- 02 10月, 2014 2 次提交
-
-
由 Anton Blanchard 提交于
There is no need for yet another copy of the command line, just use boot_command_line like everyone else. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Anton Blanchard 提交于
Unroll clear_page 8 times. A simple microbenchmark which allocates and frees a zeroed page: for (i = 0; i < iterations; i++) { unsigned long p = __get_free_page(GFP_KERNEL | __GFP_ZERO); free_page(p); } improves 20% on POWER8. This assumes cacheline sizes won't grow beyond 512 bytes or page sizes wont drop below 1kB, which is unlikely, but we could add a runtime check during early init if it makes people nervous. Michael found that some versions of gcc produce quite bad code (all multiplies), so we give gcc a hand by using shifts and adds. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
- 30 9月, 2014 11 次提交
-
-
由 Gavin Shan 提交于
The dma_get_required_mask() function is used by some drivers to query the platform about what DMA mask is needed to cover all of memory. This is a bit of a strange semantic when we have to choose between IOMMU translation or bypass, but essentially what it means is "what DMA mask will give best performances". Currently, our IOMMU backend always returns a 32-bit mask here, we don't do anything special to it when we have bypass available. This causes some drivers to choose a 32-bit mask, thus losing the ability to use the bypass window, thinking this is more efficient. The problem was reported from the driver of following device: 0004:03:00.0 0107: 1000:0087 (rev 05) 0004:03:00.0 Serial Attached SCSI controller: LSI Logic / Symbios \ Logic SAS2308 PCI-Express Fusion-MPT SAS-2 (rev 05) This patch adds an override of that function in order to, instead, return a 64-bit mask whenever a bypass window is available in order for drivers to prefer this configuration. Reported-by: NMurali N. Iyer <mniyer@us.ibm.com> Suggested-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org> Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Gavin Shan 提交于
When enabling EEH functionality on passed through devices (PE) with VFIO, the devices in the PE would be removed permanently from guest side. In that case, the PE remains frozen state. When returning PE to host, or restarting the guest again, we had mechanism unfreezing the PE by clearing PESTA/B frozen bits. However, that's not enough for some adapters, which are indicated as following "lspci" shows. Those adapters require hot reset on the parent bus to bring their firmware back to workable state. Otherwise, those adaptrs won't be operative and the host (for returning case) or the guest will fail to load the drivers for those adapters without exception. 0000:01:00.0 Ethernet controller: Emulex Corporation OneConnect \ 10Gb NIC (be3) (rev 02) 0000:01:00.0 0200: 19a2:0710 (rev 02) 0001:03:00.0 Ethernet controller: Emulex Corporation OneConnect \ NIC (Lancer) (rev 10) 0001:03:00.0 0200: 10df:e220 (rev 10) The patch adds mechanism to emulate EEH recovery (for hot reset on parent PCI bus) on 3 gates to fix the issue: open/release one adapter of the PE, enable EEH functionality on one adapter of the PE. Reported-by: NMurilo Fossa Vicentini <muvic@br.ibm.com> Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Gavin Shan 提交于
The names of PCI reset scopes aren't sychronized with firmware. The patch fixes it. Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Gavin Shan 提交于
When passing through PE to guest, that's possibly in frozen state. The driver for the pass-through devices on guest side can't be loaded successfully as reported. We already had one gate in eeh_dev_open() to clear PE frozen state accordingly, but that's not enough because the function is only called at QEMU startup for once. The patch adds another gate in eeh_pe_set_option() so that the PE frozen state can be cleared at QEMU restart time. Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Gavin Shan 提交于
The patch introduces eeh_ops::err_inject(), which allows to inject specified errors to indicated PE for testing purpose. The functionality isn't support on pSeries platform. On PowerNV, the functionality relies on OPAL API opal_pci_err_inject(). Signed-off-by: NMike Qiu <qiudayu@linux.vnet.ibm.com> Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Gavin Shan 提交于
