1. 03 May, 2014 1 commit
    • Marc Zyngier's avatar
      arm64: fixmap: fix missing sub-page offset for earlyprintk · f774b7d1
      Marc Zyngier authored
      Commit d57c33c5 (add generic fixmap.h) added (among other
      similar things) set_fixmap_io to deal with early ioremap of devices.
      
      More recently, commit bf4b558e (arm64: add early_ioremap support)
      converted the arm64 earlyprintk to use set_fixmap_io. A side effect of
      this conversion is that my virtual machines have stopped booting when
      I pass "earlyprintk=uart8250-8bit,0x3f8" to the guest kernel.
      
      Turns out that the new earlyprintk code doesn't care at all about
      sub-page offsets, and just assumes that the earlyprintk device will
      be page-aligned. Obviously, that doesn't play well with the above example.
      
      Further investigation shows that set_fixmap_io uses __set_fixmap instead
      of __set_fixmap_offset. A fix is to introduce a set_fixmap_offset_io that
      uses the latter, and to remove the superflous call to fix_to_virt
      (which only returns the value that set_fixmap_io has already given us).
      
      With this applied, my VMs are back in business. Tested on a Cortex-A57
      platform with kvmtool as platform emulation.
      
      Cc: Will Deacon <will.deacon@arm.com>
      Acked-by: default avatarMark Salter <msalter@redhat.com>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      f774b7d1
  2. 07 Apr, 2014 1 commit
  3. 13 May, 2013 1 commit
  4. 20 Mar, 2013 2 commits
  5. 22 Jan, 2013 1 commit
    • Catalin Marinas's avatar
      arm64: Add simple earlyprintk support · 2475ff9d
      Catalin Marinas authored
      This patch adds support for "earlyprintk=" parameter on the kernel
      command line. The format is:
      
        earlyprintk=<name>[,<addr>][,<options>]
      
      where <name> is the name of the (UART) device, e.g. "pl011", <addr> is
      the I/O address. The <options> aren't currently used.
      
      The mapping of the earlyprintk device is done very early during kernel
      boot and there are restrictions on which functions it can call. A
      special early_io_map() function is added which creates the mapping from
      the pre-defined EARLY_IOBASE to the device I/O address passed via the
      kernel parameter. The pgd entry corresponding to EARLY_IOBASE is
      pre-populated in head.S during kernel boot.
      
      Only PL011 is currently supported and it is assumed that the interface
      is already initialised by the boot loader before the kernel is started.
      Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
      Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
      2475ff9d