From fc0c769ffd926312848912a7c2296e1c503898c3 Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Tue, 23 Jun 2020 13:36:59 +0800 Subject: riscv: enable the Kconfig prompt of STRICT_KERNEL_RWX Due to lack of hardware breakpoint support, the kernel option CONFIG_STRICT_KERNEL_RWX should be disabled when using KGDB. However, CONFIG_STRICT_KERNEL_RWX is always enabled now. Therefore, select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT to enable CONFIG_STRICT_KERNEL_RWX by default, and then select ARCH_OPTIONAL_KERNEL_RWX to enable the Kconfig prompt of CONFIG_STRICT_KERNEL_RWX so that users can turn it off. Signed-off-by: Vincent Chen Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 2 ++ 1 file changed, 2 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 128192e14ff2..3230c1d48562 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -23,6 +23,8 @@ config RISCV select ARCH_HAS_SET_DIRECT_MAP select ARCH_HAS_SET_MEMORY select ARCH_HAS_STRICT_KERNEL_RWX if MMU + select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX + select ARCH_OPTIONAL_KERNEL_RWX_DEFAULT select ARCH_WANT_DEFAULT_TOPDOWN_MMAP_LAYOUT if MMU select ARCH_WANT_FRAME_POINTERS select ARCH_WANT_HUGE_PMD_SHARE if 64BIT -- cgit v1.2.3 From f7fc752815f8e2337548497b3afb4aef791db4ef Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Tue, 23 Jun 2020 13:37:10 +0800 Subject: riscv: Fix "no previous prototype" compile warning in kgdb.c file Some functions are only used in the kgdb.c file. Add static properities to these functions to avoid "no previous prototype" compile warnings Signed-off-by: Vincent Chen Signed-off-by: Palmer Dabbelt --- arch/riscv/kernel/kgdb.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/kernel/kgdb.c b/arch/riscv/kernel/kgdb.c index c3275f42d1ac..963ed7edcff2 100644 --- a/arch/riscv/kernel/kgdb.c +++ b/arch/riscv/kernel/kgdb.c @@ -44,18 +44,18 @@ DECLARE_INSN(c_beqz, MATCH_C_BEQZ, MASK_C_BEQZ) DECLARE_INSN(c_bnez, MATCH_C_BNEZ, MASK_C_BNEZ) DECLARE_INSN(sret, MATCH_SRET, MASK_SRET) -int decode_register_index(unsigned long opcode, int offset) +static int decode_register_index(unsigned long opcode, int offset) { return (opcode >> offset) & 0x1F; } -int decode_register_index_short(unsigned long opcode, int offset) +static int decode_register_index_short(unsigned long opcode, int offset) { return ((opcode >> offset) & 0x7) + 8; } /* Calculate the new address for after a step */ -int get_step_address(struct pt_regs *regs, unsigned long *next_addr) +static int get_step_address(struct pt_regs *regs, unsigned long *next_addr) { unsigned long pc = regs->epc; unsigned long *regs_ptr = (unsigned long *)regs; @@ -136,7 +136,7 @@ int get_step_address(struct pt_regs *regs, unsigned long *next_addr) return 0; } -int do_single_step(struct pt_regs *regs) +static int do_single_step(struct pt_regs *regs) { /* Determine where the target instruction will send us to */ unsigned long addr = 0; @@ -320,7 +320,7 @@ int kgdb_arch_handle_exception(int vector, int signo, int err_code, return err; } -int kgdb_riscv_kgdbbreak(unsigned long addr) +static int kgdb_riscv_kgdbbreak(unsigned long addr) { if (stepped_address == addr) return KGDB_SW_SINGLE_STEP; -- cgit v1.2.3 From def0aa218e6d42231540329e6f5741fdec9e7da4 Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Tue, 23 Jun 2020 13:37:25 +0800 Subject: kgdb: Move the extern declaration kgdb_has_hit_break() to generic kgdb.h Currently, only riscv kgdb.c uses the kgdb_has_hit_break() to identify the kgdb breakpoint. It causes other architectures