[v3,10/13] iommu/arm-smmu-v3: Add second level of context descriptor table
diff mbox series

Message ID 20191209180514.272727-11-jean-philippe@linaro.org
State New
Headers show
Series
  • [v3,01/13] iommu/arm-smmu-v3: Drop __GFP_ZERO flag from DMA allocation
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Commit Message

Jean-Philippe Brucker Dec. 9, 2019, 6:05 p.m. UTC
The SMMU can support up to 20 bits of SSID. Add a second level of page
tables to accommodate this. Devices that support more than 1024 SSIDs now
have a table of 1024 L1 entries (8kB), pointing to tables of 1024 context
descriptors (64kB), allocated on demand.

Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
---
 drivers/iommu/arm-smmu-v3.c | 153 +++++++++++++++++++++++++++++++++---
 1 file changed, 143 insertions(+), 10 deletions(-)

Comments

Jonathan Cameron Dec. 13, 2019, 5:07 p.m. UTC | #1
On Mon, 9 Dec 2019 19:05:11 +0100
Jean-Philippe Brucker <jean-philippe@linaro.org> wrote:

> The SMMU can support up to 20 bits of SSID. Add a second level of page
> tables to accommodate this. Devices that support more than 1024 SSIDs now
> have a table of 1024 L1 entries (8kB), pointing to tables of 1024 context
> descriptors (64kB), allocated on demand.
> 
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>

One tiny little comment inline.  I really don't mind if you ignore it ;)

