Hi Vivek, * Vivek Goyal <vgoyal at redhat.com> [2008-06-09 16:29]: > > Can you please put some more explanation comment here to explain that > why it is ok to return with success, despite the fact that we never > reserved any memory. Do you think that's ok? When booting the kdump kernel, the MP tables (for example, or other firmware-reserved memory) of the BIOS are beyond end_pfn. (kexec-tools adds exactmap parameters to the kernel so that the E820 map is no longer used.) Therefore, it's ok to return "success" here. For normal boot, the MP tables must be reserved normally. Bernhard ------------------------------------------------------------------------------ From: Bernhard Walle <bwalle@xxxxxxx> Subject: Add 'flags' parameter to reserve_bootmem_generic() This patch adds a 'flags' parameter to reserve_bootmem_generic() like it already has been added in reserve_bootmem() with commit 72a7fe3967dbf86cb34e24fbf1d957fe24d2f246. It also changes all users to use BOOTMEM_DEFAULT, which doesn't effectively change the behaviour. Since the change is x86-specific, I don't think it's necessary to add a new API for migration. There are only 4 users of that function. The change is necessary for the next patch, using reserve_bootmem_generic() for crashkernel reservation. Signed-off-by: Bernhard Walle <bwalle at suse.de> --- arch/x86/kernel/e820_64.c | 3 ++- arch/x86/kernel/efi_64.c | 3 ++- arch/x86/kernel/mpparse.c | 5 +++-- arch/x86/mm/init_64.c | 27 +++++++++++++++++++-------- include/asm-x86/proto.h | 2 +- 5 files changed, 27 insertions(+), 13 deletions(-) --- a/arch/x86/kernel/e820_64.c +++ b/arch/x86/kernel/e820_64.c @@ -118,7 +118,8 @@ void __init early_res_to_bootmem(unsigne continue; printk(KERN_INFO " early res: %d [%lx-%lx] %s\n", i, final_start, final_end - 1, r->name); - reserve_bootmem_generic(final_start, final_end - final_start); + reserve_bootmem_generic(final_start, final_end - final_start, + BOOTMEM_DEFAULT); } } --- a/arch/x86/kernel/efi_64.c +++ b/arch/x86/kernel/efi_64.c @@ -100,7 +100,8 @@ void __init efi_call_phys_epilog(void) void __init efi_reserve_bootmem(void) { reserve_bootmem_generic((unsigned long)memmap.phys_map, - memmap.nr_map * memmap.desc_size); + memmap.nr_map * memmap.desc_size, + BOOTMEM_DEFAULT); } void __iomem * __init efi_ioremap(unsigned long phys_addr, unsigned long size) --- a/arch/x86/kernel/mpparse.c +++ b/arch/x86/kernel/mpparse.c @@ -729,10 +729,11 @@ static int __init smp_scan_config(unsign if (!reserve) return 1; - reserve_bootmem_generic(virt_to_phys(mpf), PAGE_SIZE); + reserve_bootmem_generic(virt_to_phys(mpf), PAGE_SIZE, + BOOTMEM_DEFAULT); if (mpf->mpf_physptr) reserve_bootmem_generic(mpf->mpf_physptr, - PAGE_SIZE); + PAGE_SIZE, BOOTMEM_DEFAULT); #endif return 1; } --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -798,24 +798,29 @@ void free_initrd_mem(unsigned long start } #endif -void __init reserve_bootmem_generic(unsigned long phys, unsigned len) +int __init reserve_bootmem_generic(unsigned long phys, unsigned len, int flags) { #ifdef CONFIG_NUMA int nid, next_nid; #endif unsigned long pfn = phys >> PAGE_SHIFT; + int ret; if (pfn >= end_pfn) { /* - * This can happen with kdump kernels when accessing - * firmware tables: + * When booting the kdump kernel, the MP tables (for example, + * or other firmware-reserved memory) of the BIOS are beyond + * end_pfn. (kexec-tools adds exactmap parameters to the kernel + * so that the E820 map is no longer used.) Therefore, it's ok + * to return "success" here. For normal boot, the MP tables + * must be reserved normally. */ if (pfn < max_pfn_mapped) - return; + return 0; printk(KERN_ERR "reserve_bootmem: illegal reserve %lx %u\n", phys, len); - return; + return -EFAULT; } /* Should check here against the e820 map to avoid double free */ @@ -823,17 +828,23 @@ void __init reserve_bootmem_generic(unsi nid = phys_to_nid(phys); next_nid = phys_to_nid(phys + len - 1); if (nid == next_nid) - reserve_bootmem_node(NODE_DATA(nid), phys, len, BOOTMEM_DEFAULT); + ret = reserve_bootmem_node(NODE_DATA(nid), phys, len, flags); else - reserve_bootmem(phys, len, BOOTMEM_DEFAULT); + ret = reserve_bootmem(phys, len, flags); + #else - reserve_bootmem(phys, len, BOOTMEM_DEFAULT); + ret = reserve_bootmem(phys, len, flags); #endif + if (ret != 0) + return ret; + if (phys+len <= MAX_DMA_PFN*PAGE_SIZE) { dma_reserve += len / PAGE_SIZE; set_dma_reserve(dma_reserve); } + + return 0; } int kern_addr_valid(unsigned long addr) --- a/include/asm-x86/proto.h +++ b/include/asm-x86/proto.h @@ -14,7 +14,7 @@ extern void ia32_syscall(void); extern void ia32_cstar_target(void); extern void ia32_sysenter_target(void); -extern void reserve_bootmem_generic(unsigned long phys, unsigned len); +extern int reserve_bootmem_generic(unsigned long phys, unsigned len, int flags); extern void syscall32_cpu_init(void);