Add bridged amplifiers to cs42l43

Merge series from Charles Keepax <[email protected]>:

In some cs42l43 systems a couple of cs35l56 amplifiers are attached
to the cs42l43's SPI and I2S. On Windows the cs42l43 is controlled
by a SDCA class driver and these two amplifiers are controlled by
firmware running on the cs42l43. However, under Linux the decision
was made to interact with the cs42l43 directly, affording the user
greater control over the audio system. However, this has resulted
in an issue where these two bridged cs35l56 amplifiers are not
populated in ACPI and must be added manually. There is at least an
SDCA extension unit DT entry we can key off.

The process of adding this is handled using a software node, firstly the
ability to add native chip selects to software nodes must be added.
Secondly, an additional flag for naming the SPI devices is added this
allows the machine driver to key to the correct amplifier. Then finally,
the cs42l43 SPI driver adds the two amplifiers directly onto its SPI
bus.

An additional series will follow soon to add the audio machine driver
parts (in the sof-sdw driver), however that is fairly orthogonal to
this part of the process, getting the actual amplifiers registered.

1 files changed, 14 insertions, 10 deletions

diff --git a/arch/x86/kernel/nmi.c b/arch/x86/kernel/nmi.c
index 9a5b372c706f..ed163c8c8604 100644
--- a/arch/x86/kernel/nmi.c
+++ b/arch/x86/kernel/nmi.c
@@ -580,7 +580,7 @@ EXPORT_SYMBOL_GPL(asm_exc_nmi_kvm_vmx);
 
 static char *nmi_check_stall_msg[] = {
 /*									*/
-/* +--------- nsp->idt_seq_snap & 0x1: CPU is in NMI handler.		*/
+/* +--------- nmi_seq & 0x1: CPU is currently in NMI handler.		*/
 /* | +------ cpu_is_offline(cpu)					*/
 /* | | +--- nsp->idt_calls_snap != atomic_long_read(&nsp->idt_calls):	*/
 /* | | |	NMI handler has been invoked.				*/
@@ -628,22 +628,26 @@ void nmi_backtrace_stall_check(const struct cpumask *btp)
 		nmi_seq = READ_ONCE(nsp->idt_nmi_seq);
 		if (nsp->idt_nmi_seq_snap + 1 == nmi_seq && (nmi_seq & 0x1)) {
 			msgp = "CPU entered NMI handler function, but has not exited";
-		} else if ((nsp->idt_nmi_seq_snap & 0x1) != (nmi_seq & 0x1)) {
-			msgp = "CPU is handling NMIs";
-		} else {
-			idx = ((nsp->idt_seq_snap & 0x1) << 2) |
+		} else if (nsp->idt_nmi_seq_snap == nmi_seq ||
+			   nsp->idt_nmi_seq_snap + 1 == nmi_seq) {
+			idx = ((nmi_seq & 0x1) << 2) |
 			      (cpu_is_offline(cpu) << 1) |
 			      (nsp->idt_calls_snap != atomic_long_read(&nsp->idt_calls));
 			msgp = nmi_check_stall_msg[idx];
 			if (nsp->idt_ignored_snap != READ_ONCE(nsp->idt_ignored) && (idx & 0x1))
 				modp = ", but OK because ignore_nmis was set";
-			if (nmi_seq & 0x1)
-				msghp = " (CPU currently in NMI handler function)";
-			else if (nsp->idt_nmi_seq_snap + 1 == nmi_seq)
+			if (nsp->idt_nmi_seq_snap + 1 == nmi_seq)
 				msghp = " (CPU exited one NMI handler function)";
+			else if (nmi_seq & 0x1)
+				msghp = " (CPU currently in NMI handler function)";
+			else
+				msghp = " (CPU was never in an NMI handler function)";
+		} else {
+			msgp = "CPU is handling NMIs";
 		}
-		pr_alert("%s: CPU %d: %s%s%s, last activity: %lu jiffies ago.\n",
-			 __func__, cpu, msgp, modp, msghp, j - READ_ONCE(nsp->recv_jiffies));
+		pr_alert("%s: CPU %d: %s%s%s\n", __func__, cpu, msgp, modp, msghp);
+		pr_alert("%s: last activity: %lu jiffies ago.\n",
+			 __func__, j - READ_ONCE(nsp->recv_jiffies));
 	}
 }