The patch synchronizes firmware header file (opal.h) for PCI error injection. Signed-off-by: NMike Qiu <qiudayu@linux.vnet.ibm.com> Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Gavin Shan 提交于
The patch adds one more option (EEH_OPT_FREEZE_PE) to set_option() method to proactively freeze PE, which will be issued before resetting pass-throughed PE to drop MMIO access during reset because it's always contributing to recursive EEH error. Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Gavin Shan 提交于
eeh_check_failure() is used to check frozen state of the PE which owns the indicated I/O address. The argument "val" of the function isn't used. The patch drops it and return the frozen state of the PE as expected. Cc: Vishal Mansur <vmansur@linux.vnet.ibm.com> Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Anton Blanchard 提交于
Use cmpb which compares each byte in two 64 bit values and for each matching byte places 0xff in the target and 0x00 otherwise. A simple hash_name microbenchmark: http://ozlabs.org/~anton/junkcode/hash_name_bench.c shows this version to be 10-20% faster than running the x86 version on POWER8, depending on the length. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Michael Ellerman 提交于
It is a rarely exercised case, so we want to have a test to ensure it works as required. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Anton Blanchard 提交于
Implement a bi-arch and bi-endian version of load_unaligned_zeropad. Since the fallback case is so rare, a userspace test harness was used to test this on ppc64le, ppc64 and ppc32: http://ozlabs.org/~anton/junkcode/test_load_unaligned_zeropad.c It uses mprotect to force a SEGV across a page boundary, and a SEGV handler to lookup the exception tables and run the fixup routine. It also compares the result against a normal load. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
- 25 9月, 2014 7 次提交
-
-
由 Wei Yang 提交于
When doing vfio passthrough a VF, the kernel will crash with following message: [ 442.656459] Unable to handle kernel paging request for data at address 0x00000060 [ 442.656593] Faulting instruction address: 0xc000000000038b88 [ 442.656706] Oops: Kernel access of bad area, sig: 11 [#1] [ 442.656798] SMP NR_CPUS=1024 NUMA PowerNV [ 442.656890] Modules linked in: vfio_pci mlx4_core nf_conntrack_netbios_ns nf_conntrack_broadcast ipt_MASQUERADE ip6t_REJECT xt_conntrack bnep bluetooth rfkill ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw tg3 nfsd be2net nfs_acl ses lockd ptp enclosure pps_core kvm_hv kvm_pr shpchp binfmt_misc kvm sunrpc uinput lpfc scsi_transport_fc ipr scsi_tgt [last unloaded: mlx4_core] [ 442.658152] CPU: 40 PID: 14948 Comm: qemu-system-ppc Not tainted 3.10.42yw-pkvm+ #37 [ 442.658219] task: c000000f7e2a9a00 ti: c000000f6dc3c000 task.ti: c000000f6dc3c000 [ 442.658287] NIP: c000000000038b88 LR: c0000000004435a8 CTR: c000000000455bc0 [ 442.658352] REGS: c000000f6dc3f580 TRAP: 0300 Not tainted (3.10.42yw-pkvm+) [ 442.658419] MSR: 9000000000009032 <SF,HV,EE,ME,IR,DR,RI> CR: 28004882 XER: 20000000 [ 442.658577] CFAR: c00000000000908c DAR: 0000000000000060 DSISR: 40000000 SOFTE: 1 GPR00: c0000000004435a8 c000000f6dc3f800 c0000000012b1c10 c00000000da24000 GPR04: 0000000000000003 0000000000001004 00000000000015b3 000000000000ffff GPR08: c00000000127f5d8 0000000000000000 000000000000ffff 0000000000000000 GPR12: c000000000068078 c00000000fdd6800 000001003c320c80 000001003c3607f0 GPR16: 0000000000000001 00000000105480c8 000000001055aaa8 000001003c31ab18 GPR20: 000001003c10fb40 000001003c360ae8 000000001063bcf0 000000001063bdb0 GPR24: 000001003c15ed70 0000000010548f40 c000001fe5514c88 c000001fe5514cb0 GPR28: c00000000da24000 0000000000000000 c00000000da24000 0000000000000003 [ 442.659471] NIP [c000000000038b88] .pcibios_set_pcie_reset_state+0x28/0x130 [ 442.659530] LR [c0000000004435a8] .pci_set_pcie_reset_state+0x28/0x40 [ 442.659585] Call Trace: [ 442.659610] [c000000f6dc3f800] [00000000000719e0] 0x719e0 (unreliable) [ 442.659677] [c000000f6dc3f880] [c0000000004435a8] .pci_set_pcie_reset_state+0x28/0x40 [ 442.659757] [c000000f6dc3f900] [c000000000455bf8] .reset_fundamental+0x38/0x80 [ 442.659835] [c000000f6dc3f980] [c0000000004562a8] .pci_dev_specific_reset+0xa8/0xf0 [ 442.659913] [c000000f6dc3fa00] [c0000000004448c4] .