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authorLinus Torvalds <torvalds@linux-foundation.org>2023-04-24 10:26:22 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-04-24 10:26:22 -0700
commitd88867a24fa7e9c75b8f86df20d4f40e2fe61e9b (patch)
tree5233f7b894ecf828bcc2d3539936ac32e51739af
parent1a261a6e10e80cd7c69c3f5bdf47cd41f928fd08 (diff)
parent60261442c1b91d9e0cdc611222034286aeb18946 (diff)
Merge tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm
Pull ARM development updates from Russell King: "Four changes for v6.4: - simplify the path to the top vmlinux - three patches to fix vfp with instrumentation enabled (eg lockdep)" * tag 'for-linus' of git://git.armlinux.org.uk/~rmk/linux-arm: ARM: 9294/2: vfp: Fix broken softirq handling with instrumentation enabled ARM: 9293/1: vfp: Pass successful return address via register R3 ARM: 9292/1: vfp: Pass thread_info pointer to vfp_support_entry ARM: 9291/1: decompressor: simplify the path to the top vmlinux
-rw-r--r--arch/arm/boot/compressed/Makefile2
-rw-r--r--arch/arm/include/asm/assembler.h13
-rw-r--r--arch/arm/vfp/entry.S17
-rw-r--r--arch/arm/vfp/vfphw.S30
-rw-r--r--arch/arm/vfp/vfpmodule.c27
5 files changed, 43 insertions, 46 deletions
diff --git a/arch/arm/boot/compressed/Makefile b/arch/arm/boot/compressed/Makefile
index 2ef651a78fa2..726ecabcef09 100644
--- a/arch/arm/boot/compressed/Makefile
+++ b/arch/arm/boot/compressed/Makefile
@@ -107,7 +107,7 @@ ccflags-remove-$(CONFIG_FUNCTION_TRACER) += -pg
asflags-y := -DZIMAGE
# Supply kernel BSS size to the decompressor via a linker symbol.
-KBSS_SZ = $(shell echo $$(($$($(NM) $(obj)/../../../../vmlinux | \
+KBSS_SZ = $(shell echo $$(($$($(NM) vmlinux | \
sed -n -e 's/^\([^ ]*\) [ABD] __bss_start$$/-0x\1/p' \
-e 's/^\([^ ]*\) [ABD] __bss_stop$$/+0x\1/p') )) )
LDFLAGS_vmlinux = --defsym _kernel_bss_size=$(KBSS_SZ)
diff --git a/arch/arm/include/asm/assembler.h b/arch/arm/include/asm/assembler.h
index 06b48ce23e1c..505a306e0271 100644
--- a/arch/arm/include/asm/assembler.h
+++ b/arch/arm/include/asm/assembler.h
@@ -244,19 +244,6 @@ THUMB( fpreg .req r7 )
.endm
#endif
- .macro local_bh_disable, ti, tmp
- ldr \tmp, [\ti, #TI_PREEMPT]
- add \tmp, \tmp, #SOFTIRQ_DISABLE_OFFSET
- str \tmp, [\ti, #TI_PREEMPT]
- .endm
-
- .macro local_bh_enable_ti, ti, tmp
- get_thread_info \ti
- ldr \tmp, [\ti, #TI_PREEMPT]
- sub \tmp, \tmp, #SOFTIRQ_DISABLE_OFFSET
- str \tmp, [\ti, #TI_PREEMPT]
- .endm
-
#define USERL(l, x...) \
9999: x; \
.pushsection __ex_table,"a"; \
diff --git a/arch/arm/vfp/entry.S b/arch/arm/vfp/entry.S
index 9a89264cdcc0..7483ef8bccda 100644
--- a/arch/arm/vfp/entry.S
+++ b/arch/arm/vfp/entry.S
@@ -22,18 +22,7 @@
@ IRQs enabled.
@
ENTRY(do_vfp)
- local_bh_disable r10, r4
- ldr r4, .LCvfp
- ldr r11, [r10, #TI_CPU] @ CPU number
- add r10, r10, #TI_VFPSTATE @ r10 = workspace
- ldr pc, [r4] @ call VFP entry point
+ mov r1, r10
+ mov r3, r9
+ b vfp_entry
ENDPROC(do_vfp)
-
-ENTRY(vfp_null_entry)
- local_bh_enable_ti r10, r4
- ret lr
-ENDPROC(vfp_null_entry)
-
- .align 2
-.LCvfp:
- .word vfp_vector
diff --git a/arch/arm/vfp/vfphw.S b/arch/arm/vfp/vfphw.S
index 26c4f61ecfa3..4d8478264d82 100644
--- a/arch/arm/vfp/vfphw.S
+++ b/arch/arm/vfp/vfphw.S
@@ -6,9 +6,9 @@
* Written by Deep Blue Solutions Limited.
*
* This code is called from the kernel's undefined instruction trap.
- * r9 holds the return address for successful handling.
+ * r1 holds the thread_info pointer
+ * r3 holds the return address for successful handling.
* lr holds the return address for unrecognised instructions.
- * r10 points at the start of the private FP workspace in the thread structure
* sp points to a struct pt_regs (as defined in include/asm/proc/ptrace.h)
*/
#include <linux/init.h>
@@ -69,13 +69,15 @@
@ VFP hardware support entry point.