will encounter the "no previous prototype" warnings if the compile option has W=1. Moving the declaration of extern kgdb_has_hit_break() from risc-v kgdb.h to generic kgdb.h to avoid generating these warnings. Signed-off-by: Vincent Chen Acked-by: Daniel Thompson Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/kgdb.h | 1 - include/linux/kgdb.h | 1 + 2 files changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/kgdb.h b/arch/riscv/include/asm/kgdb.h index 8177a457caff..f45889bbb965 100644 --- a/arch/riscv/include/asm/kgdb.h +++ b/arch/riscv/include/asm/kgdb.h @@ -19,7 +19,6 @@ #ifndef __ASSEMBLY__ -extern int kgdb_has_hit_break(unsigned long addr); extern unsigned long kgdb_compiled_break; static inline void arch_kgdb_breakpoint(void) diff --git a/include/linux/kgdb.h b/include/linux/kgdb.h index 0e4e3a80d58c..477b8b7c908f 100644 --- a/include/linux/kgdb.h +++ b/include/linux/kgdb.h @@ -325,6 +325,7 @@ extern int kgdb_hex2mem(char *buf, char *mem, int count); extern int kgdb_isremovedbreak(unsigned long addr); extern void kgdb_schedule_breakpoint(void); +extern int kgdb_has_hit_break(unsigned long addr); extern int kgdb_handle_exception(int ex_vector, int signo, int err_code, -- cgit v1.2.3 From 70ee5731a40b1f07f151e52c3c4ed27d70d4f9fe Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Tue, 23 Jun 2020 13:37:35 +0800 Subject: riscv: Avoid kgdb.h including gdb_xml.h to solve unused-const-variable warning The constant arrays in gdb_xml.h are only used in arch/riscv/kernel/kgdb.c, but other c files may include the gdb_xml.h indirectly via including the kgdb.h. Hence, It will cause many unused-const-variable warnings. This patch makes the kgdb.h not to include the gdb_xml.h to solve this problem. Signed-off-by: Vincent Chen Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/gdb_xml.h | 3 +-- arch/riscv/include/asm/kgdb.h | 4 +++- 2 files changed, 4 insertions(+), 3 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/gdb_xml.h b/arch/riscv/include/asm/gdb_xml.h index 041b45f5b997..09342111f227 100644 --- a/arch/riscv/include/asm/gdb_xml.h +++ b/arch/riscv/include/asm/gdb_xml.h @@ -3,8 +3,7 @@ #ifndef __ASM_GDB_XML_H_ #define __ASM_GDB_XML_H_ -#define kgdb_arch_gdb_stub_feature riscv_gdb_stub_feature -static const char riscv_gdb_stub_feature[64] = +const char riscv_gdb_stub_feature[64] = "PacketSize=800;qXfer:features:read+;"; static const char gdb_xfer_read_target[31] = "qXfer:features:read:target.xml:"; diff --git a/arch/riscv/include/asm/kgdb.h b/arch/riscv/include/asm/kgdb.h index f45889bbb965..46677daf708b 100644 --- a/arch/riscv/include/asm/kgdb.h +++ b/arch/riscv/include/asm/kgdb.h @@ -105,7 +105,9 @@ static inline void arch_kgdb_breakpoint(void) #define DBG_REG_BADADDR_OFF 34 #define DBG_REG_CAUSE_OFF 35 -#include +extern const char riscv_gdb_stub_feature[64]; + +#define kgdb_arch_gdb_stub_feature riscv_gdb_stub_feature #endif #endif -- cgit v1.2.3 From 0cac21b02ba5f3095fd2dcc77c26a25a0b2432ed Mon Sep 17 00:00:00 2001 From: Andreas Schwab Date: Mon, 6 Jul 2020 14:32:26 +0200 Subject: riscv: use 16KB kernel stack on 64-bit With the current 8KB stack size there are frequent overflows in a 64-bit configuration. We may split IRQ stacks off in the future, but this fixes a number of issues right now. Signed-off-by: Andreas Schwab Reviewed-by: Anup Patel [Palmer: mention irqstack in the commit text] Fixes: 7db91e57a0ac ("RISC-V: Task implementation") Cc: stable@vger.kernel.org Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/thread_info.h | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/thread_info.h b/arch/riscv/include/asm/thread_info.h index 1dd12a0cbb2b..464a2bbc97ea 100644 --- a/arch/riscv/include/asm/thread_info.h +++ b/arch/riscv/include/asm/thread_info.h @@ -12,7 +12,11 @@ #include /* thread information allocation */ +#ifdef CONFIG_64BIT +#define THREAD_SIZE_ORDER (2) +#else #define THREAD_SIZE_ORDER (1) +#endif #define THREAD_SIZE (PAGE_SIZE << THREAD_SIZE_ORDER) #ifndef __ASSEMBLY__ -- cgit v1.2.3 From 38b7c2a3ffb1fce8358ddc6006cfe5c038ff9963 Mon Sep 17 00:00:00 2001 From: Palmer Dabbelt Date: Thu, 16 Jul 2020 11:57:26 -0700 Subject: RISC-V: Upgrade smp_mb__after_spinlock() to iorw,iorw While digging through the recent mmiowb preemption issue it came up that we aren't actually preventing IO from crossing a scheduling boundary. While it's a bit ugly to overload smp_mb__after_spinlock() with this behavior, it's what PowerPC is doing so there's some precedent. Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/barrier.h | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/include/asm/barrier.h b/arch/riscv/include/asm/barrier.h index 3f1737f301cc..d0e24aaa2aa0 100644 --- a/arch/riscv/include/asm/barrier.h +++ b/arch/riscv/include/asm/barrier.h @@ -58,8 +58,16 @@ do { \ * The AQ/RL pair provides a RCpc critical section, but there's not really any * way we can take advantage of that here because the ordering is only enforced * on that one lock. Thus, we're just doing a full fence. + * + * Since we allow writeX to be called from preemptive regions we need at least + * an "o" in the predecessor set to ensure device writes are visible before the + * task is marked as available for scheduling on a new hart. While I don't see + * any concrete reason we need a full IO fence, it seems safer to just upgrade + * this in order to avoid any IO crossing a scheduling boundary. In both + * instances the scheduler pairs this with an mb(), so nothing is necessary on + * the new hart. */ -#define smp_mb__after_spinlock() RISCV_FENCE(rw,rw) +#define smp_mb__after_spinlock() RISCV_FENCE(iorw,iorw) #include -- cgit v1.2.3 From 4cb699d0447be8e0906539f93cbe41e19598ee5a Mon Sep 17 00:00:00 2001 From: Vincent Chen Date: Fri, 10 Jul 2020 10:40:54 +0800 Subject: riscv: kasan: use local_tlb_flush_all() to avoid uninitialized __sbi_rfence It fails to boot the v5.8-rc4 kernel with CONFIG_KASAN because kasan_init and kasan_early_init use uninitialized __sbi_rfence as executing the tlb_flush_all(). Actually, at this moment, only the CPU which is responsible for the system initialization enables the MMU. Other CPUs are parking at the .Lsecondary_start. Hence the tlb_flush_all() is able to be replaced by local_tlb_flush_all() to avoid using uninitialized __sbi_rfence. Signed-off-by: Vincent Chen Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/kasan_init.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c index 4a8b61806633..87b4ab3d3c77 100644 --- a/arch/riscv/mm/kasan_init.c +++ b/arch/riscv/mm/kasan_init.c @@ -44,7 +44,7 @@ asmlinkage void __init kasan_early_init(void) (__pa(((uintptr_t) kasan_early_shadow_pmd))), __pgprot(_PAGE_TABLE))); - flush_tlb_all(); + local_flush_tlb_all(); } static void __init populate(void *start, void *end) @@ -79,7 +79,7 @@ static void __init populate(void *start, void *end) pfn_pgd(PFN_DOWN(__pa(&pmd[offset])), __pgprot(_PAGE_TABLE))); - flush_tlb_all(); + local_flush_tlb_all(); memset(start, 0, end - start); } -- cgit v1.2.3 From d0d8aae64566b753c4330fbd5944b88af035f299 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Wed, 15 Jul 2020 16:30:07 -0700 Subject: RISC-V: Set maximum number of mapped pages correctly Currently, maximum number of mapper pages are set to the pfn calculated from the memblock size of the memblock containing kernel. This will work until that memblock spans the entire memory. However, it will be set to a wrong value if there are multiple memblocks defined in kernel (e.g. with efi runtime services). Set the the maximum value to the pfn calculated from dram size. Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'arch/riscv') diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index f4adb3684f3d..8d22973bde40 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -150,9 +150,9 @@ void __init setup_bootmem(void) /* Reserve from the start of the kernel to the end of the kernel */ memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); - set_max_mapnr(PFN_DOWN(mem_size)); max_pfn = PFN_DOWN(memblock_end_of_DRAM()); max_low_pfn = max_pfn; + set_max_mapnr(max_low_pfn); #ifdef CONFIG_BLK_DEV_INITRD setup_initrd(); -- cgit v1.2.3 From 4400231c8acc7e513204c8470c6d796ba47dc169 Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Wed, 15 Jul 2020 16:30:08 -0700 Subject: RISC-V: Do not rely on initrd_start/end computed during early dt parsing Currently, initrd_start/end are computed during early_init_dt_scan but used during arch_setup. We will get the following panic if initrd is used and CONFIG_DEBUG_VIRTUAL is turned on. [ 0.000000] ------------[ cut here ]------------ [ 0.000000] kernel BUG at arch/riscv/mm/physaddr.c:33! [ 0.000000] Kernel BUG [#1] [ 0.000000] Modules linked in: [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 5.8.0-rc4-00015-ged0b226fed02 #886 [ 0.000000] epc: ffffffe0002058d2 ra : ffffffe0000053f0 sp : ffffffe001001f40 [ 0.000000] gp : ffffffe00106e250 tp : ffffffe001009d40 t0 : ffffffe00107ee28 [ 0.000000] t1 : 0000000000000000 t2 : ffffffe000a2e880 s0 : ffffffe001001f50 [ 0.000000] s1 : ffffffe0001383e8 a0 : ffffffe00c087e00 a1 : 0000000080200000 [ 0.000000] a2 : 00000000010bf000 a3 : ffffffe00106f3c8 a4 : ffffffe0010bf000 [ 0.000000] a5 : ffffffe000000000 a6 : 0000000000000006 a7 : 0000000000000001 [ 0.000000] s2 : ffffffe00106f068 s3 : ffffffe00106f070 s4 : 0000000080200000 [ 0.000000] s5 : 0000000082200000 s6 : 0000000000000000 s7 : 0000000000000000 [ 0.000000] s8 : 0000000080011010 s9 : 0000000080012700 s10: 0000000000000000 [ 0.000000] s11: 0000000000000000 t3 : 000000000001fe30 t4 : 000000000001fe30 [ 0.000000] t5 : 0000000000000000 t6 : ffffffe00107c471 [ 0.000000] status: 0000000000000100 badaddr: 0000000000000000 cause: 0000000000000003 [ 0.000000] random: get_random_bytes called from print_oops_end_marker+0x22/0x46 with crng_init=0 To avoid the error, initrd_start/end can be computed from phys_initrd_start/size in setup itself. It also improves the initrd placement by aligning the start and size with the page size. Fixes: 76d2a0493a17 ("RISC-V: Init and Halt Code") Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 33 +++++++++++++++++++++++++++------ 1 file changed, 27 insertions(+), 6 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 8d22973bde40..f818a47a72d1 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -95,19 +95,40 @@ void __init mem_init(void) #ifdef CONFIG_BLK_DEV_INITRD static void __init setup_initrd(void) { + phys_addr_t start; unsigned long size; - if (initrd_start >= initrd_end) { - pr_info("initrd not found or empty"); + /* Ignore the virtul address computed during