__pci_dev_reset+0x44/0x430 [ 442.659980] [c000000f6dc3fab0] [c000000000444d5c] .pci_reset_function+0x7c/0xc0 [ 442.660059] [c000000f6dc3fb30] [d00000001c141ab8] .vfio_pci_open+0xe8/0x2b0 [vfio_pci] [ 442.660139] [c000000f6dc3fbd0] [c000000000586c30] .vfio_group_fops_unl_ioctl+0x3a0/0x630 [ 442.660219] [c000000f6dc3fc90] [c000000000255fbc] .do_vfs_ioctl+0x4ec/0x7c0 [ 442.660286] [c000000f6dc3fd80] [c000000000256364] .SyS_ioctl+0xd4/0xf0 [ 442.660354] [c000000f6dc3fe30] [c000000000009e54] syscall_exit+0x0/0x98 [ 442.660420] Instruction dump: [ 442.660454] 4bfffce9 4bfffee4 7c0802a6 fbc1fff0 fbe1fff8 f8010010 f821ff81 7c7e1b78 [ 442.660566] 7c9f2378 60000000 60000000 e93e02c8 <e8690060> 2fa30000 41de00c4 2b9f0002 [ 442.660679] ---[ end trace a64ac9546bcf0328 ]--- [ 442.660724] The reason is current VF is not EEH enabled. This patch introduces a macro to convert eeh_dev to eeh_pe. By doing so, it will prevent converting with NULL pointer. Signed-off-by: NWei Yang <weiyang@linux.vnet.ibm.com> Acked-by: NGavin Shan <gwshan@linux.vnet.ibm.com> CC: Michael Ellerman <mpe@ellerman.id.au> V3 -> V4: 1. move the macro definition from include/linux/pci.h to arch/powerpc/include/asm/eeh.h V2 -> V3: 1. rebased on 3.17-rc4 2. introduce a macro 3. use this macro in several other places V1 -> V2: 1. code style and patch subject adjustment Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Paul Mackerras 提交于
This extends the instruction emulation done by analyse_instr() and emulate_step() to handle a few more instructions that are found in the kernel. Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Paul Mackerras 提交于
This splits out the instruction analysis part of emulate_step() into a separate analyse_instr() function, which decodes the instruction, but doesn't execute any load or store instructions. It does execute integer instructions and branches which can be executed purely by updating register values in the pt_regs struct. For other instructions, it returns the instruction type and other details in a new instruction_op struct. emulate_step() then uses that information to execute loads, stores, cache operations, mfmsr, mtmsr[d], and (on 64-bit) sc instructions. The reason for doing this is so that the KVM code can use it instead of having its own separate instruction emulation code. Possibly the alignment interrupt handler could also use this. Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Paul Mackerras 提交于
On PowerNV platforms, when a CPU is offline, we put it into nap mode. It's possible that the CPU wakes up from nap mode while it is still offline due to a stray IPI. A misdirected device interrupt could also potentially cause it to wake up. In that circumstance, we need to clear the interrupt so that the CPU can go back to nap mode. In the past the clearing of the interrupt was accomplished by briefly enabling interrupts and allowing the normal interrupt handling code (do_IRQ() etc.) to handle the interrupt. This has the problem that this code calls irq_enter() and irq_exit(), which call functions such as account_system_vtime() which use RCU internally. Use of RCU is not permitted on offline CPUs and will trigger errors if RCU checking is enabled. To avoid calling into any generic code which might use RCU, we adopt a different method of clearing interrupts on offline CPUs. Since we are on the PowerNV platform, we know that the system interrupt controller is a XICS being driven directly (i.e. not via hcalls) by the kernel. Hence this adds a new icp_native_flush_interrupt() function to the native-mode XICS driver and arranges to call that when an offline CPU is woken from nap. This new function reads the interrupt from the XICS. If it is an IPI, it clears the IPI; if it is a device interrupt, it prints a warning and disables the source. Then it does the end-of-interrupt processing for the interrupt. The other thing that briefly enabling interrupts did was to check and clear the irq_happened flag in this CPU's PACA. Therefore, after flushing the interrupt from the XICS, we also clear all bits except the PACA_IRQ_HARD_DIS (interrupts are hard disabled) bit from the irq_happened flag. The PACA_IRQ_HARD_DIS flag is set by power7_nap() and is left set to indicate that interrupts are hard disabled. This means we then have to ignore that flag in power7_nap(), which is reasonable since it doesn't indicate that any interrupt event needs servicing. Signed-off-by: NPaul Mackerras <paulus@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Anton Blanchard 提交于
