Re: [patch 2/3] Add flags parameter to reserve_bootmem_generic()

[Bernhard Walle <bwalle@suse.de>]

* Amul Shah <amul.shah@unisys.com> [2008-06-09 15:50]:
>
> > Don't remember the details. Perhaps Amul does (cc'ed)
> > 
> > -Andi
> >   
> 
> The short story is that the kexec kernel was panicking when trying to
> reserve the MP tables.  The panic occurs because the MP tables resided
> in a reserved memory area above the highest address (80MB phys at that
> time) in the user defined E820 map used by the kexec kernel.
> 
> I had placed my code to affect only MP table reservation (see patch
> below) because it is unique to just that code path.  Andi decided a
> generalized approach would be better in case other vendors had similar
> issues.

Ok, in that case it makes indeed sense to just return success here.
Here's my third version of that patch:

-------------------------------------------------------------------------
From: Bernhard Walle <bwalle@suse.de>
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@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     |   19 +++++++++++++------
 include/asm-x86/proto.h   |    2 +-
 5 files changed, 21 insertions(+), 11 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
@@ -798,12 +798,13 @@ 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) {
 		/*
@@ -811,11 +812,11 @@ void __init reserve_bootmem_generic(unsi
 		 * firmware tables:
 		 */
 		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 +824,23 @@ 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);