Re: [PATCH v2] initramfs: Provide a common initrd reserve function
From: Palmer Dabbelt
Date: Thu Jan 14 2021 - 21:34:08 EST
On Wed, 13 Jan 2021 18:33:58 PST (-0800), wangkefeng.wang@xxxxxxxxxx wrote:
The ARM and riscv have same logic to check and reserve
the memory of initrd, let's provide a common function to
reduce duplicated code.
Add __LINUX_INITRD_H define in initrd.h to prevent build error
(found by kernel test robot <lkp@xxxxxxxxx>) from the multiple
inclusion of same header file multiple time.
This is doing a bunch of different things:
* Fixing the lack of a preprocessor guard in initrd.h
* Adding some generic code.
* Converting two architectures over to that generic code.
It needs to be split into four patches. I'm happy to take them via the RISC-V
tree (with an Ack from for the arch/arm/ stuff), but not all together.
It looks like csky copied this as well, they at least have exactly the same
message.
Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
---
v2: fix build err
arch/arm/mm/init.c | 43 +---------------------------------
arch/riscv/mm/init.c | 53 +-----------------------------------------
include/linux/initrd.h | 11 +++++++++
init/initramfs.c | 45 +++++++++++++++++++++++++++++++++++
4 files changed, 58 insertions(+), 94 deletions(-)
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index 828a2561b229..a29e14cd626c 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -153,47 +153,6 @@ phys_addr_t __init arm_memblock_steal(phys_addr_t size, phys_addr_t align)
return phys;
}
-static void __init arm_initrd_init(void)
-{
-#ifdef CONFIG_BLK_DEV_INITRD
- phys_addr_t start;
- unsigned long size;
-
- 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 - disabling initrd\n",
- (u64)start, size);
- return;
- }
-
- if (memblock_is_region_reserved(start, size)) {
- pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region - disabling initrd\n",
- (u64)start, size);
- return;
- }
-
- memblock_reserve(start, size);
-
- /* Now convert initrd to virtual addresses */
- initrd_start = __phys_to_virt(phys_initrd_start);
- initrd_end = initrd_start + phys_initrd_size;
-#endif
-}
-
#ifdef CONFIG_CPU_ICACHE_MISMATCH_WORKAROUND
void check_cpu_icache_size(int cpuid)
{
@@ -215,7 +174,7 @@ void __init arm_memblock_init(const struct machine_desc *mdesc)
/* Register the kernel text, kernel data and initrd with memblock. */
memblock_reserve(__pa(KERNEL_START), KERNEL_END - KERNEL_START);
- arm_initrd_init();
+ reserve_initrd_mem();
arm_mm_memblock_reserve();
diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
index da53902ef0fc..93cba0d3f43f 100644
--- a/arch/riscv/mm/init.c
+++ b/arch/riscv/mm/init.c
@@ -105,55 +105,6 @@ void __init mem_init(void)
print_vm_layout();
}
-#ifdef CONFIG_BLK_DEV_INITRD
-static void __init setup_initrd(void)
-{
- phys_addr_t start;
- unsigned long size;
-
- /* 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 (memblock_is_region_reserved(start, size)) {
- pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
- (u64)start, size);
- goto disable;
- }
-
- 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",
- (void *)(initrd_start), size);
- return;
-disable:
- pr_cont(" - disabling initrd\n");
- initrd_start = 0;
- initrd_end = 0;
-}
-#endif /* CONFIG_BLK_DEV_INITRD */
-
void __init setup_bootmem(void)
{
phys_addr_t mem_start = 0;
@@ -198,9 +149,7 @@ void __init setup_bootmem(void)
dma32_phys_limit = min(4UL * SZ_1G, (unsigned long)PFN_PHYS(max_low_pfn));
set_max_mapnr(max_low_pfn);
-#ifdef CONFIG_BLK_DEV_INITRD
- setup_initrd();
-#endif /* CONFIG_BLK_DEV_INITRD */
+ reserve_initrd_mem();
/*
* Avoid using early_init_fdt_reserve_self() since __pa() does
diff --git a/include/linux/initrd.h b/include/linux/initrd.h
index 8db6f8c8030b..85c15717af34 100644
--- a/include/linux/initrd.h
+++ b/include/linux/initrd.h
@@ -1,5 +1,8 @@
/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_INITRD_H
+#define __LINUX_INITRD_H
+
#define INITRD_MINOR 250 /* shouldn't collide with /dev/ram* too soon ... */
/* starting block # of image */
@@ -15,6 +18,12 @@ extern int initrd_below_start_ok;
extern unsigned long initrd_start, initrd_end;
extern void free_initrd_mem(unsigned long, unsigned long);
+#ifdef CONFIG_BLK_DEV_INITRD
+extern void __init reserve_initrd_mem(void);
+#else
+static inline void __init reserve_initrd_mem(void) {}
+#endif
+
extern phys_addr_t phys_initrd_start;
extern unsigned long phys_initrd_size;
@@ -24,3 +33,5 @@ extern char __initramfs_start[];
extern unsigned long __initramfs_size;
void console_on_rootfs(void);
+
+#endif /* __LINUX_INITRD_H */
diff --git a/init/initramfs.c b/init/initramfs.c
index 55b74d7e5260..f75c89e9d602 100644
--- a/init/initramfs.c
+++ b/init/initramfs.c
@@ -535,6 +535,51 @@ extern unsigned long __initramfs_size;
#include <linux/initrd.h>
#include <linux/kexec.h>
+void __init reserve_initrd_mem(void)
+{
+ phys_addr_t start;
+ unsigned long size;
+
+ /* 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 (memblock_is_region_reserved(start, size)) {
+ pr_err("INITRD: 0x%08llx+0x%08lx overlaps in-use memory region\n",
+ (u64)start, size);
+ goto disable;
+ }
+
+ 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;
+
+ return;
+disable:
+ pr_cont(" - disabling initrd\n");
+ initrd_start = 0;
+ initrd_end = 0;
+}
+
void __weak __init free_initrd_mem(unsigned long start, unsigned long end)
{
#ifdef CONFIG_ARCH_KEEP_MEMBLOCK