A recent patch added a function prototype for htab_remove_mapping in c code. Fix it. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Anton Blanchard 提交于
There were a number of prototypes for functions that no longer exist. Remove them. Signed-off-by: NAnton Blanchard <anton@samba.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
由 Michael Neuling 提交于
Currently there is no way to generically check if an OPAL call exists or not from the host kernel. This adds an OPAL call opal_check_token() which tells you if the given token is present in OPAL or not. Signed-off-by: NMichael Neuling <mikey@neuling.org> Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au>
-
- 09 9月, 2014 2 次提交
-
-
由 Pranith Kumar 提交于
This patch wires up three new syscalls for powerpc. The three new syscalls are seccomp, getrandom and memfd_create. Signed-off-by: NPranith Kumar <bobby.prani@gmail.com> Reviewed-by: NDavid Herrmann <dh.herrmann@gmail.com>
-
由 Anton Blanchard 提交于
ABIv2 kernels are failing to backtrace through the kernel. An example: 39.30% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry __GI___libc_read The problem is in valid_next_sp() where we check that the new stack pointer is at least STACK_FRAME_OVERHEAD below the previous one. ABIv1 has a minimum stack frame size of 112 bytes consisting of 48 bytes and 64 bytes of parameter save area. ABIv2 changes that to 32 bytes with no paramter save area. STACK_FRAME_OVERHEAD is in theory the minimum stack frame size, but we over 240 uses of it, some of which assume that it includes space for the parameter area. We need to work through all our stack defines and rationalise them but let's fix perf now by creating STACK_FRAME_MIN_SIZE and using in valid_next_sp(). This fixes the issue: 30.64% readseek2_proce [kernel.kallsyms] [k] find_get_entry | --- find_get_entry pagecache_get_page generic_file_read_iter new_sync_read vfs_read sys_read syscall_exit __GI___libc_read Cc: stable@vger.kernel.org # 3.16+ Reported-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NAnton Blanchard <anton@samba.org>
-
- 13 8月, 2014 7 次提交
-
-
由 Aneesh Kumar K.V 提交于
On ppc64 we support 4K hash pte with 64K page size. That requires us to track the hash pte slot information on a per 4k basis. We do that by storing the slot details in the second half of pte page. The pte bit _PAGE_COMBO is used to indicate whether the second half need to be looked while building real_pte. We need to use read memory barrier while doing that so that load of hidx is not reordered w.r.t _PAGE_COMBO check. On the store side we already do a lwsync in __hash_page_4K CC: <stable@vger.kernel.org> Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Aneesh Kumar K.V 提交于
If we changed base page size of the segment, either via sub_page_protect or via remap_4k_pfn, we do a demote_segment which doesn't flush the hash table entries. We do a lazy hash page table flush for all mapped pages in the demoted segment. This happens when we handle hash page fault for these pages. We use _PAGE_COMBO bit along with _PAGE_HASHPTE to indicate whether a pte is backed by 4K hash pte. If we find _PAGE_COMBO not set on the pte, that implies that we could possibly have older 64K hash pte entries in the hash page table and we need to invalidate those entries. Use _PAGE_COMBO to determine the page size with which we should invalidate the hash table entries on unmap. CC: <stable@vger.kernel.org> Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Aneesh Kumar K.V 提交于
The segment identifier and segment size will remain the same in the loop, So we can compute it outside. We also change the hugepage_invalidate interface so that we can use it the later patch CC: <stable@vger.kernel.org> Signed-off-by: NAneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Nishanth Aravamudan 提交于
