kernel/git/stable/linux.git/arch/parisc/include, branch linux-5.7.y

parisc: Implement __smp_store_release and __smp_load_acquire barriers

2020-08-19T06:24:17+00:00

commit e96ebd589debd9a6a793608c4ec7019c38785dea upstream. This patch implements the __smp_store_release and __smp_load_acquire barriers using ordered stores and loads. This avoids the sync instruction present in the generic implementation. Cc: # 4.14+ Signed-off-by: Dave Anglin Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Revert "Release spinlocks using ordered store""

2020-08-19T06:24:17+00:00

commit 157e9afcc4fa25068b0e8743bc254a9b56010e13 upstream. This reverts commit 86d4d068df573a8c2105554624796c086d6bec3d. Signed-off-by: Helge Deller Cc: # v5.0+ Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Use ldcw instruction for SMP spinlock release barrier"

2020-08-19T06:24:17+00:00

commit 6e9f06ee6c9566f3606d93182ac8f803a148504b upstream. This reverts commit 9e5c602186a692a7e848c0da17aed40f49d30519. No need to use the ldcw instruction as SMP spinlock release barrier. Revert it to gain back speed again. Signed-off-by: Helge Deller Cc: # v5.2+ Signed-off-by: Greg Kroah-Hartman

Revert "parisc: Improve interrupt handling in arch_spin_lock_flags()"

2020-08-19T06:24:17+00:00

commit 3d05b8aebc5f10ee3ab129b61100196855dd7249 upstream. This reverts commit 2772f0efd5bbd5413db3d22e363b779ca0fa5310. It turns out that we want to implement the spinlock code differently. Signed-off-by: Helge Deller Cc: # v5.7+ Signed-off-by: Greg Kroah-Hartman

parisc: add support for cmpxchg on u8 pointers

2020-08-05T07:58:49+00:00

[ Upstream commit b344d6a83d01c52fddbefa6b3b4764da5b1022a0 ] The kernel test bot reported[1] that using set_mask_bits on a u8 causes the following issue on parisc: hppa-linux-ld: drivers/phy/ti/phy-tusb1210.o: in function `tusb1210_probe': >> (.text+0x2f4): undefined reference to `__cmpxchg_called_with_bad_pointer' >> hppa-linux-ld: (.text+0x324): undefined reference to `__cmpxchg_called_with_bad_pointer' hppa-linux-ld: (.text+0x354): undefined reference to `__cmpxchg_called_with_bad_pointer' Add support for cmpxchg on u8 pointers. [1] https://lore.kernel.org/patchwork/patch/1272617/#1468946 Reported-by: kernel test robot Signed-off-by: Liam Beguin Tested-by: Dave Anglin Signed-off-by: Helge Deller Signed-off-by: Sasha Levin

parisc: Add atomic64_set_release() define to avoid CPU soft lockups

2020-07-29T08:19:59+00:00

commit be6577af0cef934ccb036445314072e8cb9217b9 upstream. Stalls are quite frequent with recent kernels. I enabled CONFIG_SOFTLOCKUP_DETECTOR and I caught the following stall: watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [cc1:22803] CPU: 0 PID: 22803 Comm: cc1 Not tainted 5.6.17+ #3 Hardware name: 9000/800/rp3440 IAOQ[0]: d_alloc_parallel+0x384/0x688 IAOQ[1]: d_alloc_parallel+0x388/0x688 RP(r2): d_alloc_parallel+0x134/0x688 Backtrace: [<000000004036974c>] __lookup_slow+0xa4/0x200 [<0000000040369fc8>] walk_component+0x288/0x458 [<000000004036a9a0>] path_lookupat+0x88/0x198 [<000000004036e748>] filename_lookup+0xa0/0x168 [<000000004036e95c>] user_path_at_empty+0x64/0x80 [<000000004035d93c>] vfs_statx+0x104/0x158 [<000000004035dfcc>] __do_sys_lstat64+0x44/0x80 [<000000004035e5a0>] sys_lstat64+0x20/0x38 [<0000000040180054>] syscall_exit+0x0/0x14 The code was stuck in this loop in d_alloc_parallel: 4037d414: 0e 00 10 dc ldd 0(r16),ret0 4037d418: c7 fc 5f ed bb,< ret0,1f,4037d414 4037d41c: 08 00 02 40 nop This is the inner loop of bit_spin_lock which is called by hlist_bl_unlock in d_alloc_parallel: static inline void bit_spin_lock(int bitnum, unsigned long *addr) { /* * Assuming the lock is uncontended, this never enters * the body of the outer loop. If it is contended, then * within the inner loop a non-atomic test is used to * busywait with less bus contention for a good time to * attempt to acquire the lock bit. */ preempt_disable(); #if defined(CONFIG_SMP) || defined(CONFIG_DEBUG_SPINLOCK) while (unlikely(test_and_set_bit_lock(bitnum, addr))) { preempt_enable(); do { cpu_relax(); } while (test_bit(bitnum, addr)); preempt_disable(); } #endif __acquire(bitlock); } After consideration, I realized that we must be losing bit unlocks. Then, I noticed that we missed defining atomic64_set_release(). Adding this define fixes the stalls in bit operations. Signed-off-by: Dave Anglin Cc: stable@vger.kernel.org Signed-off-by: Helge Deller Signed-off-by: Greg Kroah-Hartman

