This patch contains code that interfaces with devices that are mandated by the RISC-V supervisor specification and that don't have explicit drivers anywhere else in the tree. This includes the staticly defined interrupts, the CSR-mapped timer, and virtualized SBI devices. Signed-off-by: Palmer Dabbelt <palmer@xxxxxxxxxxx> --- arch/riscv/include/asm/delay.h | 28 +++++++++ arch/riscv/include/asm/dma-mapping.h | 38 ++++++++++++ arch/riscv/include/asm/irq.h | 31 ++++++++++ arch/riscv/include/asm/irqflags.h | 63 ++++++++++++++++++++ arch/riscv/include/asm/pci.h | 48 +++++++++++++++ arch/riscv/include/asm/sbi.h | 100 +++++++++++++++++++++++++++++++ arch/riscv/include/asm/timex.h | 59 +++++++++++++++++++ arch/riscv/lib/delay.c | 110 +++++++++++++++++++++++++++++++++++ arch/riscv/mm/ioremap.c | 92 +++++++++++++++++++++++++++++ 9 files changed, 569 insertions(+) create mode 100644 arch/riscv/include/asm/delay.h create mode 100644 arch/riscv/include/asm/dma-mapping.h create mode 100644 arch/riscv/include/asm/irq.h create mode 100644 arch/riscv/include/asm/irqflags.h create mode 100644 arch/riscv/include/asm/pci.h create mode 100644 arch/riscv/include/asm/sbi.h create mode 100644 arch/riscv/include/asm/timex.h create mode 100644 arch/riscv/lib/delay.c create mode 100644 arch/riscv/mm/ioremap.c diff --git a/arch/riscv/include/asm/delay.h b/arch/riscv/include/asm/delay.h new file mode 100644 index 000000000000..cbb0c9eb96cb --- /dev/null +++ b/arch/riscv/include/asm/delay.h @@ -0,0 +1,28 @@ +/* + * Copyright (C) 2009 Chen Liqin <liqin.chen@xxxxxxxxxxxxx> + * Copyright (C) 2016 Regents of the University of California + * + * 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, version 2. + * + * 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. + */ + +#ifndef _ASM_RISCV_DELAY_H +#define _ASM_RISCV_DELAY_H + +extern unsigned long riscv_timebase; + +#define udelay udelay +extern void udelay(unsigned long usecs); + +#define ndelay ndelay +extern void ndelay(unsigned long nsecs); + +extern void __delay(unsigned long cycles); + +#endif /* _ASM_RISCV_DELAY_H */ diff --git a/arch/riscv/include/asm/dma-mapping.h b/arch/riscv/include/asm/dma-mapping.h new file mode 100644 index 000000000000..3eec1000196d --- /dev/null +++ b/arch/riscv/include/asm/dma-mapping.h @@ -0,0 +1,38 @@ +/* + * Copyright (C) 2003-2004 Hewlett-Packard Co + * David Mosberger-Tang <davidm@xxxxxxxxxx> + * Copyright (C) 2012 ARM Ltd. + * Copyright (C) 2016 SiFive, Inc. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * 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 <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_RISCV_DMA_MAPPING_H +#define __ASM_RISCV_DMA_MAPPING_H + +/* Use ops->dma_mapping_error (if it exists) or assume success */ +// #undef DMA_ERROR_CODE + +static inline const struct dma_map_ops *get_arch_dma_ops(struct bus_type *bus) +{ + return &dma_noop_ops; +} + +static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size) +{ + if (!dev->dma_mask) + return false; + + return addr + size - 1 <= *dev->dma_mask; +} + +#endif /* __ASM_RISCV_DMA_MAPPING_H */ diff --git a/arch/riscv/include/asm/irq.h b/arch/riscv/include/asm/irq.h new file mode 