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From:   Qian Cai <cai@lca.pw>
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Subject: ioremap() called early from pnv_pci_init_ioda_phb()
Message-Id: <B183CDAA-DA88-4760-9C1B-F73A8F7840E7@lca.pw>
Date:   Fri, 8 May 2020 10:39:09 -0400
Cc:     linuxppc-dev <linuxppc-dev@lists.ozlabs.org>,
        LKML <linux-kernel@vger.kernel.org>
To:     Christophe Leroy <christophe.leroy@c-s.fr>,
        Michael Ellerman <mpe@ellerman.id.au>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

 Booting POWER9 PowerNV has this message,
   =20
"ioremap() called early from pnv_pci_init_ioda_phb+0x420/0xdfc. Use =
early_ioremap() instead=E2=80=9D

but use the patch below will result in leaks because it will never call =
early_iounmap() anywhere. However, it looks me it was by design that =
phb->regs mapping would be there forever where it would be used in =
pnv_ioda_get_inval_reg(), so is just that check_early_ioremap_leak() =
initcall too strong?

--- a/arch/powerpc/platforms/powernv/pci-ioda.c
+++ b/arch/powerpc/platforms/powernv/pci-ioda.c
@@ -36,6 +36,7 @@
 #include <asm/firmware.h>
 #include <asm/pnv-pci.h>
 #include <asm/mmzone.h>
+#include <asm/early_ioremap.h>
=20
 #include <misc/cxl-base.h>
=20
@@ -3827,7 +3828,7 @@ static void __init pnv_pci_init_ioda_phb(struct =
device_node *np,
        /* Get registers */
        if (!of_address_to_resource(np, 0, &r)) {
                phb->regs_phys =3D r.start;
-               phb->regs =3D ioremap(r.start, resource_size(&r));
+               phb->regs =3D early_ioremap(r.start, resource_size(&r));
                if (phb->regs =3D=3D NULL)
                        pr_err("  Failed to map registers !\n=E2=80=9D);

[   23.080069][    T1] ------------[ cut here ]------------
[   23.080089][    T1] Debug warning: early ioremap leak of 10 areas =
detected.
[   23.080089][    T1] please boot with early_ioremap_debug and report =
the dmesg.
[   23.080157][    T1] WARNING: CPU: 4 PID: 1 at mm/early_ioremap.c:99 =
check_early_ioremap_leak+0xd4/0x108
[   23.080171][    T1] Modules linked in:
[   23.080192][    T1] CPU: 4 PID: 1 Comm: swapper/0 Not tainted =
5.7.0-rc4-next-20200508+ #4
[   23.080214][    T1] NIP:  c00000000103f2d8 LR: c00000000103f2d4 CTR: =
0000000000000000
[   23.080226][    T1] REGS: c00000003df0f860 TRAP: 0700   Not tainted  =
(5.7.0-rc4-next-20200508+)
[   23.080259][    T1] MSR:  9000000000029033 <SF,HV,EE,ME,IR,DR,RI,LE>  =
CR: 48000222  XER: 20040000
[   23.080296][    T1] CFAR: c00000000010d5a8 IRQMASK: 0=20
[   23.080296][    T1] GPR00: c00000000103f2d4 c00000003df0faf0 =
c000000001689400 0000000000000072=20
[   23.080296][    T1] GPR04: 0000000000000006 0000000000000000 =
c00000003df0f7e4 0000000000000004=20
[   23.080296][    T1] GPR08: 0000001ffbb60000 0000000000000000 =
c00000003dee6680 0000000000000002=20
[   23.080296][    T1] GPR12: 0000000000000000 c000001fffffae00 =
c000000001057860 c0000000010578b0=20
[   23.080296][    T1] GPR16: c000000001002d38 c0000000014f0660 =
c0000000014f0680 c0000000014f06a0=20
[   23.080296][    T1] GPR20: c0000000014f06c0 c0000000014f06e0 =
c0000000014f0700 c0000000014f0720=20
[   23.080296][    T1] GPR24: c000000000c4bc30 c000000486b82000 =
c0000000015a0fe0 c0000000015a0fc0=20
[   23.080296][    T1] GPR28: 0000000000000010 0000000000000010 =
c000000001061e30 000000000000000a=20
[   23.080507][    T1] NIP [c00000000103f2d8] =
check_early_ioremap_leak+0xd4/0x108
[   23.080530][    T1] LR [c00000000103f2d4] =
check_early_ioremap_leak+0xd0/0x108
[   23.080552][    T1] Call Trace:
[   23.080571][    T1] [c00000003df0faf0] [c00000000103f2d4] =
check_early_ioremap_leak+0xd0/0x108 (unreliable)
[   23.080607][    T1] [c00000003df0fb80] [c00000000001130c] =
do_one_initcall+0xcc/0x660
[   23.080648][    T1] [c00000003df0fc80] [c000000001004c18] =
kernel_init_freeable+0x480/0x568
[   23.080681][    T1] [c00000003df0fdb0] [c000000000012180] =
kernel_init+0x24/0x194
[   23.080713][    T1] [c00000003df0fe20] [c00000000000cb28] =
ret_from_kernel_thread+0x5c/0x74

This is from the early_ioremap_debug dmesg.

