path: root/arch/alpha/kernel
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authorMike Rapoport <rppt@linux.ibm.com>2020-12-14 19:09:28 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2020-12-15 12:13:42 -0800
commit36d40290c8f71daf1ba5567ab14574f36b9b8d6a (patch)
tree361f6819ffbfc5d42578820bf2a612614bce8b3e /arch/alpha/kernel
parent6d5a88cd0c1506115d71a4d3a26b60645c89df6c (diff)
alpha: switch from DISCONTIGMEM to SPARSEMEM
Patch series "arch, mm: deprecate DISCONTIGMEM", v2. It's been a while since DISCONTIGMEM is generally considered deprecated, but it is still used by four architectures. This set replaces DISCONTIGMEM with a different way to handle holes in the memory map and marks DISCONTIGMEM configuration as BROKEN in Kconfigs of these architectures with the intention to completely remove it in several releases. While for 64-bit alpha and ia64 the switch to SPARSEMEM is quite obvious and was a matter of moving some bits around, for smaller 32-bit arc and m68k SPARSEMEM is not necessarily the best thing to do. On 32-bit machines SPARSEMEM would require large sections to make section index fit in the page flags, but larger sections mean that more memory is wasted for unused memory map. Besides, pfn_to_page() and page_to_pfn() become less efficient, at least on arc. So I've decided to generalize arm's approach for freeing of unused parts of the memory map with FLATMEM and enable it for both arc and m68k. The details are in the description of patches 10 (arc) and 13 (m68k). This patch (of 13): Enable SPARSEMEM support on alpha and deprecate DISCONTIGMEM. The required changes are mostly around moving duplicated definitions of page access and address conversion macros to a common place and making sure they are available for all memory models. The DISCONTINGMEM support is marked as BROKEN an will be removed in a couple of releases. Link: https://lkml.kernel.org/r/20201101170454.9567-1-rppt@kernel.org Link: https://lkml.kernel.org/r/20201101170454.9567-2-rppt@kernel.org Signed-off-by: Mike Rapoport <rppt@linux.ibm.com> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Greg Ungerer <gerg@linux-m68k.org> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matt Turner <mattst88@gmail.com> Cc: Meelis Roos <mroos@linux.ee> Cc: Michael Schmitz <schmitzmic@gmail.com> Cc: Russell King <linux@armlinux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Vineet Gupta <vgupta@synopsys.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'arch/alpha/kernel')
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/alpha/kernel/setup.c b/arch/alpha/kernel/setup.c
index 916e42d74a86..03dda3beb3bd 100644
--- a/arch/alpha/kernel/setup.c
+++ b/arch/alpha/kernel/setup.c
@@ -648,6 +648,7 @@ setup_arch(char **cmdline_p)
/* Find our memory. */
+ sparse_init();
/* First guess at cpu cache sizes. Do this before init_arch. */