vm_map_base, empty_zero_page and invalid_pmd_table could be accessed
widely by some out-of-tree non-GPL but important file systems or drivers
(e.g. OpenZFS). Let's use EXPORT_SYMBOL() instead of EXPORT_SYMBOL_GPL()
to export them, so as to avoid build errors.
1, Details about vm_map_base:
This is a LoongArch-specific symbol and may be referenced through macros
PCI_IOBASE, VMALLOC_START and VMALLOC_END.
2, Details about empty_zero_page:
As it stands today, only 3 architectures export empty_zero_page as a GPL
symbol: IA64, LoongArch and MIPS. LoongArch gets the GPL export by
inheriting from MIPS, and the MIPS export was first introduced in commit
497d2adcbf ("[MIPS] Export empty_zero_page for sake of the ext4
module."). The IA64 export was similar: commit a7d57ecf42 ("[IA64]
Export three symbols for module use") did so for kvm.
In both IA64 and MIPS, the export of empty_zero_page was done for
satisfying some in-kernel component built as module (kvm and ext4
respectively), and given its reasonably low-level nature, GPL is a
reasonable choice. But looking at the bigger picture it is evident most
other architectures do not regard it as GPL, so in effect the symbol
probably should not be treated as such, in favor of consistency.
3, Details about invalid_pmd_table:
Keep consistency with invalid_pte_table and make it be possible by some
modules.
Cc: stable@vger.kernel.org
Reviewed-by: WANG Xuerui <git@xen0n.name>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
We can support more cache attributes (e.g., CC, SUC and WUC) and page
protection when we use TLB for ioremap(). The implementation is based
on GENERIC_IOREMAP.
The existing simple ioremap() implementation has better performance so
we keep it and introduce ARCH_IOREMAP to control the selection.
We move pagetable_init() earlier to make early ioremap() works, and we
modify the PCI ecam mapping because the TLB-based version of ioremap()
will actually take the size into account.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
The kernel build error when unslected CONFIG_MEMORY_HOTREMOVE because
arch_remove_memory() is needed by mm/memory_hotplug.c but undefined.
Some build error messages like:
LD vmlinux.o
MODPOST vmlinux.symvers
MODINFO modules.builtin.modinfo
GEN modules.builtin
LD .tmp_vmlinux.kallsyms1
loongarch64-linux-gnu-ld: mm/memory_hotplug.o: in function `.L242':
memory_hotplug.c:(.ref.text+0x930): undefined reference to `arch_remove_memory'
make: *** [Makefile:1169：vmlinux] 错误 1
Removed CONFIG_MEMORY_HOTREMOVE requirement and rearrange the file refer
to the definitions of other platform architectures.
Signed-off-by: Yupeng Li <liyupeng@zbhlos.com>
Signed-off-by: Caicai <caizp2008@163.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Add Non-Uniform Memory Access (NUMA) support for LoongArch. LoongArch
has 48-bit physical address, but the HyperTransport I/O bus only support
40-bit address, so we need a custom phys_to_dma() and dma_to_phys() to
extract the 4-bit node id (bit 44~47) from Loongson-3's 48-bit physical
address space and embed it into 40-bit. In the 40-bit dma address, node
id offset can be read from the LS7A_DMA_CFG register.
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
Add memory management support for LoongArch, including: cache and tlb
management, page fault handling and ioremap/mmap support.
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
