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-rw-r--r--arch/powerpc/kernel/asm-offsets.c5
-rw-r--r--arch/powerpc/kernel/entry_64.S44
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S137
-rw-r--r--arch/powerpc/kernel/setup_64.c101
-rw-r--r--arch/powerpc/kernel/vmlinux.lds.S9
5 files changed, 275 insertions, 21 deletions
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c
index 6b958414b4e0..f390d57cf2e1 100644
--- a/arch/powerpc/kernel/asm-offsets.c
+++ b/arch/powerpc/kernel/asm-offsets.c
@@ -237,6 +237,11 @@ int main(void)
OFFSET(PACA_NMI_EMERG_SP, paca_struct, nmi_emergency_sp);
OFFSET(PACA_IN_MCE, paca_struct, in_mce);
OFFSET(PACA_IN_NMI, paca_struct, in_nmi);
+ OFFSET(PACA_RFI_FLUSH_FALLBACK_AREA, paca_struct, rfi_flush_fallback_area);
+ OFFSET(PACA_EXRFI, paca_struct, exrfi);
+ OFFSET(PACA_L1D_FLUSH_CONGRUENCE, paca_struct, l1d_flush_congruence);
+ OFFSET(PACA_L1D_FLUSH_SETS, paca_struct, l1d_flush_sets);
+
#endif
OFFSET(PACAHWCPUID, paca_struct, hw_cpu_id);
OFFSET(PACAKEXECSTATE, paca_struct, kexec_state);
diff --git a/arch/powerpc/kernel/entry_64.S b/arch/powerpc/kernel/entry_64.S
index 3320bcac7192..2748584b767d 100644
--- a/arch/powerpc/kernel/entry_64.S
+++ b/arch/powerpc/kernel/entry_64.S
@@ -37,6 +37,11 @@
#include <asm/tm.h>
#include <asm/ppc-opcode.h>
#include <asm/export.h>
+#ifdef CONFIG_PPC_BOOK3S
+#include <asm/exception-64s.h>
+#else
+#include <asm/exception-64e.h>
+#endif
/*
* System calls.
@@ -262,13 +267,23 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ld r13,GPR13(r1) /* only restore r13 if returning to usermode */
+ ld r2,GPR2(r1)
+ ld r1,GPR1(r1)
+ mtlr r4
+ mtcr r5
+ mtspr SPRN_SRR0,r7
+ mtspr SPRN_SRR1,r8
+ RFI_TO_USER
+ b . /* prevent speculative execution */
+
+ /* exit to kernel */
1: ld r2,GPR2(r1)
ld r1,GPR1(r1)
mtlr r4
mtcr r5
mtspr SPRN_SRR0,r7
mtspr SPRN_SRR1,r8
- RFI
+ RFI_TO_KERNEL
b . /* prevent speculative execution */
.Lsyscall_error:
@@ -397,8 +412,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
mtmsrd r10, 1
mtspr SPRN_SRR0, r11
mtspr SPRN_SRR1, r12
-
- rfid
+ RFI_TO_USER
b . /* prevent speculative execution */
#endif
_ASM_NOKPROBE_SYMBOL(system_call_common);
@@ -878,7 +892,7 @@ BEGIN_FTR_SECTION
END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ACCOUNT_CPU_USER_EXIT(r13, r2, r4)
REST_GPR(13, r1)
-1:
+
mtspr SPRN_SRR1,r3
ld r2,_CCR(r1)
@@ -891,8 +905,22 @@ END_FTR_SECTION_IFSET(CPU_FTR_HAS_PPR)
ld r3,GPR3(r1)
ld r4,GPR4(r1)
ld r1,GPR1(r1)
+ RFI_TO_USER
+ b . /* prevent speculative execution */
- rfid
+1: mtspr SPRN_SRR1,r3
+
+ ld r2,_CCR(r1)
+ mtcrf 0xFF,r2
+ ld r2,_NIP(r1)
+ mtspr SPRN_SRR0,r2
+
+ ld r0,GPR0(r1)
+ ld r2,GPR2(r1)
+ ld r3,GPR3(r1)
+ ld r4,GPR4(r1)
+ ld r1,GPR1(r1)
+ RFI_TO_KERNEL
b . /* prevent speculative execution */
#endif /* CONFIG_PPC_BOOK3E */
@@ -1073,7 +1101,7 @@ __enter_rtas:
mtspr SPRN_SRR0,r5
mtspr SPRN_SRR1,r6
- rfid
+ RFI_TO_KERNEL
b . /* prevent speculative execution */
rtas_return_loc:
@@ -1098,7 +1126,7 @@ rtas_return_loc:
mtspr SPRN_SRR0,r3