100644 index 000000000000..e64c61e89f76 --- /dev/null +++ b/arch/riscv/include/asm/irq.h @@ -0,0 +1,31 @@ +/* + * Copyright (C) 2012 Regents of the University of California + * Copyright (C) 2017 SiFive + * + * 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, version 2. + * + * 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. + */ + +#ifndef _ASM_RISCV_IRQ_H +#define _ASM_RISCV_IRQ_H + +#define NR_IRQS 0 + +#define INTERRUPT_CAUSE_SOFTWARE 1 +#define INTERRUPT_CAUSE_TIMER 5 +#define INTERRUPT_CAUSE_EXTERNAL 9 + +void riscv_timer_interrupt(void); + +#include <asm-generic/irq.h> + +/* The value of csr sie before init_traps runs (core is up) */ +DECLARE_PER_CPU(atomic_long_t, riscv_early_sie); + +#endif /* _ASM_RISCV_IRQ_H */ diff --git a/arch/riscv/include/asm/irqflags.h b/arch/riscv/include/asm/irqflags.h new file mode 100644 index 000000000000..6fdc860d7f84 --- /dev/null +++ b/arch/riscv/include/asm/irqflags.h @@ -0,0 +1,63 @@ +/* + * Copyright (C) 2012 Regents of the University of California + * + * 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, version 2. + * + * 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. + */ + + +#ifndef _ASM_RISCV_IRQFLAGS_H +#define _ASM_RISCV_IRQFLAGS_H + +#include <asm/processor.h> +#include <asm/csr.h> + +/* read interrupt enabled status */ +static inline unsigned long arch_local_save_flags(void) +{ + return csr_read(sstatus); +} + +/* unconditionally enable interrupts */ +static inline void arch_local_irq_enable(void) +{ + csr_set(sstatus, SR_IE); +} + +/* unconditionally disable interrupts */ +static inline void arch_local_irq_disable(void) +{ + csr_clear(sstatus, SR_IE); +} + +/* get status and disable interrupts */ +static inline unsigned long arch_local_irq_save(void) +{ + return csr_read_clear(sstatus, SR_IE); +} + +/* test flags */ +static inline int arch_irqs_disabled_flags(unsigned long flags) +{ + return !(flags & SR_IE); +} + +/* test hardware interrupt enable bit */ +static inline int arch_irqs_disabled(void) +{ + return arch_irqs_disabled_flags(arch_local_save_flags()); +} + +/* set interrupt enabled status */ +static inline void arch_local_irq_restore(unsigned long flags) +{ + csr_set(sstatus, flags & SR_IE); +} + +#endif /* _ASM_RISCV_IRQFLAGS_H */ diff --git a/arch/riscv/include/asm/pci.h b/arch/riscv/include/asm/pci.h new file mode 100644 index 000000000000..285747fa2ef0 --- /dev/null +++ b/arch/riscv/include/asm/pci.h @@ -0,0 +1,48 @@ +/* + * Copyright (C) 2016 SiFive + * + * 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, version 2. + * + * 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. + */ + +#ifndef __ASM_RISCV_PCI_H +#define __ASM_RISCV_PCI_H + +#include <linux/types.h> +#include <linux/slab.h> +#include <linux/dma-mapping.h> + +#include <asm/io.h> + +#define PCIBIOS_MIN_IO 0 +#define PCIBIOS_MIN_MEM 0 + +/* RISC-V shim does not initialize PCI bus */ +#define pcibios_assign_all_busses() 1 + +/* RISC-V TileLink and PCIe share the share address space */ +#define PCI_DMA_BUS_IS_PHYS 1 + +extern int isa_dma_bridge_buggy; + +#ifdef CONFIG_PCI +static inline int pci_get_legacy_ide_irq(struct pci_dev *dev, int channel) +{ + /* no legacy