From: Patrick Rudolph <[email protected]>
Fix a bug where the kernel module can't be loaded after it has been
unloaded as the devices are still present and conflicting with the
to be created coreboot devices.
Signed-off-by: Patrick Rudolph <[email protected]>
---
drivers/firmware/google/coreboot_table.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/drivers/firmware/google/coreboot_table.c b/drivers/firmware/google/coreboot_table.c
index 8d132e4f008a..0205987a4fd4 100644
--- a/drivers/firmware/google/coreboot_table.c
+++ b/drivers/firmware/google/coreboot_table.c
@@ -163,8 +163,15 @@ static int coreboot_table_probe(struct platform_device *pdev)
return ret;
}
+static int __cb_dev_unregister(struct device *dev, void *dummy)
+{
+ device_unregister(dev);
+ return 0;
+}
+
static int coreboot_table_remove(struct platform_device *pdev)
{
+ bus_for_each_dev(&coreboot_bus_type, NULL, NULL, __cb_dev_unregister);
bus_unregister(&coreboot_bus_type);
return 0;
}
--
2.21.0
From: Arthur Heymans <[email protected]>
Fix a bug where the kernel module couldn't be loaded after unloading,
as the platform driver wasn't released on exit.
Signed-off-by: Arthur Heymans <[email protected]>
Signed-off-by: Patrick Rudolph <[email protected]>
---
drivers/firmware/google/gsmi.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c
index edaa4e5d84ad..974c769b75cf 100644
--- a/drivers/firmware/google/gsmi.c
+++ b/drivers/firmware/google/gsmi.c
@@ -1016,6 +1016,9 @@ static __init int gsmi_init(void)
dma_pool_destroy(gsmi_dev.dma_pool);
platform_device_unregister(gsmi_dev.pdev);
pr_info("gsmi: failed to load: %d\n", ret);
+#ifdef CONFIG_PM
+ platform_driver_unregister(&gsmi_driver_info);
+#endif
return ret;
}
@@ -1037,6 +1040,9 @@ static void __exit gsmi_exit(void)
gsmi_buf_free(gsmi_dev.name_buf);
dma_pool_destroy(gsmi_dev.dma_pool);
platform_device_unregister(gsmi_dev.pdev);
+#ifdef CONFIG_PM
+ platform_driver_unregister(&gsmi_driver_info);
+#endif
}
module_init(gsmi_init);
--
2.21.0
From: Arthur Heymans <[email protected]>
Currently this driver is loaded if the DMI string matches coreboot
and has a proper smi_command in the ACPI FADT table, but a GSMI handler in
SMM is an optional feature in coreboot.
So probe for a SMM GSMI handler before initializing the driver.
If the smihandler leaves the calling argument in %eax in the SMM save state
untouched that generally means the is no handler for GSMI.
Signed-off-by: Arthur Heymans <[email protected]>
Signed-off-by: Patrick Rudolph <[email protected]>
---
drivers/firmware/google/gsmi.c | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)
diff --git a/drivers/firmware/google/gsmi.c b/drivers/firmware/google/gsmi.c
index 974c769b75cf..5b2011ebbe26 100644
--- a/drivers/firmware/google/gsmi.c
+++ b/drivers/firmware/google/gsmi.c
@@ -76,6 +76,7 @@
#define GSMI_CMD_LOG_S0IX_RESUME 0x0b
#define GSMI_CMD_CLEAR_CONFIG 0x20
#define GSMI_CMD_HANDSHAKE_TYPE 0xC1
+#define GSMI_CMD_RESERVED 0xff
/* Magic entry type for kernel events */
#define GSMI_LOG_ENTRY_TYPE_KERNEL 0xDEAD
@@ -746,6 +747,7 @@ MODULE_DEVICE_TABLE(dmi, gsmi_dmi_table);
static __init int gsmi_system_valid(void)
{
u32 hash;
+ u16 cmd, result;
if (!dmi_check_system(gsmi_dmi_table))
return -ENODEV;
@@ -780,6 +782,23 @@ static __init int gsmi_system_valid(void)
return -ENODEV;
}
+ /* Test the smihandler with a bogus command. If it leaves the
+ * calling argument in %ax untouched, there is no handler for
+ * GSMI commands.
+ */
+ cmd = GSMI_CALLBACK | GSMI_CMD_RESERVED << 8;
+ asm volatile (
+ "outb %%al, %%dx\n\t"
+ : "=a" (result)
+ : "0" (cmd),
+ "d" (acpi_gbl_FADT.smi_command)
+ : "memory", "cc"
+ );
+ if (cmd == result) {
+ pr_info("gsmi: no gsmi handler in firmware\n");
+ return -ENODEV;
+ }
+
/* Found */
return 0;
}
--
2.21.0
On Mon, Nov 18, 2019 at 09:38:58AM +0100, [email protected] wrote:
> From: Patrick Rudolph <[email protected]>
>
> Fix a bug where the kernel module can't be loaded after it has been
> unloaded as the devices are still present and conflicting with the
> to be created coreboot devices.
>
> Signed-off-by: Patrick Rudolph <[email protected]>
> ---
> drivers/firmware/google/coreboot_table.c | 7 +++++++
> 1 file changed, 7 insertions(+)
You forgot to document what changed from v1 of this patch and/or series
somewhere :(
Usually it just goes below the --- line on each patch.
Can you fix that up and send a v3 of this series?
thanks
greg k-h