mtspr SPRN_SRR1,r4
- rfid
+ RFI_TO_KERNEL
b . /* prevent speculative execution */
_ASM_NOKPROBE_SYMBOL(__enter_rtas)
_ASM_NOKPROBE_SYMBOL(rtas_return_loc)
@@ -1171,7 +1199,7 @@ _GLOBAL(enter_prom)
LOAD_REG_IMMEDIATE(r12, MSR_SF | MSR_ISF | MSR_LE)
andc r11,r11,r12
mtsrr1 r11
- rfid
+ RFI_TO_KERNEL
#endif /* CONFIG_PPC_BOOK3E */
1: /* Return from OF */
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index e441b469dc8f..2dc10bf646b8 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -256,7 +256,7 @@ BEGIN_FTR_SECTION
LOAD_HANDLER(r12, machine_check_handle_early)
1: mtspr SPRN_SRR0,r12
mtspr SPRN_SRR1,r11
- rfid
+ RFI_TO_KERNEL
b . /* prevent speculative execution */
2:
/* Stack overflow. Stay on emergency stack and panic.
@@ -445,7 +445,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
li r3,MSR_ME
andc r10,r10,r3 /* Turn off MSR_ME */
mtspr SPRN_SRR1,r10
- rfid
+ RFI_TO_KERNEL
b .
2:
/*
@@ -463,7 +463,7 @@ EXC_COMMON_BEGIN(machine_check_handle_early)
*/
bl machine_check_queue_event
MACHINE_CHECK_HANDLER_WINDUP
- rfid
+ RFI_TO_USER_OR_KERNEL
9:
/* Deliver the machine check to host kernel in V mode. */
MACHINE_CHECK_HANDLER_WINDUP
@@ -598,6 +598,9 @@ EXC_COMMON_BEGIN(slb_miss_common)
stw r9,PACA_EXSLB+EX_CCR(r13) /* save CR in exc. frame */
std r10,PACA_EXSLB+EX_LR(r13) /* save LR */
+ andi. r9,r11,MSR_PR // Check for exception from userspace
+ cmpdi cr4,r9,MSR_PR // And save the result in CR4 for later
+
/*
* Test MSR_RI before calling slb_allocate_realmode, because the
* MSR in r11 gets clobbered. However we still want to allocate
@@ -624,9 +627,12 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
/* All done -- return from exception. */
+ bne cr4,1f /* returning to kernel */
+
.machine push
.machine "power4"
mtcrf 0x80,r9
+ mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */
mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */
mtcrf 0x02,r9 /* I/D indication is in cr6 */
mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */
@@ -640,9 +646,30 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
ld r11,PACA_EXSLB+EX_R11(r13)
ld r12,PACA_EXSLB+EX_R12(r13)
ld r13,PACA_EXSLB+EX_R13(r13)
- rfid
+ RFI_TO_USER
+ b . /* prevent speculative execution */
+1:
+.machine push
+.machine "power4"
+ mtcrf 0x80,r9
+ mtcrf 0x08,r9 /* MSR[PR] indication is in cr4 */
+ mtcrf 0x04,r9 /* MSR[RI] indication is in cr5 */
+ mtcrf 0x02,r9 /* I/D indication is in cr6 */
+ mtcrf 0x01,r9 /* slb_allocate uses cr0 and cr7 */
+.machine pop
+
+ RESTORE_CTR(r9, PACA_EXSLB)
+ RESTORE_PPR_PACA(PACA_EXSLB, r9)
+ mr r3,r12
+ ld r9,PACA_EXSLB+EX_R9(r13)
+ ld r10,PACA_EXSLB+EX_R10(r13)
+ ld r11,PACA_EXSLB+EX_R11(r13)
+ ld r12,PACA_EXSLB+EX_R12(r13)
+ ld r13,PACA_EXSLB+EX_R13(r13)
+ RFI_TO_KERNEL
b . /* prevent speculative execution */
+
2: std r3,PACA_EXSLB+EX_DAR(r13)
mr r3,r12
mfspr r11,SPRN_SRR0
@@ -651,7 +678,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
mtspr SPRN_SRR0,r10
ld r10,PACAKMSR(r13)
mtspr SPRN_SRR1,r10
- rfid
+ RFI_TO_KERNEL
b .
