kernel.git/arch/riscv/kernel/setup.c, branch linux-4.19.y

riscv: set max_pfn to the PFN of the last page

2020-05-27T15:37:28Z

commit c749bb2d554825e007cbc43b791f54e124dadfce upstream. The current max_pfn equals to zero. In this case, I found it caused users cannot get some page information through /proc such as kpagecount in v5.6 kernel because of new sanity checks. The following message is displayed by stress-ng test suite with the command "stress-ng --verbose --physpage 1 -t 1" on HiFive unleashed board. # stress-ng --verbose --physpage 1 -t 1 stress-ng: debug: [109] 4 processors online, 4 processors configured stress-ng: info: [109] dispatching hogs: 1 physpage stress-ng: debug: [109] cache allocate: reducing cache level from L3 (too high) to L0 stress-ng: debug: [109] get_cpu_cache: invalid cache_level: 0 stress-ng: info: [109] cache allocate: using built-in defaults as no suitable cache found stress-ng: debug: [109] cache allocate: default cache size: 2048K stress-ng: debug: [109] starting stressors stress-ng: debug: [109] 1 stressor spawned stress-ng: debug: [110] stress-ng-physpage: started [110] (instance 0) stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd34de000 in /proc/kpagecount, errno=0 (Success) stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success) ... stress-ng: error: [110] stress-ng-physpage: cannot read page count for address 0x3fd32db078 in /proc/kpagecount, errno=0 (Success) stress-ng: debug: [110] stress-ng-physpage: exited [110] (instance 0) stress-ng: debug: [109] process [110] terminated stress-ng: info: [109] successful run completed in 1.00s # After applying this patch, the kernel can pass the test. # stress-ng --verbose --physpage 1 -t 1 stress-ng: debug: [104] 4 processors online, 4 processors configured stress-ng: info: [104] dispatching hogs: 1 physpage stress-ng: info: [104] cache allocate: using defaults, can't determine cache details from sysfs stress-ng: debug: [104] cache allocate: default cache size: 2048K stress-ng: debug: [104] starting stressors stress-ng: debug: [104] 1 stressor spawned stress-ng: debug: [105] stress-ng-physpage: started [105] (instance 0) stress-ng: debug: [105] stress-ng-physpage: exited [105] (instance 0) stress-ng: debug: [104] process [105] terminated stress-ng: info: [104] successful run completed in 1.01s # Cc: stable@vger.kernel.org Signed-off-by: Vincent Chen Reviewed-by: Anup Patel Reviewed-by: Yash Shah Tested-by: Yash Shah Signed-off-by: Palmer Dabbelt [Palmer: back-ported to 4.19] Signed-off-by: Palmer Dabbelt Signed-off-by: Greg Kroah-Hartman

riscv: fixup max_low_pfn with PFN_DOWN.

2019-03-13T21:02:27Z

[ Upstream commit 28198c4639b39899a728ac89aea29d2a7a72562f ] max_low_pfn should be pfn_size not byte_size. Signed-off-by: Guo Ren Signed-off-by: Mao Han Signed-off-by: Palmer Dabbelt Signed-off-by: Sasha Levin

RISCV: Fix end PFN for low memory

2018-10-02T19:50:01Z

Use memblock_end_of_DRAM which provides correct last low memory PFN. Without that, DMA32 region becomes empty resulting in zero pages being allocated for DMA32. This patch is based on earlier patch from palmer which never merged into 4.19. I just edited the commit text to make more sense. Signed-off-by: Atish Patra Signed-off-by: Palmer Dabbelt

riscv: Do not overwrite initrd_start and initrd_end

2018-09-05T00:04:50Z

setup_initrd() overwrites initrd_start and initrd_end if __initramfs_size is larger than 0, which is always true even if there is no embedded initramfs. This prevents booting qemu with "-initrd" parameter. Overwriting initrd_start and initrd_end is not necessary since __initramfs_start and __initramfs_size are used directly in populate_rootfs() to load the built-in initramfs, so just drop that code. Signed-off-by: Guenter Roeck Signed-off-by: Palmer Dabbelt

RISC-V: Add early printk support via the SBI console

2018-08-13T15:31:30Z

This code lives entirely within the RISC-V arch code. I've left it within an "#ifdef CONFIG_EARLY_PRINTK" despite always having EARLY_PRINTK support on RISC-V just in case someone wants to remove it. Reviewed-by: Christoph Hellwig Signed-off-by: Palmer Dabbelt

riscv: remove unnecessary of_platform_populate call

2018-07-04T21:12:38Z

The DT core will call of_platform_default_populate, so it is not necessary for arch specific code to call it unless there are custom match entries, auxdata or parent device. Neither of those apply here, so remove the call. Cc: Palmer Dabbelt Cc: Albert Ou Cc: linux-riscv@lists.infradead.org Signed-off-by: Rob Herring Signed-off-by: Palmer Dabbelt

riscv: add swiotlb support

2018-05-19T06:46:26Z

All RISC-V platforms today lack an IOMMU. However, legacy PCI devices sometimes require DMA-memory to be in the low 32 bits. To make this work, we enable the software-based bounce buffers from swiotlb. They only impose overhead when the device in question cannot address the full 64-bit address space, so a perfect fit. This patch assumes that DMA is coherent with the processor and the PCI bus. It also assumes that the processor and devices share a common address space. This is true for all RISC-V platforms so far. [changelog stolen from an earlier patch by Palmer Dabbelt that did the more complicated swiotlb wireup before the recent consolidation] Signed-off-by: Christoph Hellwig Reviewed-by: Palmer Dabbelt

Rename sbi_save to parse_dtb to improve code readability

2018-02-20T18:56:26Z

The sbi_ prefix would seem to indicate an SBI interface, and save is not very specific. After applying this patch, reading head.S makes more sense. Signed-off-by: Michael Clark Signed-off-by: Palmer Dabbelt

riscv: add ZONE_DMA32

2018-01-31T03:14:27Z

This patch allows devices that require memory that can be addressed using 32-bit addresses to work easily on RISC-V systems. The newly improved dma-direct ops will tap into this pool automatically for 32-bit addressing. Based on an earlier patch from Wesley W. Terpstra. CC: Wesley W. Terpstra Signed-off-by: Christoph Hellwig Signed-off-by: Palmer Dabbelt

RISC-V: Remove mem_end command line processing

2018-01-31T03:09:53Z

This is just some cruft left over from before the port converted to device tree. The right way to handle memory regions is to specify them in the device tree, which BBL (our simplest bootloader) is already capable of doing. This patch simply removes the cruft. Signed-off-by: Palmer Dabbelt