| Message ID | 1461085990-2547-7-git-send-email-eric.auger@linaro.org |
|---|---|
| State | Superseded |
| Headers | show |
Marc, On 04/20/2016 11:27 AM, Marc Zyngier wrote: > On 19/04/16 18:13, Eric Auger wrote: >> This patch implements the msi_doorbell_info callback in the >> gicv2m driver. >> >> The driver now is able to return its doorbell characteristics >> (base, size, prot). A single doorbell is exposed. >> >> This will allow the msi layer to iommu_map this doorbell when >> requested. >> >> Signed-off-by: Eric Auger <eric.auger@linaro.org> >> >> --- >> >> v7: creation >> --- >> drivers/irqchip/irq-gic-v2m.c | 32 +++++++++++++++++++++++++++++++- >> 1 file changed, 31 insertions(+), 1 deletion(-) >> >> diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c >> index 28f047c..54690b9 100644 >> --- a/drivers/irqchip/irq-gic-v2m.c >> +++ b/drivers/irqchip/irq-gic-v2m.c >> @@ -24,6 +24,8 @@ >> #include <linux/of_pci.h> >> #include <linux/slab.h> >> #include <linux/spinlock.h> >> +#include <linux/percpu.h> >> +#include <linux/iommu.h> >> >> /* >> * MSI_TYPER: >> @@ -64,6 +66,7 @@ struct v2m_data { >> u32 nr_spis; /* The number of SPIs for MSIs */ >> unsigned long *bm; /* MSI vector bitmap */ >> u32 flags; /* v2m flags for specific implementation */ >> + struct irq_chip_msi_doorbell_info doorbell_info; >> }; >> >> static void gicv2m_mask_msi_irq(struct irq_data *d) >> @@ -105,6 +108,16 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) >> msg->data -= v2m->spi_start; >> } >> >> +static const struct irq_chip_msi_doorbell_info * >> +gicv2m_msi_doorbell_info(struct irq_data *data) >> +{ >> + struct v2m_data *v2m = irq_data_get_irq_chip_data(data); >> + >> + if (!v2m) >> + return NULL; > > How can this ever be NULL? I think you can drop that test. OK > >> + return (const struct irq_chip_msi_doorbell_info *)(&v2m->doorbell_info); > > Please don't do that. Use "const" in the functions that are using > irq_chip_msi_doorbell_info, but do not make this "const" here. It definitively compiles without casting so obviously this is not needed but is there any other wrong thing I don't see? we still want this function to return a pointer to a const? > >> +} >> + >> static struct irq_chip gicv2m_irq_chip = { >> .name = "GICv2m", >> .irq_mask = irq_chip_mask_parent, >> @@ -112,6 +125,7 @@ static struct irq_chip gicv2m_irq_chip = { >> .irq_eoi = irq_chip_eoi_parent, >> .irq_set_affinity = irq_chip_set_affinity_parent, >> .irq_compose_msi_msg = gicv2m_compose_msi_msg, >> + .msi_doorbell_info = gicv2m_msi_doorbell_info, >> }; >> >> static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain, >> @@ -247,6 +261,7 @@ static void gicv2m_teardown(void) >> >> list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) { >> list_del(&v2m->entry); >> + free_percpu(v2m->doorbell_info.percpu_doorbells); >> kfree(v2m->bm); >> iounmap(v2m->base); >> of_node_put(to_of_node(v2m->fwnode)); >> @@ -299,6 +314,7 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, >> { >> int ret; >> struct v2m_data *v2m; >> + struct irq_chip_msi_doorbell __percpu *doorbell; >> >> v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL); >> if (!v2m) { >> @@ -311,11 +327,23 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, >> >> memcpy(&v2m->res, res, sizeof(struct