powerpc/legacy_serial: cache serial port and info in add_legacy_port()

Caching the port and info in local variables makes the code more compact
and easier to understand.

Signed-off-by: "Jiri Slaby (SUSE)" <jirislaby@kernel.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: linuxppc-dev@lists.ozlabs.org
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/20250611100319.186924-3-jirislaby@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/powerpc/kernel/legacy_serial.c b/arch/powerpc/kernel/legacy_serial.c
index 1da2f6e7d2a1345af04876d7b095751db0756bc8..d9080189c28c93baa386fde4b91a275ee6bc54fa 100644 (file)
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -77,6 +77,8 @@ static int __init add_legacy_port(struct device_node *np, int want_index,
                                  phys_addr_t taddr, unsigned long irq,
                                  upf_t flags, int irq_check_parent)
 {
+       struct plat_serial8250_port *legacy_port;
+       struct legacy_serial_info *legacy_info;
        const __be32 *clk, *spd, *rs;
        u32 clock = BASE_BAUD * 16;
        u32 shift = 0;
@@ -110,16 +112,17 @@ static int __init add_legacy_port(struct device_node *np, int want_index,
        if (index >= legacy_serial_count)
                legacy_serial_count = index + 1;
 
+       legacy_port = &legacy_serial_ports[index];
+       legacy_info = &legacy_serial_infos[index];
+
        /* Check if there is a port who already claimed our slot */
-       if (legacy_serial_infos[index].np != NULL) {
+       if (legacy_info->np != NULL) {
                /* if we still have some room, move it, else override */
                if (legacy_serial_count < MAX_LEGACY_SERIAL_PORTS) {
                        printk(KERN_DEBUG "Moved legacy port %d -> %d\n",
                               index, legacy_serial_count);
-                       legacy_serial_ports[legacy_serial_count] =
-                               legacy_serial_ports[index];
-                       legacy_serial_infos[legacy_serial_count] =
-                               legacy_serial_infos[index];
+                       legacy_serial_ports[legacy_serial_count] = *legacy_port;
+                       legacy_serial_infos[legacy_serial_count] = *legacy_info;
                        legacy_serial_count++;
                } else {
                        printk(KERN_DEBUG "Replacing legacy port %d\n", index);
@@ -127,36 +130,33 @@ static int __init add_legacy_port(struct device_node *np, int want_index,
        }
 
        /* Now fill the entry */
-       memset(&legacy_serial_ports[index], 0,
-              sizeof(struct plat_serial8250_port));
+       memset(legacy_port, 0, sizeof(*legacy_port));
        if (iotype == UPIO_PORT)
-               legacy_serial_ports[index].iobase = base;
+               legacy_port->iobase = base;
        else
-               legacy_serial_ports[index].mapbase = base;
-
-       legacy_serial_ports[index].iotype = iotype;
-       legacy_serial_ports[index].uartclk = clock;
-       legacy_serial_ports[index].irq = irq;
-       legacy_serial_ports[index].flags = flags;
-       legacy_serial_ports[index].regshift = shift;
-       legacy_serial_infos[index].taddr = taddr;
-       legacy_serial_infos[index].np = of_node_get(np);
-       legacy_serial_infos[index].clock = clock;
-       legacy_serial_infos[index].speed = spd ? be32_to_cpup(spd) : 0;
-       legacy_serial_infos[index].irq_check_parent = irq_check_parent;
+               legacy_port->mapbase = base;
+
+       legacy_port->iotype = iotype;
+       legacy_port->uartclk = clock;
+       legacy_port->irq = irq;
+       legacy_port->flags = flags;
+       legacy_port->regshift = shift;
+       legacy_info->taddr = taddr;
+       legacy_info->np = of_node_get(np);
+       legacy_info->clock = clock;
+       legacy_info->speed = spd ? be32_to_cpup(spd) : 0;
+       legacy_info->irq_check_parent = irq_check_parent;
 
        if (iotype == UPIO_TSI) {
-               legacy_serial_ports[index].serial_in = tsi_serial_in;
-               legacy_serial_ports[index].serial_out = tsi_serial_out;
+               legacy_port->serial_in = tsi_serial_in;
+               legacy_port->serial_out = tsi_serial_out;
        }
 
-       printk(KERN_DEBUG "Found legacy serial port %d for %pOF\n",
-              index, np);
+       printk(KERN_DEBUG "Found legacy serial port %d for %pOF\n", index, np);
        printk(KERN_DEBUG "  %s=%llx, taddr=%llx, irq=%lx, clk=%d, speed=%d\n",
               (iotype == UPIO_PORT) ? "port" : "mem",
               (unsigned long long)base, (unsigned long long)taddr, irq,
-              legacy_serial_ports[index].uartclk,
-              legacy_serial_infos[index].speed);
+              legacy_port->uartclk, legacy_info->speed);
 
        return index;
 }