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MIPS: smp-cps: rework core/VPE initialisation

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When hotplug and/or a powered down idle state are supported cases will
arise where a non-zero VPE must be brought online without VPE 0, and it
where multiple VPEs must be onlined simultaneously. This patch prepares
for that by:

  - Splitting struct boot_config into core & VPE boot config structures,
    allocated one per core or VPE respectively. This allows for multiple
    VPEs to be onlined simultaneously without clobbering each others
    configuration.

  - Indicating which VPEs should be online within a core at any given
    time using a bitmap. This allows multiple VPEs to be brought online
    simultaneously and also indicates to VPE 0 whether it should halt
    after starting any non-zero VPEs that should be online within the
    core. For example if all VPEs within a core are offlined via hotplug
    and the user onlines the second VPE within that core:

      1) The core will be powered up.

      2) VPE 0 will run from the BEV (ie. mips_cps_core_entry) to
         initialise the core.

      3) VPE 0 will start VPE 1 because its bit is set in the cores
         bitmap.

      4) VPE 0 will halt itself because its bit is clear in the cores
         bitmap.

  - Moving the core & VPE initialisation to assembly code which does not
    make any use of the stack. This is because if a non-zero VPE is to
    be brought online in a powered down core then when VPE 0 of that
    core runs it may not have a valid stack, and even if it did then
    it's messy to run through parts of generic kernel code on VPE 0
    before starting the correct VPE.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
This commit is contained in:
Paul Burton
2014-04-14 12:04:27 +01:00
parent d674dd14e8
commit 245a7868d2
5 changed files with 374 additions and 161 deletions
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14
arch/mips/kernel/asm-offsets.c
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@@ -487,10 +487,14 @@ void output_kvm_defines(void)
void output_cps_defines(void)
{
COMMENT(" MIPS CPS offsets. ");
OFFSET(BOOTCFG_CORE, boot_config, core);
OFFSET(BOOTCFG_VPE, boot_config, vpe);
OFFSET(BOOTCFG_PC, boot_config, pc);
OFFSET(BOOTCFG_SP, boot_config, sp);
OFFSET(BOOTCFG_GP, boot_config, gp);
OFFSET(COREBOOTCFG_VPEMASK, core_boot_config, vpe_mask);
OFFSET(COREBOOTCFG_VPECONFIG, core_boot_config, vpe_config);
DEFINE(COREBOOTCFG_SIZE, sizeof(struct core_boot_config));
OFFSET(VPEBOOTCFG_PC, vpe_boot_config, pc);
OFFSET(VPEBOOTCFG_SP, vpe_boot_config, sp);
OFFSET(VPEBOOTCFG_GP, vpe_boot_config, gp);
DEFINE(VPEBOOTCFG_SIZE, sizeof(struct vpe_boot_config));
}
#endif