8: std r3,PACA_EXSLB+EX_DAR(r13)
@@ -662,7 +689,7 @@ END_MMU_FTR_SECTION_IFCLR(MMU_FTR_TYPE_RADIX)
mtspr SPRN_SRR0,r10
ld r10,PACAKMSR(r13)
mtspr SPRN_SRR1,r10
- rfid
+ RFI_TO_KERNEL
b .
EXC_COMMON_BEGIN(unrecov_slb)
@@ -901,7 +928,7 @@ EXC_COMMON(trap_0b_common, 0xb00, unknown_exception)
mtspr SPRN_SRR0,r10 ; \
ld r10,PACAKMSR(r13) ; \
mtspr SPRN_SRR1,r10 ; \
- rfid ; \
+ RFI_TO_KERNEL ; \
b . ; /* prevent speculative execution */
#ifdef CONFIG_PPC_FAST_ENDIAN_SWITCH
@@ -917,7 +944,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_REAL_LE) \
xori r12,r12,MSR_LE ; \
mtspr SPRN_SRR1,r12 ; \
mr r13,r9 ; \
- rfid ; /* return to userspace */ \
+ RFI_TO_USER ; /* return to userspace */ \
b . ; /* prevent speculative execution */
#else
#define SYSCALL_FASTENDIAN_TEST
@@ -1063,7 +1090,7 @@ TRAMP_REAL_BEGIN(hmi_exception_early)
mtcr r11
REST_GPR(11, r1)
ld r1,GPR1(r1)
- hrfid
+ HRFI_TO_USER_OR_KERNEL
1: mtcr r11
REST_GPR(11, r1)
@@ -1314,7 +1341,7 @@ END_FTR_SECTION_IFSET(CPU_FTR_CFAR)
ld r11,PACA_EXGEN+EX_R11(r13)
ld r12,PACA_EXGEN+EX_R12(r13)
ld r13,PACA_EXGEN+EX_R13(r13)
- HRFID
+ HRFI_TO_UNKNOWN
b .
#endif
@@ -1418,10 +1445,94 @@ masked_##_H##interrupt: \
ld r10,PACA_EXGEN+EX_R10(r13); \
ld r11,PACA_EXGEN+EX_R11(r13); \
/* returns to kernel where r13 must be set up, so don't restore it */ \
- ##_H##rfid; \
+ ##_H##RFI_TO_KERNEL; \
b .; \
MASKED_DEC_HANDLER(_H)
+TRAMP_REAL_BEGIN(rfi_flush_fallback)
+ SET_SCRATCH0(r13);
+ GET_PACA(r13);
+ std r9,PACA_EXRFI+EX_R9(r13)
+ std r10,PACA_EXRFI+EX_R10(r13)
+ std r11,PACA_EXRFI+EX_R11(r13)
+ std r12,PACA_EXRFI+EX_R12(r13)
+ std r8,PACA_EXRFI+EX_R13(r13)
+ mfctr r9
+ ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
+ ld r11,PACA_L1D_FLUSH_SETS(r13)
+ ld r12,PACA_L1D_FLUSH_CONGRUENCE(r13)
+ /*
+ * The load adresses are at staggered offsets within cachelines,
+ * which suits some pipelines better (on others it should not
+ * hurt).