Reviewed-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

> ---
>  drivers/iommu/arm-smmu-v3.c | 153 +++++++++++++++++++++++++++++++++---
>  1 file changed, 143 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index fc5119f34187..52adcdfda58b 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -224,6 +224,7 @@
>  
>  #define STRTAB_STE_0_S1FMT		GENMASK_ULL(5, 4)
>  #define STRTAB_STE_0_S1FMT_LINEAR	0
> +#define STRTAB_STE_0_S1FMT_64K_L2	2
>  #define STRTAB_STE_0_S1CTXPTR_MASK	GENMASK_ULL(51, 6)
>  #define STRTAB_STE_0_S1CDMAX		GENMASK_ULL(63, 59)
>  
> @@ -263,7 +264,20 @@
>  
>  #define STRTAB_STE_3_S2TTB_MASK		GENMASK_ULL(51, 4)
>  
> -/* Context descriptor (stage-1 only) */
> +/*
> + * Context descriptors.
> + *
> + * Linear: when less than 1024 SSIDs are supported
> + * 2lvl: at most 1024 L1 entries,
> + *       1024 lazy entries per table.
> + */
> +#define CTXDESC_SPLIT			10
> +#define CTXDESC_L2_ENTRIES		(1 << CTXDESC_SPLIT)
> +
> +#define CTXDESC_L1_DESC_DWORDS		1
> +#define CTXDESC_L1_DESC_VALID		1
> +#define CTXDESC_L1_DESC_L2PTR_MASK	GENMASK_ULL(51, 12)
> +
>  #define CTXDESC_CD_DWORDS		8
>  #define CTXDESC_CD_0_TCR_T0SZ		GENMASK_ULL(5, 0)
>  #define ARM64_TCR_T0SZ			GENMASK_ULL(5, 0)
> @@ -575,7 +589,10 @@ struct arm_smmu_cd_table {
>  };
>  
>  struct arm_smmu_s1_cfg {
> -	struct arm_smmu_cd_table	table;
> +	struct arm_smmu_cd_table	*tables;
> +	size_t				num_tables;
> +	__le64				*l1ptr;
> +	dma_addr_t			l1ptr_dma;
>  	struct arm_smmu_ctx_desc	cd;
>  	u8				s1fmt;
>  	u8				s1cdmax;
> @@ -1521,9 +1538,53 @@ static void arm_smmu_free_cd_leaf_table(struct arm_smmu_device *smmu,
>  {
>  	size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
>  
> +	if (!table->ptr)
> +		return;
>  	dmam_free_coherent(smmu->dev, size, table->ptr, table->ptr_dma);
>  }
>  
> +static void arm_smmu_write_cd_l1_desc(__le64 *dst,
> +				      struct arm_smmu_cd_table *table)
> +{
> +	u64 val = (table->ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) |
> +		  CTXDESC_L1_DESC_VALID;
> +
> +	WRITE_ONCE(*dst, cpu_to_le64(val));
> +}
> +
> +static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
> +				   u32 ssid)
> +{
> +	__le64 *l1ptr;
> +	unsigned int idx;
> +	struct arm_smmu_cd_table *table;
> +	struct arm_smmu_device *smmu = smmu_domain->smmu;
> +	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
> +
> +	if (cfg->s1fmt == STRTAB_STE_0_S1FMT_LINEAR) {
> +		table = &cfg->tables[0];
> +		idx = ssid;
> +	} else {
> +		idx = ssid >> CTXDESC_SPLIT;
> +		if (idx >= cfg->num_tables)
> +			return NULL;
> +
> +		table = &cfg->tables[idx];
> +		if (!table->ptr) {
> +			if (arm_smmu_alloc_cd_leaf_table(smmu, table,
> +							 CTXDESC_L2_ENTRIES))
> +				return NULL;
> +
> +			l1ptr = cfg->l1ptr + idx * CTXDESC_L1_DESC_DWORDS;
> +			arm_smmu_write_cd_l1_desc(l1ptr, table);
> +			/* An invalid L1CD can be cached */
> +			arm_smmu_sync_cd(smmu_domain, ssid, false);
> +		}
> +		idx = ssid & (CTXDESC_L2_ENTRIES - 1);
> +	}
> +	return table->ptr + idx * CTXDESC_CD_DWORDS;
> +}
> +
>  static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
>  {
>  	u64 val = 0;
> @@ -1556,8 +1617,10 @@ static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
>  	u64 val;
>  	bool cd_live;
>  	struct arm_smmu_device *smmu = smmu_domain->smmu;
> -	__le64 *cdptr = smmu_domain->s1_cfg.table.ptr + ssid *
> -			CTXDESC_CD_DWORDS;
> +	__le64 *cdptr = arm_smmu_get_cd_ptr(smmu_domain, ssid);
> +
> +	if (!cdptr)
> +		return -ENOMEM;
>  
>  	val = le64_to_cpu(cdptr[0]);
>  	cd_live = !!(val & CTXDESC_CD_0_V);
> @@ -1604,20 +1667,87 @@ static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
>  
>  static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain)
>  {
> +	int ret;
> +	size_t size = 0;
> +	size_t max_contexts;
>  	struct arm_smmu_device *smmu = smmu_domain->smmu;
>  	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
>  
> -	cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
> -	return arm_smmu_alloc_cd_leaf_table(smmu, &cfg->table,
> -					    1 << cfg->s1cdmax);
> +	max_contexts = 1 << cfg->s1cdmax;
> +
> +	if (!(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB) ||
> +	    max_contexts <= CTXDESC_L2_ENTRIES) {
> +		cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
> +		cfg->num_tables = 1;
> +	} else {
> +		cfg->s1fmt = STRTAB_STE_0_S1FMT_64K_L2;
> +		cfg->num_tables = DIV_ROUND_UP(max_contexts,
> +					       CTXDESC_L2_ENTRIES);
> +
> +		size = cfg->num_tables * (CTXDESC_L1_DESC_DWORDS << 3);
> +		cfg->l1ptr = dmam_alloc_coherent(smmu->dev, size,
> +						 &cfg->l1ptr_dma,
> +						 GFP_KERNEL);
> +		if (!cfg->l1ptr) {
> +			dev_warn(smmu->dev,
> +				 "failed to allocate L1 context table\n");
> +			return -ENOMEM;
> +		}
> +	}
> +
> +	cfg->tables = devm_kzalloc(smmu->dev, sizeof(struct arm_smmu_cd_table) *
> +				   cfg->num_tables, GFP_KERNEL);
> +	if (!cfg->tables) {
> +		ret = -ENOMEM;
> +		goto err_free_l1;
> +	}
> +
> +	/*
> +	 * Only allocate a leaf table for linear case. With two levels, leaf
> +	 * tables are allocated lazily.
> +	 */
> +	if (!cfg->l1ptr) {

This might have been the tiniest bit clearer if the check matched the description
by checking it's a linear table rather than what is kind of a side effect of it
not being non linear.

	if (cfg->s1fmt == STRTAB_STE_0_S1FMT_LINEAR)


