[PATCH v3 3/4] powerpc: increase MIN RMA size for CAS negotiation

[Sourabh Jain]

From: Avnish Chouhan <avnish at linux.ibm.com>

Change RMA size from 512 MB to 768 MB which will result
in more RMA at boot time for PowerPC. When PowerPC LPAR use/uses vTPM,
Secure Boot or FADump, the 512 MB RMA memory is not sufficient for
booting. With this 512 MB RMA, GRUB2 run out of memory and unable to
load the necessary. Sometimes even usage of CDROM which requires more
memory for installation along with the options mentioned above troubles
the boot memory and result in boot failures. Increasing the RMA size
will resolves multiple out of memory issues observed in PowerPC.

Failure details:

1. GRUB2

kern/ieee1275/init.c:550: mm requested region of size 8513000, flags 1
kern/ieee1275/init.c:563: Cannot satisfy allocation and retain minimum runtime
space
kern/ieee1275/init.c:550: mm requested region of size 8513000, flags 0
kern/ieee1275/init.c:563: Cannot satisfy allocation and retain minimum runtime
space
kern/file.c:215: Closing `/ppc/ppc64/initrd.img' ...
kern/disk.c:297: Closing
`ieee1275//vdevice/v-scsi
@30000067/disk at 8300000000000000'...
kern/disk.c:311: Closing
`ieee1275//vdevice/v-scsi
@30000067/disk at 8300000000000000' succeeded.
kern/file.c:225: Closing `/ppc/ppc64/initrd.img' failed with 3.
kern/file.c:148: Opening `/ppc/ppc64/initrd.img' succeeded.
error: ../../grub-core/kern/mm.c:552:out of memory.

2. Kernel

[    0.777633] List of all partitions:
[    0.777639] No filesystem could mount root, tried:
[    0.777640]
[    0.777649] Kernel panic - not syncing: VFS: Unable to mount root fs on "" or unknown-block(0,0)
[    0.777658] CPU: 17 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-0.rc4.20.el10.ppc64le #1
[    0.777669] Hardware name: IBM,9009-22A POWER9 (architected) 0x4e0202 0xf000005 of:IBM,FW950.B0 (VL950_149) hv:phyp pSeries
[    0.777678] Call Trace:
[    0.777682] [c000000003db7b60] [c000000001119714] dump_stack_lvl+0x88/0xc4 (unreliable)
[    0.777700] [c000000003db7b90] [c00000000016c274] panic+0x174/0x460
[    0.777711] [c000000003db7c30] [c00000000200631c] mount_root_generic+0x320/0x354
[    0.777724] [c000000003db7d00] [c0000000020066f8] prepare_namespace+0x27c/0x2f4
[    0.777735] [c000000003db7d90] [c000000002005824] kernel_init_freeable+0x254/0x294
[    0.777747] [c000000003db7df0] [c00000000001131c] kernel_init+0x30/0x1c4
[    0.777757] [c000000003db7e50] [c00000000000debc] ret_from_kernel_user_thread+0x14/0x1c
[    0.777768] --- interrupt: 0 at 0x0
[    0.784238] pstore: backend (nvram) writing error (-1)
[    0.790447] Rebooting in 10 seconds..

Cc: Brian King <brking at linux.ibm.com>
Cc: Hari Bathini <hbathini at linux.ibm.com>
Cc: Madhavan Srinivasan <maddy at linux.ibm.com>
Cc: Meghana Prakash <meghanaprakash at in.ibm.com>
Cc: Michael Ellerman <mpe at ellerman.id.au>
Cc: Mahesh Salgaonkar <mahesh at linux.ibm.com>
Cc: Sourabh Jain <sourabhjain at linux.ibm.com>
Signed-off-by: Avnish Chouhan <avnish at linux.ibm.com>
---
 arch/powerpc/include/asm/prom.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/powerpc/include/asm/prom.h b/arch/powerpc/include/asm/prom.h
index b4e504b914e4..f679a11a7e7f 100644
--- a/arch/powerpc/include/asm/prom.h
+++ b/arch/powerpc/include/asm/prom.h
@@ -17,7 +17,7 @@
 struct device_node;
 struct property;
 
-#define MIN_RMA			512		/* Minimum RMA (in MB) for CAS negotiation */
+#define MIN_RMA			768		/* Minimum RMA (in MB) for CAS negotiation */
 
 #define OF_DT_BEGIN_NODE	0x1		/* Start of node, full name */
 #define OF_DT_END_NODE		0x2		/* End node */
-- 
2.48.1