resource)); >> >> + v2m->doorbell_info.percpu_doorbells = >> + alloc_percpu(struct irq_chip_msi_doorbell); >> + if (WARN_ON(!v2m->doorbell_info.percpu_doorbells)) { >> + ret = -ENOMEM; >> + goto err_free_v2m; >> + } >> + doorbell = per_cpu_ptr(v2m->doorbell_info.percpu_doorbells, 0); >> + doorbell->base = v2m->res.start; >> + doorbell->size = 4; >> + doorbell->prot = IOMMU_WRITE; > > You probably need to also have something that says IOMMU_DEVICE or > something similar, because I'm afraid you're getting a memory mapping > here. I've had a quick look at the two other series, but couldn't find > anything that would force the memory attributes. Yes you're right I currently just enforce the direction (which is checked against what VFIO user registered). Do you refer to IOMMU_MMIO, latterly proposed on the ML. In the positive, yes I intend to add it once it gets upstreamed. Thanks Eric > >> + v2m->doorbell_info.nb_doorbells = 1; >> + >> v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res)); >> if (!v2m->base) { >> pr_err("Failed to map GICv2m resource\n"); >> ret = -ENOMEM; >> - goto err_free_v2m; >> + goto err_free_v2m_doorbells; >> } >> >> if (spi_start && nr_spis) { >> @@ -359,6 +387,8 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, >> >> err_iounmap: >> iounmap(v2m->base); >> +err_free_v2m_doorbells: >> + free_percpu(v2m->doorbell_info.percpu_doorbells); >> err_free_v2m: >> kfree(v2m); >> return ret; >> > > Thanks, > > M. >
Marc, On 04/20/2016 07:56 PM, Marc Zyngier wrote: > On Wed, 20 Apr 2016 14:33:17 +0200 > Eric Auger <eric.auger@linaro.org> wrote: > >> Marc, >> On 04/20/2016 11:27 AM, Marc Zyngier wrote: >>> On 19/04/16 18:13, Eric Auger wrote: >>>> This patch implements the msi_doorbell_info callback in the >>>> gicv2m driver. >>>> >>>> The driver now is able to return its doorbell characteristics >>>> (base, size, prot). A single doorbell is exposed. >>>> >>>> This will allow the msi layer to iommu_map this doorbell when >>>> requested. >>>> >>>> Signed-off-by: Eric Auger <eric.auger@linaro.org> >>>> >>>> --- >>>> >>>> v7: creation >>>> --- >>>> drivers/irqchip/irq-gic-v2m.c | 32 +++++++++++++++++++++++++++++++- >>>> 1 file changed, 31 insertions(+), 1 deletion(-) >>>> >>>> diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c >>>> index 28f047c..54690b9 100644 >>>> --- a/drivers/irqchip/irq-gic-v2m.c >>>> +++ b/drivers/irqchip/irq-gic-v2m.c >>>> @@ -24,6 +24,8 @@ >>>> #include <linux/of_pci.h> >>>> #include <linux/slab.h> >>>> #include <linux/spinlock.h> >>>> +#include <linux/percpu.h> >>>> +#include <linux/iommu.h> >>>> >>>> /* >>>> * MSI_TYPER: >>>> @@ -64,6 +66,7 @@ struct v2m_data { >>>> u32 nr_spis; /* The number of SPIs for MSIs */ >>>> unsigned long *bm; /* MSI vector bitmap */ >>>> u32 flags; /* v2m flags for specific implementation */ >>>> + struct irq_chip_msi_doorbell_info doorbell_info; >>>> }; >>>> >>>> static void gicv2m_mask_msi_irq(struct irq_data *d) >>>> @@ -105,6 +108,16 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) >>>> msg->data -= v2m->spi_start; >>>> } >>>> >>>> +static const struct irq_chip_msi_doorbell_info * >>>> +gicv2m_msi_doorbell_info(struct irq_data *data) >>>> +{ >>>> + struct v2m_data *v2m = irq_data_get_irq_chip_data(data); >>>> + >>>> + if (!v2m) >>>> + return