> +		ret = arm_smmu_alloc_cd_leaf_table(smmu, &cfg->tables[0],
> +						   max_contexts);
> +		if (ret)
> +			goto err_free_tables;
> +	}
> +
> +	return 0;
> +
> +err_free_tables:
> +	devm_kfree(smmu->dev, cfg->tables);
> +	cfg->tables = NULL;
> +err_free_l1:
> +	if (cfg->l1ptr) {
> +		dmam_free_coherent(smmu->dev, size, cfg->l1ptr, cfg->l1ptr_dma);
> +		cfg->l1ptr = NULL;
> +		cfg->l1ptr_dma = 0;
> +	}
> +	return ret;
>  }
>  
>  static void arm_smmu_free_cd_tables(struct arm_smmu_domain *smmu_domain)
>  {
> +	int i;
>  	struct arm_smmu_device *smmu = smmu_domain->smmu;
>  	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
> +	size_t num_leaf_entries = 1 << cfg->s1cdmax;
> +	struct arm_smmu_cd_table *table = cfg->tables;
> +
> +	if (cfg->l1ptr) {
> +		size_t size = cfg->num_tables * (CTXDESC_L1_DESC_DWORDS << 3);
>  
> -	arm_smmu_free_cd_leaf_table(smmu, &cfg->table, 1 << cfg->s1cdmax);
> +		dmam_free_coherent(smmu->dev, size, cfg->l1ptr, cfg->l1ptr_dma);
> +		cfg->l1ptr = NULL;
> +		cfg->l1ptr_dma = 0;
> +		num_leaf_entries = CTXDESC_L2_ENTRIES;
> +	}
> +
> +	for (i = 0; i < cfg->num_tables; i++, table++)
> +		arm_smmu_free_cd_leaf_table(smmu, table, num_leaf_entries);
> +	devm_kfree(smmu->dev, cfg->tables);
> +	cfg->tables = NULL;
>  }
>  
>  /* Stream table manipulation functions */
> @@ -1737,6 +1867,9 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
>  	}
>  
>  	if (s1_cfg) {
> +		dma_addr_t ptr_dma = s1_cfg->l1ptr ? s1_cfg->l1ptr_dma :
> +				     s1_cfg->tables[0].ptr_dma;
> +
>  		BUG_ON(ste_live);
>  		dst[1] = cpu_to_le64(
>  			 FIELD_PREP(STRTAB_STE_1_S1DSS, STRTAB_STE_1_S1DSS_SSID0) |
> @@ -1749,7 +1882,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
>  		   !(smmu->features & ARM_SMMU_FEAT_STALL_FORCE))
>  			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
>  
> -		val |= (s1_cfg->table.ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
> +		val |= (ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
>  			FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS) |
>  			FIELD_PREP(STRTAB_STE_0_S1CDMAX, s1_cfg->s1cdmax) |
>  			FIELD_PREP(STRTAB_STE_0_S1FMT, s1_cfg->s1fmt);
> @@ -2265,7 +2398,7 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)
>  	if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>  		struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
>  
> -		if (cfg->table.ptr) {
> +		if (cfg->tables) {
>  			arm_smmu_free_cd_tables(smmu_domain);
>  			arm_smmu_bitmap_free(smmu->asid_map, cfg->cd.asid);
>  		}
Auger Eric Dec. 18, 2019, 9:59 a.m. UTC | #2
Hi Jean,

