From 6065e736f82c817c9a597a31ee67f0ce4628e948 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Mon, 26 Feb 2024 16:34:46 -0800 Subject: riscv: Fix TASK_SIZE on 64-bit NOMMU On NOMMU, userspace memory can come from anywhere in physical RAM. The current definition of TASK_SIZE is wrong if any RAM exists above 4G, causing spurious failures in the userspace access routines. Fixes: 6bd33e1ece52 ("riscv: add nommu support") Fixes: c3f896dcf1e4 ("mm: switch the test_vmalloc module to use __vmalloc_node") Signed-off-by: Samuel Holland Reviewed-by: Jisheng Zhang Reviewed-by: Bo Gan Link: https://lore.kernel.org/r/20240227003630.3634533-2-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/pgtable.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h index 0c94260b5d0c..a564a39e5676 100644 --- a/arch/riscv/include/asm/pgtable.h +++ b/arch/riscv/include/asm/pgtable.h @@ -882,7 +882,7 @@ static inline pte_t pte_swp_clear_exclusive(pte_t pte) #define PAGE_SHARED __pgprot(0) #define PAGE_KERNEL __pgprot(0) #define swapper_pg_dir NULL -#define TASK_SIZE 0xffffffffUL +#define TASK_SIZE _AC(-1, UL) #define VMALLOC_START _AC(0, UL) #define VMALLOC_END TASK_SIZE -- cgit v1.2.3 From aea702dde7e9876fb00571a2602f25130847bf0f Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Mon, 26 Feb 2024 16:34:47 -0800 Subject: riscv: Fix loading 64-bit NOMMU kernels past the start of RAM commit 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") added logic to allow using RAM below the kernel load address. However, this does not work for NOMMU, where PAGE_OFFSET is fixed to the kernel load address. Since that range of memory corresponds to PFNs below ARCH_PFN_OFFSET, mm initialization runs off the beginning of mem_map and corrupts adjacent kernel memory. Fix this by restoring the previous behavior for NOMMU kernels. Fixes: 3335068f8721 ("riscv: Use PUD/P4D/PGD pages for the linear mapping") Signed-off-by: Samuel Holland Link: https://lore.kernel.org/r/20240227003630.3634533-3-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/include/asm/page.h | 2 +- arch/riscv/mm/init.c | 2 +- 2 files changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/riscv/include/asm/page.h b/arch/riscv/include/asm/page.h index 57e887bfa34c..94b3d6930fc3 100644 --- a/arch/riscv/include/asm/page.h +++ b/arch/riscv/include/asm/page.h @@ -89,7 +89,7 @@ typedef struct page *pgtable_t; #define PTE_FMT "%08lx" #endif -#ifdef CONFIG_64BIT +#if defined(CONFIG_64BIT) && defined(CONFIG_MMU) /* * We override this value as its generic definition uses __pa too early in * the boot process (before kernel_map.va_pa_offset is set). diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c index 32cad6a65ccd..b3e63dec3ab5 100644 --- a/arch/riscv/mm/init.c +++ b/arch/riscv/mm/init.c @@ -232,7 +232,7 @@ static void __init setup_bootmem(void) * In 64-bit, any use of __va/__pa before this point is wrong as we * did not know the start of DRAM before. */ - if (IS_ENABLED(CONFIG_64BIT)) + if (IS_ENABLED(CONFIG_64BIT) && IS_ENABLED(CONFIG_MMU)) kernel_map.va_pa_offset = PAGE_OFFSET - phys_ram_base; /* -- cgit v1.2.3 From 9c4319d697448e738b1e20d187d9391164c84a89 Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Mon, 26 Feb 2024 16:34:48 -0800 Subject: riscv: Remove MMU dependency from Zbb and Zicboz The Zbb and Zicboz ISA extensions have no dependency on an MMU and are equally useful on NOMMU kernels. Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20240227003630.3634533-4-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index bffbd869a068..ef53c00470d6 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -581,7 +581,6 @@ config TOOLCHAIN_HAS_ZBB config RISCV_ISA_ZBB bool "Zbb extension support for bit manipulation instructions" depends on TOOLCHAIN_HAS_ZBB - depends on MMU depends on RISCV_ALTERNATIVE default y help @@ -613,7 +612,6 @@ config RISCV_ISA_ZICBOM config RISCV_ISA_ZICBOZ bool "Zicboz extension support for faster zeroing of memory" - depends on MMU depends on RISCV_ALTERNATIVE default y help -- cgit v1.2.3 From f862bbf4cdca696ef3073c5cf3d340b778a3e42a Mon Sep 17 00:00:00 2001 From: Samuel Holland Date: Mon, 26 Feb 2024 16:34:49 -0800 Subject: riscv: Allow NOMMU kernels to run in S-mode For ease of testing, it is convenient to run NOMMU kernels in supervisor mode. The only required change is to offset the kernel load address, since the beginning of RAM is usually reserved for M-mode firmware. Signed-off-by: Samuel Holland Reviewed-by: Conor Dooley Link: https://lore.kernel.org/r/20240227003630.3634533-5-samuel.holland@sifive.com Signed-off-by: Palmer Dabbelt --- arch/riscv/Kconfig | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index ef53c00470d6..0dc09b2ac2f6 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -64,7 +64,7 @@ config RISCV select ARCH_WANTS_THP_SWAP if HAVE_ARCH_TRANSPARENT_HUGEPAGE select BINFMT_FLAT_NO_DATA_START_OFFSET if !MMU select BUILDTIME_TABLE_SORT if MMU - select CLINT_TIMER if !MMU + select CLINT_TIMER if RISCV_M_MODE select CLONE_BACKWARDS select COMMON_CLK select CPU_PM if CPU_IDLE || HIBERNATION || SUSPEND @@ -220,8 +220,12 @@ config ARCH_MMAP_RND_COMPAT_BITS_MAX # set if we run in machine mode, cleared if we run in supervisor mode config RISCV_M_MODE - bool - default !MMU + bool "Build a kernel that runs in machine mode" + depends on !MMU + default y + help + Select this option if you want to run the kernel in M-mode, + without the assistance of any other firmware. # set if we are running in S-mode and can use SBI calls config RISCV_SBI @@ -238,8 +242,9 @@ config MMU config PAGE_OFFSET hex - default 0xC0000000 if 32BIT && MMU - default 0x80000000 if !MMU + default 0x80000000 if !MMU && RISCV_M_MODE + default 0x80200000 if !MMU + default 0xc0000000 if 32BIT default 0xff60000000000000 if 64BIT config KASAN_SHADOW_OFFSET -- cgit v1.2.3