* ARM Xen Bug #45: Is there a solution? @ 2016-05-23 15:47 Dirk Behme 2016-05-23 20:15 ` Julien Grall 0 siblings, 1 reply; 9+ messages in thread From: Dirk Behme @ 2016-05-23 15:47 UTC (permalink / raw) To: Stefano Stabellini, Julien Grall, Ian Jackson, xen-devel Hello, is there a solution for arm: domain 0 disables clocks which are in fact being used http://bugs.xenproject.org/xen/bug/45 ? On an ARM based board I have to use 'clk_ignore_unused' preventing that Dom0 disables the UART clock for the console UART configured with console=hvc0. Best regards Dirk _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: ARM Xen Bug #45: Is there a solution? 2016-05-23 15:47 ARM Xen Bug #45: Is there a solution? Dirk Behme @ 2016-05-23 20:15 ` Julien Grall 2016-05-24 13:39 ` Dirk Behme 0 siblings, 1 reply; 9+ messages in thread From: Julien Grall @ 2016-05-23 20:15 UTC (permalink / raw) To: Dirk Behme, Stefano Stabellini, Ian Jackson, xen-devel On 23/05/2016 16:47, Dirk Behme wrote: > Hello, Hello Dirk, > is there a solution for > > arm: domain 0 disables clocks which are in fact being used > http://bugs.xenproject.org/xen/bug/45 > > ? > > On an ARM based board I have to use 'clk_ignore_unused' preventing that > Dom0 disables the UART clock for the console UART configured with > console=hvc0. There is no better solution than passing "clk_ignore_unused" on the kernel command line so far. Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: ARM Xen Bug #45: Is there a solution? 2016-05-23 20:15 ` Julien Grall @ 2016-05-24 13:39 ` Dirk Behme 2016-05-24 20:05 ` Julien Grall 0 siblings, 1 reply; 9+ messages in thread From: Dirk Behme @ 2016-05-24 13:39 UTC (permalink / raw) To: Julien Grall, Stefano Stabellini, Ian Jackson, xen-devel Hi Julien, On 23.05.2016 22:15, Julien Grall wrote: > Hello Dirk, > >> is there a solution for >> >> arm: domain 0 disables clocks which are in fact being used >> http://bugs.xenproject.org/xen/bug/45 >> >> ? >> >> On an ARM based board I have to use 'clk_ignore_unused' preventing that >> Dom0 disables the UART clock for the console UART configured with >> console=hvc0. > > There is no better solution than passing "clk_ignore_unused" on the > kernel command line so far. What would be the solution for this issue? The "propagate any clock related properties from the UART node into the Xen hypervisor node" mentioned in the ticket? Best regards Dirk _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: ARM Xen Bug #45: Is there a solution? 2016-05-24 13:39 ` Dirk Behme @ 2016-05-24 20:05 ` Julien Grall 2016-05-25 15:10 ` Dirk Behme 0 siblings, 1 reply; 9+ messages in thread From: Julien Grall @ 2016-05-24 20:05 UTC (permalink / raw) To: Dirk Behme, Stefano Stabellini, Ian Jackson, xen-devel On 24/05/2016 14:39, Dirk Behme wrote: > Hi Julien, Hello Dirk, > On 23.05.2016 22:15, Julien Grall wrote: >> Hello Dirk, >> >>> is there a solution for >>> >>> arm: domain 0 disables clocks which are in fact being used >>> http://bugs.xenproject.org/xen/bug/45 >>> >>> ? >>> >>> On an ARM based board I have to use 'clk_ignore_unused' preventing that >>> Dom0 disables the UART clock for the console UART configured with >>> console=hvc0. >> >> There is no better solution than passing "clk_ignore_unused" on the >> kernel command line so far. > > > What would be the solution for this issue? The > > "propagate any clock related properties from the UART > node into the Xen hypervisor node" > > mentioned in the ticket? That is correct. Xen would copy the property "clocks" of the UART into the hypervisor node. DOM0 would then parse the clocks associated to this node and mark them as used by Xen (I think CLK_IGNORE_UNUSED could do the job for us). Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: ARM Xen Bug #45: Is there a solution? 2016-05-24 20:05 ` Julien Grall @ 2016-05-25 15:10 ` Dirk Behme 2016-05-26 9:00 ` Julien Grall 0 siblings, 1 reply; 9+ messages in thread From: Dirk Behme @ 2016-05-25 15:10 UTC (permalink / raw) To: Julien Grall, xen-devel; +Cc: Stefano Stabellini, Ian Jackson Hi Julien, On 24.05.2016 22:05, Julien Grall wrote: > > > On 24/05/2016 14:39, Dirk Behme wrote: >> Hi Julien, > > Hello Dirk, > >> On 23.05.2016 22:15, Julien Grall wrote: >>> Hello Dirk, >>> >>>> is there a solution for >>>> >>>> arm: domain 0 disables clocks which are in fact being used >>>> http://bugs.xenproject.org/xen/bug/45 >>>> >>>> ? >>>> >>>> On an ARM based board I have to use 'clk_ignore_unused' preventing >>>> that >>>> Dom0 disables the UART clock for the console UART configured with >>>> console=hvc0. >>> >>> There is no better solution than passing "clk_ignore_unused" on the >>> kernel command line so far. >> >> >> What would be the solution for this issue? The >> >> "propagate any clock related properties from the UART >> node into the Xen hypervisor node" >> >> mentioned in the ticket? > > That is correct. Xen would copy the property "clocks" of the UART into > the hypervisor node. > > DOM0 would then parse the clocks associated to this node and mark them > as used by Xen (I think CLK_IGNORE_UNUSED could do the job for us). I've started to look into this: I'd think in arm_uart.c in dt_uart_init() after if ( !dev ) we know the UART node we are looking for. From this we have to read the clock configuration. To be clarified: How to read the clock configuration? I couldn't find any convenient function dt_device_get_clock() or similar for that. Now, we have the clocks we are looking for. These are needed in domain_build.c in make_hypervisor_node(), then. To be clarified: How to pass the clock configuration from arm_uart.c to domain_build.c (and not break the non-dt / non-ARM platforms)? Any ideas or comments? Best regards Dirk _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: ARM Xen Bug #45: Is there a solution? 2016-05-25 15:10 ` Dirk Behme @ 2016-05-26 9:00 ` Julien Grall 2016-05-27 12:34 ` Dirk Behme 0 siblings, 1 reply; 9+ messages in thread From: Julien Grall @ 2016-05-26 9:00 UTC (permalink / raw) To: Dirk Behme, xen-devel; +Cc: Stefano Stabellini, Ian Jackson On 25/05/2016 16:10, Dirk Behme wrote: > Hi Julien, Hello Dirk, > On 24.05.2016 22:05, Julien Grall wrote: >> >> >> On 24/05/2016 14:39, Dirk Behme wrote: >>> Hi Julien, >> >> Hello Dirk, >> >>> On 23.05.2016 22:15, Julien Grall wrote: >>>> Hello Dirk, >>>> >>>>> is there a solution for >>>>> >>>>> arm: domain 0 disables clocks which are in fact being used >>>>> http://bugs.xenproject.org/xen/bug/45 >>>>> >>>>> ? >>>>> >>>>> On an ARM based board I have to use 'clk_ignore_unused' preventing >>>>> that >>>>> Dom0 disables the UART clock for the console UART configured with >>>>> console=hvc0. >>>> >>>> There is no better solution than passing "clk_ignore_unused" on the >>>> kernel command line so far. >>> >>> >>> What would be the solution for this issue? The >>> >>> "propagate any clock related properties from the UART >>> node into the Xen hypervisor node" >>> >>> mentioned in the ticket? >> >> That is correct. Xen would copy the property "clocks" of the UART into >> the