On 12/9/19 7:05 PM, Jean-Philippe Brucker wrote:
> The SMMU can support up to 20 bits of SSID. Add a second level of page
> tables to accommodate this. Devices that support more than 1024 SSIDs now
> have a table of 1024 L1 entries (8kB), pointing to tables of 1024 context
> descriptors (64kB), allocated on demand.
> 
> Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
> ---
>  drivers/iommu/arm-smmu-v3.c | 153 +++++++++++++++++++++++++++++++++---
>  1 file changed, 143 insertions(+), 10 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
> index fc5119f34187..52adcdfda58b 100644
> --- a/drivers/iommu/arm-smmu-v3.c
> +++ b/drivers/iommu/arm-smmu-v3.c
> @@ -224,6 +224,7 @@
>  
>  #define STRTAB_STE_0_S1FMT		GENMASK_ULL(5, 4)
>  #define STRTAB_STE_0_S1FMT_LINEAR	0
> +#define STRTAB_STE_0_S1FMT_64K_L2	2
>  #define STRTAB_STE_0_S1CTXPTR_MASK	GENMASK_ULL(51, 6)
>  #define STRTAB_STE_0_S1CDMAX		GENMASK_ULL(63, 59)
>  
> @@ -263,7 +264,20 @@
>  
>  #define STRTAB_STE_3_S2TTB_MASK		GENMASK_ULL(51, 4)
>  
> -/* Context descriptor (stage-1 only) */
> +/*
> + * Context descriptors.
> + *
> + * Linear: when less than 1024 SSIDs are supported
> + * 2lvl: at most 1024 L1 entries,
> + *       1024 lazy entries per table.
> + */
> +#define CTXDESC_SPLIT			10
> +#define CTXDESC_L2_ENTRIES		(1 << CTXDESC_SPLIT)
> +
> +#define CTXDESC_L1_DESC_DWORDS		1
> +#define CTXDESC_L1_DESC_VALID		1
> +#define CTXDESC_L1_DESC_L2PTR_MASK	GENMASK_ULL(51, 12)
> +
>  #define CTXDESC_CD_DWORDS		8
>  #define CTXDESC_CD_0_TCR_T0SZ		GENMASK_ULL(5, 0)
>  #define ARM64_TCR_T0SZ			GENMASK_ULL(5, 0)
> @@ -575,7 +589,10 @@ struct arm_smmu_cd_table {
>  };
>  
>  struct arm_smmu_s1_cfg {
> -	struct arm_smmu_cd_table	table;
> +	struct arm_smmu_cd_table	*tables;
> +	size_t				num_tables;
> +	__le64				*l1ptr;
you may add a comment saying that l1ptr and l1ptr_dma are only set/used
in non linear case and one comment saying that "tables" represent leaf
tables.
> +	dma_addr_t			l1ptr_dma;
>  	struct arm_smmu_ctx_desc	cd;
>  	u8				s1fmt;
>  	u8				s1cdmax;
> @@ -1521,9 +1538,53 @@ static void arm_smmu_free_cd_leaf_table(struct arm_smmu_device *smmu,
>  {
>  	size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
>  
> +	if (!table->ptr)
> +		return;
>  	dmam_free_coherent(smmu->dev, size, table->ptr, table->ptr_dma);
>  }
>  
> +static void arm_smmu_write_cd_l1_desc(__le64 *dst,
> +				      struct arm_smmu_cd_table *table)
> +{
> +	u64 val = (table->ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) |
> +		  CTXDESC_L1_DESC_VALID;
> +
> +	WRITE_ONCE(*dst, cpu_to_le64(val));
> +}
> +
> +static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
> +				   u32 ssid)
> +{
> +	__le64 *l1ptr;
> +	unsigned int idx;
> +	struct arm_smmu_cd_table *table;
> +	struct arm_smmu_device *smmu = smmu_domain->smmu;
> +	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
> +
> +	if (cfg->s1fmt == STRTAB_STE_0_S1FMT_LINEAR) {
> +		table = &cfg->tables[0];
> +		idx = ssid;
> +	} else {
nit: you may avoid this extra indent by either returning above or go to
a label.
> +		idx = ssid >> CTXDESC_SPLIT;
> +		if (idx >= cfg->num_tables)
> +			return NULL;
> +
> +		table = &cfg->tables[idx];
> +		if (!table->ptr) {
> +			if (arm_smmu_alloc_cd_leaf_table(smmu, table,
> +							 CTXDESC_L2_ENTRIES))
> +				return NULL;
> +
> +			l1ptr = cfg->l1ptr + idx * CTXDESC_L1_DESC_DWORDS;
> +			arm_smmu_write_cd_l1_desc(l1ptr, table);
> +			/* An invalid L1CD can be cached */
> +			arm_smmu_sync_cd(smmu_domain, ssid, false);
> +		}
> +		idx = ssid & (CTXDESC_L2_ENTRIES - 1);
> +	}
> +	return table->ptr + idx * CTXDESC_CD_DWORDS;> +}
> +
>  static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
>  {
>  	u64 val = 0;
> @@ -1556,8 +1617,10 @@ static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
>  	u64 val;
>  	bool cd_live;
>  	struct arm_smmu_device *smmu = smmu_domain->smmu;
> -	__le64 *cdptr = smmu_domain->s1_cfg.table.ptr + ssid *
> -			CTXDESC_CD_DWORDS;
> +	__le64 *cdptr = arm_smmu_get_cd_ptr(smmu_domain, ssid);
> +
> +	if (!cdptr)
> +		return -ENOMEM;
-ENOMEM does not fit well with (idx >= cfg->num_tables) case
Besides the idx is checked against the max table capacity only in non
