Re: [PATCH v4 1/4] crypto: caam - Prevent crash on suspend with iMX8QM / iMX8ULP

[Peng Fan <peng.fan@oss.nxp.com>]

On Thu, Jun 05, 2025 at 01:28:01PM +0000, John Ernberg wrote:
>Since the CAAM on these SoCs is managed by another ARM core, called the
>SECO (Security Controller) on iMX8QM and Secure Enclave on iMX8ULP, which
>also reserves access to register page 0 suspend operations cannot touch
>this page.
>
>This is similar to when running OPTEE, where OPTEE will reserve page 0.
>
>Track this situation using a new state variable no_page0, reflecting if
>page 0 is reserved elsewhere, either by other management cores in SoC or
>by OPTEE.
>
>Replace the optee_en check in suspend/resume with the new check.
>
>optee_en cannot go away as it's needed elsewhere to gate OPTEE specific
>situations.
>
>Fixes the following splat at suspend:
>
>    Internal error: synchronous external abort: 0000000096000010 [#1] SMP
>    Hardware name: Freescale i.MX8QXP ACU6C (DT)
>    pstate: 60400005 (nZCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
>    pc : readl+0x0/0x18
>    lr : rd_reg32+0x18/0x3c
>    sp : ffffffc08192ba20
>    x29: ffffffc08192ba20 x28: ffffff8025190000 x27: 0000000000000000
>    x26: ffffffc0808ae808 x25: ffffffc080922338 x24: ffffff8020e89090
>    x23: 0000000000000000 x22: ffffffc080922000 x21: ffffff8020e89010
>    x20: ffffffc080387ef8 x19: ffffff8020e89010 x18: 000000005d8000d5
>    x17: 0000000030f35963 x16: 000000008f785f3f x15: 000000003b8ef57c
>    x14: 00000000c418aef8 x13: 00000000f5fea526 x12: 0000000000000001
>    x11: 0000000000000002 x10: 0000000000000001 x9 : 0000000000000000
>    x8 : ffffff8025190870 x7 : ffffff8021726880 x6 : 0000000000000002
>    x5 : ffffff80217268f0 x4 : ffffff8021726880 x3 : ffffffc081200000
>    x2 : 0000000000000001 x1 : ffffff8020e89010 x0 : ffffffc081200004
>    Call trace:
>     readl+0x0/0x18
>     caam_ctrl_suspend+0x30/0xdc
>     dpm_run_callback.constprop.0+0x24/0x5c
>     device_suspend+0x170/0x2e8
>     dpm_suspend+0xa0/0x104
>     dpm_suspend_start+0x48/0x50
>     suspend_devices_and_enter+0x7c/0x45c
>     pm_suspend+0x148/0x160
>     state_store+0xb4/0xf8
>     kobj_attr_store+0x14/0x24
>     sysfs_kf_write+0x38/0x48
>     kernfs_fop_write_iter+0xb4/0x178
>     vfs_write+0x118/0x178
>     ksys_write+0x6c/0xd0
>     __arm64_sys_write+0x14/0x1c
>     invoke_syscall.constprop.0+0x64/0xb0
>     do_el0_svc+0x90/0xb0
>     el0_svc+0x18/0x44
>     el0t_64_sync_handler+0x88/0x124
>     el0t_64_sync+0x150/0x154
>    Code: 88dffc21 88dffc21 5ac00800 d65f03c0 (b9400000)
>
>Fixes: d2835701d93c ("crypto: caam - i.MX8ULP donot have CAAM page0 access")
>Cc: stable@kernel.org # v6.10+
>Signed-off-by: John Ernberg <john.ernberg@actia.se>
>

Reviewed-by: Peng Fan <peng.fan@nxp.com>