+ */
+ addi r12,r12,8
+ mtctr r11
+ DCBT_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
+
+ /* order ld/st prior to dcbt stop all streams with flushing */
+ sync
+1: li r8,0
+ .rept 8 /* 8-way set associative */
+ ldx r11,r10,r8
+ add r8,r8,r12
+ xor r11,r11,r11 // Ensure r11 is 0 even if fallback area is not
+ add r8,r8,r11 // Add 0, this creates a dependency on the ldx
+ .endr
+ addi r10,r10,128 /* 128 byte cache line */
+ bdnz 1b
+
+ mtctr r9
+ ld r9,PACA_EXRFI+EX_R9(r13)
+ ld r10,PACA_EXRFI+EX_R10(r13)
+ ld r11,PACA_EXRFI+EX_R11(r13)
+ ld r12,PACA_EXRFI+EX_R12(r13)
+ ld r8,PACA_EXRFI+EX_R13(r13)
+ GET_SCRATCH0(r13);
+ rfid
+
+TRAMP_REAL_BEGIN(hrfi_flush_fallback)
+ SET_SCRATCH0(r13);
+ GET_PACA(r13);
+ std r9,PACA_EXRFI+EX_R9(r13)
+ std r10,PACA_EXRFI+EX_R10(r13)
+ std r11,PACA_EXRFI+EX_R11(r13)
+ std r12,PACA_EXRFI+EX_R12(r13)
+ std r8,PACA_EXRFI+EX_R13(r13)
+ mfctr r9
+ ld r10,PACA_RFI_FLUSH_FALLBACK_AREA(r13)
+ ld r11,PACA_L1D_FLUSH_SETS(r13)
+ ld r12,PACA_L1D_FLUSH_CONGRUENCE(r13)
+ /*
+ * The load adresses are at staggered offsets within cachelines,
+ * which suits some pipelines better (on others it should not
+ * hurt).
+ */
+ addi r12,r12,8
+ mtctr r11
+ DCBT_STOP_ALL_STREAM_IDS(r11) /* Stop prefetch streams */
+
+ /* order ld/st prior to dcbt stop all streams with flushing */
+ sync
+1: li r8,0
+ .rept 8 /* 8-way set associative */
+ ldx r11,r10,r8
+ add r8,r8,r12
+ xor r11,r11,r11 // Ensure r11 is 0 even if fallback area is not
+ add r8,r8,r11 // Add 0, this creates a dependency on the ldx
+ .endr
+ addi r10,r10,128 /* 128 byte cache line */
+ bdnz 1b
+
+ mtctr r9
+ ld r9,PACA_EXRFI+EX_R9(r13)
+ ld r10,PACA_EXRFI+EX_R10(r13)
+ ld r11,PACA_EXRFI+EX_R11(r13)
+ ld r12,PACA_EXRFI+EX_R12(r13)
+ ld r8,PACA_EXRFI+EX_R13(r13)
+ GET_SCRATCH0(r13);
+ hrfid
+
/*
* Real mode exceptions actually use this too, but alternate
* instruction code patches (which end up in the common .text area)
@@ -1441,7 +1552,7 @@ TRAMP_REAL_BEGIN(kvmppc_skip_interrupt)
addi r13, r13, 4
mtspr SPRN_SRR0, r13
GET_SCRATCH0(r13)
- rfid
+ RFI_TO_KERNEL
b .
TRAMP_REAL_BEGIN(kvmppc_skip_Hinterrupt)
@@ -1453,7 +1564,7 @@ TRAMP_REAL_BEGIN(kvmppc_skip_Hinterrupt)
addi r13, r13, 4
mtspr SPRN_HSRR0, r13
GET_SCRATCH0(r13)
- hrfid
+ HRFI_TO_KERNEL
b .
#endif
diff --git a/arch/powerpc/kernel/setup_64.c b/arch/powerpc/kernel/setup_64.c
index 8956a9856604..491be4179ddd 100644
--- a/arch/powerpc/kernel/setup_64.c
+++ b/arch/powerpc/kernel/setup_64.c
@@ -801,3 +801,104 @@ static int __init disable_hardlockup_detector(void)
return 0;
}
early_initcall(disable_hardlockup_detector);
+
+#ifdef CONFIG_PPC_BOOK3S_64
+static enum l1d_flush_type enabled_flush_types;
+static void *l1d_flush_fallback_area;
+static bool no_rfi_flush;
+bool rfi_flush;
+
+static int __init handle_no_rfi_flush(char *p)
+{
+ pr_info("rfi-flush: disabled on command line.");
+ no_rfi_flush = true;
+ return 0;
+}
+early_param("no_rfi_flush", handle_no_rfi_flush);
+
+/*
+ * The RFI flush is not KPTI, but because users will see doco that says to use
+ * nopti we hijack that option here to also disable the RFI flush.