mm/special: create generic fallbacks for pte_special() and pte_mkspecial()

2020-04-10T22:36:21+00:00

Currently there are many platforms that dont enable ARCH_HAS_PTE_SPECIAL but required to define quite similar fallback stubs for special page table entry helpers such as pte_special() and pte_mkspecial(), as they get build in generic MM without a config check. This creates two generic fallback stub definitions for these helpers, eliminating much code duplication. mips platform has a special case where pte_special() and pte_mkspecial() visibility is wider than what ARCH_HAS_PTE_SPECIAL enablement requires. This restricts those symbol visibility in order to avoid redefinitions which is now exposed through this new generic stubs and subsequent build failure. arm platform set_pte_at() definition needs to be moved into a C file just to prevent a build failure. [anshuman.khandual@arm.com: use defined(CONFIG_ARCH_HAS_PTE_SPECIAL) in mips per Thomas] Link: http://lkml.kernel.org/r/1583851924-21603-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Acked-by: Guo Ren [csky] Acked-by: Geert Uytterhoeven [m68k] Acked-by: Stafford Horne [openrisc] Acked-by: Helge Deller [parisc] Cc: Richard Henderson Cc: Ivan Kokshaysky Cc: Matt Turner Cc: Russell King Cc: Brian Cain Cc: Tony Luck Cc: Fenghua Yu Cc: Sam Creasey Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Greentime Hu Cc: Vincent Chen Cc: Ley Foon Tan Cc: Jonas Bonn Cc: Stefan Kristiansson Cc: "James E.J. Bottomley" Cc: "David S. Miller" Cc: Jeff Dike Cc: Richard Weinberger Cc: Anton Ivanov Cc: Guan Xuetao Cc: Chris Zankel Cc: Max Filippov Cc: Thomas Bogendoerfer Link: http://lkml.kernel.org/r/1583802551-15406-1-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

mm/vma: define a default value for VM_DATA_DEFAULT_FLAGS

2020-04-10T22:36:21+00:00

There are many platforms with exact same value for VM_DATA_DEFAULT_FLAGS This creates a default value for VM_DATA_DEFAULT_FLAGS in line with the existing VM_STACK_DEFAULT_FLAGS. While here, also define some more macros with standard VMA access flag combinations that are used frequently across many platforms. Apart from simplification, this reduces code duplication as well. Signed-off-by: Anshuman Khandual Signed-off-by: Andrew Morton Reviewed-by: Vlastimil Babka Acked-by: Geert Uytterhoeven Cc: Richard Henderson Cc: Vineet Gupta Cc: Russell King Cc: Catalin Marinas Cc: Mark Salter Cc: Guo Ren Cc: Yoshinori Sato Cc: Brian Cain Cc: Tony Luck Cc: Michal Simek Cc: Ralf Baechle Cc: Paul Burton Cc: Nick Hu Cc: Ley Foon Tan Cc: Jonas Bonn Cc: "James E.J. Bottomley" Cc: Michael Ellerman Cc: Paul Walmsley Cc: Heiko Carstens Cc: Rich Felker Cc: "David S. Miller" Cc: Guan Xuetao Cc: Thomas Gleixner Cc: Jeff Dike Cc: Chris Zankel Link: http://lkml.kernel.org/r/1583391014-8170-2-git-send-email-anshuman.khandual@arm.com Signed-off-by: Linus Torvalds

parisc: Rework arch_rw locking functions

2020-04-05T20:29:55+00:00

Clean up the arch read/write locking functions based on the arc implemenation. This improves readability of those functions. Signed-off-by: Helge Deller

parisc: Improve interrupt handling in arch_spin_lock_flags()

2020-04-05T20:16:38+00:00

Rewrite arch_spin_lock() and arch_spin_lock_flags() to not re-enable and disable the PSW_SM_I interrupt flag too often. Signed-off-by: Helge Deller