NULL; >>> >>> How can this ever be NULL? I think you can drop that test. >> OK >>> >>>> + return (const struct irq_chip_msi_doorbell_info *)(&v2m->doorbell_info); >>> >>> Please don't do that. Use "const" in the functions that are using >>> irq_chip_msi_doorbell_info, but do not make this "const" here. >> It definitively compiles without casting so obviously this is not needed >> but is there any other wrong thing I don't see? >> we still want this function to return a pointer to a const? > > I don't think we can return a const pointer, because it is obviously > not (the memory has been kmalloc'ed, and you've written to it, so it is > not really "read-only"). I see what you are afraid of now and I will remove it; will ask some compiler guys ;-) Have a nice evening Eric > > Maybe I'm being overly zealous, but I've seen compilers taking amazing > shortcuts when offered a const qualifier... > >>> >>>> +} >>>> + >>>> static struct irq_chip gicv2m_irq_chip = { >>>> .name = "GICv2m", >>>> .irq_mask = irq_chip_mask_parent, >>>> @@ -112,6 +125,7 @@ static struct irq_chip gicv2m_irq_chip = { >>>> .irq_eoi = irq_chip_eoi_parent, >>>> .irq_set_affinity = irq_chip_set_affinity_parent, >>>> .irq_compose_msi_msg = gicv2m_compose_msi_msg, >>>> + .msi_doorbell_info = gicv2m_msi_doorbell_info, >>>> }; >>>> >>>> static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain, >>>> @@ -247,6 +261,7 @@ static void gicv2m_teardown(void) >>>> >>>> list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) { >>>> list_del(&v2m->entry); >>>> + free_percpu(v2m->doorbell_info.percpu_doorbells); >>>> kfree(v2m->bm); >>>> iounmap(v2m->base); >>>> of_node_put(to_of_node(v2m->fwnode)); >>>> @@ -299,6 +314,7 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, >>>> { >>>> int ret; >>>> struct v2m_data *v2m; >>>> + struct irq_chip_msi_doorbell __percpu *doorbell; >>>> >>>> v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL); >>>> if (!v2m) { >>>> @@ -311,11 +327,23 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, >>>> >>>> memcpy(&v2m->res, res, sizeof(struct resource)); >>>> >>>> + v2m->doorbell_info.percpu_doorbells = >>>> + alloc_percpu(struct irq_chip_msi_doorbell); >>>> + if (WARN_ON(!v2m->doorbell_info.percpu_doorbells)) { >>>> + ret = -ENOMEM; >>>> + goto err_free_v2m; >>>> + } >>>> + doorbell = per_cpu_ptr(v2m->doorbell_info.percpu_doorbells, 0); >>>> + doorbell->base = v2m->res.start; >>>> + doorbell->size = 4; >>>> + doorbell->prot = IOMMU_WRITE; >>> >>> You probably need to also have something that says IOMMU_DEVICE or >>> something similar, because I'm afraid you're getting a memory mapping >>> here. I've had a quick look at the two other series, but couldn't find >>> anything that would force the memory attributes. >> Yes you're right I currently just enforce the direction (which is >> checked against what VFIO user registered). Do you refer to IOMMU_MMIO, >> latterly proposed on the ML. In the positive, yes I intend to add it >> once it gets upstreamed. > > Yeah, Robin's patches should become a dependency here, because there is > absolutely no guarantee that the device write to the doorbell won't be > treated a normal cacheable memory, with disastrous effects. > > Thanks, > > M. >
