On 2014/9/12 10:10, Jiang Liu wrote:
> 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.
Reviewed-by: Yijing Wang <wangyijing@xxxxxxxxxx>
>
> Signed-off-by: Jiang Liu <jiang.liu@xxxxxxxxxxxxxxx>
> ---
> 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 afd46eb9a5de..b3405c50627f 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);
> @@ -928,11 +929,32 @@ 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;
> @@ -946,13 +968,16 @@ 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;
> @@ -1002,9 +1027,11 @@ 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;
> }
> @@ -1028,6 +1055,7 @@ 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 4af2206e41bc..7daa74ed46d0 100644
> --- a/drivers/iommu/intel-iommu.c
> +++ b/drivers/iommu/intel-iommu.c
> @@ -328,17 +328,10 @@ 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 */
> @@ -2728,12 +2721,12 @@ 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 fac8ca34f9a8..c8a576bc3a98 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
>
--
Thanks!
Yijing
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