From 457da57646686fcb38b3f61b153920ca08200078 Mon Sep 17 00:00:00 2001 From: Suravee Suthikulpanit Date: Mon, 18 Nov 2024 05:49:36 +0000 Subject: [PATCH] iommu/amd: Lock DTE before updating the entry with WRITE_ONCE() When updating only within a 64-bit tuple of a DTE, just lock the DTE and use WRITE_ONCE() because it is writing to memory read back by HW. Suggested-by: Jason Gunthorpe Reviewed-by: Jason Gunthorpe Signed-off-by: Suravee Suthikulpanit Link: https://lore.kernel.org/r/20241118054937.5203-9-suravee.suthikulpanit@amd.com Signed-off-by: Joerg Roedel --- drivers/iommu/amd/amd_iommu.h | 1 + drivers/iommu/amd/iommu.c | 43 +++++++++++++++++++---------------- 2 files changed, 25 insertions(+), 19 deletions(-) diff --git a/drivers/iommu/amd/amd_iommu.h b/drivers/iommu/amd/amd_iommu.h index 66b413615d0c..11be5a62d666 100644 --- a/drivers/iommu/amd/amd_iommu.h +++ b/drivers/iommu/amd/amd_iommu.h @@ -186,3 +186,4 @@ struct dev_table_entry *get_dev_table(struct amd_iommu *iommu); #endif struct dev_table_entry *amd_iommu_get_ivhd_dte_flags(u16 segid, u16 devid); +struct iommu_dev_data *search_dev_data(struct amd_iommu *iommu, u16 devid); diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c index 3ccad9fd0302..3aa80f140cdb 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -347,7 +347,7 @@ static struct iommu_dev_data *alloc_dev_data(struct amd_iommu *iommu, u16 devid) return dev_data; } -static struct iommu_dev_data *search_dev_data(struct amd_iommu *iommu, u16 devid) +struct iommu_dev_data *search_dev_data(struct amd_iommu *iommu, u16 devid) { struct iommu_dev_data *dev_data; struct llist_node *node; @@ -2845,12 +2845,12 @@ static int amd_iommu_set_dirty_tracking(struct iommu_domain *domain, bool enable) { struct protection_domain *pdomain = to_pdomain(domain); - struct dev_table_entry *dev_table; + struct dev_table_entry *dte; struct iommu_dev_data *dev_data; bool domain_flush = false; struct amd_iommu *iommu; unsigned long flags; - u64 pte_root; + u64 new; spin_lock_irqsave(&pdomain->lock, flags); if (!(pdomain->dirty_tracking ^ enable)) { @@ -2859,16 +2859,15 @@ static int amd_iommu_set_dirty_tracking(struct iommu_domain *domain, } list_for_each_entry(dev_data, &pdomain->dev_list, list) { + spin_lock(&dev_data->dte_lock); iommu = get_amd_iommu_from_dev_data(dev_data); - - dev_table = get_dev_table(iommu); - pte_root = dev_table[dev_data->devid].data[0]; - - pte_root = (enable ? pte_root | DTE_FLAG_HAD : - pte_root & ~DTE_FLAG_HAD); + dte = &get_dev_table(iommu)[dev_data->devid]; + new = dte->data[0]; + new = (enable ? new | DTE_FLAG_HAD : new & ~DTE_FLAG_HAD); + dte->data[0] = new; + spin_unlock(&dev_data->dte_lock); /* Flush device DTE */ - dev_table[dev_data->devid].data[0] = pte_root; device_flush_dte(dev_data); domain_flush = true; } @@ -3135,17 +3134,23 @@ static void iommu_flush_irt_and_complete(struct amd_iommu *iommu, u16 devid) static void set_dte_irq_entry(struct amd_iommu *iommu, u16 devid, struct irq_remap_table *table) { - u64 dte; - struct dev_table_entry *dev_table = get_dev_table(iommu); + u64 new; + struct dev_table_entry *dte = &get_dev_table(iommu)[devid]; + struct iommu_dev_data *dev_data = search_dev_data(iommu, devid); + + if (dev_data) + spin_lock(&dev_data->dte_lock); - dte = dev_table[devid].data[2]; - dte &= ~DTE_IRQ_PHYS_ADDR_MASK; - dte |= iommu_virt_to_phys(table->table); - dte |= DTE_IRQ_REMAP_INTCTL; - dte |= DTE_INTTABLEN; - dte |= DTE_IRQ_REMAP_ENABLE; + new = READ_ONCE(dte->data[2]); + new &= ~DTE_IRQ_PHYS_ADDR_MASK; + new |= iommu_virt_to_phys(table->table); + new |= DTE_IRQ_REMAP_INTCTL; + new |= DTE_INTTABLEN; + new |= DTE_IRQ_REMAP_ENABLE; + WRITE_ONCE(dte->data[2], new); - dev_table[devid].data[2] = dte; + if (dev_data) + spin_unlock(&dev_data->dte_lock); } static struct irq_remap_table *get_irq_table(struct amd_iommu *iommu, u16 devid)