diff --git a/drivers/irqchip/irq-gic-v2m.c b/drivers/irqchip/irq-gic-v2m.c index 28f047c..54690b9 100644 --- a/drivers/irqchip/irq-gic-v2m.c +++ b/drivers/irqchip/irq-gic-v2m.c @@ -24,6 +24,8 @@ #include <linux/of_pci.h> #include <linux/slab.h> #include <linux/spinlock.h> +#include <linux/percpu.h> +#include <linux/iommu.h> /* * MSI_TYPER: @@ -64,6 +66,7 @@ struct v2m_data { u32 nr_spis; /* The number of SPIs for MSIs */ unsigned long *bm; /* MSI vector bitmap */ u32 flags; /* v2m flags for specific implementation */ + struct irq_chip_msi_doorbell_info doorbell_info; }; static void gicv2m_mask_msi_irq(struct irq_data *d) @@ -105,6 +108,16 @@ static void gicv2m_compose_msi_msg(struct irq_data *data, struct msi_msg *msg) msg->data -= v2m->spi_start; } +static const struct irq_chip_msi_doorbell_info * +gicv2m_msi_doorbell_info(struct irq_data *data) +{ + struct v2m_data *v2m = irq_data_get_irq_chip_data(data); + + if (!v2m) + return NULL; + return (const struct irq_chip_msi_doorbell_info *)(&v2m->doorbell_info); +} + static struct irq_chip gicv2m_irq_chip = { .name = "GICv2m", .irq_mask = irq_chip_mask_parent, @@ -112,6 +125,7 @@ static struct irq_chip gicv2m_irq_chip = { .irq_eoi = irq_chip_eoi_parent, .irq_set_affinity = irq_chip_set_affinity_parent, .irq_compose_msi_msg = gicv2m_compose_msi_msg, + .msi_doorbell_info = gicv2m_msi_doorbell_info, }; static int gicv2m_irq_gic_domain_alloc(struct irq_domain *domain, @@ -247,6 +261,7 @@ static void gicv2m_teardown(void) list_for_each_entry_safe(v2m, tmp, &v2m_nodes, entry) { list_del(&v2m->entry); + free_percpu(v2m->doorbell_info.percpu_doorbells); kfree(v2m->bm); iounmap(v2m->base); of_node_put(to_of_node(v2m->fwnode)); @@ -299,6 +314,7 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, { int ret; struct v2m_data *v2m; + struct irq_chip_msi_doorbell __percpu *doorbell; v2m = kzalloc(sizeof(struct v2m_data), GFP_KERNEL); if (!v2m) { @@ -311,11 +327,23 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, memcpy(&v2m->res, res, sizeof(struct resource)); + v2m->doorbell_info.percpu_doorbells = + alloc_percpu(struct irq_chip_msi_doorbell); + if (WARN_ON(!v2m->doorbell_info.percpu_doorbells)) { + ret = -ENOMEM; + goto err_free_v2m; + } + doorbell = per_cpu_ptr(v2m->doorbell_info.percpu_doorbells, 0); + doorbell->base = v2m->res.start; + doorbell->size = 4; + doorbell->prot = IOMMU_WRITE; + v2m->doorbell_info.nb_doorbells = 1; + v2m->base = ioremap(v2m->res.start, resource_size(&v2m->res)); if (!v2m->base) { pr_err("Failed to map GICv2m resource\n"); ret = -ENOMEM; - goto err_free_v2m; + goto err_free_v2m_doorbells; } if (spi_start && nr_spis) { @@ -359,6 +387,8 @@ static int __init gicv2m_init_one(struct fwnode_handle *fwnode, err_iounmap: iounmap(v2m->base); +err_free_v2m_doorbells: + free_percpu(v2m->doorbell_info.percpu_doorbells); err_free_v2m: kfree(v2m); return ret;
This patch implements the msi_doorbell_info callback in the gicv2m driver. The driver now is able to return its doorbell characteristics (base, size, prot). A single doorbell is exposed. This will allow the msi layer to iommu_map this doorbell when requested. Signed-off-by: Eric Auger <eric.auger@linaro.org> --- v7: creation --- drivers/irqchip/irq-gic-v2m.c | 32 +++++++++++++++++++++++++++++++- 1 file changed, 31 insertions(+), 1 deletion(-) -- 1.9.1