I'm currently trying to port a Western Digital MyBook Live to
a 4.4.6 kernel. The device has a APM82181 and the board is called
Apollo-3G, which is a derivative of the "amcc,canyonland".
Almost everything is working, except when I try to enable the
ppc4xx-rng in the dts. Then the machine dies with the following:
[ 0.801839] Machine check in kernel mode.
[ 0.805830] Data Read PLB Error
[ 0.808962] Oops: Machine check, sig: 7 [#1]
[ 0.813208] Canyonlands
[ 0.815646] Modules linked in:
[ 0.818710] CPU: 0 PID: 1 Comm: swapper Not tainted 4.4.6 #39
[ 0.824436] task: cf830000 ti: cfff2000 task.ti: cf834000
[ 0.829808] NIP: c01b9a00 LR: c01b99e8 CTR: 00000000
[ 0.834751] REGS: cfff3f10 TRAP: 0214 Not tainted (4.4.6)
[ 0.840382] MSR: 00029000 <CE,EE,ME> CR: 820c3222 XER: 00000000
[ 0.846515]
GPR00: c01b99e8 cf835d50 cf830000 d1080000 d1100000 cf857800 00200000 00000004
GPR08: 00000000 d10e0000 d10e0080 0020051b 820c3428 00000000 c0001c54 00000000
GPR16: 00000000 00000000 00000000 00000000 00000000 00000000 c0420000 c03d7290
GPR24: 00000043 00000000 c044e1cc c03a500f 00000001 00000000 cfffb9b8 00000005
[ 0.876429] NIP [c01b9a00] ppc4xx_rng_enable+0xec/0x12c
[ 0.881634] LR [c01b99e8] ppc4xx_rng_enable+0xd4/0x12c
[ 0.886752] Call Trace:
[ 0.889194] [cf835d50] [c01b99e8] ppc4xx_rng_enable+0xd4/0x12c (unreliable)
[ 0.896141] [cf835db0] [c01b9ab8] ppc4xx_rng_probe+0x2c/0x80
[ 0.901791] [cf835dc0] [c01c0614] platform_drv_probe+0x34/0x70
[ 0.907606] [cf835dd0] [c01beda8] driver_probe_device+0x110/0x264
[ 0.913679] [cf835e00] [c01bef74] __driver_attach+0x78/0xac
[ 0.919243] [cf835e20] [c01bd300] bus_for_each_dev+0x9c/0xac
[ 0.924885] [cf835e50] [c01be49c] bus_add_driver+0xe0/0x1fc
[ 0.930441] [cf835e70] [c01bf688] driver_register+0xb4/0x104
[ 0.936086] [cf835e90] [c0001704] do_one_initcall+0x11c/0x1ac
[ 0.941825] [cf835f00] [c03d7af0] kernel_init_freeable+0x128/0x1c4
[ 0.947989] [cf835f30] [c0001c68] kernel_init+0x14/0x114
[ 0.953288] [cf835f40] [c000a748] ret_from_kernel_thread+0x5c/0x64
[ 0.959449] Instruction dump:
[ 0.962415] 2f9f0004 3bff0001 409effa8 38800000 7fc3f378 4806f6c5 2c030000 41a2ff68
[ 0.970197] 3d230006 39490080 7c0004ac 7d00542c <0c080000> 4c00012c 2f9c0000 550a03da
[ 0.978180] ---[ end trace cff1212128646932 ]---
The crash is caused by a bad read in ppc4xx_rng_enable [0]. From what I
can tell, the driver is mapping the crypto control registers. The
problem is that they are claimed by the main crypto driver: crypto4xx [1].
I'm not sure what to do in this case. In my opinion the crypto4xx driver
should just initialize the trng [see patch]. I would like to move the
trng into the crypto-ppc4xx, but given that this breaks some of the DTS
out there I'm not sure.
Regards,
Christian
---
>From 2159e200fcb68f88a94b1d5570d6000c100133a8 Mon Sep 17 00:00:00 2001
From: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
Date: Fri, 25 Mar 2016 19:00:05 +0100
Subject: [PATCH] ppc4xx-rng: fix crash during init
This patch fixes a crash that happens in the ppc4xx-rng driver
when accessing the main crypto core to enable the true random
number generator.
Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
---
drivers/char/hw_random/ppc4xx-rng.c | 42 ---------------------------------
drivers/crypto/amcc/crypto4xx_core.c | 1 +
drivers/crypto/amcc/crypto4xx_reg_def.h | 1 +
3 files changed, 2 insertions(+), 42 deletions(-)
diff --git a/drivers/char/hw_random/ppc4xx-rng.c b/drivers/char/hw_random/ppc4xx-rng.c
index c0db438..a9a8a29 100644
--- a/drivers/char/hw_random/ppc4xx-rng.c
+++ b/drivers/char/hw_random/ppc4xx-rng.c
@@ -17,9 +17,6 @@
#include <linux/of_platform.h>
#include <asm/io.h>
-#define PPC4XX_TRNG_DEV_CTRL 0x60080
-
-#define PPC4XX_TRNGE 0x00020000
#define PPC4XX_TRNG_CTRL 0x0008
#define PPC4XX_TRNG_CTRL_DALM 0x20
#define PPC4XX_TRNG_STAT 0x0004
@@ -51,40 +48,6 @@ static int ppc4xx_rng_data_read(struct hwrng *rng, u32 *data)
return 4;
}
-static int ppc4xx_rng_enable(int enable)
-{
- struct device_node *ctrl;
- void __iomem *ctrl_reg;
- int err = 0;
- u32 val;
-
- /* Find the main crypto device node and map it to turn the TRNG on */
- ctrl = of_find_compatible_node(NULL, NULL, "amcc,ppc4xx-crypto");
- if (!ctrl)
- return -ENODEV;
-
- ctrl_reg = of_iomap(ctrl, 0);
- if (!ctrl_reg) {
- err = -ENODEV;
- goto out;
- }
-
- val = in_le32(ctrl_reg + PPC4XX_TRNG_DEV_CTRL);
-
- if (enable)
- val |= PPC4XX_TRNGE;
- else
- val = val & ~PPC4XX_TRNGE;
-
- out_le32(ctrl_reg + PPC4XX_TRNG_DEV_CTRL, val);
- iounmap(ctrl_reg);
-
-out:
- of_node_put(ctrl);
-
- return err;
-}
-
static struct hwrng ppc4xx_rng = {
.name = MODULE_NAME,
.data_present = ppc4xx_rng_data_present,
@@ -100,10 +63,6 @@ static int ppc4xx_rng_probe(struct platform_device *dev)
if (!rng_regs)
return -ENODEV;
- err = ppc4xx_rng_enable(1);
- if (err)
- return err;
-
out_le32(rng_regs + PPC4XX_TRNG_CTRL, PPC4XX_TRNG_CTRL_DALM);
ppc4xx_rng.priv = (unsigned long) rng_regs;
@@ -117,7 +76,6 @@ static int ppc4xx_rng_remove(struct platform_device *dev)
void __iomem *rng_regs = (void __iomem *) ppc4xx_rng.priv;
hwrng_unregister(&ppc4xx_rng);
- ppc4xx_rng_enable(0);
iounmap(rng_regs);
return 0;
diff --git a/drivers/crypto/amcc/crypto4xx_core.c b/drivers/crypto/amcc/crypto4xx_core.c
index 62134c8..cb0b262 100644
--- a/drivers/crypto/amcc/crypto4xx_core.c
+++ b/drivers/crypto/amcc/crypto4xx_core.c
@@ -90,6 +90,7 @@ static void crypto4xx_hw_init(struct crypto4xx_device *dev)
writel(ring_ctrl.w, dev->ce_base + CRYPTO4XX_RING_CTRL);
device_ctrl = readl(dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
device_ctrl |= PPC4XX_DC_3DES_EN;
+ device_ctrl |= PPC4XX_TRNGE;
writel(device_ctrl, dev->ce_base + CRYPTO4XX_DEVICE_CTRL);
writel(dev->gdr_pa, dev->ce_base + CRYPTO4XX_GATH_RING_BASE);
writel(dev->sdr_pa, dev->ce_base + CRYPTO4XX_SCAT_RING_BASE);
diff --git a/drivers/crypto/amcc/crypto4xx_reg_def.h b/drivers/crypto/amcc/crypto4xx_reg_def.h
index 5f5fbc0..914efc6 100644
--- a/drivers/crypto/amcc/crypto4xx_reg_def.h
+++ b/drivers/crypto/amcc/crypto4xx_reg_def.h
@@ -124,6 +124,7 @@
#define PPC4XX_BYTE_ORDER 0x22222
#define PPC4XX_INTERRUPT_CLR 0x3ffff
#define PPC4XX_PRNG_CTRL_AUTO_EN 0x3
+#define PPC4XX_TRNGE 0x00020000
#define PPC4XX_DC_3DES_EN 1
#define PPC4XX_INT_DESCR_CNT 4
#define PPC4XX_INT_TIMEOUT_CNT 0
--
2.8.0.rc3
[0] <http://lxr.free-electrons.com/source/drivers/char/hw_random/ppc4xx-rng.c#L72>
[1] <http://lxr.free-electrons.com/source/drivers/crypto/amcc/>
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