question about work on CMA integration into DMA
Hello! I am working on some driver, which needs to allocate a big contiguous memory block (~10 MB) and has to work on multiple platforms (x86, arm, arm64, mips, powerpc). CMA - is the most appropriate way in this case, but I have faced an unexpected problem - the fact that the CMA subsystem is not integrated into the DMA subsystem for powerpc, and I cannot request memory from CMA area from my kernel module. The question is: is there any work in progress on CMA to DMA integration? Or is it decided not to perform such work at all? And, is there any legal way to allocate a big contiguous memory block from the kernel module on powerpc? Thanks for your help, Max
Re: [PATCH 0/8] add generic builtin command line
Do you mean, that you haven't seen patch for ARM, which I sent on September 27 along with cover and patch 1? It is strange, because you was the one from recipients. If so, you can see this patch here: https://lore.kernel.org/patchwork/patch/992779/ On Tue, Oct 23, 2018 at 5:48 PM Russell King - ARM Linux wrote: > > On Tue, Oct 23, 2018 at 05:43:18PM +0300, Maksym Kokhan wrote: > > We still have no response to patches for x86, arm, arm64 and powerpc. > > Is current generic command line implementation appropriate for these > > architectures? > > Is it possible to merge these patches in the current form (for x86, > > arm, arm64 and powerpc)? > > You may wish to consider your recipients - I seem to only have received > the cover and patch 1 (which doesn't include any ARM specific bits). > It may be that you're not getting responses because people haven't seen > your patches. > > Thanks. > > -- > RMK's Patch system: http://www.armlinux.org.uk/developer/patches/ > FTTC broadband for 0.8mile line in suburbia: sync at 12.1Mbps down 622kbps up > According to speedtest.net: 11.9Mbps down 500kbps up
Re: [PATCH 0/8] add generic builtin command line
On Mon, Oct 8, 2018 at 9:01 PM Maksym Kokhan wrote: > > Hi, Daniel > > On Sat, Sep 29, 2018 at 9:17 PM wrote: > > > > On Thu, Sep 27, 2018 at 07:55:08PM +0300, Maksym Kokhan wrote: > > > Daniel Walker (7): > > > add generic builtin command line > > > drivers: of: ifdef out cmdline section > > > x86: convert to generic builtin command line > > > arm: convert to generic builtin command line > > > arm64: convert to generic builtin command line > > > mips: convert to generic builtin command line > > > powerpc: convert to generic builtin command line > > > > > > > When I originally submitted these I had a very good conversion with Rob > > Herring > > on the device tree changes. It seemed fairly clear that my approach in these > > changes could be done better. It effected specifically arm64, but a lot of > > other > > platforms use the device tree integrally. With arm64 you can reduce the > > changes > > down to only Kconfig changes, and that would likely be the case for many of > > the > > other architecture. I made patches to do this a while back, but have not had > > time to test them and push them out. > > Can you please share this patches? I could test them and use to improve this > generic command line implementation. > > > In terms of mips I think there's a fair amount of work needed to pull out > > their > > architecture specific mangling into something generic. Part of my > > motivation for > > these was to take the architecture specific feature and open that up for > > all the > > architecture. So it makes sense that the mips changes should become part of > > that. > > This is really makes sense, and we have intentions to implement it > afterward. It would be easier to initially merge this simple > implementation and then develop it step by step. > > > The only changes which have no comments are the generic changes, x86, and > > powerpc. Those patches have been used at Cisco for years with no issues. > > I added those changes into my -next tree for a round of testing. Assuming > > there > > are no issues I can work out the merging with the architecture maintainers. > > As for the other changes I think they can be done in time, as long as the > > generic parts of upstream the rest can be worked on by any of the > > architecture > > developers. > > Thanks, > Maksym We still have no response to patches for x86, arm, arm64 and powerpc. Is current generic command line implementation appropriate for these architectures? Is it possible to merge these patches in the current form (for x86, arm, arm64 and powerpc)? Thanks, Maksym
Re: [PATCH 0/8] add generic builtin command line
Hi, Daniel On Sat, Sep 29, 2018 at 9:17 PM wrote: > > On Thu, Sep 27, 2018 at 07:55:08PM +0300, Maksym Kokhan wrote: > > Daniel Walker (7): > > add generic builtin command line > > drivers: of: ifdef out cmdline section > > x86: convert to generic builtin command line > > arm: convert to generic builtin command line > > arm64: convert to generic builtin command line > > mips: convert to generic builtin command line > > powerpc: convert to generic builtin command line > > > > When I originally submitted these I had a very good conversion with Rob > Herring > on the device tree changes. It seemed fairly clear that my approach in these > changes could be done better. It effected specifically arm64, but a lot of > other > platforms use the device tree integrally. With arm64 you can reduce the > changes > down to only Kconfig changes, and that would likely be the case for many of > the > other architecture. I made patches to do this a while back, but have not had > time to test them and push them out. Can you please share this patches? I could test them and use to improve this generic command line implementation. > In terms of mips I think there's a fair amount of work needed to pull out > their > architecture specific mangling into something generic. Part of my motivation > for > these was to take the architecture specific feature and open that up for all > the > architecture. So it makes sense that the mips changes should become part of > that. This is really makes sense, and we have intentions to implement it afterward. It would be easier to initially merge this simple implementation and then develop it step by step. > The only changes which have no comments are the generic changes, x86, and > powerpc. Those patches have been used at Cisco for years with no issues. > I added those changes into my -next tree for a round of testing. Assuming > there > are no issues I can work out the merging with the architecture maintainers. > As for the other changes I think they can be done in time, as long as the > generic parts of upstream the rest can be worked on by any of the architecture > developers. Thanks, Maksym
[PATCH 8/8] powerpc: convert to generic builtin command line
From: Daniel Walker
This updates the powerpc code to use the CONFIG_GENERIC_CMDLINE
option.
