Re: [PATCH v2 2/2] powerpc/legacy_serial: Use early_ioremap()

[Christophe Leroy]

Le 20/04/2021 à 15:32, Christophe Leroy a écrit :
From: Christophe Leroy <christophe.le...@c-s.fr>

Oops, I forgot to reset the Author. Michael if you apply this patch please update the author and 
remove the old Signed-off-by

Thanks


[    0.000000] ioremap() called early from 
find_legacy_serial_ports+0x3cc/0x474. Use early_ioremap() instead

find_legacy_serial_ports() is called early from setup_arch(), before
paging_init(). vmalloc is not available yet, ioremap shouldn't be
used that early.

Use early_ioremap() and switch to a regular ioremap() later.

Signed-off-by: Christophe Leroy <christophe.le...@c-s.fr>
Signed-off-by: Christophe Leroy <christophe.le...@csgroup.eu>
---
  arch/powerpc/kernel/legacy_serial.c | 33 +++++++++++++++++++++++++----
  1 file changed, 29 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/kernel/legacy_serial.c 
b/arch/powerpc/kernel/legacy_serial.c
index f061e06e9f51..8b2c1a8553a0 100644
--- a/arch/powerpc/kernel/legacy_serial.c
+++ b/arch/powerpc/kernel/legacy_serial.c
@@ -15,6 +15,7 @@
  #include <asm/udbg.h>
  #include <asm/pci-bridge.h>
  #include <asm/ppc-pci.h>
+#include <asm/early_ioremap.h>
  
  #undef DEBUG
  
@@ -34,6 +35,7 @@ static struct legacy_serial_info {
        unsigned int                    clock;
        int                             irq_check_parent;
        phys_addr_t                     taddr;
+       void __iomem                    *early_addr;
  } legacy_serial_infos[MAX_LEGACY_SERIAL_PORTS];
  
  static const struct of_device_id legacy_serial_parents[] __initconst = {
@@ -325,17 +327,16 @@ static void __init setup_legacy_serial_console(int 
console)
  {
        struct legacy_serial_info *info = &legacy_serial_infos[console];
        struct plat_serial8250_port *port = &legacy_serial_ports[console];
-       void __iomem *addr;
        unsigned int stride;
  
  	stride = 1 << port->regshift;
  
  	/* Check if a translated MMIO address has been found */
        if (info->taddr) {
-               addr = ioremap(info->taddr, 0x1000);
-               if (addr == NULL)
+               info->early_addr = early_ioremap(info->taddr, 0x1000);
+               if (info->early_addr == NULL)
                        return;
-               udbg_uart_init_mmio(addr, stride);
+               udbg_uart_init_mmio(info->early_addr, stride);
        } else {
                /* Check if it's PIO and we support untranslated PIO */
                if (port->iotype == UPIO_PORT && isa_io_special)
@@ -353,6 +354,30 @@ static void __init setup_legacy_serial_console(int console)
        udbg_uart_setup(info->speed, info->clock);
  }
  
+static int __init ioremap_legacy_serial_console(void)
+{
+       struct legacy_serial_info *info = 
&legacy_serial_infos[legacy_serial_console];
+       struct plat_serial8250_port *port = 
&legacy_serial_ports[legacy_serial_console];
+       void __iomem *vaddr;
+
+       if (legacy_serial_console < 0)
+               return 0;
+
+       if (!info->early_addr)
+               return 0;
+
+       vaddr = ioremap(info->taddr, 0x1000);
+       if (WARN_ON(!vaddr))
+               return -ENOMEM;
+
+       udbg_uart_init_mmio(vaddr, 1 << port->regshift);
+       early_iounmap(info->early_addr, 0x1000);
+       info->early_addr = NULL;
+
+       return 0;
+}
+early_initcall(ioremap_legacy_serial_console);
+
  /*
   * This is called very early, as part of setup_system() or eventually
   * setup_arch(), basically before anything else in this file. This function