IRQ on risc-v */ + return -ENODEV; +} + +static inline int pci_proc_domain(struct pci_bus *bus) +{ + /* always show the domain in /proc */ + return 1; +} +#endif /* CONFIG_PCI */ + +#endif /* __ASM_PCI_H */ diff --git a/arch/riscv/include/asm/sbi.h b/arch/riscv/include/asm/sbi.h new file mode 100644 index 000000000000..b6bb10b92fe2 --- /dev/null +++ b/arch/riscv/include/asm/sbi.h @@ -0,0 +1,100 @@ +/* + * Copyright (C) 2015 Regents of the University of California + * + * 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, version 2. + * + * 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. + */ + +#ifndef _ASM_RISCV_SBI_H +#define _ASM_RISCV_SBI_H + +#include <linux/types.h> + +#define SBI_SET_TIMER 0 +#define SBI_CONSOLE_PUTCHAR 1 +#define SBI_CONSOLE_GETCHAR 2 +#define SBI_CLEAR_IPI 3 +#define SBI_SEND_IPI 4 +#define SBI_REMOTE_FENCE_I 5 +#define SBI_REMOTE_SFENCE_VMA 6 +#define SBI_REMOTE_SFENCE_VMA_ASID 7 +#define SBI_SHUTDOWN 8 + +#define SBI_CALL(which, arg0, arg1, arg2) ({ \ + register uintptr_t a0 asm ("a0") = (uintptr_t)(arg0); \ + register uintptr_t a1 asm ("a1") = (uintptr_t)(arg1); \ + register uintptr_t a2 asm ("a2") = (uintptr_t)(arg2); \ + register uintptr_t a7 asm ("a7") = (uintptr_t)(which); \ + asm volatile ("ecall" \ + : "+r" (a0) \ + : "r" (a1), "r" (a2), "r" (a7) \ + : "memory"); \ + a0; \ +}) + +/* Lazy implementations until SBI is finalized */ +#define SBI_CALL_0(which) SBI_CALL(which, 0, 0, 0) +#define SBI_CALL_1(which, arg0) SBI_CALL(which, arg0, 0, 0) +#define SBI_CALL_2(which, arg0, arg1) SBI_CALL(which, arg0, arg1, 0) + +static inline void sbi_console_putchar(int ch) +{ + SBI_CALL_1(SBI_CONSOLE_PUTCHAR, ch); +} + +static inline int sbi_console_getchar(void) +{ + return SBI_CALL_0(SBI_CONSOLE_GETCHAR); +} + +static inline void sbi_set_timer(uint64_t stime_value) +{ +#if __riscv_xlen == 32 + SBI_CALL_2(SBI_SET_TIMER, stime_value, stime_value >> 32); +#else + SBI_CALL_1(SBI_SET_TIMER, stime_value); +#endif +} + +static inline void sbi_shutdown(void) +{ + SBI_CALL_0(SBI_SHUTDOWN); +} + +static inline void sbi_clear_ipi(void) +{ + SBI_CALL_0(SBI_CLEAR_IPI); +} + +static inline void sbi_send_ipi(const unsigned long *hart_mask) +{ + SBI_CALL_1(SBI_SEND_IPI, hart_mask); +} + +static inline void sbi_remote_fence_i(const unsigned long *hart_mask) +{ + SBI_CALL_1(SBI_REMOTE_FENCE_I, hart_mask); +} + +static inline void sbi_remote_sfence_vma(const unsigned long *hart_mask, + unsigned long start, + unsigned long size) +{ + SBI_CALL_1(SBI_REMOTE_SFENCE_VMA, hart_mask); +} + +static inline void sbi_remote_sfence_vma_asid(const unsigned long *hart_mask, + unsigned long start, + unsigned long size, + unsigned long asid) +{ + SBI_CALL_1(SBI_REMOTE_SFENCE_VMA_ASID, hart_mask); +} + +#endif diff --git a/arch/riscv/include/asm/timex.h b/arch/riscv/include/asm/timex.h new file mode 100644 index 000000000000..3df4932d8964 --- /dev/null +++ b/arch/riscv/include/asm/timex.h @@ -0,0 +1,59 @@ +/* + * Copyright (C) 2012 Regents of the University of California + * + * 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, version 2. + * + * 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. + */ + +#ifndef _ASM_RISCV_TIMEX_H +#define _ASM_RISCV_TIMEX_H + +#include <asm/param.h> + +typedef unsigned long cycles_t; + +static inline cycles_t get_cycles(void) +{ + cycles_t n; + + __asm__ __volatile__ ( + "rdtime %0" + : "=r" (n)); + return n; +} + +#ifdef CONFIG_64BIT +static inline uint64_t get_cycles64(void) +{ + return get_cycles(); +} +#else +static inline uint64_t get_cycles64(void) +{ + u32 lo, hi, tmp; + __asm__ __volatile__ ( + "1:\n" + "rdtimeh %0\n" + "rdtime %1\n" + "rdtimeh %2\n" + "bne %0, %2, 1b" + : "=&r" (hi), "=&r" (lo), "=&r" (tmp)); + return ((u64)hi << 32) | lo; +} +#endif + +#define ARCH_HAS_READ_CURRENT_TIMER + +static inline int read_current_timer(unsigned long *timer_val) +{ + *timer_val = get_cycles(); + return 0; +} + +#endif /* _ASM_RISCV_TIMEX_H */ diff --git a/arch/riscv/lib/delay.c b/arch/riscv/lib/delay.c new file mode 100644 index 000000000000..1cc4ac3964b4 --- /dev/null +++ b/arch/riscv/lib/delay.c @@ -0,0 +1,110 @@ +/* + * Copyright (C) 2012 Regents of the University of California + * + * 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, version 2. + * + * 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. + */ + +#include <linux/delay.h> +#include <linux/param.h> +#include <linux/timex.h> +#include <linux/export.h> + +/* + * This is copies from arch/arm/include/asm/delay.h + * + * Loop (or tick) based delay: + * + * loops = loops_per_jiffy * jiffies_per_sec * delay_us / us_per_sec + * + * where: + * + * jiffies_per_sec = HZ + * us_per_sec = 1000000 + * + * Therefore the constant part is HZ / 1000000 which is a small + * fractional number. To make this usable with integer math, we + * scale up this constant by 2^31, perform the actual multiplication, + * and scale the result back down by 2^31 with a simple shift: + * + * loops = (loops_per_jiffy * delay_us * UDELAY_MULT) >> 31 + * + * where: + * + * UDELAY_MULT = 2^31 * HZ / 1000000 + * = (2^31 / 1000000) * HZ + * = 2147.483648 * HZ + * = 2147 * HZ + 483648 * HZ / 1000000 + * + * 31 is the biggest scale shift value that won't overflow 32 bits for + * delay_us * UDELAY_MULT assuming HZ <= 1000 and delay_us <= 2000. + */ +#define MAX_UDELAY_US 2000 +#define MAX_UDELAY_HZ 1000 +#define UDELAY_MULT (2147UL * HZ + 483648UL * HZ / 1000000UL) +#define UDELAY_SHIFT 31 + +#if HZ > MAX_UDELAY_HZ +#error "HZ > MAX_UDELAY_HZ" +#endif + +/* + * RISC-V supports both UDELAY and NDELAY. This is largely the same as above, + * but with different constants. I added 10 bits to the shift to get this, but + * the result is that I need a 64-bit multiply, which is slow on 32-bit + * platforms. + * + * NDELAY_MULT = 2^41 * HZ / 1000000000 + * = (2^41 / 1000000000) * HZ + * = 2199.02325555 * HZ + * = 2199 * HZ + 23255550 * HZ / 1000000000 + * + * The maximum here is to avoid 64-bit overflow, but it isn't checked as it + * won't happen. + */ +#define MAX_NDELAY_NS (1ULL << 42) +#define MAX_NDELAY_HZ MAX_UDELAY_HZ +#define NDELAY_MULT ((unsigned long long)(2199ULL * HZ + 23255550ULL * HZ / 1000000000ULL)) +#define NDELAY_SHIFT 41 + +#if HZ > MAX_NDELAY_HZ +#error "HZ > MAX_NDELAY_HZ" +#endif + +void __delay(unsigned long cycles) +{ + u64 t0 = get_cycles(); + + while ((unsigned long)(get_cycles() - t0) < cycles) + cpu_relax(); +} + +void udelay(unsigned long usecs) +{ + unsigned long ucycles = usecs * lpj_fine * UDELAY_MULT; + + if (unlikely(usecs > MAX_UDELAY_US)) { + __delay((u64)usecs * riscv_timebase / 1000000ULL); + return; + } + + __delay(ucycles >> UDELAY_SHIFT); +} +EXPORT_SYMBOL(udelay); + +void ndelay(unsigned long nsecs) +{ + /* + * This doesn't bother checking for overflow, as it won't happen (it's + * an hour) of delay. + */ + unsigned long long ncycles = nsecs * lpj_fine * NDELAY_MULT; + __delay(ncycles >> NDELAY_SHIFT); +} +EXPORT_SYMBOL(ndelay); diff --git a/arch/riscv/mm/ioremap.c b/arch/riscv/mm/ioremap.c new file mode 100644 index 000000000000..e99194a4077e --- /dev/null +++ b/arch/riscv/mm/ioremap.c @@ -0,0 +1,92 @@ +/* + * (C) Copyright 1995 1996 Linus Torvalds + * (C) Copyright 2012 Regents of the University of California + * + * 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, version 2. + * + * 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. + */ + +#include <linux/export.h> +#include <linux/mm.h> +#include <linux/vmalloc.h> +#include <linux/io.h> + +#include <asm/pgtable.h> + +/* + * Remap an arbitrary physical address space into the kernel virtual + * address space. Needed when the kernel wants to access high addresses + * directly. + * + * NOTE! We need to allow non-page-aligned mappings too: we will obviously + * have to convert them into an offset in a page-aligned mapping, but the + * caller shouldn't need to know that small detail. + */ +static void __iomem *__ioremap_caller(phys_addr_t addr, size_t size, + pgprot_t prot, void *caller) +{ + phys_addr_t last_addr; + unsigned long offset, vaddr; + struct vm_struct *area; + + /* Disallow wrap-around or zero size */ + last_addr = addr + size - 1; + if (!size || last_addr < addr) + return NULL; + + /* Page-align mappings */ + offset = addr & (~PAGE_MASK); + addr &= PAGE_MASK; + size = PAGE_ALIGN(size + offset); + + area = get_vm_area_caller(size, VM_IOREMAP, caller); + if (!area) + return NULL; + vaddr = (unsigned long)area->addr; + + if (ioremap_page_range(vaddr, vaddr + size, addr, prot)) { + free_vm_area(area); + return NULL; + } + + return (void __iomem *)(vaddr + offset); +} + +/* + * ioremap - map bus memory into CPU space + * @offset: bus address of the memory + * @size: size of the resource to map + * + * ioremap performs a platform specific sequence of operations to + * make bus memory CPU accessible via the readb/readw/readl/writeb/ + * writew/writel functions and the other mmio helpers. The returned + * address is not guaranteed to be usable directly as a virtual + * address. + * + * Must be freed with iounmap. + */ +void __iomem *ioremap(phys_addr_t offset, unsigned long size) +{ + return __ioremap_caller(offset, size, PAGE_KERNEL, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(ioremap); + + +/** + * iounmap - Free a IO remapping + * @addr: virtual address from ioremap_* + * + * Caller must ensure there is only one unmapping for the same pointer. + */ +void iounmap(void __iomem *addr) +{ + vunmap((void *)((unsigned long)addr & PAGE_MASK)); +} +EXPORT_SYMBOL(iounmap); -- 2.13.0