linear mode. Can't you check the ssid against cfg->s1cdmax earlier?
>  
>  	val = le64_to_cpu(cdptr[0]);
>  	cd_live = !!(val & CTXDESC_CD_0_V);
> @@ -1604,20 +1667,87 @@ static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
>  
>  static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain)
>  {
> +	int ret;
> +	size_t size = 0;
> +	size_t max_contexts;
>  	struct arm_smmu_device *smmu = smmu_domain->smmu;
>  	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
>  
> -	cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
> -	return arm_smmu_alloc_cd_leaf_table(smmu, &cfg->table,
> -					    1 << cfg->s1cdmax);
> +	max_contexts = 1 << cfg->s1cdmax;
> +
> +	if (!(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB) ||
> +	    max_contexts <= CTXDESC_L2_ENTRIES) {
> +		cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
> +		cfg->num_tables = 1;
> +	} else {
> +		cfg->s1fmt = STRTAB_STE_0_S1FMT_64K_L2;
> +		cfg->num_tables = DIV_ROUND_UP(max_contexts,
> +					       CTXDESC_L2_ENTRIES);
> +
> +		size = cfg->num_tables * (CTXDESC_L1_DESC_DWORDS << 3);
> +		cfg->l1ptr = dmam_alloc_coherent(smmu->dev, size,
> +						 &cfg->l1ptr_dma,
> +						 GFP_KERNEL);
> +		if (!cfg->l1ptr) {
> +			dev_warn(smmu->dev,
> +				 "failed to allocate L1 context table\n");
> +			return -ENOMEM;
> +		}
> +	}
> +
> +	cfg->tables = devm_kzalloc(smmu->dev, sizeof(struct arm_smmu_cd_table) *
> +				   cfg->num_tables, GFP_KERNEL);
> +	if (!cfg->tables) {
> +		ret = -ENOMEM;
> +		goto err_free_l1;
> +	}
> +
> +	/*
> +	 * Only allocate a leaf table for linear case. With two levels, leaf
> +	 * tables are allocated lazily.
> +	 */
> +	if (!cfg->l1ptr) {
> +		ret = arm_smmu_alloc_cd_leaf_table(smmu, &cfg->tables[0],
> +						   max_contexts);
> +		if (ret)
> +			goto err_free_tables;
> +	}
> +
> +	return 0;
> +
> +err_free_tables:
> +	devm_kfree(smmu->dev, cfg->tables);
> +	cfg->tables = NULL;
> +err_free_l1:
> +	if (cfg->l1ptr) {
> +		dmam_free_coherent(smmu->dev, size, cfg->l1ptr, cfg->l1ptr_dma);
> +		cfg->l1ptr = NULL;
> +		cfg->l1ptr_dma = 0;
> +	}
> +	return ret;
>  }
>  
>  static void arm_smmu_free_cd_tables(struct arm_smmu_domain *smmu_domain)
>  {
> +	int i;
>  	struct arm_smmu_device *smmu = smmu_domain->smmu;
>  	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
> +	size_t num_leaf_entries = 1 << cfg->s1cdmax;
> +	struct arm_smmu_cd_table *table = cfg->tables;
> +
> +	if (cfg->l1ptr) {
> +		size_t size = cfg->num_tables * (CTXDESC_L1_DESC_DWORDS << 3);
>  
> -	arm_smmu_free_cd_leaf_table(smmu, &cfg->table, 1 << cfg->s1cdmax);
> +		dmam_free_coherent(smmu->dev, size, cfg->l1ptr, cfg->l1ptr_dma);
> +		cfg->l1ptr = NULL;
> +		cfg->l1ptr_dma = 0;
> +		num_leaf_entries = CTXDESC_L2_ENTRIES;
> +	}
> +
> +	for (i = 0; i < cfg->num_tables; i++, table++)
> +		arm_smmu_free_cd_leaf_table(smmu, table, num_leaf_entries);
> +	devm_kfree(smmu->dev, cfg->tables);
> +	cfg->tables = NULL;
>  }
>  
>  /* Stream table manipulation functions */
> @@ -1737,6 +1867,9 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
>  	}
>  
>  	if (s1_cfg) {
> +		dma_addr_t ptr_dma = s1_cfg->l1ptr ? s1_cfg->l1ptr_dma :
> +				     s1_cfg->tables[0].ptr_dma;
> +
>  		BUG_ON(ste_live);
>  		dst[1] = cpu_to_le64(
>  			 FIELD_PREP(STRTAB_STE_1_S1DSS, STRTAB_STE_1_S1DSS_SSID0) |
> @@ -1749,7 +1882,7 @@ static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
>  		   !(smmu->features & ARM_SMMU_FEAT_STALL_FORCE))
>  			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
>  
> -		val |= (s1_cfg->table.ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
> +		val |= (ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
>  			FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS) |
>  			FIELD_PREP(STRTAB_STE_0_S1CDMAX, s1_cfg->s1cdmax) |
>  			FIELD_PREP(STRTAB_STE_0_S1FMT, s1_cfg->s1fmt);
> @@ -2265,7 +2398,7 @@ static void arm_smmu_domain_free(struct iommu_domain *domain)
>  	if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
>  		struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
>  
> -		if (cfg->table.ptr) {
> +		if (cfg->tables) {
>  			arm_smmu_free_cd_tables(smmu_domain);
>  			arm_smmu_bitmap_free(smmu->asid_map, cfg->cd.asid);
>  		}
> 
Otherwise looks good to me.

