From: Kefeng Wang <wangkefeng.wang@huawei.com>
To: <catalin.marinas@arm.com>, <will@kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-kernel@vger.kernel.org>
Cc: <vijayb@linux.microsoft.com>, <f.fainelli@gmail.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>
Subject: [PATCH v2 2/3] arm64: mm: Don't defer reserve_crashkernel() with dma_force_32bit
Date: Thu, 31 Mar 2022 10:59:45 +0800 [thread overview]
Message-ID: <20220331025946.51163-3-wangkefeng.wang@huawei.com> (raw)
In-Reply-To: <20220331025946.51163-1-wangkefeng.wang@huawei.com>
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..653b16acd09a 100644
--- a/arch/arm64/include/asm/kexec.h
+++ b/arch/arm64/include/asm/kexec.h
@@ -94,6 +94,7 @@ static inline void crash_post_resume(void) {}
void cpu_soft_restart(unsigned long el2_switch, unsigned long entry,
unsigned long arg0, unsigned long arg1,
unsigned long arg2);
+bool crashkernel_could_early_reserve(void)
#endif
#define ARCH_HAS_KIMAGE_ARCH
diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index fb01eb489fa9..329e236c3c52 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) || 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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next prev parent reply other threads:[~2022-03-31 2:49 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-31 2:59 [PATCH v2 0/3] arm64: mm: Do not defer reserve_crashkernel() Kefeng Wang
2022-03-31 2:59 ` [PATCH v2 1/3] arm64: mm: Do not defer reserve_crashkernel() if only ZONE_DMA32 Kefeng Wang
2022-03-31 2:59 ` Kefeng Wang [this message]
2022-03-31 7:01 ` [PATCH v2 2/3] arm64: mm: Don't defer reserve_crashkernel() with dma_force_32bit kernel test robot
2022-03-31 7:10 ` Kefeng Wang
2022-03-31 2:59 ` [PATCH v2 3/3] arm64: mm: Cleanup useless parameters in zone_sizes_init() Kefeng Wang
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