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[PATCH v2 00/04] iommu/ipmmu-vmsa: IPMMU multi-arch update V2

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  [PATCH v2 00/04] iommu/ipmmu-vmsa: IPMMU multi-arch update V2 Magnus Damm <magnus.damm@gmail.com> - 2016-03-15 05:20 +0100
    [PATCH v2 02/04] iommu/ipmmu-vmsa: Rework interrupt code and use bitmap for context Magnus Damm <magnus.damm@gmail.com> - 2016-03-15 05:20 +0100
    [PATCH v2 04/04] iommu/ipmmu-vmsa: Drop LPAE Kconfig dependency Magnus Damm <magnus.damm@gmail.com> - 2016-03-15 05:20 +0100

#1357797 — [PATCH v2 00/04] iommu/ipmmu-vmsa: IPMMU multi-arch update V2

iommu/ipmmu-vmsa: IPMMU multi-arch update V2

[PATCH v2 01/04] iommu/ipmmu-vmsa: Remove platform data handling
[PATCH v2 02/04] iommu/ipmmu-vmsa: Rework interrupt code and use bitmap for context
[PATCH v2 03/04] iommu/ipmmu-vmsa: Break out 32-bit ARM mapping code
[PATCH v2 04/04] iommu/ipmmu-vmsa: Drop LPAE Kconfig dependency

These patches update the IPMMU driver with a few minor changes
to support build on multiple architectures.

With these patches applied the driver is known to compile without issues
on 32-bit ARM, 64-bit ARM and x86_64.

Changes since V1:
 - Got rid of patch 2 and 3 from initial series
 - Updated bitmap code locking and also used lighter bitop functions
 - Updated the Kconfig bits to apply on top of ARCH_RENESAS

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 Built on top of next-20160314

 drivers/iommu/Kconfig      |    1 
 drivers/iommu/ipmmu-vmsa.c |  146 +++++++++++++++++++++++++++++---------------
 2 files changed, 97 insertions(+), 50 deletions(-)

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#1357799 — [PATCH v2 02/04] iommu/ipmmu-vmsa: Rework interrupt code and use bitmap for context

From: Magnus Damm <damm+renesas@opensource.se>

Introduce a bitmap for context handing and convert the
interrupt routine to go handle all registered contexts.

At this point the number of contexts are still limited.

Also remove the use of the ARM specific mapping variable
from ipmmu_irq() to allow compile on ARM64.

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
---

 Changes since V1: (Thanks to Laurent for feedback!)
 - Use simple find_first_zero()/set_bit()/clear_bit() for context management.
 - For allocation rely on spinlock held when calling ipmmu_domain_init_context()
 - For test/free use atomic bitops
 - Return IRQ_HANDLED if any of the contexts generated interrupts

 drivers/iommu/ipmmu-vmsa.c |   47 ++++++++++++++++++++++++++++++++------------
 1 file changed, 35 insertions(+), 12 deletions(-)

--- 0003/drivers/iommu/ipmmu-vmsa.c
+++ work/drivers/iommu/ipmmu-vmsa.c	2016-03-15 12:42:18.940513000 +0900
@@ -8,6 +8,7 @@
  * the Free Software Foundation; version 2 of the License.
  */
 
+#include <linux/bitmap.h>
 #include <linux/delay.h>
 #include <linux/dma-mapping.h>
 #include <linux/err.h>
@@ -26,12 +27,16 @@
 
 #include "io-pgtable.h"
 
+#define IPMMU_CTX_MAX 1
+
 struct ipmmu_vmsa_device {
 	struct device *dev;
 	void __iomem *base;
 	struct list_head list;
 
 	unsigned int num_utlbs;
+	DECLARE_BITMAP(ctx, IPMMU_CTX_MAX);
+	struct ipmmu_vmsa_domain *domains[IPMMU_CTX_MAX];
 
 	struct dma_iommu_mapping *mapping;
 };
@@ -296,6 +301,7 @@ static struct iommu_gather_ops ipmmu_gat
 static int ipmmu_domain_init_context(struct ipmmu_vmsa_domain *domain)
 {
 	u64 ttbr;
+	int ret;
 
 	/*
 	 * Allocate the page table operations.
@@ -325,10 +331,17 @@ static int ipmmu_domain_init_context(str
 		return -EINVAL;
 