[    0.000000][    T0] ------------[ cut here ]------------
[    0.000000][    T0] __early_ioremap(0x000600c3c0010000, 00010000) [0] =
=3D> 00000000 + ffffffffffbe0000
[    0.000000][    T0] WARNING: CPU: 0 PID: 0 at mm/early_ioremap.c:162 =
__early_ioremap+0x2d8/0x408
[    0.000000][    T0] Modules linked in:
[    0.000000][    T0] CPU: 0 PID: 0 Comm: swapper Not tainted =
5.7.0-rc4-next-20200508+ #4
[    0.000000][    T0] NIP:  c00000000103f5e4 LR: c00000000103f5e0 CTR: =
c0000000001e77f0
[    0.000000][    T0] REGS: c00000000168f980 TRAP: 0700   Not tainted  =
(5.7.0-rc4-next-20200508+)
[    0.000000][    T0] MSR:  9000000000021033 <SF,HV,ME,IR,DR,RI,LE>  =
CR: 28000248  XER: 20040000
[    0.000000][    T0] CFAR: c00000000010d5a8 IRQMASK: 1=20
[    0.000000][    T0] GPR00: c00000000103f5e0 c00000000168fc10 =
c000000001689400 0000000000000050=20
[    0.000000][    T0] GPR04: c00000000152f6f8 0000000000000000 =
c00000000168f904 0000000000000000=20
[    0.000000][    T0] GPR08: 0000000000000000 0000000000000000 =
c00000000162f600 0000000000000002=20
[    0.000000][    T0] GPR12: c0000000001e77f0 c000000005b30000 =
0000000000000000 0000000000000000=20
[    0.000000][    T0] GPR16: 0000000000000000 0000000000000000 =
0000000000000000 0000000000001000=20
[    0.000000][    T0] GPR20: 0000000000000000 80000000000001ae =
0000000000000000 0000000000000000=20
[    0.000000][    T0] GPR24: 0000000000010000 c000000001061da8 =
0000000000000008 0000000000000008=20
[    0.000000][    T0] GPR28: 0000000000000000 c000000001061db0 =
0000000000000000 c000000001061eb8=20
[    0.000000][    T0] NIP [c00000000103f5e4] =
__early_ioremap+0x2d8/0x408
[    0.000000][    T0] LR [c00000000103f5e0] __early_ioremap+0x2d4/0x408
[    0.000000][    T0] Call Trace:
[    0.000000][    T0] [c00000000168fc10] [c00000000103f5e0] =
__early_ioremap+0x2d4/0x408 (unreliable)
[    0.000000][    T0] [c00000000168fcf0] [c00000000101d010] =
pnv_pci_init_ioda_phb+0x420/0xdfc
[    0.000000][    T0] [c00000000168fe10] [c00000000101c9b8] =
pnv_pci_init+0x12c/0x264
[    0.000000][    T0] [c00000000168fe40] [c000000001016c40] =
pnv_setup_arch+0x2e4/0x330
[    0.000000][    T0] [c00000000168fe80] [c000000001009dd0] =
setup_arch+0x3a0/0x3ec
[    0.000000][    T0] [c00000000168fef0] [c000000001003ed0] =
start_kernel+0xb0/0x978
[    0.000000][    T0] [c00000000168ff90] [c00000000000c790] =
start_here_common+0x1c/0x8c
[    0.000000][    T0] Instruction dump:
[    0.000000][    T0] 7d39ba14 3c82ff3c 3c62ff54 7f06c378 7f88e378 =
7fc7f378 38a10068 e9290110=20
[    0.000000][    T0] 38849e90 3863e8f0 4b0cdf65 60000000 <0fe00000> =
2bbe000f 409d0018 3c62fff1=20
[    0.000000][    T0] irq event stamp: 0
[    0.000000][    T0] hardirqs last  enabled at (0): =
[<0000000000000000>] 0x0
[    0.000000][    T0] hardirqs last disabled at (0): =
[<0000000000000000>] 0x0
[    0.000000][    T0] softirqs last  enabled at (0): =
[<0000000000000000>] 0x0
[    0.000000][    T0] softirqs last disabled at (0): =
[<0000000000000000>] 0x0