Thanks

Eric
Jean-Philippe Brucker Dec. 18, 2019, 4:10 p.m. UTC | #3
On Wed, Dec 18, 2019 at 10:59:36AM +0100, Auger Eric wrote:
> >  struct arm_smmu_s1_cfg {
> > -	struct arm_smmu_cd_table	table;
> > +	struct arm_smmu_cd_table	*tables;
> > +	size_t				num_tables;
> > +	__le64				*l1ptr;
> you may add a comment saying that l1ptr and l1ptr_dma are only set/used
> in non linear case and one comment saying that "tables" represent leaf
> tables.

I now have
	/* Leaf tables or linear table */
and
	/* First level tables, when two level are used */
but I'm not entirely convinced it adds value

> > +	dma_addr_t			l1ptr_dma;
> >  	struct arm_smmu_ctx_desc	cd;
> >  	u8				s1fmt;
> >  	u8				s1cdmax;
> > @@ -1521,9 +1538,53 @@ static void arm_smmu_free_cd_leaf_table(struct arm_smmu_device *smmu,
> >  {
> >  	size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
> >  
> > +	if (!table->ptr)
> > +		return;
> >  	dmam_free_coherent(smmu->dev, size, table->ptr, table->ptr_dma);
> >  }
> >  
> > +static void arm_smmu_write_cd_l1_desc(__le64 *dst,
> > +				      struct arm_smmu_cd_table *table)
> > +{
> > +	u64 val = (table->ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) |
> > +		  CTXDESC_L1_DESC_VALID;
> > +
> > +	WRITE_ONCE(*dst, cpu_to_le64(val));
> > +}
> > +
> > +static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
> > +				   u32 ssid)
> > +{
> > +	__le64 *l1ptr;
> > +	unsigned int idx;
> > +	struct arm_smmu_cd_table *table;
> > +	struct arm_smmu_device *smmu = smmu_domain->smmu;
> > +	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
> > +
> > +	if (cfg->s1fmt == STRTAB_STE_0_S1FMT_LINEAR) {
> > +		table = &cfg->tables[0];
> > +		idx = ssid;
> > +	} else {
> nit: you may avoid this extra indent by either returning above or go to
> a label.
> > +		idx = ssid >> CTXDESC_SPLIT;
> > +		if (idx >= cfg->num_tables)
> > +			return NULL;
> > +
> > +		table = &cfg->tables[idx];
> > +		if (!table->ptr) {
> > +			if (arm_smmu_alloc_cd_leaf_table(smmu, table,
> > +							 CTXDESC_L2_ENTRIES))
> > +				return NULL;
> > +
> > +			l1ptr = cfg->l1ptr + idx * CTXDESC_L1_DESC_DWORDS;
> > +			arm_smmu_write_cd_l1_desc(l1ptr, table);
> > +			/* An invalid L1CD can be cached */
> > +			arm_smmu_sync_cd(smmu_domain, ssid, false);
> > +		}
> > +		idx = ssid & (CTXDESC_L2_ENTRIES - 1);
> > +	}
> > +	return table->ptr + idx * CTXDESC_CD_DWORDS;> +}
> > +
> >  static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
> >  {
> >  	u64 val = 0;
> > @@ -1556,8 +1617,10 @@ static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
> >  	u64 val;
> >  	bool cd_live;
> >  	struct arm_smmu_device *smmu = smmu_domain->smmu;
> > -	__le64 *cdptr = smmu_domain->s1_cfg.table.ptr + ssid *
> > -			CTXDESC_CD_DWORDS;
> > +	__le64 *cdptr = arm_smmu_get_cd_ptr(smmu_domain, ssid);
> > +
> > +	if (!cdptr)
> > +		return -ENOMEM;
> -ENOMEM does not fit well with (idx >= cfg->num_tables) case
> Besides the idx is checked against the max table capacity only in non
> linear mode. Can't you check the ssid against cfg->s1cdmax earlier?

Ok, I'll move that check here

Thanks,
Jean

Patch
diff mbox series

diff --git a/drivers/iommu/arm-smmu-v3.c b/drivers/iommu/arm-smmu-v3.c
index fc5119f34187..52adcdfda58b 100644
--- a/drivers/iommu/arm-smmu-v3.c
+++ b/drivers/iommu/arm-smmu-v3.c
@@ -224,6 +224,7 @@ 
 
 #define STRTAB_STE_0_S1FMT		GENMASK_ULL(5, 4)
 #define STRTAB_STE_0_S1FMT_LINEAR	0
+#define STRTAB_STE_0_S1FMT_64K_L2	2
 #define STRTAB_STE_0_S1CTXPTR_MASK	GENMASK_ULL(51, 6)
 #define STRTAB_STE_0_S1CDMAX		GENMASK_ULL(63, 59)
 
@@ -263,7 +264,20 @@ 
 
 #define STRTAB_STE_3_S2TTB_MASK		GENMASK_ULL(51, 4)
 
