From 78d8e7046111425bb688cddc4303d79cb0f0d281 Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Sun, 9 Nov 2014 22:47:57 +0800 Subject: [PATCH] iommu/vt-d: Dynamically allocate and free seq_id for DMAR units Introduce functions to support dynamic IOMMU seq_id allocating and releasing, which will be used to support DMAR hotplug. Also rename IOMMU_UNITS_SUPPORTED as DMAR_UNITS_SUPPORTED. Signed-off-by: Jiang Liu Reviewed-by: Yijing Wang Signed-off-by: Joerg Roedel --- drivers/iommu/dmar.c | 40 ++++++++++++++++++++++++++++++++++------ drivers/iommu/intel-iommu.c | 13 +++---------- include/linux/dmar.h | 6 ++++++ 3 files changed, 43 insertions(+), 16 deletions(-) diff --git a/drivers/iommu/dmar.c b/drivers/iommu/dmar.c index 586dd2aa2ca2..78aa1b2af113 100644 --- a/drivers/iommu/dmar.c +++ b/drivers/iommu/dmar.c @@ -70,6 +70,7 @@ LIST_HEAD(dmar_drhd_units); struct acpi_table_header * __initdata dmar_tbl; static acpi_size dmar_tbl_size; static int dmar_dev_scope_status = 1; +static unsigned long dmar_seq_ids[BITS_TO_LONGS(DMAR_UNITS_SUPPORTED)]; static int alloc_iommu(struct dmar_drhd_unit *drhd); static void free_iommu(struct intel_iommu *iommu); @@ -944,11 +945,32 @@ out: return err; } +static int dmar_alloc_seq_id(struct intel_iommu *iommu) +{ + iommu->seq_id = find_first_zero_bit(dmar_seq_ids, + DMAR_UNITS_SUPPORTED); + if (iommu->seq_id >= DMAR_UNITS_SUPPORTED) { + iommu->seq_id = -1; + } else { + set_bit(iommu->seq_id, dmar_seq_ids); + sprintf(iommu->name, "dmar%d", iommu->seq_id); + } + + return iommu->seq_id; +} + +static void dmar_free_seq_id(struct intel_iommu *iommu) +{ + if (iommu->seq_id >= 0) { + clear_bit(iommu->seq_id, dmar_seq_ids); + iommu->seq_id = -1; + } +} + static int alloc_iommu(struct dmar_drhd_unit *drhd) { struct intel_iommu *iommu; u32 ver, sts; - static int iommu_allocated = 0; int agaw = 0; int msagaw = 0; int err; @@ -962,13 +984,16 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd) if (!iommu) return -ENOMEM; - iommu->seq_id = iommu_allocated++; - sprintf (iommu->name, "dmar%d", iommu->seq_id); + if (dmar_alloc_seq_id(iommu) < 0) { + pr_err("IOMMU: failed to allocate seq_id\n"); + err = -ENOSPC; + goto error; + } err = map_iommu(iommu, drhd->reg_base_addr); if (err) { pr_err("IOMMU: failed to map %s\n", iommu->name); - goto error; + goto error_free_seq_id; } err = -EINVAL; @@ -1018,9 +1043,11 @@ static int alloc_iommu(struct dmar_drhd_unit *drhd) return 0; - err_unmap: +err_unmap: unmap_iommu(iommu); - error: +error_free_seq_id: + dmar_free_seq_id(iommu); +error: kfree(iommu); return err; } @@ -1044,6 +1071,7 @@ static void free_iommu(struct intel_iommu *iommu) if (iommu->reg) unmap_iommu(iommu); + dmar_free_seq_id(iommu); kfree(iommu); } diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c index b9cc9c2b03fc..2779354321f5 100644 --- a/drivers/iommu/intel-iommu.c +++ b/drivers/iommu/intel-iommu.c @@ -330,17 +330,10 @@ static int hw_pass_through = 1; /* si_domain contains mulitple devices */ #define DOMAIN_FLAG_STATIC_IDENTITY (1 << 1) -/* define the limit of IOMMUs supported in each domain */ -#ifdef CONFIG_X86 -# define IOMMU_UNITS_SUPPORTED MAX_IO_APICS -#else -# define IOMMU_UNITS_SUPPORTED 64 -#endif - struct dmar_domain { int id; /* domain id */ int nid; /* node id */ - DECLARE_BITMAP(iommu_bmp, IOMMU_UNITS_SUPPORTED); + DECLARE_BITMAP(iommu_bmp, DMAR_UNITS_SUPPORTED); /* bitmap of iommus this domain uses*/ struct list_head devices; /* all devices' list */ @@ -2730,12 +2723,12 @@ static int __init init_dmars(void) * threaded kernel __init code path all other access are read * only */ - if (g_num_of_iommus < IOMMU_UNITS_SUPPORTED) { + if (g_num_of_iommus < DMAR_UNITS_SUPPORTED) { g_num_of_iommus++; continue; } printk_once(KERN_ERR "intel-iommu: exceeded %d IOMMUs\n", - IOMMU_UNITS_SUPPORTED); + DMAR_UNITS_SUPPORTED); } g_iommus = kcalloc(g_num_of_iommus, sizeof(struct intel_iommu *), diff --git a/include/linux/dmar.h b/include/linux/dmar.h index 495df5e48f80..725204fc433e 100644 --- a/include/linux/dmar.h +++ b/include/linux/dmar.h @@ -30,6 +30,12 @@ struct acpi_dmar_header; +#ifdef CONFIG_X86 +# define DMAR_UNITS_SUPPORTED MAX_IO_APICS +#else +# define DMAR_UNITS_SUPPORTED 64 +#endif + /* DMAR Flags */ #define DMAR_INTR_REMAP 0x1 #define DMAR_X2APIC_OPT_OUT 0x2 -- 2.11.0