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  1. 29 Mar, 2021 1 commit
    • Tiezhu Yang's avatar
      MIPS/bpf: Enable bpf_probe_read{, str}() on MIPS again · 66633abd
      Tiezhu Yang authored 
      After commit 0ebeea8c ("bpf: Restrict bpf_probe_read{, str}() only to
archs where they work"), bpf_probe_read{, str}() functions were no longer
available on MIPS, so there exist some errors when running bpf program:

root@linux:/home/loongson/bcc# python examples/tracing/task_switch.py
bpf: Failed to load program: Invalid argument
[...]
11: (85) call bpf_probe_read#4
unknown func bpf_probe_read#4
[...]
Exception: Failed to load BPF program count_sched: Invalid argument

ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE should be restricted to archs
with non-overlapping address ranges, but they can overlap in EVA mode
on MIPS, so select ARCH_HAS_NON_OVERLAPPING_ADDRESS_SPACE if !EVA in
arch/mips/Kconfig, otherwise the bpf old helper bpf_probe_read() will
not be available.

This is similar with the commit d195b1d1 ("powerpc/bpf: Enable
bpf_probe_read{, str}() on powerpc again").

Fixes: 0ebeea8c ("bpf: Restrict bpf_probe_read{, str}() only to archs where they work")
Signed-off-by: default avatarTiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
      66633abd
  3. 25 Mar, 2021 9 commits
  5. 24 Mar, 2021 10 commits
  7. 14 Mar, 2021 2 commits
    • Wang Qing's avatar
      mips: kernel: use DEFINE_DEBUGFS_ATTRIBUTE with debugfs_create_file_unsafe() · 63d6c981
      Wang Qing authored 
      debugfs_create_file_unsafe does not protect the fops handed to it
against file removal. DEFINE_DEBUGFS_ATTRIBUTE makes the fops aware of
the file lifetime and thus protects it against removal.
Signed-off-by: default avatarWang Qing <wangqing@vivo.com>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
      63d6c981
    • Huang Pei's avatar
      MIPS: clean up CONFIG_MIPS_PGD_C0_CONTEXT handling · c6972fb9
      Huang Pei authored 
      +. LOONGSON64 use 0x98xx_xxxx_xxxx_xxxx as xphys cached, instread of
0xa8xx_xxxx_xxxx_xxxx

+. let CONFIG_MIPS_PGD_C0_CONTEXT depend on 64bit

+. cast CAC_BASE into u64 to silence warning on MIPS32

CP0 Context has enough room for wraping pgd into its 41-bit PTEBase field.

+. For XPHYS, the trick is that pgd is 4kB aligned, and the PABITS <= 53,
only save 53 - 12 = 41 bits, aka :

   bit[63:59] | 0000 00 |  bit[53:12] | 0000 0000 0000

+. for CKSEG0, only save 29 - 12 = 17 bits

when switching pgd, only need to save bit[53:12] or bit[28:12] into
CP0 Context's bit[63:23], see folling asm generated at run time

tlbmiss_handler_setup_pgd:
	.set	push
	.set	noreorder

	dsra	a2, a0, 29
	move	a3, a0
	dins	a0, zero, 29, 35
	daddiu	a2, a2, 4	//for CKSEG0, a2 from 0xfffffffffffffffc
				//into 0

	movn	a0, a3, a2
	dsll	a0, a0, 11
	jr	ra
	dmtc0	a0, CP0_CONTEXT

	.set	pop

when using it on page walking

	dmfc0	k0, CP0_CONTEXT
	dins	k0, zero, 0, 23	         // zero badv2
	ori	k0, k0, (CAC_BASE >> 53) // *prefix* with bit[63:59]
	drotr	k0, k0, 11		 // kick it in the right place
Signed-off-by: default avatarHuang Pei <huangpei@loongson.cn>
Signed-off-by: default avatarThomas Bogendoerfer <tsbogend@alpha.franken.de>
      c6972fb9
  9. 12 Mar, 2021 18 commits
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