diff options
Diffstat (limited to 'arch/powerpc/lib/feature-fixups.c')
| -rw-r--r-- | arch/powerpc/lib/feature-fixups.c | 52 |
1 files changed, 48 insertions, 4 deletions
diff --git a/arch/powerpc/lib/feature-fixups.c b/arch/powerpc/lib/feature-fixups.c index 4537459d012f..cda17bee5afe 100644 --- a/arch/powerpc/lib/feature-fixups.c +++ b/arch/powerpc/lib/feature-fixups.c @@ -17,6 +17,7 @@ #include <linux/stop_machine.h> #include <asm/cputable.h> #include <asm/code-patching.h> +#include <asm/interrupt.h> #include <asm/page.h> #include <asm/sections.h> #include <asm/setup.h> @@ -225,6 +226,9 @@ static void do_stf_exit_barrier_fixups(enum stf_barrier_type types) : "unknown"); } +static bool stf_exit_reentrant = false; +static bool rfi_exit_reentrant = false; + static int __do_stf_barrier_fixups(void *data) { enum stf_barrier_type *types = data; @@ -239,11 +243,27 @@ void do_stf_barrier_fixups(enum stf_barrier_type types) { /* * The call to the fallback entry flush, and the fallback/sync-ori exit - * flush can not be safely patched in/out while other CPUs are executing - * them. So call __do_stf_barrier_fixups() on one CPU while all other CPUs - * spin in the stop machine core with interrupts hard disabled. + * flush can not be safely patched in/out while other CPUs are + * executing them. So call __do_stf_barrier_fixups() on one CPU while + * all other CPUs spin in the stop machine core with interrupts hard + * disabled. + * + * The branch to mark interrupt exits non-reentrant is enabled first, + * then stop_machine runs which will ensure all CPUs are out of the + * low level interrupt exit code before patching. After the patching, + * if allowed, then flip the branch to allow fast exits. */ + static_branch_enable(&interrupt_exit_not_reentrant); + stop_machine(__do_stf_barrier_fixups, &types, NULL); + + if ((types & STF_BARRIER_FALLBACK) || (types & STF_BARRIER_SYNC_ORI)) + stf_exit_reentrant = false; + else + stf_exit_reentrant = true; + + if (stf_exit_reentrant && rfi_exit_reentrant) + static_branch_disable(&interrupt_exit_not_reentrant); } void do_uaccess_flush_fixups(enum l1d_flush_type types) @@ -409,8 +429,9 @@ void do_entry_flush_fixups(enum l1d_flush_type types) stop_machine(__do_entry_flush_fixups, &types, NULL); } -void do_rfi_flush_fixups(enum l1d_flush_type types) +static int __do_rfi_flush_fixups(void *data) { + enum l1d_flush_type types = *(enum l1d_flush_type *)data; unsigned int instrs[3], *dest; long *start, *end; int i; @@ -453,6 +474,29 @@ void do_rfi_flush_fixups(enum l1d_flush_type types) : "ori type" : (types & L1D_FLUSH_MTTRIG) ? "mttrig type" : "unknown"); + + return 0; +} + +void do_rfi_flush_fixups(enum l1d_flush_type types) +{ + /* + * stop_machine gets all CPUs out of the interrupt exit handler same + * as do_stf_barrier_fixups. do_rfi_flush_fixups patching can run + * without stop_machine, so this could be achieved with a broadcast + * IPI instead, but this matches the stf sequence. + */ + static_branch_enable(&interrupt_exit_not_reentrant); + + stop_machine(__do_rfi_flush_fixups, &types, NULL); + + if (types & L1D_FLUSH_FALLBACK) + rfi_exit_reentrant = false; + else + rfi_exit_reentrant = true; + + if (stf_exit_reentrant && rfi_exit_reentrant) + static_branch_disable(&interrupt_exit_not_reentrant); } void do_barrier_nospec_fixups_range(bool enable, void *fixup_start, void *fixup_end) |