[maksym.kok...@globallogic.com: add strlcat to prom_init_check.sh
whitelist]
Cc: Daniel Walker
Cc: Daniel Walker
Signed-off-by: Daniel Walker
Signed-off-by: Maksym Kokhan
---
arch/powerpc/Kconfig | 23 +--
arch/powerpc/kernel/prom.c | 4
arch/powerpc/kernel/prom_init.c| 8
arch/powerpc/kernel/prom_init_check.sh | 2 +-
4 files changed, 10 insertions(+), 27 deletions(-)
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index a806692..f87906a 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -172,6 +172,7 @@ config PPC
select GENERIC_STRNCPY_FROM_USER
select GENERIC_STRNLEN_USER
select GENERIC_TIME_VSYSCALL
+ select GENERIC_CMDLINE
select HAVE_ARCH_AUDITSYSCALL
select HAVE_ARCH_JUMP_LABEL
select HAVE_ARCH_KGDB
@@ -787,28 +788,6 @@ config PPC_DENORMALISATION
Add support for handling denormalisation of single precision
values. Useful for bare metal only. If unsure say Y here.
-config CMDLINE_BOOL
- bool "Default bootloader kernel arguments"
-
-config CMDLINE
- string "Initial kernel command string"
- depends on CMDLINE_BOOL
- default "console=ttyS0,9600 console=tty0 root=/dev/sda2"
- help
- On some platforms, there is currently no way for the boot loader to
- pass arguments to the kernel. For these platforms, you can supply
- some command-line options at build time by entering them here. In
- most cases you will need to specify the root device here.
-
-config CMDLINE_FORCE
- bool "Always use the default kernel command string"
- depends on CMDLINE_BOOL
- help
- Always use the default kernel command string, even if the boot
- loader passes other arguments to the kernel.
- This is useful if you cannot or don't want to change the
- command-line options your boot loader passes to the kernel.
