Merge: CVE-2024-53072: platform/x86/amd/pmc: Detect when STB is not available

MR: https://gitlab.com/redhat/centos-stream/src/kernel/centos-stream-9/-/merge_requests/5819

JIRA: https://issues.redhat.com/browse/RHEL-68176
CVE: CVE-2024-53072

```
platform/x86/amd/pmc: Detect when STB is not available

Loading the amd_pmc module as:

    amd_pmc enable_stb=1

...can result in the following messages in the kernel ring buffer:

    amd_pmc AMDI0009:00: SMU cmd failed. err: 0xff
    ioremap on RAM at 0x0000000000000000 - 0x0000000000ffffff
    WARNING: CPU: 10 PID: 2151 at arch/x86/mm/ioremap.c:217 __ioremap_caller+0x2cd/0x340

Further debugging reveals that this occurs when the requests for
S2D_PHYS_ADDR_LOW and S2D_PHYS_ADDR_HIGH return a value of 0,
indicating that the STB is inaccessible. To prevent the ioremap
warning and provide clarity to the user, handle the invalid address
and display an error message.

Link: https://lore.kernel.org/platform-driver-x86/c588ff5d-3e04-4549-9a86-284b9b4419ba@amd.com
Fixes: 3d7d407 ("platform/x86: amd-pmc: Add support for AMD Spill to DRAM STB feature")
Acked-by: Shyam Sundar S K <Shyam-sundar.S-k@amd.com>
Signed-off-by: Corey Hickey <bugfood-c@fatooh.org>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20241028180241.1341624-1-bugfood-ml@fatooh.org
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
(cherry picked from commit bceec87)
```

Signed-off-by: CKI Backport Bot <cki-ci-bot+cki-gitlab-backport-bot@redhat.com>

---

<small>Created 2024-11-19 20:59 UTC by backporter - [KWF FAQ](https://red.ht/kernel_workflow_doc) - [Slack #team-kernel-workflow](https://redhat-internal.slack.com/archives/C04LRUPMJQ5) - [Source](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/webhook/utils/backporter.py) - [Documentation](https://gitlab.com/cki-project/kernel-workflow/-/blob/main/docs/README.backporter.md) - [Report an issue](https://gitlab.com/cki-project/kernel-workflow/-/issues/new?issue%5Btitle%5D=backporter%20webhook%20issue)</small>

Approved-by: Tony Camuso <tcamuso@redhat.com>
Approved-by: Steve Best <sbest@redhat.com>
Approved-by: CKI KWF Bot <cki-ci-bot+kwf-gitlab-com@redhat.com>

Merged-by: Rado Vrbovsky <rvrbovsk@redhat.com>

Author: emmil

drivers/platform/x86/amd/pmc/pmc.c

@@ -993,6 +993,11 @@ static int amd_pmc_s2d_init(struct amd_pmc_dev *dev)
 	amd_pmc_send_cmd(dev, S2D_PHYS_ADDR_LOW, &phys_addr_low, dev->s2d_msg_id, true);
 	amd_pmc_send_cmd(dev, S2D_PHYS_ADDR_HIGH, &phys_addr_hi, dev->s2d_msg_id, true);
 
+	if (!phys_addr_hi && !phys_addr_low) {
+		dev_err(dev->dev, "STB is not enabled on the system; disable enable_stb or contact system vendor\n");
+		return -EINVAL;
+	}
+
 	stb_phys_addr = ((u64)phys_addr_hi << 32 | phys_addr_low);
 
 	/* Clear msg_port for other SMU operation */