Re: [PATCH 09/31] powerpc/pseries/pci: Add a msi_free() handler to clear XIVE data
From: Cédric Le Goater <clg@kaod.org>
Date: 2021-05-20 13:10:57
Adding Marc. On 4/30/21 10:03 AM, Cédric Le Goater wrote:
The MSI domain clears the IRQ with msi_domain_free(), which calls irq_domain_free_irqs_top(), which clears the handler data. This is a problem for the XIVE controller since we need to unmap MMIO pages and free a specific XIVE structure. The 'msi_free()' handler is called before irq_domain_free_irqs_top() when the handler data is still available. Use that to clear the XIVE controller data.
This feels like a clumsy way of doing so. irq_domain_free_irqs_parent() would be my preferred way to clear the lowlevel handler data but we can't today. Could there be a smarter way ? Thanks, C.
quoted hunk ↗ jump to hunk
Cc: Thomas Gleixner <redacted> Signed-off-by: Cédric Le Goater <clg@kaod.org> --- arch/powerpc/include/asm/xive.h | 1 + arch/powerpc/platforms/pseries/msi.c | 16 +++++++++++++++- arch/powerpc/sysdev/xive/common.c | 5 ++++- 3 files changed, 20 insertions(+), 2 deletions(-)diff --git a/arch/powerpc/include/asm/xive.h b/arch/powerpc/include/asm/xive.h index aa094a8655b0..20ae50ab083c 100644 --- a/arch/powerpc/include/asm/xive.h +++ b/arch/powerpc/include/asm/xive.h@@ -111,6 +111,7 @@ void xive_native_free_vp_block(u32 vp_base); int xive_native_populate_irq_data(u32 hw_irq, struct xive_irq_data *data); void xive_cleanup_irq_data(struct xive_irq_data *xd); +void xive_irq_free_data(unsigned int virq); void xive_native_free_irq(u32 irq); int xive_native_configure_irq(u32 hw_irq, u32 target, u8 prio, u32 sw_irq);diff --git a/arch/powerpc/platforms/pseries/msi.c b/arch/powerpc/platforms/pseries/msi.c index a41c448520d4..da9d63a088bb 100644 --- a/arch/powerpc/platforms/pseries/msi.c +++ b/arch/powerpc/platforms/pseries/msi.c@@ -529,6 +529,19 @@ static int pseries_msi_ops_prepare(struct irq_domain *domain, struct device *dev return rtas_prepare_msi_irqs(pdev, nvec, type, arg); } +/* + * ->msi_free() is called before irq_domain_free_irqs_top() when the + * handler data is still available. Use that to clear the XIVE + * controller data. + */ +static void pseries_msi_ops_msi_free(struct irq_domain *domain, + struct msi_domain_info *info, + unsigned int irq) +{ + if (xive_enabled()) + xive_irq_free_data(irq); +} + /* * RTAS can not disable one MSI at a time. It's all or nothing. Do it * at the end after all IRQs have been freed.@@ -546,6 +559,7 @@ static void pseries_msi_domain_free_irqs(struct irq_domain *domain, static struct msi_domain_ops pseries_pci_msi_domain_ops = { .msi_prepare = pseries_msi_ops_prepare, + .msi_free = pseries_msi_ops_msi_free, .domain_free_irqs = pseries_msi_domain_free_irqs, };@@ -660,7 +674,7 @@ static void pseries_irq_domain_free(struct irq_domain *domain, unsigned int virq pr_debug("%s bridge %pOF %d #%d\n", __func__, phb->dn, virq, nr_irqs); - irq_domain_free_irqs_parent(domain, virq, nr_irqs); + /* XIVE domain data is cleared through ->msi_free() */ } static const struct irq_domain_ops pseries_irq_domain_ops = {diff --git a/arch/powerpc/sysdev/xive/common.c b/arch/powerpc/sysdev/xive/common.c index 3485baf9ec8c..191cd80ec534 100644 --- a/arch/powerpc/sysdev/xive/common.c +++ b/arch/powerpc/sysdev/xive/common.c@@ -980,6 +980,8 @@ EXPORT_SYMBOL_GPL(is_xive_irq); void xive_cleanup_irq_data(struct xive_irq_data *xd) { + pr_debug("%s for HW %x\n", __func__, xd->hw_irq); + if (xd->eoi_mmio) { unmap_kernel_range((unsigned long)xd->eoi_mmio, 1u << xd->esb_shift);@@ -1025,7 +1027,7 @@ static int xive_irq_alloc_data(unsigned int virq, irq_hw_number_t hw) return 0; } -static void xive_irq_free_data(unsigned int virq) +void xive_irq_free_data(unsigned int virq) { struct xive_irq_data *xd = irq_get_handler_data(virq);@@ -1035,6 +1037,7 @@ static void xive_irq_free_data(unsigned int virq) xive_cleanup_irq_data(xd); kfree(xd); } +EXPORT_SYMBOL_GPL(xive_irq_free_data); #ifdef CONFIG_SMP