It appears that commits 7f06f21d ("powerpc/tm: Add checking to treclaim/trechkpt") and e4e38121 ("KVM: PPC: Book3S HV: Add transactional memory support") both added definitions of TEXASR_FS. Remove one of them. At the same time, fix the alignment of the remaining definition (should be tab-separated like the rest of the #defines). Signed-off-by: NNishanth Aravamudan <nacc@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Vasant Hegde 提交于
PowerNV platform is capable of capturing host memory region when system crashes (because of host/firmware). We have new OPAL API to register/ unregister memory region to be captured when system crashes. This patch adds support for new API. Also during boot time we register kernel log buffer and unregister before doing kexec. Signed-off-by: NVasant Hegde <hegdevasant@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Michael Ellerman 提交于
We have been a bit slack about updating the CPU_FTRS_POSSIBLE and CPU_FTRS_ALWAYS masks. When we added POWER8, and also POWER8E we forgot to update the ALWAYS mask. And when we added POWER8_DD1 we forgot to update both the POSSIBLE and ALWAYS masks. Luckily this hasn't caused any actual bugs AFAICS. Failing to update the ALWAYS mask just forgoes a potential optimisation opportunity. Failing to update the POSSIBLE mask for POWER8_DD1 is also OK because it only removes a bit rather than adding any. Regardless they should all be in both masks so as to avoid any future bugs when the set of ALWAYS/POSSIBLE bits changes, or the masks themselves change. Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au> Acked-by: NMichael Neuling <mikey@neuling.org> Acked-by: NJoel Stanley <joel@jms.id.au> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Michael Ellerman 提交于
The kernel defines the function spin_is_locked(), which can be used to check if a spinlock is currently locked. Using spin_is_locked() on a lock you don't hold is obviously racy. That is, even though you may observe that the lock is unlocked, it may become locked at any time. There is (at least) one exception to that, which is if two locks are used as a pair, and the holder of each checks the status of the other before doing any update. Assuming *A and *B are two locks, and *COUNTER is a shared non-atomic value: The first CPU does: spin_lock(*A) if spin_is_locked(*B) # nothing else smp_mb() LOAD r = *COUNTER r++ STORE *COUNTER = r spin_unlock(*A) And the second CPU does: spin_lock(*B) if spin_is_locked(*A) # nothing else smp_mb() LOAD r = *COUNTER r++ STORE *COUNTER = r spin_unlock(*B) Although this is a strange locking construct, it should work. It seems to be understood, but not documented, that spin_is_locked() is not a memory barrier, so in the examples above and below the caller inserts its own memory barrier before acting on the result of spin_is_locked(). For now we assume spin_is_locked() is implemented as below, and we break it out in our examples: bool spin_is_locked(*LOCK) { LOAD l = *LOCK return l.locked } Our intuition is that there should be no problem even if the two code sequences run simultaneously such as: CPU 0 CPU 1 ================================================== spin_lock(*A) spin_lock(*B) LOAD b = *B LOAD a = *A if b.locked # true if a.locked # true # nothing # nothing spin_unlock(*A) spin_unlock(*B) If one CPU gets the lock before the other then it will do the update and the other CPU will back off: CPU 0 CPU 1 ================================================== spin_lock(*A) LOAD b = *B spin_lock(*B) if b.locked # false LOAD a = *A else if a.locked # true smp_mb() # nothing LOAD r1 = *COUNTER spin_unlock(*B) r1++ STORE *COUNTER = r1 spin_unlock(*A) However in reality spin_lock() itself is not indivisible. On powerpc we implement it as a load-and-reserve and store-conditional. Ignoring the retry logic for the lost reservation case, it boils down to: spin_lock(*LOCK) { LOAD l = *LOCK l.locked = true STORE *LOCK = l ACQUIRE_BARRIER } The ACQUIRE_BARRIER is required to give spin_lock() ACQUIRE semantics as defined in memory-barriers.txt: This acts as a one-way permeable barrier. It guarantees that all memory operations after the ACQUIRE operation will appear to happen after the ACQUIRE operation with respect to the other components of the system. On modern powerpc systems we use lwsync for ACQUIRE_BARRIER. lwsync is also know as "lightweight sync", or "sync 1". As described in Power ISA v2.07 section B.2.1.1, in this scenario the lwsync is not the