hypervisor node. >> >> DOM0 would then parse the clocks associated to this node and mark them >> as used by Xen (I think CLK_IGNORE_UNUSED could do the job for us). > > > I've started to look into this: > > I'd think in arm_uart.c in dt_uart_init() after > > if ( !dev ) > > we know the UART node we are looking for. From this we have to read the > clock configuration. > > To be clarified: How to read the clock configuration? I couldn't find > any convenient function dt_device_get_clock() or similar for that. Xen does not need to parse the content of the property "clocks" but copy the raw value to the DOM0 DT. You cand find the value of a property with dt_get_property. > > Now, we have the clocks we are looking for. > > These are needed in domain_build.c in make_hypervisor_node(), then. > > To be clarified: How to pass the clock configuration from arm_uart.c to > domain_build.c (and not break the non-dt / non-ARM platforms)? > > Any ideas or comments? All the devices (UART included) used by Xen will return DOMID_XEN when dt_device_used_by is called to the node. You could use it to collect the clocks of all those devices and gather the value in a single property to be created in the hypervisor node. Regards, -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: ARM Xen Bug #45: Is there a solution? 2016-05-26 9:00 ` Julien Grall @ 2016-05-27 12:34 ` Dirk Behme 2016-05-31 10:44 ` Julien Grall 0 siblings, 1 reply; 9+ messages in thread From: Dirk Behme @ 2016-05-27 12:34 UTC (permalink / raw) To: Julien Grall, xen-devel; +Cc: Stefano Stabellini, Ian Jackson On 26.05.2016 11:00, Julien Grall wrote: > On 25/05/2016 16:10, Dirk Behme wrote: >> On 24.05.2016 22:05, Julien Grall wrote: >>> On 24/05/2016 14:39, Dirk Behme wrote: >>>> On 23.05.2016 22:15, Julien Grall wrote: >>>>> Hello Dirk, >>>>> >>>>>> is there a solution for >>>>>> >>>>>> arm: domain 0 disables clocks which are in fact being used >>>>>> http://bugs.xenproject.org/xen/bug/45 >>>>>> >>>>>> ? >>>>>> >>>>>> On an ARM based board I have to use 'clk_ignore_unused' preventing >>>>>> that >>>>>> Dom0 disables the UART clock for the console UART configured with >>>>>> console=hvc0. >>>>> >>>>> There is no better solution than passing "clk_ignore_unused" on the >>>>> kernel command line so far. >>>> >>>> >>>> What would be the solution for this issue? The >>>> >>>> "propagate any clock related properties from the UART >>>> node into the Xen hypervisor node" >>>> >>>> mentioned in the ticket? >>> >>> That is correct. Xen would copy the property "clocks" of the UART into >>> the hypervisor node. >>> >>> DOM0 would then parse the clocks associated to this node and mark them >>> as used by Xen (I think CLK_IGNORE_UNUSED could do the job for us). >> >> >> I've started to look into this: >> >> I'd think in arm_uart.c in dt_uart_init() after >> >> if ( !dev ) >> >> we know the UART node we are looking for. From this we have to read the >> clock configuration. >> >> To be clarified: How to read the clock configuration? I couldn't find >> any convenient function dt_device_get_clock() or similar for that. > > Xen does not need to parse the content of the property "clocks" but > copy the raw value to the DOM0 DT. > > You cand find the value of a property with dt_get_property. > >> >> Now, we have the clocks we are looking for. >> >> These are needed in domain_build.c in make_hypervisor_node(), then. >> >> To be clarified: How to pass the clock configuration from arm_uart.c to >> domain_build.c (and not break the non-dt / non-ARM