-
config EXTRA_TARGETS
string "Additional default image types"
help
diff --git a/arch/powerpc/kernel/prom.c b/arch/powerpc/kernel/prom.c
index c4d7078..f8c6e63 100644
--- a/arch/powerpc/kernel/prom.c
+++ b/arch/powerpc/kernel/prom.c
@@ -34,6 +34,7 @@
#include
#include
#include
+#include
#include
#include
@@ -716,6 +717,9 @@ void __init early_init_devtree(void *params)
*/
of_scan_flat_dt(early_init_dt_scan_chosen_ppc, boot_command_line);
+ /* append and prepend any arguments built into the kernel. */
+ cmdline_add_builtin(boot_command_line, NULL, COMMAND_LINE_SIZE);
+
/* Scan memory nodes and rebuild MEMBLOCKs */
of_scan_flat_dt(early_init_dt_scan_root, NULL);
of_scan_flat_dt(early_init_dt_scan_memory_ppc, NULL);
diff --git a/arch/powerpc/kernel/prom_init.c b/arch/powerpc/kernel/prom_init.c
index 9b38a2e..e9214c6 100644
--- a/arch/powerpc/kernel/prom_init.c
+++ b/arch/powerpc/kernel/prom_init.c
@@ -30,6 +30,7 @@
#include
#include
#include
+#include
#include
#include
#include
@@ -634,11 +635,10 @@ static void __init early_cmdline_parse(void)
p = prom_cmd_line;
if ((long)prom.chosen > 0)
l = prom_getprop(prom.chosen, "bootargs", p,
COMMAND_LINE_SIZE-1);
-#ifdef CONFIG_CMDLINE
+
if (l <= 0 || p[0] == '\0') /* dbl check */
- strlcpy(prom_cmd_line,
- CONFIG_CMDLINE, sizeof(prom_cmd_line));
-#endif /* CONFIG_CMDLINE */
+ cmdline_add_builtin(prom_cmd_line, NULL, sizeof(prom_cmd_line));
+
prom_printf("command line: %s\n", prom_cmd_line);
#ifdef CONFIG_PPC64
diff --git a/arch/powerpc/kernel/prom_init_check.sh
b/arch/powerpc/kernel/prom_init_check.sh
index acb6b92..b1d7ca1 100644
--- a/arch/powerpc/kernel/prom_init_check.sh
+++ b/arch/powerpc/kernel/prom_init_check.sh
@@ -18,7 +18,7 @@
WHITELIST="add_reloc_offset __bss_start __bss_stop copy_and_flush
_end enter_prom memcpy memset reloc_offset __secondary_hold
-__secondary_hold_acknowledge __secondary_hold_spinloop __start
+__secondary_hold_acknowledge __secondary_hold_spinloop __start strlcat
strcmp strcpy strlcpy strlen strncmp strstr kstrtobool logo_linux_clut224
reloc_got2 kernstart_addr memstart_addr linux_banner _stext
__prom_init_toc_start __prom_init_toc_end btext_setup_display TOC."
--
2.7.4
[PATCH 1/8] add generic builtin command line
From: Daniel Walker
This code allows architectures to use a generic builtin command line.
The state of the builtin command line options across architecture is
diverse. On x86 and mips they have pretty much the same code and the
code prepends the builtin command line onto the boot loader provided
one. On powerpc there is only a builtin override and nothing else.
The code in this commit unifies the mips and x86 code into a generic
header file under the CONFIG_GENERIC_CMDLINE option. When this
option is enabled the architecture can call the cmdline_add_builtin()
to add the builtin command line.
[maksym.kok...@globallogic.com: fix cmdline_add_builtin() macro]
Cc: Daniel Walker
Cc: Daniel Walker
Signed-off-by: Daniel Walker
Signed-off-by: Maksym Kokhan
---
include/linux/cmdline.h | 70 +
init/Kconfig| 68 +++
2 files changed, 138 insertions(+)
create mode 100644 include/linux/cmdline.h
diff --git a/include/linux/cmdline.h b/include/linux/cmdline.h
new file mode 100644
index 000..75ef278
--- /dev/null
+++ b/include/linux/cmdline.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _LINUX_CMDLINE_H
+#define _LINUX_CMDLINE_H
+
+/*
+ *
+ * Copyright (C) 2015. Cisco Systems, Inc.
+ *
+ * Generic Append/Prepend cmdline support.
+ */
+
+#if defined(CONFIG_GENERIC_CMDLINE) && defined(CONFIG_CMDLINE_BOOL)
+
+#ifndef CONFIG_CMDLINE_OVERRIDE
+/*
+ * This function will append or prepend a builtin command line to the command
+ * line provided by the bootloader. Kconfig options can be used to alter
+ * the behavior of this builtin command line.
+ * @dest: The destination of the final appended/prepended string
+ * @src: The starting string or NULL if there isn't one.
+ * @tmp: temporary space used for prepending
+ * @length: the maximum length of the strings above.
