kernel/arch/powerpc/platforms/pseries/setup.c, branch linux-5.1.y

powerpc: prefer memblock APIs returning virtual address

2019-03-08T02:32:03Z

Patch series "memblock: simplify several early memory allocation", v4. These patches simplify some of the early memory allocations by replacing usage of older memblock APIs with newer and shinier ones. Quite a few places in the arch/ code allocated memory using a memblock API that returns a physical address of the allocated area, then converted this physical address to a virtual one and then used memset(0) to clear the allocated range. More recent memblock APIs do all the three steps in one call and their usage simplifies the code. It's important to note that regardless of API used, the core allocation is nearly identical for any set of memblock allocators: first it tries to find a free memory with all the constraints specified by the caller and then falls back to the allocation with some or all constraints disabled. The first three patches perform the conversion of call sites that have exact requirements for the node and the possible memory range. The fourth patch is a bit one-off as it simplifies openrisc's implementation of pte_alloc_one_kernel(), and not only the memblock usage. The fifth patch takes care of simpler cases when the allocation can be satisfied with a simple call to memblock_alloc(). The sixth patch removes one-liner wrappers for memblock_alloc on arm and unicore32, as suggested by Christoph. This patch (of 6): There are a several places that allocate memory using memblock APIs that return a physical address, convert the returned address to the virtual address and frequently also memset(0) the allocated range. Update these places to use memblock allocators already returning a virtual address. Use memblock functions that clear the allocated memory instead of calling memset(0) where appropriate. The calls to memblock_alloc_base() that were not followed by memset(0) are replaced with memblock_alloc_try_nid_raw(). Since the latter does not panic() when the allocation fails, the appropriate panic() calls are added to the call sites. Link: http://lkml.kernel.org/r/1546248566-14910-2-git-send-email-rppt@linux.ibm.com Signed-off-by: Mike Rapoport Cc: Arnd Bergmann Cc: Benjamin Herrenschmidt Cc: "David S. Miller" Cc: Guan Xuetao Cc: Greentime Hu Cc: Heiko Carstens Cc: Jonas Bonn Cc: Martin Schwidefsky Cc: Michael Ellerman Cc: Michal Hocko Cc: Michal Simek Cc: Mark Salter Cc: Paul Mackerras Cc: Rich Felker Cc: Russell King Cc: Stefan Kristiansson Cc: Stafford Horne Cc: Vincent Chen Cc: Yoshinori Sato Cc: Christoph Hellwig Cc: Michal Simek Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

powerpc: Use of_node_name_eq for node name comparisons

2018-12-22T10:29:50Z

Convert string compares of DT node names to use of_node_name_eq helper instead. This removes direct access to the node name pointer. A couple of open coded iterating thru the child node names are converted to use for_each_child_of_node() instead. Signed-off-by: Rob Herring Signed-off-by: Michael Ellerman

powerpc: Use device_type helpers to access the node type

2018-11-26T11:33:37Z

Remove directly accessing device_node.type pointer and use the accessors instead. This will eventually allow removing the type pointer. Replace the open coded iterating over child nodes with for_each_child_of_node() while we're here. Signed-off-by: Rob Herring Signed-off-by: Michael Ellerman

powerpc/pseries: Dump the SLB contents on SLB MCE errors.

2018-09-19T11:59:41Z

If we get a machine check exceptions due to SLB errors then dump the current SLB contents which will be very much helpful in debugging the root cause of SLB errors. Introduce an exclusive buffer per cpu to hold faulty SLB entries. In real mode mce handler saves the old SLB contents into this buffer accessible through paca and print it out later in virtual mode. With this patch the console will log SLB contents like below on SLB MCE errors: [ 507.297236] SLB contents of cpu 0x1 [ 507.297237] Last SLB entry inserted at slot 16 [ 507.297238] 00 c000000008000000 400ea1b217000500 [ 507.297239] 1T ESID= c00000 VSID= ea1b217 LLP:100 [ 507.297240] 01 d000000008000000 400d43642f000510 [ 507.297242] 1T ESID= d00000 VSID= d43642f LLP:110 [ 507.297243] 11 f000000008000000 400a86c85f000500 [ 507.297244] 1T ESID= f00000 VSID= a86c85f LLP:100 [ 507.297245] 12 00007f0008000000 4008119624000d90 [ 507.297246] 1T ESID= 7f VSID= 8119624 LLP:110 [ 507.297247] 13 0000000018000000 00092885f5150d90 [ 507.297247] 256M ESID= 1 VSID= 92885f5150 LLP:110 [ 507.297248] 14 0000010008000000 4009e7cb50000d90 [ 507.297249] 1T ESID= 1 VSID= 9e7cb50 LLP:110 [ 507.297250] 15 d000000008000000 400d43642f000510 [ 507.297251] 1T ESID= d00000 VSID= d43642f LLP:110 [ 507.297252] 16 d000000008000000 400d43642f000510 [ 507.297253] 1T ESID= d00000 VSID= d43642f LLP:110 [ 507.297253] ---------------------------------- [ 507.297254] SLB cache ptr value = 3 [ 507.297254] Valid SLB cache entries: [ 507.297255] 00 EA[0-35]= 7f000 [ 507.297256] 01 EA[0-35]= 1 [ 507.297257] 02 EA[0-35]= 1000 [ 507.297257] Rest of SLB cache entries: [ 507.297258] 03 EA[0-35]= 7f000 [ 507.297258] 04 EA[0-35]= 1 [ 507.297259] 05 EA[0-35]= 1000 [ 507.297260] 06 EA[0-35]= 12 [ 507.297260] 07 EA[0-35]= 7f000 Suggested-by: Aneesh Kumar K.V Suggested-by: Michael Ellerman Signed-off-by: Mahesh Salgaonkar Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman

powerpc/pseries: Flush SLB contents on SLB MCE errors.

2018-09-19T11:59:22Z

On pseries, as of today system crashes if we get a machine check exceptions due to SLB errors. These are soft errors and can be fixed by flushing the SLBs so the kernel can continue to function instead of system crash. We do this in real mode before turning on MMU. Otherwise we would run into nested machine checks. This patch now fetches the rtas error log in real mode and flushes the SLBs on SLB/ERAT errors. Signed-off-by: Mahesh Salgaonkar Signed-off-by: Michal Suchanek Reviewed-by: Nicholas Piggin Signed-off-by: Michael Ellerman

Merge tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux

2018-08-17T18:32:50Z

Pull powerpc updates from Michael Ellerman: "Notable changes: - A fix for a bug in our page table fragment allocator, where a page table page could be freed and reallocated for something else while still in use, leading to memory corruption etc. The fix reuses pt_mm in struct page (x86 only) for a powerpc only refcount. - Fixes to our pkey support. Several are user-visible changes, but bring us in to line with x86 behaviour and/or fix outright bugs. Thanks to Florian Weimer for reporting many of these. - A series to improve the hvc driver & related OPAL console code, which have been seen to cause hardlockups at times. The hvc driver changes in particular have been in linux-next for ~month. - Increase our MAX_PHYSMEM_BITS to 128TB when SPARSEMEM_VMEMMAP=y. - Remove Power8 DD1 and Power9 DD1 support, neither chip should be in use anywhere other than as a paper weight. - An optimised memcmp implementation using Power7-or-later VMX instructions - Support for barrier_nospec on some NXP CPUs. - Support for flushing the count cache on context switch on some IBM CPUs (controlled by firmware), as a Spectre v2 mitigation. - A series to enhance the information we print on unhandled signals to bring it into line with other arches, including showing the offending VMA and dumping the instructions around the fault. Thanks to: Aaro Koskinen, Akshay Adiga, Alastair D'Silva, Alexey Kardashevskiy, Alexey Spirkov, Alistair Popple, Andrew Donnellan, Aneesh Kumar K.V, Anju T Sudhakar, Arnd Bergmann, Bartosz Golaszewski, Benjamin Herrenschmidt, Bharat Bhushan, Bjoern Noetel, Boqun Feng, Breno Leitao, Bryant G. Ly, Camelia Groza, Christophe Leroy, Christoph Hellwig, Cyril Bur, Dan Carpenter, Daniel Klamt, Darren Stevens, Dave Young, David Gibson, Diana Craciun, Finn Thain, Florian Weimer, Frederic Barrat, Gautham R. Shenoy, Geert Uytterhoeven, Geoff Levand, Guenter Roeck, Gustavo Romero, Haren Myneni, Hari Bathini, Joel Stanley, Jonathan Neuschäfer, Kees Cook, Madhavan Srinivasan, Mahesh Salgaonkar, Markus Elfring, Mathieu Malaterre, Mauro S. M. Rodrigues, Michael Hanselmann, Michael Neuling, Michael Schmitz, Mukesh Ojha, Murilo Opsfelder Araujo, Nicholas Piggin, Parth Y Shah, Paul Mackerras, Paul Menzel, Ram Pai, Randy Dunlap, Rashmica Gupta, Reza Arbab, Rodrigo R. Galvao, Russell Currey, Sam Bobroff, Scott Wood, Shilpasri G Bhat, Simon Guo, Souptick Joarder, Stan Johnson, Thiago Jung Bauermann, Tyrel Datwyler, Vaibhav Jain, Vasant Hegde, Venkat Rao, zhong jiang" * tag 'powerpc-4.19-1' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: (234 commits) powerpc/mm/book3s/radix: Add mapping statistics powerpc/uaccess: Enable get_user(u64, *p) on 32-bit powerpc/mm/hash: Remove unnecessary do { } while(0) loop powerpc/64s: move machine check SLB flushing to mm/slb.c powerpc/powernv/idle: Fix build error powerpc/mm/tlbflush: update the mmu_gather page size while iterating address range powerpc/mm: remove warning about ‘type’ being set powerpc/32: Include setup.h header file to fix warnings powerpc: Move `path` variable inside DEBUG_PROM powerpc/powermac: Make some functions static powerpc/powermac: Remove variable x that's never read cxl: remove a dead branch powerpc/powermac: Add missing include of header pmac.h powerpc/kexec: Use common error handling code in setup_new_fdt() powerpc/xmon: Add address lookup for percpu symbols powerpc/mm: remove huge_pte_offset_and_shift() prototype powerpc/lib: Use patch_site to patch copy_32 functions once cache is enabled powerpc/pseries: Fix endianness while restoring of r3 in MCE handler. powerpc/fadump: merge adjacent memory ranges to reduce PT_LOAD segements powerpc/fadump: handle crash memory ranges array index overflow ...