barrier itself. It instead causes the LOAD of *LOCK to act as the barrier, preventing any loads or stores in the locked region from occurring prior to the load of *LOCK. Whether this behaviour is in accordance with the definition of ACQUIRE semantics in memory-barriers.txt is open to discussion, we may switch to a different barrier in future. What this means in practice is that the following can occur: CPU 0 CPU 1 ================================================== LOAD a = *A LOAD b = *B a.locked = true b.locked = true LOAD b = *B LOAD a = *A STORE *A = a STORE *B = b if b.locked # false if a.locked # false else else smp_mb() smp_mb() LOAD r1 = *COUNTER LOAD r2 = *COUNTER r1++ r2++ STORE *COUNTER = r1 STORE *COUNTER = r2 # Lost update spin_unlock(*A) spin_unlock(*B) That is, the load of *B can occur prior to the store that makes *A visibly locked. And similarly for CPU 1. The result is both CPUs hold their lock and believe the other lock is unlocked. The easiest fix for this is to add a full memory barrier to the start of spin_is_locked(), so adding to our previous definition would give us: bool spin_is_locked(*LOCK) { smp_mb() LOAD l = *LOCK return l.locked } The new barrier orders the store to the lock we are locking vs the load of the other lock: CPU 0 CPU 1 ================================================== LOAD a = *A LOAD b = *B a.locked = true b.locked = true STORE *A = a STORE *B = b smp_mb() smp_mb() LOAD b = *B LOAD a = *A if b.locked # true if a.locked # true # nothing # nothing spin_unlock(*A) spin_unlock(*B) Although the above example is theoretical, there is code similar to this example in sem_lock() in ipc/sem.c. This commit in addition to the next commit appears to be a fix for crashes we are seeing in that code where we believe this race happens in practice. Signed-off-by: NMichael Ellerman <mpe@ellerman.id.au> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
- 09 8月, 2014 2 次提交
-
-
由 Andy Lutomirski 提交于
The core mm code will provide a default gate area based on FIXADDR_USER_START and FIXADDR_USER_END if !defined(__HAVE_ARCH_GATE_AREA) && defined(AT_SYSINFO_EHDR). This default is only useful for ia64. arm64, ppc, s390, sh, tile, 64-bit UML, and x86_32 have their own code just to disable it. arm, 32-bit UML, and x86_64 have gate areas, but they have their own implementations. This gets rid of the default and moves the code into ia64. This should save some code on architectures without a gate area: it's now possible to inline the gate_area functions in the default case. Signed-off-by: NAndy Lutomirski <luto@amacapital.net> Acked-by: NNathan Lynch <nathan_lynch@mentor.com> Acked-by: NH. Peter Anvin <hpa@linux.intel.com> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [in principle] Acked-by: Richard Weinberger <richard@nod.at> [for um] Acked-by: Will Deacon <will.deacon@arm.com> [for arm64] Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Chris Metcalf <cmetcalf@tilera.com> Cc: Jeff Dike <jdike@addtoit.com> Cc: Richard Weinberger <richard@nod.at> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Nathan Lynch <Nathan_Lynch@mentor.com> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
由 Laura Abbott 提交于
Rather than have architectures #define ARCH_HAS_SG_CHAIN in an architecture specific scatterlist.h, make it a proper Kconfig option and use that instead. At same time, remove the header files are are now mostly useless and just include asm-generic/scatterlist.h. [sfr@canb.auug.org.au: powerpc files now need asm/dma.h] Signed-off-by: NLaura Abbott <lauraa@codeaurora.org> Acked-by: Thomas Gleixner <tglx@linutronix.de> [x86] Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> [powerpc] Acked-by: NHeiko Carstens <heiko.carstens@de.ibm.com> Cc: Russell King <linux@arm.linux.org.uk> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: "James E.J. Bottomley" <JBottomley@parallels.com> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: NStephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: NAndrew Morton <akpm@linux-foundation.org> Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
-
- 05 8月, 2014 9 次提交
-
-
由 Madhusudanan Kandasamy 提交于
