linux-dev/drivers/tty/hvc, branch linus/master

Merge tag 'for-linus-5.19-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip

2022-06-04T20:42:53Z

Pull more xen updates from Juergen Gross: "Two cleanup patches for Xen related code and (more important) an update of MAINTAINERS for Xen, as Boris Ostrovsky decided to step down" * tag 'for-linus-5.19-rc1b-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: replace xen_remap() with memremap() MAINTAINERS: Update Xen maintainership xen: switch gnttab_end_foreign_access() to take a struct page pointer

xen: replace xen_remap() with memremap()

2022-06-01T05:24:17Z

xen_remap() is used to establish mappings for frames not under direct control of the kernel: for Xenstore and console ring pages, and for grant pages of non-PV guests. Today xen_remap() is defined to use ioremap() on x86 (doing uncached mappings), and ioremap_cache() on Arm (doing cached mappings). Uncached mappings for those use cases are bad for performance, so they should be avoided if possible. As all use cases of xen_remap() don't require uncached mappings (the mapped area is always physical RAM), a mapping using the standard WB cache mode is fine. As sparse is flagging some of the xen_remap() use cases to be not appropriate for iomem(), as the result is not annotated with the __iomem modifier, eliminate xen_remap() completely and replace all use cases with memremap() specifying the MEMREMAP_WB caching mode. xen_unmap() can be replaced with memunmap(). Reported-by: kernel test robot Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Acked-by: Stefano Stabellini Link: https://lore.kernel.org/r/20220530082634.6339-1-jgross@suse.com Signed-off-by: Juergen Gross

tty: hvc: dcc: Bind driver to CPU core0 for reads and writes

2022-05-05T20:45:57Z

Some external debuggers do not handle reads/writes from/to DCC on secondary cores. Each core has its own DCC device registers, so when a core reads or writes from/to DCC, it only accesses its own DCC device. Since kernel code can run on any core, every time the kernel wants to write to the console, it might write to a different DCC. In SMP mode, external debugger creates multiple windows, and each window shows the DCC output only from that core's DCC. The result is that console output is either lost or scattered across windows. Selecting this debug option will enable code that serializes all console input and output to core 0. The DCC driver will create input and output FIFOs that all cores will use. Reads and writes from/to DCC are handled by a workqueue that runs only core 0. This is a debug feature to be used only in early stage development where debug serial console support would not be present. It disables PM feature like CPU hotplug and is not suitable for production environment. Signed-off-by: Shanker Donthineni Acked-by: Adam Wallis Signed-off-by: Timur Tabi Signed-off-by: Elliot Berman Signed-off-by: Sai Prakash Ranjan Link: https://lore.kernel.org/r/20220428090858.14489-1-quic_saipraka@quicinc.com Signed-off-by: Greg Kroah-Hartman

tty: hvcs: simplify if-if to if-else

2022-04-26T11:24:22Z

Use if and else instead of if(A) and if (!A) and fix a coding style. Signed-off-by: Wan Jiabing Link: https://lore.kernel.org/r/20220424091310.98780-1-wanjiabing@vivo.com Signed-off-by: Greg Kroah-Hartman

tty/hvc_opal: simplify if-if to if-else

2022-04-26T11:24:17Z

Use if and else instead of if(A) and if (!A). Reviewed-by: Jiri Slaby Signed-off-by: Wan Jiabing Link: https://lore.kernel.org/r/20220426071041.168282-1-wanjiabing@vivo.com Signed-off-by: Greg Kroah-Hartman

tty: hvc: Prepare cleanup of powerpc's asm/prom.h

2022-04-15T06:42:26Z

powerpc's asm/prom.h brings some headers that it doesn't need itself. In order to clean it up, first add missing headers in users of asm/prom.h Signed-off-by: Christophe Leroy Link: https://lore.kernel.org/r/8b3dbd25bbeb7949e1b0a2170fee7b9cc5a6f806.1648833418.git.christophe.leroy@csgroup.eu Signed-off-by: Greg Kroah-Hartman

