *oval, u32 __user *uaddr)
+{
+ int oldval = 0, ret = 0;
+
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+ switch (op) {
+ case FUTEX_OP_SET: /* *(int *)UADDR = OPARG; */
+ __futex_atomic_op("copyd $r62 = %[op]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ADD: /* *(int *)UADDR += OPARG; */
+ __futex_atomic_op("addw $r62 = $r63, %[op]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_OR: /* *(int *)UADDR |= OPARG; */
+ __futex_atomic_op("orw $r62 = $r63, %[op]",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_ANDN: /* *(int *)UADDR &= ~OPARG; */
+ __futex_atomic_op("andnw $r62 = %[op], $r63",
+ ret, oldval, uaddr, oparg);
+ break;
+ case FUTEX_OP_XOR:
+ __futex_atomic_op("xorw $r62 = $r63, %[op]",
+ ret, oldval, uaddr, oparg);
+ break;
+ default:
+ ret = -ENOSYS;
+ }
+
+ if (!ret)
+ *oval = oldval;
+
+ return ret;
+}
+
+static inline int futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
+ u32 oldval, u32 newval)
+{
+ int ret = 0;
+
+ if (!access_ok(uaddr, sizeof(u32)))
+ return -EFAULT;
+ __enable_user_access();
+ __asm__ __volatile__ (
+ " fence \n"/* commit previous stores */
+ " copyd $r63 = %[ov] \n"/* init "expect" with ov */
+ " copyd $r62 = %[nv] \n"/* init "update" with nv */
+ " ;;\n "
+ "1: acswapw 0[%[u]], $r62r63 \n"
+ " ;;\n "
+ " cb.dnez $r62? 3f \n"/* if acswap ok -> return */
+ " ;;\n "
+ "2: lws $r63 = 0[%[u]] \n"/* fail -> load old value */
+ " ;;\n "
+ " compw.ne $r62 = $r63, %[ov] \n"/* check if equal to "old" */
+ " ;;\n "
+ " cb.deqz $r62? 1b \n"/* if not equal, try again */
+ " ;;\n "
+ "3: \n"
+ " .section .fixup,\"ax\" \n"
+ "4: make %[r] = 3b \n"
+ " ;;\n "
+ " make %[r] = %[e] \n"
+ " igoto %[r] \n"/* goto 3b */
+ " ;;\n "
+ " .previous \n"
+ " .section __ex_table,\"a\" \n"
+ " .align 8 \n"
+ " .dword 1b,4b \n"
+ " .dword 2b,4b \n"
+ ".previous \n"
+ : [r] "+r" (ret)
+ : [ov] "r" (oldval), [nv] "r" (newval),
+ [e] "i" (-EFAULT), [u] "r" (uaddr)
+ : "r62", "r63", "memory");
+ __disable_user_access();
+ *uval = oldval;
+ return ret;
+}
+
+#endif
+#endif /* _ASM_KVX_FUTEX_H */
diff --git a/arch/kvx/include/asm/io.h b/arch/kvx/include/asm/io.h
new file mode 100644
index 000000000000..c5e458c59bbb
--- /dev/null
+++ b/arch/kvx/include/asm/io.h
@@ -0,0 +1,34 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#ifndef _ASM_KVX_IO_H
+#define _ASM_KVX_IO_H
+
+#include <linux/types.h>
+
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+#define _PAGE_IOREMAP _PAGE_KERNEL_DEVICE
+
+/*
+ * String version of I/O memory access operations.
+ */
+extern void __memcpy_fromio(void *to, const volatile void __iomem *from,
+ size_t count);
+extern void __memcpy_toio(volatile void __iomem *to, const void *from,
+ size_t count);
+extern void __memset_io(volatile void __iomem *dst, int c, size_t count);
+
+#define memset_io(c, v, l) __memset_io((c), (v), (l))
+#define memcpy_fromio(a, c, l) __memcpy_fromio((a), (c), (l))
+#define memcpy_toio(c, a, l) __memcpy_toio((c), (a), (l))
+
+#include <asm-generic/io.h>
+
+extern int devmem_is_allowed(unsigned long pfn);
+
+#endif /* _ASM_KVX_IO_H */
diff --git a/arch/kvx/kernel/asm-offsets.c b/arch/kvx/kernel/asm-offsets.c
new file mode 100644
index 000000000000..3e79b6dd13bd
--- /dev/null
+++ b/arch/kvx/kernel/asm-offsets.c
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ * Guillaume Thouvenin
+ * Yann Sionneau
+ */
+
+#include <linux/preempt.h>
+#include <linux/thread_info.h>
+#include <linux/kbuild.h>
+#include <linux/stddef.h>
+#include <linux/sched.h>
+#include <linux/bug.h>
+
+#include <asm/processor.h>
+#include <asm/ptrace.h>
+#include <asm/page.h>
+#include <asm/fixmap.h>
+#include <asm/page_size.h>
+#include <asm/pgtable.h>
+#include <asm/ptrace.h>
+#include <asm/tlb_defs.h>
+#include <asm/mmu_stats.h>
+#include <asm/stacktrace.h>
+
+int foo(void)
+{
+ BUILD_BUG_ON(sizeof(struct pt_regs) != PT_REGS_STRUCT_EXPECTED_SIZE);
+ /*
+ * For stack alignment purposes we must make sure the pt_regs size is
+ * a mutliple of stack_align
+ */
+ BUILD_BUG_ON(!IS_ALIGNED(sizeof(struct pt_regs), STACK_ALIGNMENT));
+
+ /* Check that user_pt_regs size matches the beginning of pt_regs */
+ BUILD_BUG_ON((offsetof(struct user_pt_regs, spc) + sizeof(uint64_t)) !=
+ sizeof(struct user_pt_regs));
+
+ DEFINE(FIX_GDB_MEM_BASE_IDX, FIX_GDB_BARE_DISPLACED_MEM_BASE);
+
+#ifdef CONFIG_DEBUG_EXCEPTION_STACK
+ DEFINE(STACK_REG_SIZE, ALIGN(sizeof(uint64_t), STACK_ALIGNMENT));
+#endif
+
+ /*
+ * We allocate a pt_regs on the stack when entering the kernel. This
+ * ensures the alignment is sane.