@
@ r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
+@ r1 = thread_info pointer
@ r2 = PC value to resume execution after successful emulation
-@ r9 = normal "successful" return address
-@ r10 = vfp_state union
-@ r11 = CPU number
+@ r3 = normal "successful" return address
@ lr = unrecognised instruction return address
@ IRQs enabled.
ENTRY(vfp_support_entry)
+ ldr r11, [r1, #TI_CPU] @ CPU number
+ add r10, r1, #TI_VFPSTATE @ r10 = workspace
+
DBGSTR3 "instr %08x pc %08x state %p", r0, r2, r10
.fpu vfpv2
@@ -85,9 +87,9 @@ ENTRY(vfp_support_entry)
bne look_for_VFP_exceptions @ VFP is already enabled
DBGSTR1 "enable %x", r10
- ldr r3, vfp_current_hw_state_address
+ ldr r9, vfp_current_hw_state_address
orr r1, r1, #FPEXC_EN @ user FPEXC has the enable bit set
- ldr r4, [r3, r11, lsl #2] @ vfp_current_hw_state pointer
+ ldr r4, [r9, r11, lsl #2] @ vfp_current_hw_state pointer
bic r5, r1, #FPEXC_EX @ make sure exceptions are disabled
cmp r4, r10 @ this thread owns the hw context?
#ifndef CONFIG_SMP
@@ -146,7 +148,7 @@ vfp_reload_hw:
#endif
DBGSTR1 "load state %p", r10
- str r10, [r3, r11, lsl #2] @ update the vfp_current_hw_state pointer
+ str r10, [r9, r11, lsl #2] @ update the vfp_current_hw_state pointer
@ Load the saved state back into the VFP
VFPFLDMIA r10, r5 @ reload the working registers while
@ FPEXC is in a safe state
@@ -175,9 +177,12 @@ vfp_hw_state_valid:
@ else it's one 32-bit instruction, so
@ always subtract 4 from the following
@ instruction address.
- local_bh_enable_ti r10, r4
- ret r9 @ we think we have handled things
+ mov lr, r3 @ we think we have handled things
+local_bh_enable_and_ret:
+ adr r0, .
+ mov r1, #SOFTIRQ_DISABLE_OFFSET
+ b __local_bh_enable_ip @ tail call
look_for_VFP_exceptions:
@ Check for synchronous or asynchronous exception
@@ -200,13 +205,12 @@ skip:
@ not recognised by VFP
DBGSTR "not VFP"
- local_bh_enable_ti r10, r4
- ret lr
+ b local_bh_enable_and_ret
process_exception:
DBGSTR "bounce"
mov r2, sp @ nothing stacked - regdump is at TOS
- mov lr, r9 @ setup for a return to the user code.
+ mov lr, r3 @ setup for a return to the user code.
@ Now call the C code to package up the bounce to the support code
@ r0 holds the trigger instruction
diff --git a/arch/arm/vfp/vfpmodule.c b/arch/arm/vfp/vfpmodule.c
index 01bc48d73847..349dcb944a93 100644
--- a/arch/arm/vfp/vfpmodule.c
+++ b/arch/arm/vfp/vfpmodule.c
@@ -32,10 +32,9 @@
/*
* Our undef handlers (in entry.S)
*/
-asmlinkage void vfp_support_entry(void);
-asmlinkage void vfp_null_entry(void);
+asmlinkage void vfp_support_entry(u32, void *, u32, u32);
-asmlinkage void (*vfp_vector)(void) = vfp_null_entry;
+static bool have_vfp __ro_after_init;
/*
* Dual-use variable.
@@ -645,6 +644,25 @@ static int vfp_starting_cpu(unsigned int unused)
return 0;
}
+/*
+ * Entered with:
+ *
+ * r0 = instruction opcode (32-bit ARM or two 16-bit Thumb)
+ * r1 = thread_info pointer
+ * r2 = PC value to resume execution after successful emulation
+ * r3 = normal "successful" return address
+ * lr = unrecognised instruction return address
+ */
+asmlinkage void vfp_entry(u32 trigger, struct thread_info *ti, u32 resume_pc,
+ u32 resume_return_address)
+{
+ if (unlikely(!have_vfp))
+ return;
+
+ local_bh_disable();
+ vfp_support_entry(trigger, ti, resume_pc, resume_return_address);
+}
+
#ifdef CONFIG_KERNEL_MODE_NEON
static int vfp_kmode_exception(struct pt_regs *regs, unsigned int instr)
@@ -798,7 +816,6 @@ static int __init vfp_init(void)
vfpsid = fmrx(FPSID);
barrier();
unregister_undef_hook(&vfp_detect_hook);
- vfp_vector = vfp_null_entry;
pr_info("VFP support v0.3: ");
if (VFP_arch) {
@@ -883,7 +900,7 @@ static int __init vfp_init(void)
"arm/vfp:starting", vfp_starting_cpu,
vfp_dying_cpu);
- vfp_vector = vfp_support_entry;
+ have_vfp = true;
thread_register_notifier(&vfp_notifier_block);
vfp_pm_init();