kernel.git/arch/powerpc/kexec, branch linux-6.0.y

powerpc/kexec: Fix build failure from uninitialised variable

2022-08-10T05:55:20Z

clang 14 won't build because ret is uninitialised and can be returned if both prop and fdtprop are NULL. Drop the ret variable and return an error in that failure case. Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window") Suggested-by: Christophe Leroy Signed-off-by: Russell Currey Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220810054331.373761-1-ruscur@russell.cc

powerpc/64e: Fix kexec build error

2022-08-03T06:32:18Z

When building ppc64_book3e_allmodconfig the build fails with: arch/powerpc/kexec/file_load_64.c:1063:14: error: implicit declaration of function ‘firmware_has_feature’ 1063 | if (!firmware_has_feature(FW_FEATURE_LPAR)) | ^~~~~~~~~~~~~~~~~~~~ Add a direct include of asm/firmware.h to fix the error. Fixes: b1fc44eaa9ba ("pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window") Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220803063152.1249270-1-mpe@ellerman.id.au

pseries/iommu/ddw: Fix kdump to work in absence of ibm,dma-window

2022-07-28T06:22:13Z

The pseries platform uses 32bit default DMA window (always 4K pages) and optional 64bit DMA window available via DDW ("Dynamic DMA Windows"), 64K or 2M pages. For ages the default one was not removed and a huge window was created in addition. Things changed with SRIOV-enabled PowerVM which creates a default-and-bigger DMA window in 64bit space (still using 4K pages) for IOV VFs so certain OSes do not need to use the DDW API in order to utilize all available TCE budget. Linux on the other hand removes the default window and creates a bigger one (with more TCEs or/and a bigger page size - 64K/2M) in a bid to map the entire RAM, and if the new window size is smaller than that - it still uses this new bigger window. The result is that the default window is removed but the "ibm,dma-window" property is not. When kdump is invoked, the existing code tries reusing the existing 64bit DMA window which location and parameters are stored in the device tree but this fails as the new property does not make it to the kdump device tree blob. So the code falls back to the default window which does not exist anymore although the device tree says that it does. The result of that is that PCI devices become unusable and cannot be used for kdumping. This preserves the DMA64 and DIRECT64 properties in the device tree blob for the crash kernel. Since the crash kernel setup is done after device drivers are loaded and probed, the proper DMA config is stored at least for boot time devices. Because DDW window is optional and the code configures the default window first, the existing code creates an IOMMU table descriptor for the non-existing default DMA window. It is harmless for kdump as it does not touch the actual window (only reads what is mapped and marks those IO pages as used) but it is bad for kexec which clears it thinking it is a smaller default window rather than a bigger DDW window. This removes the "ibm,dma-window" property from the device tree after a bigger window is created and the crash kernel setup picks it up. Fixes: 381ceda88c4c ("powerpc/pseries/iommu: Make use of DDW for indirect mapping") Signed-off-by: Alexey Kardashevskiy Acked-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220629060614.1680476-1-aik@ozlabs.ru

powerpc/crash: save cpu register data in crash_smp_send_stop()

2022-07-28T06:22:13Z

During kdump, two set of NMI IPIs are sent to secondary CPUs, if 'crash_kexec_post_notifiers' option is set. The first set of NMI IPIs to stop the CPUs and the other set to collect register data. Instead, capture register data for secondary CPUs while stopping them itself. Also, fallback to smp_send_stop() in case the function gets called without kdump configured. Signed-off-by: Hari Bathini Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/20220630064942.192283-1-hbathini@linux.ibm.com

powerpc: Include asm/firmware.h in all users of firmware_has_feature()

2022-06-29T06:45:05Z

Trying to remove asm/ppc_asm.h from all places that don't need it leads to several failures linked to firmware_has_feature(). To fix it, include asm/firmware.h in all files using firmware_has_feature() All users found with: git grep -L "firmware\.h" ` git grep -l "firmware_has_feature("` Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/11956ec181a034b51a881ac9c059eea72c679a73.1651828453.git.christophe.leroy@csgroup.eu

powerpc: Don't include asm/setup.h in asm/machdep.h

2022-06-20T01:29:49Z

asm/machdep.h doesn't need asm/setup.h Remove it. Add it directly in files that needs it. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/3b1dfb19a2c3265fb4abc2bfc7b6eae9261a998b.1654966508.git.christophe.leroy@csgroup.eu

powerpc/kasan: Mark more real-mode code as not to be instrumented

2022-05-29T00:30:42Z

This marks more files and functions that can possibly be called in real mode as not to be instrumented by KASAN. Most were found by inspection, except for get_pseries_errorlog() which was reported as causing a crash in testing. Reported-by: Nageswara R Sastry Signed-off-by: Paul Mackerras Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YoX1kZPnmUX4RZEK@cleo

powerpc/kasan: Disable address sanitization in kexec paths

2022-05-22T05:58:29Z

The kexec code paths involve code that necessarily run in real mode, as CPUs are disabled and control is transferred to the new kernel. Disable address sanitization for the kexec code and the functions called in real mode on CPUs being disabled. [paulus@ozlabs.org: combined a few work-in-progress commits of Daniel's and wrote the commit message.] Signed-off-by: Daniel Axtens Signed-off-by: Paul Mackerras [mpe: Move pseries_machine_kexec() into kexec.c so setup.c can be instrumented] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/YoTFSQ2TUSEaDdVC@cleo

powerpc: Add missing headers

2022-05-08T12:15:40Z

Don't inherit headers "by chances" from asm/prom.h, asm/mpc52xx.h, asm/pci.h etc... Include the needed headers, and remove asm/prom.h when it was needed exclusively for pulling necessary headers. Signed-off-by: Christophe Leroy Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/be8bdc934d152a7d8ee8d1a840d5596e2f7d85e0.1646767214.git.christophe.leroy@csgroup.eu

powerpc: Remove asm/prom.h from all files that don't need it

2022-05-08T12:15:04Z

Several files include asm/prom.h for no reason. Clean it up. Signed-off-by: Christophe Leroy [mpe: Drop change to prom_parse.c as reported by lkp@intel.com] Signed-off-by: Michael Ellerman Link: https://lore.kernel.org/r/7c9b8fda63dcf63e1b28f43e7ebdb95182cbc286.1646767214.git.christophe.leroy@csgroup.eu