| Message ID | 1452840929-19612-11-git-send-email-zhaoshenglong@huawei.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Fri, 15 Jan 2016, Shannon Zhao wrote: > From: Shannon Zhao <shannon.zhao@linaro.org> > > Move xen_early_init() before efi_init(), then when calling efi_init() > could initialize Xen specific UEFI. > > Check if it runs on Xen hypervisor through the flat dts. > > Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > --- > arch/arm/xen/enlighten.c | 56 ++++++++++++++++++++++++++++++++++------------- > arch/arm64/kernel/setup.c | 2 +- > 2 files changed, 42 insertions(+), 16 deletions(-) > > diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > index 4e78c49..5d0fe68 100644 > --- a/arch/arm/xen/enlighten.c > +++ b/arch/arm/xen/enlighten.c > @@ -19,6 +19,7 @@ > #include <linux/irqreturn.h> > #include <linux/module.h> > #include <linux/of.h> > +#include <linux/of_fdt.h> > #include <linux/of_irq.h> > #include <linux/of_address.h> > #include <linux/cpuidle.h> > @@ -52,8 +53,6 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; > > static __read_mostly unsigned int xen_events_irq; > > -static __initdata struct device_node *xen_node; > - > int xen_remap_domain_gfn_array(struct vm_area_struct *vma, > unsigned long addr, > xen_pfn_t *gfn, int nr, > @@ -222,6 +221,33 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) > return IRQ_HANDLED; > } > > +static __initdata struct { > + const char *compat; > + const char *prefix; > + const char *version; > + bool found; > +} xen_node = {"xen,xen", "xen,xen-", NULL, false}; > + > +static int __init fdt_find_xen_node(unsigned long node, const char *uname, > + int depth, void *data) > +{ > + const void *s = NULL; > + int len; > + > + if (depth != 1 || strcmp(uname, "hypervisor") != 0) > + return 0; > + > + if (of_flat_dt_is_compatible(node, xen_node.compat)) > + xen_node.found = true; > + > + s = of_get_flat_dt_prop(node, "compatible", &len); > + if (strlen(xen_node.prefix) + 3 < len && > + !strncmp(xen_node.prefix, s, strlen(xen_node.prefix))) > + xen_node.version = s + strlen(xen_node.prefix); > + > + return 0; > +} > + > /* > * see Documentation/devicetree/bindings/arm/xen.txt for the > * documentation of the Xen Device Tree format. > @@ -229,26 +255,18 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) > #define GRANT_TABLE_PHYSADDR 0 > void __init xen_early_init(void) > { > - int len; > - const char *s = NULL; > - const char *version = NULL; > - const char *xen_prefix = "xen,xen-"; > - > - xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); > - if (!xen_node) { > + of_scan_flat_dt(fdt_find_xen_node, NULL); > + if (!xen_node.found) { > pr_debug("No Xen support\n"); > return; > } > - s = of_get_property(xen_node, "compatible", &len); > - if (strlen(xen_prefix) + 3 < len && > - !strncmp(xen_prefix, s, strlen(xen_prefix))) > - version = s + strlen(xen_prefix); > - if (version == NULL) { > + > + if (xen_node.version == NULL) { > pr_debug("Xen version not found\n"); > return; > } This is going to access data within the fdt, after it has been unflattened (by the unflatten_device_tree call). Is that allowed? If that's not allowed, then you could copy the version string to xen_node.version, rather than just copying the pointer. Otherwise you could move the version check entirely within fdt_find_xen_node and remove the version field from xen_node. > - pr_info("Xen %s support found\n", version); > + pr_info("Xen %s support found\n", xen_node.version); > > xen_domain_type = XEN_HVM_DOMAIN; > > @@ -296,6 +314,14 @@ static int __init