device tree parsing */ + initrd_start = initrd_end = 0; + + if (!phys_initrd_size) + return; + /* + * Round the memory region to page boundaries as per free_initrd_mem() + * This allows us to detect whether the pages overlapping the initrd + * are in use, but more importantly, reserves the entire set of pages + * as we don't want these pages allocated for other purposes. + */ + start = round_down(phys_initrd_start, PAGE_SIZE); + size = phys_initrd_size + (phys_initrd_start - start); + size = round_up(size, PAGE_SIZE); + + if (!memblock_is_region_memory(start, size)) { + pr_err("INITRD: 0x%08llx+0x%08lx is not a memory region", + (u64)start, size); goto disable; } - if (__pa_symbol(initrd_end) > PFN_PHYS(max_low_pfn)) { - pr_err("initrd extends beyond end of memory"); + + if (memblock_is_region_reserved(start, size)) { + pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n", + (u64)start, size); goto disable; } - size = initrd_end - initrd_start; - memblock_reserve(__pa_symbol(initrd_start), size); + memblock_reserve(start, size); + /* Now convert initrd to virtual addresses */ + initrd_start = (unsigned long)__va(phys_initrd_start); + initrd_end = initrd_start + phys_initrd_size; initrd_below_start_ok = 1; pr_info("Initial ramdisk at: 0x%p (%lu bytes)\n", -- cgit v1.2.3 From fa5a198359053c8e21dcc2b39c0e13871059bc9f Mon Sep 17 00:00:00 2001 From: Atish Patra Date: Wed, 15 Jul 2020 16:30:09 -0700 Subject: riscv: Parse all memory blocks to remove unusable memory Currently, maximum physical memory allowed is equal to -PAGE_OFFSET. That's why we remove any memory blocks spanning beyond that size. However, it is done only for memblock containing linux kernel which will not work if there are multiple memblocks. Process all memory blocks to figure out how much memory needs to be removed and remove at the end instead of updating the memblock list in place. Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt --- arch/riscv/mm/init.c | 31 +++++++++++++++++-------------- 1 file changed, 17 insertions(+), 14 deletions(-) (limited to 'arch/riscv') diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index f818a47a72d1..79e9d55bdf1a 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -147,26 +147,29 @@ void __init setup_bootmem(void) { struct memblock_region *reg; phys_addr_t mem_size = 0; + phys_addr_t total_mem = 0; + phys_addr_t mem_start, end = 0; phys_addr_t vmlinux_end = __pa_symbol(&_end); phys_addr_t vmlinux_start = __pa_symbol(&_start); /* Find the memory region containing the kernel */ for_each_memblock(memory, reg) { - phys_addr_t end = reg->base + reg->size; - - if (reg->base <= vmlinux_start && vmlinux_end <= end) { - mem_size = min(reg->size, (phys_addr_t)-PAGE_OFFSET); - - /* - * Remove memblock from the end of usable area to the - * end of region - */ - if (reg->base + mem_size < end) - memblock_remove(reg->base + mem_size, - end - reg->base - mem_size); - } + end = reg->base + reg->size; + if (!total_mem) + mem_start = reg->base; + if (reg->base <= vmlinux_start && vmlinux_end <= end) + BUG_ON(reg->size == 0); + total_mem = total_mem + reg->size; } - BUG_ON(mem_size == 0); + + /* + * Remove memblock from the end of usable area to the + * end of region + */ + mem_size = min(total_mem, (phys_addr_t)-PAGE_OFFSET); + if (mem_start + mem_size < end) + memblock_remove(mem_start + mem_size, + end - mem_start - mem_size); /* Reserve from the start of the kernel to the end of the kernel */ memblock_reserve(vmlinux_start, vmlinux_end - vmlinux_start); -- cgit v1.2.3