From a5c05453a13ab324ad8719e8a23dfb6af01f3652 Mon Sep 17 00:00:00 2001
From: Christian Marangi <ansuelsmth@gmail.com>
Date: Thu, 20 Jun 2024 17:26:42 +0200
Subject: mips: bmips: rework and cache CBR addr handling

Rework the handling of the CBR address and cache it. This address
doesn't change and can be cached instead of reading the register every
time.

This is in preparation of permitting to tweak the CBR address in DT with
broken SoC or bootloader.

bmips_cbr_addr is defined in setup.c for each arch to keep compatibility
with legacy brcm47xx/brcm63xx and generic BMIPS target.

Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
---
 arch/mips/bcm47xx/prom.c  | 3 +++
 arch/mips/bcm47xx/setup.c | 4 ++++
 2 files changed, 7 insertions(+)

(limited to 'arch/mips/bcm47xx')

diff --git a/arch/mips/bcm47xx/prom.c b/arch/mips/bcm47xx/prom.c
index 58fb7c2dc3b8..66e3ee2b04e6 100644
--- a/arch/mips/bcm47xx/prom.c
+++ b/arch/mips/bcm47xx/prom.c
@@ -32,6 +32,7 @@
 #include <linux/ssb/ssb_driver_chipcommon.h>
 #include <linux/ssb/ssb_regs.h>
 #include <linux/smp.h>
+#include <asm/bmips.h>
 #include <asm/bootinfo.h>
 #include <bcm47xx.h>
 #include <bcm47xx_board.h>
@@ -110,6 +111,8 @@ static __init void prom_init_mem(void)
 
 void __init prom_init(void)
 {
+	/* Cache CBR addr before CPU/DMA setup */
+	bmips_cbr_addr = BMIPS_GET_CBR();
 	prom_init_mem();
 	setup_8250_early_printk_port(CKSEG1ADDR(BCM47XX_SERIAL_ADDR), 0, 0);
 }
diff --git a/arch/mips/bcm47xx/setup.c b/arch/mips/bcm47xx/setup.c
index 94bf839576c1..2f1ee0560aba 100644
--- a/arch/mips/bcm47xx/setup.c
+++ b/arch/mips/bcm47xx/setup.c
@@ -37,6 +37,7 @@
 #include <linux/ssb/ssb.h>
 #include <linux/ssb/ssb_embedded.h>
 #include <linux/bcma/bcma_soc.h>
+#include <asm/bmips.h>
 #include <asm/bootinfo.h>
 #include <asm/idle.h>
 #include <asm/prom.h>
@@ -45,6 +46,9 @@
 #include <bcm47xx.h>
 #include <bcm47xx_board.h>
 
+/* CBR addr doesn't change and we can cache it */
+void __iomem *bmips_cbr_addr __read_mostly;
+
 union bcm47xx_bus bcm47xx_bus;
 EXPORT_SYMBOL(bcm47xx_bus);
 
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