+ */
+static int __init handle_no_pti(char *p)
+{
+ pr_info("rfi-flush: disabling due to 'nopti' on command line.\n");
+ handle_no_rfi_flush(NULL);
+ return 0;
+}
+early_param("nopti", handle_no_pti);
+
+static void do_nothing(void *unused)
+{
+ /*
+ * We don't need to do the flush explicitly, just enter+exit kernel is
+ * sufficient, the RFI exit handlers will do the right thing.
+ */
+}
+
+void rfi_flush_enable(bool enable)
+{
+ if (rfi_flush == enable)
+ return;
+
+ if (enable) {
+ do_rfi_flush_fixups(enabled_flush_types);
+ on_each_cpu(do_nothing, NULL, 1);
+ } else
+ do_rfi_flush_fixups(L1D_FLUSH_NONE);
+
+ rfi_flush = enable;
+}
+
+static void init_fallback_flush(void)
+{
+ u64 l1d_size, limit;
+ int cpu;
+
+ l1d_size = ppc64_caches.l1d.size;
+ limit = min(safe_stack_limit(), ppc64_rma_size);
+
+ /*
+ * Align to L1d size, and size it at 2x L1d size, to catch possible
+ * hardware prefetch runoff. We don't have a recipe for load patterns to
+ * reliably avoid the prefetcher.
+ */
+ l1d_flush_fallback_area = __va(memblock_alloc_base(l1d_size * 2, l1d_size, limit));
+ memset(l1d_flush_fallback_area, 0, l1d_size * 2);
+
+ for_each_possible_cpu(cpu) {
+ /*
+ * The fallback flush is currently coded for 8-way
+ * associativity. Different associativity is possible, but it
+ * will be treated as 8-way and may not evict the lines as
+ * effectively.
+ *
+ * 128 byte lines are mandatory.
+ */
+ u64 c = l1d_size / 8;
+
+ paca[cpu].rfi_flush_fallback_area = l1d_flush_fallback_area;
+ paca[cpu].l1d_flush_congruence = c;
+ paca[cpu].l1d_flush_sets = c / 128;
+ }
+}
+
+void __init setup_rfi_flush(enum l1d_flush_type types, bool enable)
+{
+ if (types & L1D_FLUSH_FALLBACK) {
+ pr_info("rfi-flush: Using fallback displacement flush\n");
+ init_fallback_flush();
+ }
+
+ if (types & L1D_FLUSH_ORI)
+ pr_info("rfi-flush: Using ori type flush\n");
+
+ if (types & L1D_FLUSH_MTTRIG)
+ pr_info("rfi-flush: Using mttrig type flush\n");
+
+ enabled_flush_types = types;
+
+ if (!no_rfi_flush)
+ rfi_flush_enable(enable);
+}
+#endif /* CONFIG_PPC_BOOK3S_64 */
diff --git a/arch/powerpc/kernel/vmlinux.lds.S b/arch/powerpc/kernel/vmlinux.lds.S
index 0494e1566ee2..307843d23682 100644
--- a/arch/powerpc/kernel/vmlinux.lds.S
+++ b/arch/powerpc/kernel/vmlinux.lds.S
@@ -132,6 +132,15 @@ SECTIONS
/* Read-only data */
RO_DATA(PAGE_SIZE)
+#ifdef CONFIG_PPC64
+ . = ALIGN(8);
+ __rfi_flush_fixup : AT(ADDR(__rfi_flush_fixup) - LOAD_OFFSET) {
+ __start___rfi_flush_fixup = .;
+ *(__rfi_flush_fixup)
+ __stop___rfi_flush_fixup = .;
+ }
+#endif
+
EXCEPTION_TABLE(0)
NOTES :kernel :notes
generated by cgit v1.2.3-70-g09d2 (git 2.47.1) at 2024-12-30 23:04:52 +0000