Re: [PATCH] MIPS: BMIPS: Disable pref 30 for buggy CPUs

[Jiaxun Yang]

在 2020/7/31 下午12:24, Florian Fainelli 写道:

Disable pref 30 by utilizing the standard quirk method and matching the
affected SoCs: 7344, 7346, 7425.

Signed-off-by: Florian Fainelli <f.faine...@gmail.com>
---
  arch/mips/bmips/setup.c | 17 +++++++++++++++++
  1 file changed, 17 insertions(+)

diff --git a/arch/mips/bmips/setup.c b/arch/mips/bmips/setup.c
index 19308df5f577..df0efea12611 100644
--- a/arch/mips/bmips/setup.c
+++ b/arch/mips/bmips/setup.c
@@ -110,6 +110,20 @@ static void bcm6368_quirks(void)
        bcm63xx_fixup_cpu1();
  }

+static void bmips5000_pref30_quirk(void)

+{
+       __asm__ __volatile__(
+       "  li      $8, 0x5a455048\n"
+       "  .word   0x4088b00f\n"      /* mtc0 $8, $22, 15 */
+       "  nop; nop; nop\n"
+       "  .word   0x4008b008\n"      /* mfc0 $8, $22, 8 */
+       /* disable "pref 30" on buggy CPUs */
+       "  lui     $9, 0x0800\n"
+       "  or      $8, $9\n"
+       "  .word   0x4088b008\n"      /* mtc0 $8, $22, 8 */
+       : : : "$8", "$9");
+}

Hi,

Is there any toolchain issue blocking read_c0_**** family helpers being
used?

Use .word looks unreasonable.

Thanks

- Jiaxun

+
  static const struct bmips_quirk bmips_quirk_list[] = {
        { "brcm,bcm3368",             &bcm6358_quirks                     },
        { "brcm,bcm3384-viper",               &bcm3384_viper_quirks             
  },
@@ -120,6 +134,9 @@ static const struct bmips_quirk bmips_quirk_list[] = {
        { "brcm,bcm6368",             &bcm6368_quirks                     },
        { "brcm,bcm63168",            &bcm6368_quirks                     },
        { "brcm,bcm63268",            &bcm6368_quirks                     },
+       { "brcm,bcm7344",             &bmips5000_pref30_quirk             },
+       { "brcm,bcm7346",             &bmips5000_pref30_quirk             },
+       { "brcm,bcm7425",             &bmips5000_pref30_quirk             },
        { },
  };