+ */
+ DEFINE(PT_SIZE_ON_STACK, sizeof(struct pt_regs));
+ DEFINE(TI_FLAGS_SIZE, sizeof(unsigned long));
+ DEFINE(QUAD_REG_SIZE, 4 * sizeof(uint64_t));
+
+ /*
+ * When restoring registers, we do not want to restore r12
+ * right now since this is our stack pointer. Allow to save
+ * only $r13 by using this offset.
+ */
+ OFFSET(PT_R12, pt_regs, r12);
+ OFFSET(PT_R13, pt_regs, r13);
+ OFFSET(PT_TP, pt_regs, tp);
+ OFFSET(PT_R14R15, pt_regs, r14);
+ OFFSET(PT_R16R17, pt_regs, r16);
+ OFFSET(PT_R18R19, pt_regs, r18);
+ OFFSET(PT_FP, pt_regs, fp);
+ OFFSET(PT_SPS, pt_regs, sps);
+
+ /* Quad description */
+ OFFSET(PT_Q0, pt_regs, r0);
+ OFFSET(PT_Q4, pt_regs, r4);
+ OFFSET(PT_Q8, pt_regs, r8);
+ OFFSET(PT_Q12, pt_regs, r12);
+ OFFSET(PT_Q16, pt_regs, r16);
+ OFFSET(PT_Q20, pt_regs, r20);
+ OFFSET(PT_Q24, pt_regs, r24);
+ OFFSET(PT_Q28, pt_regs, r28);
+ OFFSET(PT_Q32, pt_regs, r32);
+ OFFSET(PT_Q36, pt_regs, r36);
+ OFFSET(PT_R38, pt_regs, r38);
+ OFFSET(PT_Q40, pt_regs, r40);
+ OFFSET(PT_Q44, pt_regs, r44);
+ OFFSET(PT_Q48, pt_regs, r48);
+ OFFSET(PT_Q52, pt_regs, r52);
+ OFFSET(PT_Q56, pt_regs, r56);
+ OFFSET(PT_Q60, pt_regs, r60);
+ OFFSET(PT_CS_SPC_SPS_ES, pt_regs, cs);
+ OFFSET(PT_LC_LE_LS_RA, pt_regs, lc);
+ OFFSET(PT_ILR, pt_regs, ilr);
+ OFFSET(PT_ORIG_R0, pt_regs, orig_r0);
+
+ /*
+ * Flags in thread info
+ */
+ OFFSET(TASK_TI_FLAGS, task_struct, thread_info.flags);
+
+ /*
+ * Stack pointers
+ */
+ OFFSET(TASK_THREAD_KERNEL_SP, task_struct, thread.kernel_sp);
+
+ /*
+ * Offsets to save registers in switch_to using quads
+ */
+ OFFSET(CTX_SWITCH_RA_SP_R18_R19, task_struct, thread.ctx_switch.ra);
+ OFFSET(CTX_SWITCH_Q20, task_struct, thread.ctx_switch.r20);
+ OFFSET(CTX_SWITCH_Q24, task_struct, thread.ctx_switch.r24);
+ OFFSET(CTX_SWITCH_Q28, task_struct, thread.ctx_switch.r28);
+ OFFSET(CTX_SWITCH_FP, task_struct, thread.ctx_switch.fp);
+
+#ifdef CONFIG_ENABLE_TCA
+ OFFSET(CTX_SWITCH_TCA_REGS, task_struct, thread.ctx_switch.tca_regs[0]);
+ OFFSET(CTX_SWITCH_TCA_REGS_SAVED, task_struct,
+ thread.ctx_switch.tca_regs_saved);
+ DEFINE(TCA_REG_SIZE, sizeof(struct tca_reg));
+#endif
+
+ /* Save area offset */
+ OFFSET(TASK_THREAD_SAVE_AREA, task_struct, thread.save_area);
+
+ /* Fast tlb refill defines */
+ OFFSET(TASK_ACTIVE_MM, task_struct, active_mm);
+ OFFSET(MM_PGD, mm_struct, pgd);
+#ifdef CONFIG_KVX_DEBUG_ASN
+ OFFSET(MM_CTXT_ASN, mm_struct, context.asn);
+#endif
+
+#ifdef CONFIG_KVX_MMU_STATS
+ DEFINE(MMU_REFILL_SIZE, sizeof(struct mmu_refill_stats));
+
+ OFFSET(MMU_STATS_REFILL_USER_OFF, mmu_stats,
+ refill[MMU_REFILL_TYPE_USER]);
+ OFFSET(MMU_STATS_REFILL_KERNEL_OFF, mmu_stats,
