Commit 677a60bd authored by James Morse's avatar James Morse Committed by Catalin Marinas
Browse files

firmware: arm_sdei: Discover SDEI support via ACPI 



SDEI defines a new ACPI table to indicate the presence of the interface.
The conduit is discovered in the same way as PSCI.

For ACPI we need to create the platform device ourselves as SDEI doesn't
have an entry in the DSDT.

The SDEI platform device should be created after ACPI has been initialised
so that we can parse the table, but before GHES devices are created, which
may register SDE events if they use SDEI as their notification type.

Reviewed-by: default avatarLorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: default avatarJames Morse <james.morse@arm.com>
Acked-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
parent fa31ab77

drivers/firmware/arm_sdei.c

+40 −1
Original line number Diff line number Diff line
@@ -908,6 +908,14 @@ static int sdei_get_conduit(struct platform_device *pdev) 
		}



		pr_warn("invalid \"method\" property: %s\n", method);

	} else if (IS_ENABLED(CONFIG_ACPI) && !acpi_disabled) {

		if (acpi_psci_use_hvc()) {

			sdei_firmware_call = &sdei_smccc_hvc;

			return CONDUIT_HVC;

		} else {

			sdei_firmware_call = &sdei_smccc_smc;

			return CONDUIT_SMC;

		}

	}



	return CONDUIT_INVALID;
@@ -1021,14 +1029,45 @@ static bool __init sdei_present_dt(void) 
	return true;

}



static bool __init sdei_present_acpi(void)

{

	acpi_status status;

	struct platform_device *pdev;

	struct acpi_table_header *sdei_table_header;



	if (acpi_disabled)

		return false;



	status = acpi_get_table(ACPI_SIG_SDEI, 0, &sdei_table_header);

	if (ACPI_FAILURE(status) && status != AE_NOT_FOUND) {

		const char *msg = acpi_format_exception(status);



		pr_info("Failed to get ACPI:SDEI table, %s\n", msg);

	}

	if (ACPI_FAILURE(status))

		return false;



	pdev = platform_device_register_simple(sdei_driver.driver.name, 0, NULL,

					       0);

	if (IS_ERR(pdev))

		return false;



	return true;

}



static int __init sdei_init(void)

{

	if (sdei_present_dt())

	if (sdei_present_dt() || sdei_present_acpi())

		platform_driver_register(&sdei_driver);



	return 0;

}



/*

 * On an ACPI system SDEI needs to be ready before HEST:GHES tries to register

 * its events. ACPI is initialised from a subsys_initcall(), GHES is initialised

 * by device_initcall(). We want to be called in the middle.

 */

subsys_initcall_sync(sdei_init);



int sdei_event_handler(struct pt_regs *regs,

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