-/* Context descriptor (stage-1 only) */
+/*
+ * Context descriptors.
+ *
+ * Linear: when less than 1024 SSIDs are supported
+ * 2lvl: at most 1024 L1 entries,
+ *       1024 lazy entries per table.
+ */
+#define CTXDESC_SPLIT			10
+#define CTXDESC_L2_ENTRIES		(1 << CTXDESC_SPLIT)
+
+#define CTXDESC_L1_DESC_DWORDS		1
+#define CTXDESC_L1_DESC_VALID		1
+#define CTXDESC_L1_DESC_L2PTR_MASK	GENMASK_ULL(51, 12)
+
 #define CTXDESC_CD_DWORDS		8
 #define CTXDESC_CD_0_TCR_T0SZ		GENMASK_ULL(5, 0)
 #define ARM64_TCR_T0SZ			GENMASK_ULL(5, 0)
@@ -575,7 +589,10 @@  struct arm_smmu_cd_table {
 };
 
 struct arm_smmu_s1_cfg {
-	struct arm_smmu_cd_table	table;
+	struct arm_smmu_cd_table	*tables;
+	size_t				num_tables;
+	__le64				*l1ptr;
+	dma_addr_t			l1ptr_dma;
 	struct arm_smmu_ctx_desc	cd;
 	u8				s1fmt;
 	u8				s1cdmax;
@@ -1521,9 +1538,53 @@  static void arm_smmu_free_cd_leaf_table(struct arm_smmu_device *smmu,
 {
 	size_t size = num_entries * (CTXDESC_CD_DWORDS << 3);
 
+	if (!table->ptr)
+		return;
 	dmam_free_coherent(smmu->dev, size, table->ptr, table->ptr_dma);
 }
 
+static void arm_smmu_write_cd_l1_desc(__le64 *dst,
+				      struct arm_smmu_cd_table *table)
+{
+	u64 val = (table->ptr_dma & CTXDESC_L1_DESC_L2PTR_MASK) |
+		  CTXDESC_L1_DESC_VALID;
+
+	WRITE_ONCE(*dst, cpu_to_le64(val));
+}
+
+static __le64 *arm_smmu_get_cd_ptr(struct arm_smmu_domain *smmu_domain,
+				   u32 ssid)
+{
+	__le64 *l1ptr;
+	unsigned int idx;
+	struct arm_smmu_cd_table *table;
+	struct arm_smmu_device *smmu = smmu_domain->smmu;
+	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
+
+	if (cfg->s1fmt == STRTAB_STE_0_S1FMT_LINEAR) {
+		table = &cfg->tables[0];
+		idx = ssid;
+	} else {
+		idx = ssid >> CTXDESC_SPLIT;
+		if (idx >= cfg->num_tables)
+			return NULL;
+
+		table = &cfg->tables[idx];
+		if (!table->ptr) {
+			if (arm_smmu_alloc_cd_leaf_table(smmu, table,
+							 CTXDESC_L2_ENTRIES))
+				return NULL;
+
+			l1ptr = cfg->l1ptr + idx * CTXDESC_L1_DESC_DWORDS;
+			arm_smmu_write_cd_l1_desc(l1ptr, table);
+			/* An invalid L1CD can be cached */
+			arm_smmu_sync_cd(smmu_domain, ssid, false);
+		}
+		idx = ssid & (CTXDESC_L2_ENTRIES - 1);
+	}
+	return table->ptr + idx * CTXDESC_CD_DWORDS;
+}
+
 static u64 arm_smmu_cpu_tcr_to_cd(u64 tcr)
 {
 	u64 val = 0;
@@ -1556,8 +1617,10 @@  static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
 	u64 val;
 	bool cd_live;
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
-	__le64 *cdptr = smmu_domain->s1_cfg.table.ptr + ssid *
-			CTXDESC_CD_DWORDS;
+	__le64 *cdptr = arm_smmu_get_cd_ptr(smmu_domain, ssid);
+
+	if (!cdptr)
+		return -ENOMEM;
 
 	val = le64_to_cpu(cdptr[0]);
 	cd_live = !!(val & CTXDESC_CD_0_V);
@@ -1604,20 +1667,87 @@  static int arm_smmu_write_ctx_desc(struct arm_smmu_domain *smmu_domain,
 
 static int arm_smmu_alloc_cd_tables(struct arm_smmu_domain *smmu_domain)
 {
+	int ret;
+	size_t size = 0;
+	size_t max_contexts;
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
 