platforms)? >> >> Any ideas or comments? > > All the devices (UART included) used by Xen will return DOMID_XEN when > dt_device_used_by is called to the node. > > You could use it to collect the clocks of all those devices and gather > the value in a single property to be created in the hypervisor node. Anything like below (untested) [1]? I'm unhappy about the global variables and the max clocks, though. Best regards Dirk [1] --- xen/arch/arm/domain_build.c | 24 ++++++++++++++++++++++++ 1 file changed, 24 insertions(+) Index: xen.git/xen/arch/arm/domain_build.c =================================================================== --- xen.git.orig/xen/arch/arm/domain_build.c +++ xen.git/xen/arch/arm/domain_build.c @@ -42,6 +42,10 @@ static void __init parse_dom0_mem(const } custom_param("dom0_mem", parse_dom0_mem); +#define MAX_DT_CLOCKS 256 +static unsigned char dt_clocks[MAX_DT_CLOCKS]; +static unsigned int clk_cnt; + //#define DEBUG_DT #ifdef DEBUG_DT @@ -657,6 +661,10 @@ static int make_hypervisor_node(const st if ( res ) return res; + res = fdt_property(fdt, "clocks", dt_clocks, clk_cnt); + if ( res ) + return res; + res = fdt_end_node(fdt); return res; @@ -1213,9 +1221,11 @@ static int handle_node(struct domain *d, { /* sentinel */ }, }; struct dt_device_node *child; + unsigned int len; int res; const char *name; const char *path; + const char *clocks; path = dt_node_full_name(node); @@ -1246,6 +1256,20 @@ static int handle_node(struct domain *d, if ( dt_device_used_by(node) == DOMID_XEN ) { DPRINT(" Skip it (used by Xen)\n"); + + /* + * Remember the clock used by the skipped node + * We add it later to the hypervisor node to make the + * Linux kernel aware of its usage + */ + clocks = dt_get_property(node, "clocks", &len); + if ( clk_cnt + len >= MAX_DT_CLOCKS ) { + printk("Failed to remember the clock node of %s\n", path); + printk("Use the Linux kernel command 'clk_ignore_unused'\n"); + return 0; + } + memcpy(&dt_clocks[clk_cnt], clocks, len); + clk_cnt += len; return 0; } _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: ARM Xen Bug #45: Is there a solution? 2016-05-27 12:34 ` Dirk Behme @ 2016-05-31 10:44 ` Julien Grall [not found] ` <574DC0DC.9040904@gmx.de> 0 siblings, 1 reply; 9+ messages in thread From: Julien Grall @ 2016-05-31 10:44 UTC (permalink / raw) To: Dirk Behme, xen-devel; +Cc: Stefano Stabellini, Ian Jackson Hello Dirk, On 27/05/16 13:34, Dirk Behme wrote: > On 26.05.2016 11:00, Julien Grall wrote: >> On 25/05/2016 16:10, Dirk Behme wrote: >>> On 24.05.2016 22:05, Julien Grall wrote: >>>> On 24/05/2016 14:39, Dirk Behme wrote: >>>>> On 23.05.2016 22:15, Julien Grall wrote: >> All the devices (UART included) used by Xen will return DOMID_XEN when >> dt_device_used_by is called to the node. >> >> You could use it to collect the clocks of all those devices and gather >> the value in a single property to be created in the hypervisor node. > > > Anything like below (untested) [1]? Yes. > I'm unhappy about the global variables and the max clocks, though. How about moving those variables in the structure kernel_info? > > Best regards > > Dirk > > [1] > > --- > xen/arch/arm/domain_build.c | 24 ++++++++++++++++++++++++ > 1 file changed, 24 insertions(+) > > Index: xen.git/xen/arch/arm/domain_build.c > =================================================================== > --- xen.git.orig/xen/arch/arm/domain_build.c > +++ xen.git/xen/arch/arm/domain_build.c > @@ -42,6 +42,10 @@ static void __init parse_dom0_mem(const > } > custom_param("dom0_mem", parse_dom0_mem); > > +#define