bmips: enable the data Read Ahead Cache for BMIPS4350
authorDaniel González Cabanelas <dgcbueu@gmail.com>
Sat, 17 Jun 2023 17:34:05 +0000 (19:34 +0200)
committerÁlvaro Fernández Rojas <noltari@gmail.com>
Mon, 19 Jun 2023 18:42:19 +0000 (20:42 +0200)
The data RAC is left disabled by the bootloader in some SoCs, at least in
the core it boots from. Enabling this feature increases the performance up
to +30% depending on the task.

The kernel enables the whole RAC unconditionally on BMIPS3300 CPUs. Enable
the data RAC in a similar way also for BMIPS4350.

Tested on DGND3700 v1 (BCM6368) and HG556a (BCM6358).

Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>
(cherry picked from commit 6d1265b14850abaf8980e5cebef3e559b1fdcfb9)

target/linux/bmips/patches-5.15/204-mips-bmips-enable-RAC-on-BMIPS4350.patch [new file with mode: 0644]

diff --git a/target/linux/bmips/patches-5.15/204-mips-bmips-enable-RAC-on-BMIPS4350.patch b/target/linux/bmips/patches-5.15/204-mips-bmips-enable-RAC-on-BMIPS4350.patch
new file mode 100644 (file)
index 0000000..26bd03e
--- /dev/null
@@ -0,0 +1,42 @@
+From 7f862eaedac56b67972393f0a9affcd2fe53479b Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Daniel=20Gonz=C3=A1lez=20Cabanelas?= <dgcbueu@gmail.com>
+Date: Sun, 18 Jun 2023 19:59:25 +0200
+Subject: [PATCH] mips: bmips: enable RAC on BMIPS4350
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+The data RAC is left disabled by the bootloader in some SoCs, at least in
+the core it boots from.
+Enabling this feature increases the performance up to +30% depending on the
+task.
+
+Signed-off-by: Daniel González Cabanelas <dgcbueu@gmail.com>
+Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>
+---
+ arch/mips/kernel/smp-bmips.c | 14 ++++++++++++++
+ 1 file changed, 14 insertions(+)
+
+--- a/arch/mips/kernel/smp-bmips.c
++++ b/arch/mips/kernel/smp-bmips.c
+@@ -614,6 +614,20 @@ void bmips_cpu_setup(void)
+               __raw_readl(cbr + BMIPS_RAC_ADDRESS_RANGE);
+               break;
++      case CPU_BMIPS4350:
++              /* Enable data RAC */
++              if (!(read_c0_brcm_cmt_local() & (1 << 31))) {
++                      cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG);
++                      __raw_writel(cfg | 0xa, cbr + BMIPS_RAC_CONFIG);
++                      __raw_readl(cbr + BMIPS_RAC_CONFIG);
++              } else {
++                      cbr = (void __iomem *)0xff400000;
++                      cfg = __raw_readl(cbr + BMIPS_RAC_CONFIG_1);
++                      __raw_writel(cfg | 0xa, cbr + BMIPS_RAC_CONFIG_1);
++                      __raw_readl(cbr + BMIPS_RAC_CONFIG_1);
++              }
++              break;
++
+       case CPU_BMIPS4380:
+               /* CBG workaround for early BMIPS4380 CPUs */
+               switch (read_c0_prid()) {