-	cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
-	return arm_smmu_alloc_cd_leaf_table(smmu, &cfg->table,
-					    1 << cfg->s1cdmax);
+	max_contexts = 1 << cfg->s1cdmax;
+
+	if (!(smmu->features & ARM_SMMU_FEAT_2_LVL_CDTAB) ||
+	    max_contexts <= CTXDESC_L2_ENTRIES) {
+		cfg->s1fmt = STRTAB_STE_0_S1FMT_LINEAR;
+		cfg->num_tables = 1;
+	} else {
+		cfg->s1fmt = STRTAB_STE_0_S1FMT_64K_L2;
+		cfg->num_tables = DIV_ROUND_UP(max_contexts,
+					       CTXDESC_L2_ENTRIES);
+
+		size = cfg->num_tables * (CTXDESC_L1_DESC_DWORDS << 3);
+		cfg->l1ptr = dmam_alloc_coherent(smmu->dev, size,
+						 &cfg->l1ptr_dma,
+						 GFP_KERNEL);
+		if (!cfg->l1ptr) {
+			dev_warn(smmu->dev,
+				 "failed to allocate L1 context table\n");
+			return -ENOMEM;
+		}
+	}
+
+	cfg->tables = devm_kzalloc(smmu->dev, sizeof(struct arm_smmu_cd_table) *
+				   cfg->num_tables, GFP_KERNEL);
+	if (!cfg->tables) {
+		ret = -ENOMEM;
+		goto err_free_l1;
+	}
+
+	/*
+	 * Only allocate a leaf table for linear case. With two levels, leaf
+	 * tables are allocated lazily.
+	 */
+	if (!cfg->l1ptr) {
+		ret = arm_smmu_alloc_cd_leaf_table(smmu, &cfg->tables[0],
+						   max_contexts);
+		if (ret)
+			goto err_free_tables;
+	}
+
+	return 0;
+
+err_free_tables:
+	devm_kfree(smmu->dev, cfg->tables);
+	cfg->tables = NULL;
+err_free_l1:
+	if (cfg->l1ptr) {
+		dmam_free_coherent(smmu->dev, size, cfg->l1ptr, cfg->l1ptr_dma);
+		cfg->l1ptr = NULL;
+		cfg->l1ptr_dma = 0;
+	}
+	return ret;
 }
 
 static void arm_smmu_free_cd_tables(struct arm_smmu_domain *smmu_domain)
 {
+	int i;
 	struct arm_smmu_device *smmu = smmu_domain->smmu;
 	struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
+	size_t num_leaf_entries = 1 << cfg->s1cdmax;
+	struct arm_smmu_cd_table *table = cfg->tables;
+
+	if (cfg->l1ptr) {
+		size_t size = cfg->num_tables * (CTXDESC_L1_DESC_DWORDS << 3);
 
-	arm_smmu_free_cd_leaf_table(smmu, &cfg->table, 1 << cfg->s1cdmax);
+		dmam_free_coherent(smmu->dev, size, cfg->l1ptr, cfg->l1ptr_dma);
+		cfg->l1ptr = NULL;
+		cfg->l1ptr_dma = 0;
+		num_leaf_entries = CTXDESC_L2_ENTRIES;
+	}
+
+	for (i = 0; i < cfg->num_tables; i++, table++)
+		arm_smmu_free_cd_leaf_table(smmu, table, num_leaf_entries);
+	devm_kfree(smmu->dev, cfg->tables);
+	cfg->tables = NULL;
 }
 
 /* Stream table manipulation functions */
@@ -1737,6 +1867,9 @@  static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
 	}
 
 	if (s1_cfg) {
+		dma_addr_t ptr_dma = s1_cfg->l1ptr ? s1_cfg->l1ptr_dma :
+				     s1_cfg->tables[0].ptr_dma;
+
 		BUG_ON(ste_live);
 		dst[1] = cpu_to_le64(
 			 FIELD_PREP(STRTAB_STE_1_S1DSS, STRTAB_STE_1_S1DSS_SSID0) |
@@ -1749,7 +1882,7 @@  static void arm_smmu_write_strtab_ent(struct arm_smmu_master *master, u32 sid,
 		   !(smmu->features & ARM_SMMU_FEAT_STALL_FORCE))
 			dst[1] |= cpu_to_le64(STRTAB_STE_1_S1STALLD);
 
-		val |= (s1_cfg->table.ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
+		val |= (ptr_dma & STRTAB_STE_0_S1CTXPTR_MASK) |
 			FIELD_PREP(STRTAB_STE_0_CFG, STRTAB_STE_0_CFG_S1_TRANS) |
 			FIELD_PREP(STRTAB_STE_0_S1CDMAX, s1_cfg->s1cdmax) |
 			FIELD_PREP(STRTAB_STE_0_S1FMT, s1_cfg->s1fmt);
@@ -2265,7 +2398,7 @@  static void arm_smmu_domain_free(struct iommu_domain *domain)
 	if (smmu_domain->stage == ARM_SMMU_DOMAIN_S1) {
 		struct arm_smmu_s1_cfg *cfg = &smmu_domain->s1_cfg;
 
-		if (cfg->table.ptr) {
+		if (cfg->tables) {
 			arm_smmu_free_cd_tables(smmu_domain);
 			arm_smmu_bitmap_free(smmu->asid_map, cfg->cd.asid);
 		}