powerpc/pseries: Query hypervisor for count cache flush settings

2018-08-07T14:32:26Z

Use the existing hypercall to determine the appropriate settings for the count cache flush, and then call the generic powerpc code to set it up based on the security feature flags. Signed-off-by: Michael Ellerman

powerpc/64: Call setup_barrier_nospec() from setup_arch()

2018-08-07T14:32:23Z

Currently we require platform code to call setup_barrier_nospec(). But if we add an empty definition for the !CONFIG_PPC_BARRIER_NOSPEC case then we can call it in setup_arch(). Signed-off-by: Diana Craciun Signed-off-by: Michael Ellerman

powerpc/pseries: Defer the logging of rtas error to irq work queue.

2018-08-07T11:49:29Z

rtas_log_buf is a buffer to hold RTAS event data that are communicated to kernel by hypervisor. This buffer is then used to pass RTAS event data to user through proc fs. This buffer is allocated from vmalloc (non-linear mapping) area. On Machine check interrupt, register r3 points to RTAS extended event log passed by hypervisor that contains the MCE event. The pseries machine check handler then logs this error into rtas_log_buf. The rtas_log_buf is a vmalloc-ed (non-linear) buffer we end up taking up a page fault (vector 0x300) while accessing it. Since machine check interrupt handler runs in NMI context we can not afford to take any page fault. Page faults are not honored in NMI context and causes kernel panic. Apart from that, as Nick pointed out, pSeries_log_error() also takes a spin_lock while logging error which is not safe in NMI context. It may endup in deadlock if we get another MCE before releasing the lock. Fix this by deferring the logging of rtas error to irq work queue. Current implementation uses two different buffers to hold rtas error log depending on whether extended log is provided or not. This makes bit difficult to identify which buffer has valid data that needs to logged later in irq work. Simplify this using single buffer, one per paca, and copy rtas log to it irrespective of whether extended log is provided or not. Allocate this buffer below RMA region so that it can be accessed in real mode mce handler. Fixes: b96672dd840f ("powerpc: Machine check interrupt is a non-maskable interrupt") Cc: stable@vger.kernel.org # v4.14+ Reviewed-by: Nicholas Piggin Signed-off-by: Mahesh Salgaonkar Signed-off-by: Michael Ellerman

PCI: Fix is_added/is_busmaster race condition

2018-07-31T16:27:54Z

When a PCI device is detected, pdev->is_added is set to 1 and proc and sysfs entries are created. When the device is removed, pdev->is_added is checked for one and then device is detached with clearing of proc and sys entries and at end, pdev->is_added is set to 0. is_added and is_busmaster are bit fields in pci_dev structure sharing same memory location. A strange issue was observed with multiple removal and rescan of a PCIe NVMe device using sysfs commands where is_added flag was observed as zero instead of one while removing device and proc,sys entries are not cleared. This causes issue in later device addition with warning message "proc_dir_entry" already registered. Debugging revealed a race condition between the PCI core setting the is_added bit in pci_bus_add_device() and the NVMe driver reset work-queue setting the is_busmaster bit in pci_set_master(). As these fields are not handled atomically, that clears the is_added bit. Move the is_added bit to a separate private flag variable and use atomic functions to set and retrieve the device addition state. This avoids the race because is_added no longer shares a memory location with is_busmaster. Link: https://bugzilla.kernel.org/show_bug.cgi?id=200283 Signed-off-by: Hari Vyas Signed-off-by: Bjorn Helgaas Reviewed-by: Lukas Wunner Acked-by: Michael Ellerman