+ refill[MMU_REFILL_TYPE_KERNEL]);
+ OFFSET(MMU_STATS_REFILL_KERNEL_DIRECT_OFF, mmu_stats,
+ refill[MMU_REFILL_TYPE_KERNEL_DIRECT]);
+ OFFSET(MMU_STATS_CYCLES_BETWEEN_REFILL_OFF, mmu_stats,
+ cycles_between_refill);
+ OFFSET(MMU_STATS_LAST_REFILL, mmu_stats, last_refill);
+
+ OFFSET(TASK_THREAD_ENTRY_TS, task_struct, thread.trap_entry_ts);
+#endif
+
+ DEFINE(ASM_PGDIR_SHIFT, PGDIR_SHIFT);
+ DEFINE(ASM_PMD_SHIFT, PMD_SHIFT);
+
+ DEFINE(ASM_PGDIR_BITS, PGDIR_BITS);
+ DEFINE(ASM_PMD_BITS, PMD_BITS);
+ DEFINE(ASM_PTE_BITS, PTE_BITS);
+
+ DEFINE(ASM_PTRS_PER_PGD, PTRS_PER_PGD);
+ DEFINE(ASM_PTRS_PER_PMD, PTRS_PER_PMD);
+ DEFINE(ASM_PTRS_PER_PTE, PTRS_PER_PTE);
+
+ DEFINE(ASM_TLB_PS, TLB_DEFAULT_PS);
+
+ return 0;
+}
diff --git a/arch/kvx/kernel/io.c b/arch/kvx/kernel/io.c
new file mode 100644
index 000000000000..0922c1d6d0f7
--- /dev/null
+++ b/arch/kvx/kernel/io.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * derived from arch/arm/kernel/io.c
+ *
+ * Copyright (C) 2017-2023 Kalray Inc.
+ * Author(s): Clement Leger
+ */
+
+#include <linux/export.h>
+#include <linux/types.h>
+#include <linux/io.h>
+
+#define REPLICATE_BYTE_MASK 0x0101010101010101
+
+/*
+ * Copy data from IO memory space to "real" memory space.
+ */
+void __memcpy_fromio(void *to, const volatile void __iomem *from, size_t count)
+{
+ while (count && !IS_ALIGNED((unsigned long)from, 8)) {
+ *(u8 *)to = __raw_readb(from);
+ from++;
+ to++;
+ count--;
+ }
+
+ while (count >= 8) {
+ *(u64 *)to = __raw_readq(from);
+ from += 8;
+ to += 8;
+ count -= 8;
+ }
+
+ while (count) {
+ *(u8 *)to = __raw_readb(from);
+ from++;
+ to++;
+ count--;
+ }
+}
+EXPORT_SYMBOL(__memcpy_fromio);
+
+/*
+ * Copy data from "real" memory space to IO memory space.
+ */
+void __memcpy_toio(volatile void __iomem *to, const void *from, size_t count)
+{
+ while (count && !IS_ALIGNED((unsigned long)to, 8)) {
+ __raw_writeb(*(u8 *)from, to);
+ from++;
+ to++;
+ count--;
+ }
+
+ while (count >= 8) {
+ __raw_writeq(*(u64 *)from, to);
+ from += 8;
+ to += 8;
+ count -= 8;
+ }
+
+ while (count) {
+ __raw_writeb(*(u8 *)from, to);
+ from++;
+ to++;
+ count--;
+ }
+}
+EXPORT_SYMBOL(__memcpy_toio);
+
+/*
+ * "memset" on IO memory space.
+ */
+void __memset_io(volatile void __iomem *dst, int c, size_t count)
+{
+ u64 qc = __builtin_kvx_sbmm8(c, REPLICATE_BYTE_MASK);
+
+ while (count && !IS_ALIGNED((unsigned long)dst, 8)) {
+ __raw_writeb(c, dst);
+ dst++;
+ count--;
+ }
+
+ while (count >= 8) {
+ __raw_writeq(qc, dst);
+ dst += 8;
+ count -= 8;
+ }
+
+ while (count) {
+ __raw_writeb(c, dst);
+ dst++;
+ count--;
+ }
+}
+EXPORT_SYMBOL(__memset_io);
--
2.37.2