MAX_DT_CLOCKS 256 > +static unsigned char dt_clocks[MAX_DT_CLOCKS]; > +static unsigned int clk_cnt; > + > //#define DEBUG_DT > > #ifdef DEBUG_DT > @@ -657,6 +661,10 @@ static int make_hypervisor_node(const st > if ( res ) > return res; > > + res = fdt_property(fdt, "clocks", dt_clocks, clk_cnt); > + if ( res ) > + return res; > + > res = fdt_end_node(fdt); > > return res; > @@ -1213,9 +1221,11 @@ static int handle_node(struct domain *d, > { /* sentinel */ }, > }; > struct dt_device_node *child; > + unsigned int len; > int res; > const char *name; > const char *path; > + const char *clocks; > > path = dt_node_full_name(node); > > @@ -1246,6 +1256,20 @@ static int handle_node(struct domain *d, > if ( dt_device_used_by(node) == DOMID_XEN ) > { > DPRINT(" Skip it (used by Xen)\n"); > + > + /* > + * Remember the clock used by the skipped node > + * We add it later to the hypervisor node to make the > + * Linux kernel aware of its usage > + */ > + clocks = dt_get_property(node, "clocks", &len); > + if ( clk_cnt + len >= MAX_DT_CLOCKS ) { > + printk("Failed to remember the clock node of %s\n", path); > + printk("Use the Linux kernel command 'clk_ignore_unused'\n"); > + return 0; > + } > + memcpy(&dt_clocks[clk_cnt], clocks, len); > + clk_cnt += len; > return 0; > } > -- Julien Grall _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
[parent not found: <574DC0DC.9040904@gmx.de>]
* Re: ARM Xen Bug #45: Is there a solution? [not found] ` <574DC0DC.9040904@gmx.de> @ 2016-06-21 10:27 ` Dirk Behme 0 siblings, 0 replies; 9+ messages in thread From: Dirk Behme @ 2016-06-21 10:27 UTC (permalink / raw) To: xen-devel; +Cc: Julien Grall, Stefano Stabellini > Subject: Re: ARM Xen Bug #45: Is there a solution? > Date: Tue, 31 May 2016 11:44:23 +0100 > From: Julien Grall <julien.grall@arm.com> > To: Dirk Behme <dirk.behme@gmail.com>, xen-devel@lists.xen.org > <xen-devel@lists.xen.org> > CC: Stefano Stabellini <sstabellini@kernel.org>, Ian Jackson > <Ian.Jackson@eu.citrix.com> > > Hello Dirk, > > On 27/05/16 13:34, Dirk Behme wrote: >> On 26.05.2016 11:00, Julien Grall wrote: >>> On 25/05/2016 16:10, Dirk Behme wrote: >>>> On 24.05.2016 22:05, Julien Grall wrote: >>>>> On 24/05/2016 14:39, Dirk Behme wrote: >>>>>> On 23.05.2016 22:15, Julien Grall wrote: >>> All the devices (UART included) used by Xen will return DOMID_XEN when >>> dt_device_used_by is called to the node. >>> >>> You could use it to collect the clocks of all those devices and gather >>> the value in a single property to be created in the hypervisor node. >> >> >> Anything like below (untested) [1]? > > Yes. > >> I'm unhappy about the global variables and the max clocks, though. > > How about moving those variables in the structure kernel_info? Just for the logs to finish this thread: https://lists.xen.org/archives/html/xen-devel/2016-06/msg02607.html http://lists.infradead.org/pipermail/linux-arm-kernel/2016-June/438067.html Best regards Dirk _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel ^ permalink raw reply [flat|nested] 9+ messages in thread
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2016-05-23 15:47 ARM Xen Bug #45: Is there a solution? Dirk Behme
2016-05-23 20:15 ` Julien Grall
2016-05-24 13:39 ` Dirk Behme
2016-05-24 20:05 ` Julien Grall
2016-05-25 15:10 ` Dirk Behme
2016-05-26 9:00 ` Julien Grall
2016-05-27 12:34 ` Dirk Behme
2016-05-31 10:44 ` Julien Grall
[not found] ` <574DC0DC.9040904@gmx.de>
2016-06-21 10:27 ` Dirk Behme
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