remap_4k_pfn() silently truncates upper bits of input 4K PFN if it cannot be contained in PTE. This leads invalid memory mapping and could result in a system crash when the memory is accessed. This patch fails remap_4k_pfn() and returns -EINVAL if the input 4K PFN cannot be contained in PTE. V3 : Added parentheses to protect 'pfn' and entire macro as suggested by Brian. V2 : Rewritten to avoid helper function as suggested by Stephen Rothwell. Signed-off-by: NMadhusudanan Kandasamy <kmadhu@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Mahesh Salgaonkar 提交于
When we hit the HMI in Linux, invoke opal call to handle/recover from HMI errors in real mode and then in virtual mode during check_irq_replay() invoke opal_poll_events()/opal_do_notifier() to retrieve HMI event from OPAL and act accordingly. Now that we are ready to handle HMI interrupt directly in linux, remove the HMI interrupt registration with firmware. Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Mahesh Salgaonkar 提交于
Handle Hypervisor Maintenance Interrupt (HMI) in Linux. This patch implements basic infrastructure to handle HMI in Linux host. The design is to invoke opal handle hmi in real mode for recovery and set irq_pending when we hit HMI. During check_irq_replay pull opal hmi event and print hmi info on console. Signed-off-by: NMahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Gavin Shan 提交于
The patch synchronizes header file with firmware to have new OPAL API opal_pci_eeh_freeze_set(), which is used to freeze the specified PE in order to support "compound" PE. Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Guo Chao 提交于
This patch enables M64 aperatus for PHB3. We already had platform hook (ppc_md.pcibios_window_alignment) to affect the PCI resource assignment done in PCI core so that each PE's M32 resource was built on basis of M32 segment size. Similarly, we're using that for M64 assignment on basis of M64 segment size. * We're using last M64 BAR to cover M64 aperatus, and it's shared by all 256 PEs. * We don't support P7IOC yet. However, some function callbacks are added to (struct pnv_phb) so that we can reuse them on P7IOC in future. * PE, corresponding to PCI bus with large M64 BAR device attached, might span multiple M64 segments. We introduce "compound" PE to cover the case. The compound PE is a list of PEs and the master PE is used as before. The slave PEs are just for MMIO isolation. Signed-off-by: NGuo Chao <yan@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Gavin Shan 提交于
The patch allows PE (struct eeh_pe) instance to have auxillary data, whose size is configurable on basis of platform. For PowerNV, the auxillary data will be used to cache PHB diag-data for that PE (frozen PE or fenced PHB). In turn, we can retrieve the diag-data at any later points. It's useful for the case of VFIO PCI devices where the error log should be cached, and then be retrieved by the guest at later point. Also, it can avoid PHB diag-data overwritting if another frozen PE reported and the previous diag-data isn't fetched by guest. Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Gavin Shan 提交于
It's followup of commit ddf0322a ("powerpc/powernv: Fix endianness problems in EEH"). The patch helps to get non-endian-dependent diag-data. Cc: Guo Chao <yan@linux.vnet.ibm.com> Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Gavin Shan 提交于
According to the experiment I did, PCI config access is blocked on P7IOC frozen PE by hardware, but PHB3 doesn't do that. That means we always get 0xFF's while dumping PCI config space of the frozen PE on P7IOC. We don't have the problem on PHB3. So we have to enable I/O prioir to collecting error log. Otherwise, meaningless 0xFF's are always returned. The patch fixes it by EEH flag (EEH_ENABLE_IO_FOR_LOG), which is selectively set to indicate the case for: P7IOC on PowerNV platform, pSeries platform. Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-
由 Gavin Shan 提交于
There are multiple global EEH flags. Almost each flag has its own accessor, which doesn't make sense. The patch refactors EEH flag accessors so that they look unified: eeh_add_flag(): Add EEH flag eeh_clear_flag(): Clear EEH flag eeh_has_flag(): Check if one specific flag has been set eeh_enabled(): Check if EEH functionality has been enabled Signed-off-by: NGavin Shan <gwshan@linux.vnet.ibm.com> Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>
-