xen_guest_init(void) > } > #endif > } else { > + struct device_node *xen_node; > + > + xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); > + if (!xen_node) { > + pr_debug("No Xen support\n"); > + return -ENODEV; > + } It makes sense to move this into a DT specific init function called from xen_guest_init. Also, given that at this point we know that a Xen node should be present, it makes sense to return EFAULT on error, instead of ENODEV. The error message could be changed to something like: "Xen support was detected before, but it has disappeared" and should be pr_err. > xen_events_irq = irq_of_parse_and_map(xen_node, 0); > } > > diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c > index 8119479..a4a2878 100644 > --- a/arch/arm64/kernel/setup.c > +++ b/arch/arm64/kernel/setup.c > @@ -313,6 +313,7 @@ void __init setup_arch(char **cmdline_p) > */ > local_async_enable(); > > + xen_early_init(); > efi_init(); > arm64_memblock_init(); > > @@ -334,7 +335,6 @@ void __init setup_arch(char **cmdline_p) > } else { > psci_acpi_init(); > } > - xen_early_init(); > > cpu_read_bootcpu_ops(); > smp_init_cpus();
On 2016/1/18 22:59, Stefano Stabellini wrote: > On Fri, 15 Jan 2016, Shannon Zhao wrote: >> From: Shannon Zhao <shannon.zhao@linaro.org> >> >> Move xen_early_init() before efi_init(), then when calling efi_init() >> could initialize Xen specific UEFI. >> >> Check if it runs on Xen hypervisor through the flat dts. >> >> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> >> --- >> arch/arm/xen/enlighten.c | 56 ++++++++++++++++++++++++++++++++++------------- >> arch/arm64/kernel/setup.c | 2 +- >> 2 files changed, 42 insertions(+), 16 deletions(-) >> >> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c >> index 4e78c49..5d0fe68 100644 >> --- a/arch/arm/xen/enlighten.c >> +++ b/arch/arm/xen/enlighten.c >> @@ -19,6 +19,7 @@ >> #include <linux/irqreturn.h> >> #include <linux/module.h> >> #include <linux/of.h> >> +#include <linux/of_fdt.h> >> #include <linux/of_irq.h> >> #include <linux/of_address.h> >> #include <linux/cpuidle.h> >> @@ -52,8 +53,6 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; >> >> static __read_mostly unsigned int xen_events_irq; >> >> -static __initdata struct device_node *xen_node; >> - >> int xen_remap_domain_gfn_array(struct vm_area_struct *vma, >> unsigned long addr, >> xen_pfn_t *gfn, int nr, >> @@ -222,6 +221,33 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) >> return IRQ_HANDLED; >> } >> >> +static __initdata struct { >> + const char *compat; >> + const char *prefix; >> + const char *version; >> + bool found; >> +} xen_node = {"xen,xen", "xen,xen-", NULL, false}; >> + >> +static int __init fdt_find_xen_node(unsigned long node, const char *uname, >> + int depth, void *data) >> +{ >> + const void *s = NULL; >> + int len; >> + >> + if (depth != 1 || strcmp(uname, "hypervisor") != 0) >> + return 0; >> + >> + if (of_flat_dt_is_compatible(node, xen_node.compat)) >> + xen_node.found = true; >> + >> + s = of_get_flat_dt_prop(node, "compatible", &len); >> + if (strlen(xen_node.prefix) + 3 < len && >> + !strncmp(xen_node.prefix, s, strlen(xen_node.prefix))) >> + xen_node.version = s + strlen(xen_node.prefix); >> + >> + return 0; >> +} >> + >> /* >> * see Documentation/devicetree/bindings/arm/xen.txt for the >> * documentation of the Xen Device Tree format. >> @@ -229,26 +255,18 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) >> #define GRANT_TABLE_PHYSADDR 0 >> void __init xen_early_init(void) >> { >> - int len; >> - const char *s = NULL; >> - const char *version = NULL; >> - const char *xen_prefix = "xen,xen-"; >> - >> - xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); >> - if (!xen_node) { >> + of_scan_flat_dt(fdt_find_xen_node, NULL); >> + if (!xen_node.found) { >> pr_debug("No Xen support\n"); >> return; >> } >> - s = of_get_property(xen_node, "compatible", &len); >> - if (strlen(xen_prefix) + 3 < len && >> - !strncmp(xen_prefix, s, strlen(xen_prefix))) >> - version = s + strlen(xen_prefix); >> - if (version == NULL) { >> + >> + if (xen_node.version == NULL) { >> pr_debug("Xen version not found\n"); >> return; >> } > > This is going to access data within the fdt, after it has been > unflattened (by the unflatten_device_tree call). Is that allowed? > > If that's not allowed, then you could copy the version string to > xen_node.version, rather than just copying the pointer. Otherwise you > could move the version check entirely within fdt_find_xen_node and > remove the version field from xen_node. > A little confused. Since here we move xen_early_init before efi_init and before unflatten_device_tree as well, at this moment in xen_early_init the fdt is flattened. The xen_node.version is only set in fdt_find_xen_node and accessed in xen_early_init. > >> - pr_info("Xen %s support found\n", version); >> + pr_info("Xen %s support found\n", xen_node.version); >> >> xen_domain_type = XEN_HVM_DOMAIN; >> >> @@ -296,6 +314,14 @@ static int __init xen_guest_init(void) >> } >> #endif >> } else { >> + struct device_node *xen_node; >> + >> + xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); >> + if (!xen_node) { >> + pr_debug("No Xen support\n"); >> + return -ENODEV; >> + } > > It makes sense to move this into a DT specific init function called from > xen_guest_init. Also, given that at this point we know that a Xen node > should be present, it makes sense to return EFAULT on error, instead of > ENODEV. The error message could be changed to something like: "Xen > support was detected before, but it has disappeared" and should be > pr_err. > OK, thanks. > >> xen_events_irq = irq_of_parse_and_map(xen_node, 0); >> } >> >> diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c >> index 8119479..a4a2878 100644 >> --- a/arch/arm64/kernel/setup.c >> +++ b/arch/arm64/kernel/setup.c >> @@ -313,6 +313,7 @@ void __init setup_arch(char **cmdline_p) >> */ >> local_async_enable(); >> >> + xen_early_init(); >> efi_init(); >> arm64_memblock_init(); >> >> @@ -334,7 +335,6 @@ void __init setup_arch(char **cmdline_p) >> } else { >> psci_acpi_init(); >> } >> - xen_early_init(); >> >> cpu_read_bootcpu_ops(); >> smp_init_cpus(); > > . >
On Tue, 19 Jan 2016, Shannon Zhao wrote: > On 2016/1/18 22:59, Stefano Stabellini wrote: > > On Fri, 15 Jan 2016, Shannon Zhao wrote: > >> From: Shannon Zhao <shannon.zhao@linaro.org> > >> > >> Move xen_early_init() before efi_init(), then when calling efi_init() > >> could initialize Xen specific UEFI. > >> > >> Check if it runs on Xen hypervisor through the flat dts. > >> > >> Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> > >> --- > >> arch/arm/xen/enlighten.c | 56 ++++++++++++++++++++++++++++++++++------------- > >> arch/arm64/kernel/setup.c | 2 +- > >> 2 files changed, 42 insertions(+), 16 deletions(-) > >> > >> diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c > >> index 4e78c49..5d0fe68 100644 > >> --- a/arch/arm/xen/enlighten.c > >> +++ b/arch/arm/xen/enlighten.c > >> @@ -19,6 +19,7 @@ > >> #include <linux/irqreturn.h> > >> #include <linux/module.h> > >> #include <linux/of.h> > >> +#include <linux/of_fdt.h> > >> #include <linux/of_irq.h> > >> #include <linux/of_address.h> > >> #include <linux/cpuidle.h> > >> @@ -52,8 +53,6 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; > >> > >> static __read_mostly unsigned int xen_events_irq; > >> > >> -static __initdata struct device_node *xen_node; > >> - > >> int xen_remap_domain_gfn_array(struct vm_area_struct *vma, > >> unsigned long addr, > >> xen_pfn_t *gfn, int nr, > >> @@ -222,6 +221,33 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) > >> return IRQ_HANDLED; > >> } > >> > >> +static __initdata struct { > >> + const char *compat; > >> + const char *prefix; > >> + const char *version; > >> + bool found; > >> +} xen_node = {"xen,xen", "xen,xen-", NULL, false}; > >> + > >> +static int __init fdt_find_xen_node(unsigned long node, const char *uname, > >> + int depth, void *data) > >> +{ > >> + const void *s = NULL; > >> + int len; > >> + > >> + if (depth != 1 || strcmp(uname, "hypervisor") != 0) > >> + return 0; > >> + > >> + if (of_flat_dt_is_compatible(node, xen_node.compat)) > >> + xen_node.found = true; > >> + > >> + s = of_get_flat_dt_prop(node, "compatible", &len); > >> + if (strlen(xen_node.prefix) + 3 < len && > >> + !strncmp(xen_node.prefix, s, strlen(xen_node.prefix))) > >> + xen_node.version = s + strlen(xen_node.prefix); > >> + > >> + return 0; > >> +} > >> + > >> /* > >> * see Documentation/devicetree/bindings/arm/xen.txt for the > >> * documentation of the Xen Device Tree format. > >> @@ -229,26 +255,18 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) > >> #define GRANT_TABLE_PHYSADDR 0 > >> void __init xen_early_init(void) > >> { > >> - int len; > >> - const char *s = NULL; > >> - const char *version = NULL; > >> - const char *xen_prefix = "xen,xen-"; > >> - > >> - xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); > >> - if (!xen_node) { > >> + of_scan_flat_dt(fdt_find_xen_node, NULL); > >> + if (!xen_node.found) { > >> pr_debug("No Xen support\n"); > >> return; > >> } > >> - s = of_get_property(xen_node, "compatible", &len); > >> - if (strlen(xen_prefix) + 3 < len && > >> - !strncmp(xen_prefix, s, strlen(xen_prefix))) > >> - version = s + strlen(xen_prefix); > >> - if (version == NULL) { > >> + > >> + if (xen_node.version == NULL) { > >> pr_debug("Xen version not found\n"); > >> return; > >> } > > > > This is going to access data within the fdt, after it has been > > unflattened (by the unflatten_device_tree call). Is that allowed? > > > > If that's not allowed, then you could copy the version string to > > xen_node.version, rather than just copying the pointer. Otherwise you > > could move the version check entirely within fdt_find_xen_node and > > remove the version field from xen_node. > > > A little confused. Since here we move xen_early_init before efi_init and > before unflatten_device_tree as well, at this moment in xen_early_init > the fdt is flattened. The xen_node.version is only set in > fdt_find_xen_node and accessed in xen_early_init. You are right, sorry, I must have been confused. It might be good to rename the xen_node variable that this patch introduced in xen_guest_init. > >> - pr_info("Xen %s support found\n", version); > >> + pr_info("Xen %s support found\n", xen_node.version); > >> > >> xen_domain_type = XEN_HVM_DOMAIN; > >> > >> @@ -296,6 +314,14 @@ static int __init xen_guest_init(void) > >> } > >> #endif > >> } else { > >> + struct device_node *xen_node; > >> + > >> + xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); > >> + if (!xen_node) { > >> + pr_debug("No Xen support\n"); > >> + return -ENODEV; > >> + } > > > > It makes sense to move this into a DT specific init function called from > > xen_guest_init. Also, given that at this point we know that a Xen node > > should be present, it makes sense to return EFAULT on error, instead of > > ENODEV. The error message could be changed to something like: "Xen > > support was detected before, but it has disappeared" and should be > > pr_err. > > > OK, thanks.
