Messages in this thread Patch in this message | | | From | Kefeng Wang <> | Subject | [PATCH v2 resend 2/3] arm64: mm: Don't defer reserve_crashkernel() with dma_force_32bit | Date | Thu, 31 Mar 2022 15:40:54 +0800 |
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ARM64 enable ZONE_DMA by default, and with ZONE_DMA crash kernel memory reservation is delayed until DMA zone memory range size initilazation performed in zone_sizes_init(), but for most platforms use 32bit dma_zone_bits, so add dma_force_32bit kernel parameter if ZONE_DMA enabled, and initialize arm64_dma_phys_limit to dma32_phys_limit in arm64_memblock_init() if dma_force_32bit is setup, this could let the crash kernel reservation earlier, and allows linear creation with block mapping.
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> --- arch/arm64/include/asm/kexec.h | 1 + arch/arm64/mm/init.c | 42 ++++++++++++++++++++++++++-------- arch/arm64/mm/mmu.c | 4 ++-- 3 files changed, 36 insertions(+), 11 deletions(-)
diff --git a/arch/arm64/include/asm/kexec.h b/arch/arm64/include/asm/kexec.h index 9839bfc163d7..8bea40aea359 100644 --- a/arch/arm64/include/asm/kexec.h +++ b/arch/arm64/include/asm/kexec.h @@ -95,6 +95,7 @@ void cpu_soft_restart(unsigned long el2_switch, unsigned long entry, unsigned long arg0, unsigned long arg1, unsigned long arg2); #endif +bool crashkernel_could_early_reserve(void); #define ARCH_HAS_KIMAGE_ARCH diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index fb01eb489fa9..0aafa9181607 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -66,7 +66,8 @@ EXPORT_SYMBOL(memstart_addr); * depending on DMA memory zones configs (ZONE_DMA) -- * * In absence of ZONE_DMA and ZONE_DMA32 configs arm64_dma_phys_limit - * initialized here and if only with ZONE_DMA32 arm64_dma_phys_limit + * initialized here, and if only with ZONE_DMA32 or if with ZONE_DMA + * and dma_force_32bit kernel parameter, the arm64_dma_phys_limit is * initialised to dma32_phys_limit. This lets early reservation of * crash kernel memory which has a dependency on arm64_dma_phys_limit. * Reserving memory early for crash kernel allows linear creation of block @@ -92,6 +93,27 @@ phys_addr_t __ro_after_init arm64_dma_phys_limit; phys_addr_t __ro_after_init arm64_dma_phys_limit = PHYS_MASK + 1; #endif +static bool __ro_after_init arm64_dma_force_32bit; +#ifdef CONFIG_ZONE_DMA +static int __init arm64_dma_force_32bit_setup(char *p) +{ + zone_dma_bits = 32; + arm64_dma_force_32bit = true; + + return 0; +} +early_param("dma_force_32bit", arm64_dma_force_32bit_setup); +#endif + +bool __init crashkernel_could_early_reserve(void) +{ + if (!IS_ENABLED(CONFIG_ZONE_DMA)) + return true; + if (arm64_dma_force_32bit) + return true; + return false; +} + /* * reserve_crashkernel() - reserves memory for crash kernel * @@ -163,12 +185,14 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) { unsigned long max_zone_pfns[MAX_NR_ZONES] = {0}; #ifdef CONFIG_ZONE_DMA - unsigned int acpi_zone_dma_bits; - unsigned int dt_zone_dma_bits; + if (!arm64_dma_force_32bit) { + unsigned int acpi_zone_dma_bits; + unsigned int dt_zone_dma_bits; - acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address()); - dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL)); - zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits); + acpi_zone_dma_bits = fls64(acpi_iort_dma_get_max_cpu_address()); + dt_zone_dma_bits = fls64(of_dma_get_max_cpu_address(NULL)); + zone_dma_bits = min3(32U, dt_zone_dma_bits, acpi_zone_dma_bits); + } arm64_dma_phys_limit = max_zone_phys(zone_dma_bits); max_zone_pfns[ZONE_DMA] = PFN_DOWN(arm64_dma_phys_limit); #endif @@ -336,8 +360,8 @@ void __init arm64_memblock_init(void) early_init_fdt_scan_reserved_mem(); dma32_phys_limit = max_zone_phys(32); - if (!IS_ENABLED(CONFIG_ZONE_DMA)) { - if (IS_ENABLED(CONFIG_ZONE_DMA32)) + if (crashkernel_could_early_reserve()) { + if (IS_ENABLED(CONFIG_ZONE_DMA32) || arm64_dma_force_32bit) arm64_dma_phys_limit = dma32_phys_limit; reserve_crashkernel(); } @@ -388,7 +412,7 @@ void __init bootmem_init(void) * request_standard_resources() depends on crashkernel's memory being * reserved, so do it here. */ - if (IS_ENABLED(CONFIG_ZONE_DMA)) + if (!crashkernel_could_early_reserve()) reserve_crashkernel(); memblock_dump_all(); diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index 23734481318a..8f7e8452d906 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -529,7 +529,7 @@ static void __init map_mem(pgd_t *pgdp) #ifdef CONFIG_KEXEC_CORE if (crash_mem_map) { - if (IS_ENABLED(CONFIG_ZONE_DMA)) + if (!crashkernel_could_early_reserve()) flags |= NO_BLOCK_MAPPINGS | NO_CONT_MAPPINGS; else if (crashk_res.end) memblock_mark_nomap(crashk_res.start, @@ -570,7 +570,7 @@ static void __init map_mem(pgd_t *pgdp) * through /sys/kernel/kexec_crash_size interface. */ #ifdef CONFIG_KEXEC_CORE - if (crash_mem_map && !IS_ENABLED(CONFIG_ZONE_DMA)) { + if (crash_mem_map && crashkernel_could_early_reserve()) { if (crashk_res.end) { __map_memblock(pgdp, crashk_res.start, crashk_res.end + 1, -- 2.26.2
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