diff mbox series

[v3,04/25] x86: mp_init: Switch parameter names in start_aps()

Message ID 20200706033741.2169374-5-sjg@chromium.org
State Superseded
Headers show
Series x86: Enhance MTRR functionality to support multiple CPUs | expand

Commit Message

Simon Glass July 6, 2020, 3:37 a.m. UTC 
These parameters are named differently from elsewhere in this file. Switch
them to avoid confusion.

Also add comments to this function.

Signed-off-by: Simon Glass <sjg at chromium.org>
Reviewed-by: Bin Meng <bmeng.cn at gmail.com>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner at br-automation.com>
---

(no changes since v2)

Changes in v2:
- Add comments to explain what start_aps() does

 arch/x86/cpu/mp_init.c | 25 +++++++++++++++++++------
 1 file changed, 19 insertions(+), 6 deletions(-)
diff mbox series

Patch

diff --git a/arch/x86/cpu/mp_init.c b/arch/x86/cpu/mp_init.c
index e77d7f2cd6..8b00d57c88 100644
--- a/arch/x86/cpu/mp_init.c
+++ b/arch/x86/cpu/mp_init.c
@@ -308,13 +308,26 @@  static int apic_wait_timeout(int total_delay, const char *msg)
 	return 0;
 }
 
-static int start_aps(int ap_count, atomic_t *num_aps)
+/**
+ * start_aps() - Start up the APs and count how many we find
+ *
+ * This is called on the boot processor to start up all the other processors
+ * (here called APs).
+ *
+ * @num_aps: Number of APs we expect to find
+ * @ap_count: Initially zero. Incremented by this function for each AP found
+ * @return 0 if all APs were set up correctly or there are none to set up,
+ *	-ENOSPC if the SIPI vector is too high in memory,
+ *	-ETIMEDOUT if the ICR is busy or the second SIPI fails to complete
+ *	-EIO if not all APs check in correctly
+ */
+static int start_aps(int num_aps, atomic_t *ap_count)
 {
 	int sipi_vector;
 	/* Max location is 4KiB below 1MiB */
 	const int max_vector_loc = ((1 << 20) - (1 << 12)) >> 12;
 
-	if (ap_count == 0)
+	if (num_aps == 0)
 		return 0;
 
 	/* The vector is sent as a 4k aligned address in one byte */
@@ -326,7 +339,7 @@  static int start_aps(int ap_count, atomic_t *num_aps)
 		return -ENOSPC;
 	}
 
-	debug("Attempting to start %d APs\n", ap_count);
+	debug("Attempting to start %d APs\n", num_aps);
 
 	if (apic_wait_timeout(1000, "ICR not to be busy"))
 		return -ETIMEDOUT;
@@ -349,7 +362,7 @@  static int start_aps(int ap_count, atomic_t *num_aps)
 		return -ETIMEDOUT;
 
 	/* Wait for CPUs to check in up to 200 us */
-	wait_for_aps(num_aps, ap_count, 200, 15);
+	wait_for_aps(ap_count, num_aps, 200, 15);
 
 	/* Send 2nd SIPI */
 	if (apic_wait_timeout(1000, "ICR not to be busy"))
@@ -362,9 +375,9 @@  static int start_aps(int ap_count, atomic_t *num_aps)
 		return -ETIMEDOUT;
 
 	/* Wait for CPUs to check in */
-	if (wait_for_aps(num_aps, ap_count, 10000, 50)) {
+	if (wait_for_aps(ap_count, num_aps, 10000, 50)) {
 		debug("Not all APs checked in: %d/%d\n",
-		      atomic_read(num_aps), ap_count);
+		      atomic_read(ap_count), num_aps);
 		return -EIO;
 	}