 	/*
-	 * TODO: When adding support for multiple contexts, find an unused
-	 * context.
+	 * Find an unused context.
 	 */
-	domain->context_id = 0;
+	ret = find_first_zero_bit(domain->mmu->ctx, IPMMU_CTX_MAX);
+	if (ret == IPMMU_CTX_MAX) {
+		free_io_pgtable_ops(domain->iop);
+		return -EBUSY;
+	}
+
+	domain->context_id = ret;
+	domain->mmu->domains[ret] = domain;
+	set_bit(ret, domain->mmu->ctx);
 
 	/* TTBR0 */
 	ttbr = domain->cfg.arm_lpae_s1_cfg.ttbr[0];
@@ -372,6 +385,8 @@ static int ipmmu_domain_init_context(str
 
 static void ipmmu_domain_destroy_context(struct ipmmu_vmsa_domain *domain)
 {
+	clear_bit(domain->context_id, domain->mmu->ctx);
+
 	/*
 	 * Disable the context. Flush the TLB as required when modifying the
 	 * context registers.
@@ -389,10 +404,15 @@ static void ipmmu_domain_destroy_context
 static irqreturn_t ipmmu_domain_irq(struct ipmmu_vmsa_domain *domain)
 {
 	const u32 err_mask = IMSTR_MHIT | IMSTR_ABORT | IMSTR_PF | IMSTR_TF;
-	struct ipmmu_vmsa_device *mmu = domain->mmu;
+	struct ipmmu_vmsa_device *mmu;
 	u32 status;
 	u32 iova;
 
+	if (!domain)
+		return IRQ_NONE;
+
+	mmu = domain->mmu;
+
 	status = ipmmu_ctx_read(domain, IMSTR);
 	if (!(status & err_mask))
 		return IRQ_NONE;
@@ -437,16 +457,18 @@ static irqreturn_t ipmmu_domain_irq(stru
 static irqreturn_t ipmmu_irq(int irq, void *dev)
 {
 	struct ipmmu_vmsa_device *mmu = dev;
-	struct iommu_domain *io_domain;
-	struct ipmmu_vmsa_domain *domain;
-
-	if (!mmu->mapping)
-		return IRQ_NONE;
+	irqreturn_t status = IRQ_NONE;
+	unsigned int i;
 
-	io_domain = mmu->mapping->domain;
-	domain = to_vmsa_domain(io_domain);
+	/* Check interrupts for all active contexts */
+	for (i = 0; i < IPMMU_CTX_MAX; i++) {
+		if (!test_bit(i, mmu->ctx))
+			continue;
+		if (ipmmu_domain_irq(mmu->domains[i]) == IRQ_HANDLED)
+			status = IRQ_HANDLED;
+	}
 
-	return ipmmu_domain_irq(domain);
+	return status;
 }
 
 /* -----------------------------------------------------------------------------
@@ -774,6 +796,7 @@ static int ipmmu_probe(struct platform_d
 
 	mmu->dev = &pdev->dev;
 	mmu->num_utlbs = 32;
+	bitmap_zero(mmu->ctx, IPMMU_CTX_MAX);
 
 	/* Map I/O memory and request IRQ. */
 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);

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#1357800 — [PATCH v2 04/04] iommu/ipmmu-vmsa: Drop LPAE Kconfig dependency

From: Magnus Damm <damm+renesas@opensource.se>

Neither the ARM page table code enabled by IOMMU_IO_PGTABLE_LPAE
nor the IPMMU_VMSA driver actually depends on ARM_LPAE, so get
rid of the dependency.

Tested with ipmmu-vmsa on r8a7794 ALT and a kernel config using:
 # CONFIG_ARM_LPAE is not set

Signed-off-by: Magnus Damm <damm+renesas@opensource.se>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
---

 Changes since V1:
 - Rebased on top of ARCH_RENESAS change
 - Added Acked-by from Laurent

 This time the result also compiles on x86. Need to be
 applied as last patch in the following series:
 [PATCH v2 00/04] iommu/ipmmu-vmsa: IPMMU multi-arch update V2
 
 drivers/iommu/Kconfig |    1 -
 1 file changed, 1 deletion(-)

--- 0001/drivers/iommu/Kconfig
+++ work/drivers/iommu/Kconfig	2016-03-15 12:28:45.210513000 +0900
@@ -284,7 +284,6 @@ config EXYNOS_IOMMU_DEBUG
 
 config IPMMU_VMSA
 	bool "Renesas VMSA-compatible IPMMU"
-	depends on ARM_LPAE
 	depends on ARCH_RENESAS || COMPILE_TEST
 	select IOMMU_API
 	select IOMMU_IO_PGTABLE_LPAE

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