linux/drivers/firmware/psci.c

470 lines
11 KiB

drivers: psci: make PSCI 1.0 functions initialization version dependent The PSCI specifications [1] and the SMC calling convention mandate that unimplemented functions ids must return NOT_SUPPORTED (0xffffffff) if a function id is called but it is not implemented. Consequently, PSCI 1.0 function ids that require the 1.0 PSCI_FEATURES call to be initialized: CPU_SUSPEND (psci_init_cpu_suspend()) SYSTEM_SUSPEND (psci_init_system_suspend()) call the PSCI_FEATURES function id independently of the detected PSCI firmware version, since, if the PSCI_FEATURES function id is not implemented, it must return NOT_SUPPORTED according to the PSCI specifications, causing the initialization functions to fail as expected. Some existing PSCI implementations (ie Qemu PSCI emulation), do not comply with the SMC calling convention and fail if function ids that are not implemented are called from the OS, causing boot failures. To solve this issue, this patch adds code that checks the PSCI firmware version before calling PSCI 1.0 initialization functions so that the OS makes sure that it is calling 1.0 functions only if the firmware version detected is 1.0 or greater, therefore avoiding PSCI calls that are bound to fail and might cause system boot failures owing to non-compliant PSCI firmware implementations. [1] http://infocenter.arm.com/help/topic/com.arm.doc.den0022c/DEN0022C_Power_State_Coordination_Interface.pdf Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Mark Rutland <mark.rutland@arm.com> Tested-by: Kevin Hilman <khilman@kernel.org> Acked-by: Sudeep Holla <sudeep.holla@arm.com> Signed-off-by: Olof Johansson <olof@lixom.net>
2015-10-23 15:46:50 +01:00
Merge branch 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm Pull ARM development updates from Russell King: "Included in this update: - moving PSCI code from ARM64/ARM to drivers/ - removal of some architecture internals from global kernel view - addition of software based "privileged no access" support using the old domains register to turn off the ability for kernel loads/stores to access userspace. Only the proper accessors will be usable. - addition of early fixup support for early console - re-addition (and reimplementation) of OMAP special interconnect barrier - removal of finish_arch_switch() - only expose cpuX/online in sysfs if hotpluggable - a number of code cleanups" * 'for-linus' of git://ftp.arm.linux.org.uk/~rmk/linux-arm: (41 commits) ARM: software-based priviledged-no-access support ARM: entry: provide uaccess assembly macro hooks ARM: entry: get rid of multiple macro definitions ARM: 8421/1: smp: Collapse arch_cpu_idle_dead() into cpu_die() ARM: uaccess: provide uaccess_save_and_enable() and uaccess_restore() ARM: mm: improve do_ldrd_abort macro ARM: entry: ensure that IRQs are enabled when calling syscall_trace_exit() ARM: entry: efficiency cleanups ARM: entry: get rid of asm_trace_hardirqs_on_cond ARM: uaccess: simplify user access assembly ARM: domains: remove DOMAIN_TABLE ARM: domains: keep vectors in separate domain ARM: domains: get rid of manager mode for user domain ARM: domains: move initial domain setting value to asm/domains.h ARM: domains: provide domain_mask() ARM: domains: switch to keeping domain value in register ARM: 8419/1: dma-mapping: harmonize definition of DMA_ERROR_CODE ARM: 8417/1: refactor bitops functions with BIT_MASK() and BIT_WORD() ARM: 8416/1: Feroceon: use of_iomap() to map register base ARM: 8415/1: early fixmap support for earlycon ...
2015-09-03 16:27:01 -07:00