From: Heiko Carstens Date: Mon, 4 Dec 2006 14:40:42 +0000 (+0100) Subject: [S390] Use diag260 for memory size detection. X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=d57de5a36791cb1b7285649c62f183b0d3505f7d;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git [S390] Use diag260 for memory size detection. Avoid the tprot loop if diag260 works and reports that there are no holes in memory. The tprot instruction can lead to a significant delay in the ipl process if the virtual guest has a lot of memory and the host is under memory pressure. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- diff --git a/arch/s390/kernel/head64.S b/arch/s390/kernel/head64.S index 42f54d48244..cc6dbc57eb9 100644 --- a/arch/s390/kernel/head64.S +++ b/arch/s390/kernel/head64.S @@ -70,7 +70,22 @@ startup_continue: sgr %r5,%r5 # set src,length and pad to zero mvcle %r2,%r4,0 # clear mem jo .-4 # branch back, if not finish + # set program check new psw mask + mvc __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13) + larl %r1,.Lslowmemdetect # set program check address + stg %r1,__LC_PGM_NEW_PSW+8 + lghi %r1,0xc + diag %r0,%r1,0x260 # get memory size of virtual machine + cgr %r0,%r1 # different? -> old detection routine + jne .Lslowmemdetect + aghi %r1,1 # size is one more than end + larl %r2,memory_chunk + stg %r1,8(%r2) # store size of chunk + larl %r2,memory_size + stg %r1,0(%r2) # set memory size + j .Ldonemem +.Lslowmemdetect: l %r2,.Lrcp-.LPG1(%r13) # Read SCP forced command word .Lservicecall: stosm .Lpmask-.LPG1(%r13),0x01 # authorize ext interrupts @@ -139,8 +154,6 @@ startup_continue: .int 0x100000 .Lfchunk: - # set program check new psw mask - mvc __LC_PGM_NEW_PSW(8),.Lpcmsk-.LPG1(%r13) # # find memory chunks.