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Commit 06ddeadc authored by James Morse's avatar James Morse Committed by Rafael J. Wysocki
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ACPI / APEI: Don't allow ghes_ack_error() to mask earlier errors 



During ghes_proc() we use ghes_ack_error() to tell an external agent
we are done with these records and it can re-use the memory.

rc may hold an error returned by ghes_read_estatus(), ENOENT causes
us to skip ghes_ack_error() (as there is nothing to ack), but rc may
also by EIO, which gets supressed.

ghes_clear_estatus() is where we mark the records as processed for
non GHESv2 error sources, and already spots the ENOENT case as
buf_paddr is set to 0 by ghes_read_estatus().

Move the ghes_ack_error() call in here to avoid extra logic with
the return code in ghes_proc().

This enables GHESv2 acking for NMI-like error sources. This is safe
as the buffer is pre-mapped by map_gen_v2() before the GHES is added
to any NMI handler lists.

This same pre-mapping step means we can't receive an error from
apei_read()/write() here as apei_check_gar() succeeded when it
was mapped, and the mapping was cached, so the address can't be
rejected at runtime. Remove the error-returns as this is now
called from a function with no return.

Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Signed-off-by: default avatarRafael J. Wysocki <rafael.j.wysocki@intel.com>
parent ee2eb3d4

drivers/acpi/apei/ghes.c

+22 −25
Original line number Original line Diff line number Diff line
@@ -197,6 +197,21 @@ static void unmap_gen_v2(struct ghes *ghes) 
	apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);

	apei_unmap_generic_address(&ghes->generic_v2->read_ack_register);

}

}





static void ghes_ack_error(struct acpi_hest_generic_v2 *gv2)

{

	int rc;

	u64 val = 0;



	rc = apei_read(&val, &gv2->read_ack_register);

	if (rc)

		return;



	val &= gv2->read_ack_preserve << gv2->read_ack_register.bit_offset;

	val |= gv2->read_ack_write    << gv2->read_ack_register.bit_offset;



	apei_write(val, &gv2->read_ack_register);

}



static struct ghes *ghes_new(struct acpi_hest_generic *generic)

static struct ghes *ghes_new(struct acpi_hest_generic *generic)

{

{

	struct ghes *ghes;

	struct ghes *ghes;
@@ -361,6 +376,13 @@ static void ghes_clear_estatus(struct ghes *ghes, u64 buf_paddr) 




	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,

	ghes_copy_tofrom_phys(ghes->estatus, buf_paddr,

			      sizeof(ghes->estatus->block_status), 0);

			      sizeof(ghes->estatus->block_status), 0);



	/*

	 * GHESv2 type HEST entries introduce support for error acknowledgment,

	 * so only acknowledge the error if this support is present.

	 */

	if (is_hest_type_generic_v2(ghes))

		ghes_ack_error(ghes->generic_v2);

}

}





static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int sev)

static void ghes_handle_memory_failure(struct acpi_hest_generic_data *gdata, int sev)
@@ -652,21 +674,6 @@ static void ghes_estatus_cache_add( 
	rcu_read_unlock();

	rcu_read_unlock();

}

}





static int ghes_ack_error(struct acpi_hest_generic_v2 *gv2)

{

	int rc;

	u64 val = 0;



	rc = apei_read(&val, &gv2->read_ack_register);

	if (rc)

		return rc;



	val &= gv2->read_ack_preserve << gv2->read_ack_register.bit_offset;

	val |= gv2->read_ack_write    << gv2->read_ack_register.bit_offset;



	return apei_write(val, &gv2->read_ack_register);

}



static void __ghes_panic(struct ghes *ghes, u64 buf_paddr)

static void __ghes_panic(struct ghes *ghes, u64 buf_paddr)

{

{

	__ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus);

	__ghes_print_estatus(KERN_EMERG, ghes->generic, ghes->estatus);
@@ -701,16 +708,6 @@ static int ghes_proc(struct ghes *ghes) 
out:

out:

	ghes_clear_estatus(ghes, buf_paddr);

	ghes_clear_estatus(ghes, buf_paddr);





	if (rc == -ENOENT)

		return rc;



	/*

	 * GHESv2 type HEST entries introduce support for error acknowledgment,

	 * so only acknowledge the error if this support is present.

	 */

	if (is_hest_type_generic_v2(ghes))

		return ghes_ack_error(ghes->generic_v2);



	return rc;

	return rc;

}

}