+ */
+static inline void
+_cmdline_add_builtin(char *dest, char *src, char *tmp, unsigned long length)
+{
+ if (src != dest && src != NULL) {
+ strlcpy(dest, " ", length);
+ strlcat(dest, src, length);
+ }
+
+ strlcat(dest, " ", length);
+
+ if (sizeof(CONFIG_CMDLINE_APPEND) > 1)
+ strlcat(dest, CONFIG_CMDLINE_APPEND, length);
+
+ if (sizeof(CONFIG_CMDLINE_PREPEND) > 1) {
+ strlcpy(tmp, CONFIG_CMDLINE_PREPEND, length);
+ strlcat(tmp, " ", length);
+ strlcat(tmp, dest, length);
+ strlcpy(dest, tmp, length);
+ }
+}
+
+#define cmdline_add_builtin(dest, src, length) \
+{ \
+ if (sizeof(CONFIG_CMDLINE_PREPEND) > 1) { \
+ static char cmdline_tmp_space[length] __initdata; \
+ _cmdline_add_builtin(dest, src, cmdline_tmp_space, length); \
+ } else {\
+ _cmdline_add_builtin(dest, src, NULL, length); \
+ } \
+}
+#else
+#define cmdline_add_builtin(dest, src, length)\
+{ \
+ strlcpy(dest, CONFIG_CMDLINE_PREPEND " " CONFIG_CMDLINE_APPEND,\
+ length); \
+}
+#endif /* !CONFIG_CMDLINE_OVERRIDE */
+
+#else
+#define cmdline_add_builtin(dest, src, length) { \
+ if (src != NULL) \
+ strlcpy(dest, src, length);\
+}
+#endif /* CONFIG_GENERIC_CMDLINE */
+
+
+#endif /* _LINUX_CMDLINE_H */
diff --git a/init/Kconfig b/init/Kconfig
index 1e234e2..e5aa676 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1751,6 +1751,74 @@ config PROFILING
config TRACEPOINTS
bool
+config GENERIC_CMDLINE
+ bool
+
+if GENERIC_CMDLINE
+
+config CMDLINE_BOOL
+ bool "Built-in kernel command line"
+ help
+ Allow for specifying boot arguments to the kernel at
+ build time. On some systems (e.g. embedded ones), it is
+ necessary or convenient to provide some or all of the
+ kernel boot arguments with the kernel itself (that is,
+ to not rely on the boot loader to provide them.)
+
+ To compile command line arguments into the kernel,
+ set this option to 'Y', then fill in the
+ the boot arguments in CONFIG_CMDLINE.
+
+ Systems with fully functional boot loaders (i.e. non-embedded)
+ should leave this option set to 'N'.
+
+config CMDLINE_APPEND
+ string "Built-in kernel command string append"
+ depends on CMDLINE_BOOL
+ default ""
+
[PATCH 0/8] add generic builtin command line
There were series of patches [1] for 4.3.0-rc3, that allowed architectures to use a generic builtin command line. I have rebased these patches on kernel 4.19.0-rc4. Things, modified in comparison with original patches: * There was some bug for mips, in the case when CONFIG_CMDLINE_PREPEND and CONFIG_CMDLINE_APPEND are empty and CMDLINE_OVERRIDE is not set, command line from bootloader was ignored, so I fixed it, modifying patch "add generic builtin command line". * Implemented new patch to resolve conflict with new kernel, which modify EFI stub code. Unfortunately, I don't have capability to test this modification on real arm board with EFI. * Removed new realisation of mips builtin command line, which was created after 4.3.0-rc3. * Kernel 4.3.0-rc3 with original patches could not be compiled for powerpc due to prom_init.c checking by prom_init_check.sh. So I added strlcat (which is used by cmdline_add_builtin macro) to prom_init_check.sh whitelist. Patches have been tested in QEMU for x86, arm (little-endian), arm64 (little-endian), mips (little-endian, 32-bit) and powerpc (big-endian, 64-bit), everything works perfectly. Also it was tested on linux-next (next-20180924 tag) for all listed above architectures. [1] : https://lore.kernel.org/patchwork/patch/604992/ Daniel Walker (7): add generic builtin command line drivers: of: ifdef out cmdline section x86: convert to generic builtin command line arm: convert to generic builtin command line arm64: convert to generic builtin command line mips: convert to generic builtin command line powerpc: convert to generic builtin command line Maksym Kokhan (1): efi: modify EFI stub code for arm/arm64 arch/arm/Kconfig| 38 +- arch/arm/kernel/atags_parse.c | 14 ++- arch/arm/kernel/devtree.c | 2 + arch/arm64/Kconfig | 17 +--- arch/arm64/kernel/setup.c | 3 ++ arch/mips/Kconfig | 24 +-- arch/mips/Kconfig.debug | 47 -- arch/mips/kernel/setup.c| 41 ++- arch/powerpc/Kconfig| 23 +-- arch/powerpc/kernel/prom.c | 4 ++ arch/powerpc/kernel/prom_init.c | 8 ++-- arch/powerpc/kernel/prom_init_check.sh | 2 +- arch/x86/Kconfig| 44 + arch/x86/kernel/setup.c | 19 ++--- drivers/firmware/efi/libstub/arm-stub.c | 10 ++--- drivers/of/fdt.c| 2 +- include/linux/cmdline.h | 70 + init/Kconfig| 68 18 files changed, 173 insertions(+), 263 deletions(-) create mode 100644 include/linux/cmdline.h -- 2.7.4