diff --git a/arch/arm/xen/enlighten.c b/arch/arm/xen/enlighten.c index 4e78c49..5d0fe68 100644 --- a/arch/arm/xen/enlighten.c +++ b/arch/arm/xen/enlighten.c @@ -19,6 +19,7 @@ #include <linux/irqreturn.h> #include <linux/module.h> #include <linux/of.h> +#include <linux/of_fdt.h> #include <linux/of_irq.h> #include <linux/of_address.h> #include <linux/cpuidle.h> @@ -52,8 +53,6 @@ struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; static __read_mostly unsigned int xen_events_irq; -static __initdata struct device_node *xen_node; - int xen_remap_domain_gfn_array(struct vm_area_struct *vma, unsigned long addr, xen_pfn_t *gfn, int nr, @@ -222,6 +221,33 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) return IRQ_HANDLED; } +static __initdata struct { + const char *compat; + const char *prefix; + const char *version; + bool found; +} xen_node = {"xen,xen", "xen,xen-", NULL, false}; + +static int __init fdt_find_xen_node(unsigned long node, const char *uname, + int depth, void *data) +{ + const void *s = NULL; + int len; + + if (depth != 1 || strcmp(uname, "hypervisor") != 0) + return 0; + + if (of_flat_dt_is_compatible(node, xen_node.compat)) + xen_node.found = true; + + s = of_get_flat_dt_prop(node, "compatible", &len); + if (strlen(xen_node.prefix) + 3 < len && + !strncmp(xen_node.prefix, s, strlen(xen_node.prefix))) + xen_node.version = s + strlen(xen_node.prefix); + + return 0; +} + /* * see Documentation/devicetree/bindings/arm/xen.txt for the * documentation of the Xen Device Tree format. @@ -229,26 +255,18 @@ static irqreturn_t xen_arm_callback(int irq, void *arg) #define GRANT_TABLE_PHYSADDR 0 void __init xen_early_init(void) { - int len; - const char *s = NULL; - const char *version = NULL; - const char *xen_prefix = "xen,xen-"; - - xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); - if (!xen_node) { + of_scan_flat_dt(fdt_find_xen_node, NULL); + if (!xen_node.found) { pr_debug("No Xen support\n"); return; } - s = of_get_property(xen_node, "compatible", &len); - if (strlen(xen_prefix) + 3 < len && - !strncmp(xen_prefix, s, strlen(xen_prefix))) - version = s + strlen(xen_prefix); - if (version == NULL) { + + if (xen_node.version == NULL) { pr_debug("Xen version not found\n"); return; } - pr_info("Xen %s support found\n", version); + pr_info("Xen %s support found\n", xen_node.version); xen_domain_type = XEN_HVM_DOMAIN; @@ -296,6 +314,14 @@ static int __init xen_guest_init(void) } #endif } else { + struct device_node *xen_node; + + xen_node = of_find_compatible_node(NULL, NULL, "xen,xen"); + if (!xen_node) { + pr_debug("No Xen support\n"); + return -ENODEV; + } + xen_events_irq = irq_of_parse_and_map(xen_node, 0); } diff --git a/arch/arm64/kernel/setup.c b/arch/arm64/kernel/setup.c index 8119479..a4a2878 100644 --- a/arch/arm64/kernel/setup.c +++ b/arch/arm64/kernel/setup.c @@ -313,6 +313,7 @@ void __init setup_arch(char **cmdline_p) */ local_async_enable(); + xen_early_init(); efi_init(); arm64_memblock_init(); @@ -334,7 +335,6 @@ void __init setup_arch(char **cmdline_p) } else { psci_acpi_init(); } - xen_early_init(); cpu_read_bootcpu_ops(); smp_init_cpus();