tty: hvc: fix return value of __setup handler

2022-03-18T12:09:57Z

__setup() handlers should return 1 to indicate that the boot option has been handled or 0 to indicate that it was not handled. Add a pr_warn() message if the option value is invalid and then always return 1. Link: lore.kernel.org/r/64644a2f-4a20-bab3-1e15-3b2cdd0defe3@omprussia.ru Fixes: 86b40567b917 ("tty: replace strict_strtoul() with kstrtoul()") Cc: Jingoo Han Cc: Greg Kroah-Hartman Cc: Jiri Slaby Cc: Michael Ellerman Cc: Julian Wiedmann Cc: Vasily Gorbik Cc: linuxppc-dev@lists.ozlabs.org Reported-by: Igor Zhbanov Signed-off-by: Randy Dunlap Link: https://lore.kernel.org/r/20220308024228.20477-1-rdunlap@infradead.org Signed-off-by: Greg Kroah-Hartman

serial: make uart_console_write->putchar()'s character an unsigned char

2022-03-03T14:06:31Z

Currently, uart_console_write->putchar's second parameter (the character) is of type int. It makes little sense, provided uart_console_write() accepts the input string as "const char *s" and passes its content -- the characters -- to putchar(). So switch the character's type to unsigned char. We don't use char as that is signed on some platforms. That would cause troubles for drivers which (implicitly) cast the char to u16 when writing to the device. Sign extension would happen in that case and the value written would be completely different to the provided char. DZ is an example of such a driver -- on MIPS, it uses u16 for dz_out in dz_console_putchar(). Note we do the char -> uchar conversion implicitly in uart_console_write(). Provided we do not change size of the data type, sign extension does not happen there, so the problem is void. This makes the types consistent and unified with the rest of the uart layer, which uses unsigned char in most places already. One exception is xmit_buf, but that is going to be converted later. Cc: Paul Cercueil Cc: Tobias Klauser Cc: Russell King Cc: Vineet Gupta Cc: Nicolas Ferre Cc: Alexandre Belloni Cc: Ludovic Desroches Cc: Florian Fainelli Cc: bcm-kernel-feedback-list@broadcom.com Cc: Alexander Shiyan Cc: Baruch Siach Cc: "Maciej W. Rozycki" Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Shawn Guo Cc: Sascha Hauer Cc: Pengutronix Kernel Team Cc: Fabio Estevam Cc: NXP Linux Team Cc: Karol Gugala Cc: Mateusz Holenko Cc: Vladimir Zapolskiy Cc: Neil Armstrong Cc: Kevin Hilman Cc: Jerome Brunet Cc: Martin Blumenstingl Cc: Taichi Sugaya Cc: Takao Orito Cc: Liviu Dudau Cc: Sudeep Holla Cc: Lorenzo Pieralisi Cc: "Andreas Färber" Cc: Manivannan Sadhasivam Cc: Michael Ellerman Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Cc: Andy Gross Cc: Bjorn Andersson Cc: Krzysztof Kozlowski Cc: Orson Zhai Cc: Baolin Wang Cc: Chunyan Zhang Cc: Patrice Chotard Cc: Maxime Coquelin Cc: Alexandre Torgue Cc: "David S. Miller" Cc: Peter Korsgaard Cc: Michal Simek Acked-by: Richard Genoud [atmel_serial] Acked-by: Uwe Kleine-König Acked-by: Paul Cercueil Acked-by: Neil Armstrong # meson_serial Signed-off-by: Jiri Slaby Link: https://lore.kernel.org/r/20220303080831.21783-1-jslaby@suse.cz Signed-off-by: Greg Kroah-Hartman

xen/console: harden hvc_xen against event channel storms

2021-12-16T07:24:08Z

The Xen console driver is still vulnerable for an attack via excessive number of events sent by the backend. Fix that by using a lateeoi event channel. For the normal domU initial console this requires the introduction of bind_evtchn_to_irq_lateeoi() as there is no xenbus device available at the time the event channel is bound to the irq. As the decision whether an interrupt was spurious or not requires to test for bytes having been read from the backend, move sending the event into the if statement, as sending an event without having found any bytes to be read is making no sense at all. This is part of XSA-391 Signed-off-by: Juergen Gross Reviewed-by: Jan Beulich --- V2: - slightly adapt spurious irq detection (Jan Beulich) V3: - fix spurious irq detection (Jan Beulich)

xen: flag hvc_xen to be not essential for system boot

2021-11-23T19:42:08Z

The Xen pv console driver is not essential for boot. Set the respective flag. Signed-off-by: Juergen Gross Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20211022064800.14978-4-jgross@suse.com Signed-off-by: Boris Ostrovsky