Serge Semin 0f5cc249ff mips: Fix incorrect max_low_pfn adjustment ... max_low_pfn variable is incorrectly adjusted if the kernel is built with high memory support and the later is detected in a running system, so the memory which actually can be directly mapped is getting into the highmem zone. See the ZONE_NORMAL range on my MIPS32r5 system: > Zone ranges: > DMA [mem 0x0000000000000000-0x0000000000ffffff] > Normal [mem 0x0000000001000000-0x0000000007ffffff] > HighMem [mem 0x0000000008000000-0x000000020fffffff] while the zones are supposed to look as follows: > Zone ranges: > DMA [mem 0x0000000000000000-0x0000000000ffffff] > Normal [mem 0x0000000001000000-0x000000001fffffff] > HighMem [mem 0x0000000020000000-0x000000020fffffff] Even though the physical memory within the range [0x08000000;0x20000000] belongs to MMIO on our system, we don't really want it to be considered as high memory since on MIPS32 that range still can be directly mapped. Note there might be other problems caused by the max_low_pfn variable misconfiguration. For instance high_memory variable is initialize with virtual address corresponding to the max_low_pfn PFN, and by design it must define the upper bound on direct map memory, then end of the normal zone. That in its turn potentially may cause problems in accessing the memory by means of the /dev/mem and /dev/kmem devices. Let's fix the discovered misconfiguration then. It turns out the commit a94e4f24ec ("MIPS: init: Drop boot_mem_map") didn't introduce the max_low_pfn adjustment quite correct. If the kernel is built with high memory support and the system is equipped with high memory, the max_low_pfn variable will need to be initialized with PFN of the most upper directly reachable memory address so the zone normal would be correctly setup. On MIPS that PFN corresponds to PFN_DOWN(HIGHMEM_START). If the system is built with no high memory support and one is detected in the running system, we'll just need to adjust the max_pfn variable to discard the found high memory from the system and leave the max_low_pfn as is, since the later will be less than PFN_DOWN(HIGHMEM_START) anyway by design of the for_each_memblock() loop performed a bit early in the bootmem_init() method. Fixes: a94e4f24ec ("MIPS: init: Drop boot_mem_map") Signed-off-by: Serge Semin <fancer.lancer@gmail.com> Signed-off-by: Thomas Bogendoerfer <tsbogend@alpha.franken.de>		2023-12-21 15:31:46 +01:00
..
alchemy	MIPS: Alchemy: only build mmc support helpers if au1xmmc is enabled	2023-09-25 11:43:55 +02:00
ath25	MIPS: ath25: Constify static irq_domain_ops	2022-02-22 09:39:03 +01:00
ath79	MIPS: ath79: remove obsolete ATH79_DEV_* configs	2023-03-17 10:28:04 +01:00
bcm47xx	mips: implement the new page table range API	2023-08-24 16:20:22 -07:00
bcm63xx	MIPS: BCM63xx: Add check for NULL for clk in clk_enable	2022-12-09 23:37:06 +01:00
bmips	MIPS: Explicitly include correct DT includes	2023-07-25 10:42:01 +02:00
boot	MIPS: compressed: Use correct instruction for 64 bit code	2023-12-21 15:30:03 +01:00
cavium-octeon	just cleanups and fixes	2023-09-07 10:35:14 -07:00
cobalt
configs	MIPS: AR7: remove platform	2023-10-19 10:39:46 +02:00
crypto	crypto: mips/crc32 - remove redundant setting of alignmask to 0	2023-10-27 18:04:24 +08:00
dec	MIPS: fix typos in comments	2022-05-04 22:22:59 +02:00
fw	MIPS: fw: Allow firmware to pass a empty env	2023-04-12 15:07:36 +02:00
generic	mips: ingenic: Enable EXT/2 divider on JZ4750/55/60 if EXT is 24 MHz	2023-06-09 09:54:17 +02:00
include	mips: dmi: Fix early remap on MIPS32	2023-12-21 15:31:25 +01:00
ingenic
jazz	vgacon, arch/*: remove unused screen_info definitions	2023-10-17 10:17:02 +02:00
kernel	mips: Fix incorrect max_low_pfn adjustment	2023-12-21 15:31:46 +01:00
kvm	MIPS: KVM: Fix a build warning about variable set but not used	2023-10-19 10:25:31 +02:00
lantiq	MIPS: Fixup explicit DT include clean-up	2023-07-28 11:41:09 +02:00
lib	mips: implement xor_unlock_is_negative_byte	2023-10-18 14:34:17 -07:00
loongson2ef	MIPS: loongson2ef: Add missing break in cs5536_isa	2023-04-12 15:12:24 +02:00
loongson32	MIPS: loongson32: Remove dma.h and nand.h	2023-10-06 10:10:13 +02:00
loongson64	MIPS: Loongson64: Handle more memory types passed from firmware	2023-12-05 18:45:24 +01:00
math-emu	MIPS: Fix comment typo	2022-09-12 15:33:24 +02:00
mm	mips: use nth_page() in place of direct struct page manipulation	2023-10-04 10:32:29 -07:00
mti-malta	vgacon: clean up global screen_info instances	2023-10-17 10:17:02 +02:00
n64
net	bpf, mips: Implement R4000 workarounds for JIT	2023-02-28 14:52:55 +01:00
pci	MIPS: lantiq: Remove unnecessary include of <linux/of_irq.h>	2023-10-19 10:26:17 +02:00
pic32	MIPS: Fixup explicit DT include clean-up	2023-07-28 11:41:09 +02:00
power
ralink	MIPS: More explicit DT include clean-ups	2023-07-28 11:41:18 +02:00
rb532	MIPS: rb532: move GPIOD definition into C-files	2022-03-30 20:26:26 +02:00
sgi-ip22	driver core: make struct bus_type.uevent() take a const *	2023-01-27 13:45:52 +01:00
sgi-ip27	MIPS: SGI-IP27: hubio: fix nasid kernel-doc warning	2023-12-11 21:42:53 +01:00
sgi-ip30	MIPS: SGI-IP30: Fix platform-device leak in bridge_platform_create()	2022-09-19 16:32:54 +02:00
sgi-ip32	MIPS: Allow modules to set board_be_handler	2021-11-09 16:07:26 +01:00
sibyte	vgacon: fix mips/sibyte build regression	2023-10-24 08:54:37 +02:00
sni	vgacon: clean up global screen_info instances	2023-10-17 10:17:02 +02:00
tools	MIPS: fix typos in comments	2022-05-04 22:22:59 +02:00
txx9	MIPS: TXx9: Do PCI error checks on own line	2023-08-28 09:59:06 +02:00
vdso	MIPS: VDSO: Conditionally export __vdso_gettimeofday()	2023-08-23 09:06:38 +02:00
Kbuild	kbuild: remove --include-dir MAKEFLAG from top Makefile	2023-02-05 18:51:22 +09:00
Kbuild.platforms	MIPS: AR7: remove platform	2023-10-19 10:39:46 +02:00
Kconfig	MIPS: Loongson64: Enable DMA noncoherent support	2023-12-05 18:45:14 +01:00
Kconfig.debug
Makefile	Revert MIPS: Loongson: Fix build error when make modules_install	2023-07-25 10:42:01 +02:00
Makefile.postlink	kbuild: remove ARCH_POSTLINK from module builds	2023-10-28 21:10:08 +09:00