From bc183779dedf969533f19cc957a4a02b69fc44d3 Mon Sep 17 00:00:00 2001
From: Hari Bathini <hbathini@linux.vnet.ibm.com>
Date: Fri, 17 Mar 2017 02:35:42 +0530
Subject: [PATCH] powerpc/fadump: Update fadump documentation
With the unnecessary restriction to reserve memory for fadump at the
top of RAM forgone, update the documentation accordingly.
Signed-off-by: Hari Bathini <hbathini@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
---
.../powerpc/firmware-assisted-dump.txt | 34 +++++++++----------
1 file changed, 17 insertions(+), 17 deletions(-)
diff --git a/Documentation/powerpc/firmware-assisted-dump.txt b/Documentation/powerpc/firmware-assisted-dump.txt
index 3007bc98af283..19b1e3d09a19b 100644
--- a/Documentation/powerpc/firmware-assisted-dump.txt
+++ b/Documentation/powerpc/firmware-assisted-dump.txt
@@ -105,21 +105,21 @@ memory is held.
If there is no waiting dump data, then only the memory required
to hold CPU state, HPTE region, boot memory dump and elfcore
-header, is reserved at the top of memory (see Fig. 1). This area
-is *not* released: this region will be kept permanently reserved,
-so that it can act as a receptacle for a copy of the boot memory
-content in addition to CPU state and HPTE region, in the case a
-crash does occur.
+header, is usually reserved at an offset greater than boot memory
+size (see Fig. 1). This area is *not* released: this region will
+be kept permanently reserved, so that it can act as a receptacle
+for a copy of the boot memory content in addition to CPU state
+and HPTE region, in the case a crash does occur.
o Memory Reservation during first kernel
- Low memory Top of memory
+ Low memory Top of memory
0 boot memory size |
- | | |<--Reserved dump area -->|
- V V | Permanent Reservation V
- +-----------+----------/ /----------+---+----+-----------+----+
- | | |CPU|HPTE| DUMP |ELF |
- +-----------+----------/ /----------+---+----+-----------+----+
+ | | |<--Reserved dump area -->| |
+ V V | Permanent Reservation | V
+ +-----------+----------/ /---+---+----+-----------+----+------+
+ | | |CPU|HPTE| DUMP |ELF | |
+ +-----------+----------/ /---+---+----+-----------+----+------+
| ^
| |
\ /
@@ -135,12 +135,12 @@ crash does occur.
0 boot memory size |
| |<------------- Reserved dump area ----------- -->|
V V V
- +-----------+----------/ /----------+---+----+-----------+----+
- | | |CPU|HPTE| DUMP |ELF |
- +-----------+----------/ /----------+---+----+-----------+----+
- | |
- V V
- Used by second /proc/vmcore
+ +-----------+----------/ /---+---+----+-----------+----+------+
+ | | |CPU|HPTE| DUMP |ELF | |
+ +-----------+----------/ /---+---+----+-----------+----+------+
+ | |
+ V V
+ Used by second /proc/vmcore
kernel to boot
Fig. 2
--
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