drivers/gpu/msm/adreno_iommu.c

/* Copyright (c) 2002,2007-2017, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 */
#include "adreno.h"
#include "kgsl_sharedmem.h"
#include "a3xx_reg.h"
#include "adreno_pm4types.h"

#define A5XX_PFP_PER_PROCESS_UCODE_VER 0x5FF064
#define A5XX_PM4_PER_PROCESS_UCODE_VER 0x5FF052

/*
 * _wait_reg() - make CP poll on a register
 * @cmds:	Pointer to memory where commands are to be added
 * @addr:	Register address to poll for
 * @val:	Value to poll for
 * @mask:	The value against which register value is masked
 * @interval:	wait interval
 */
static unsigned int _wait_reg(struct adreno_device *adreno_dev,
			unsigned int *cmds, unsigned int addr,
			unsigned int val, unsigned int mask,
			unsigned int interval)
{
	unsigned int *start = cmds;

	if (adreno_is_a3xx(adreno_dev)) {
		*cmds++ = cp_packet(adreno_dev, CP_WAIT_REG_EQ, 4);
		*cmds++ = addr;
		*cmds++ = val;
		*cmds++ = mask;
		*cmds++ = interval;
	} else {
		*cmds++ = cp_mem_packet(adreno_dev, CP_WAIT_REG_MEM, 5, 1);
		*cmds++ = 0x3; /* Mem Space = Register,  Function = Equals */
		cmds += cp_gpuaddr(adreno_dev, cmds, addr); /* Poll address */
		*cmds++ = val; /* ref val */
		*cmds++ = mask;
		*cmds++ = interval;

		/* WAIT_REG_MEM turns back on protected mode - push it off */
		*cmds++ = cp_packet(adreno_dev, CP_SET_PROTECTED_MODE, 1);
		*cmds++ = 0;
	}

	return cmds - start;
}

#define KGSL_MMU(_dev) \
	((struct kgsl_mmu *) (&(KGSL_DEVICE((_dev))->mmu)))

static unsigned int  _iommu_lock(struct adreno_device *adreno_dev,
				 unsigned int *cmds)
{
	unsigned int *start = cmds;
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	struct kgsl_iommu *iommu = KGSL_IOMMU_PRIV(device);

	/*
	 * If we don't have this register, probe should have forced
	 * global pagetables and we shouldn't get here.
	 */
	if (WARN_ONCE(iommu->micro_mmu_ctrl == UINT_MAX,
		"invalid GPU IOMMU lock sequence\n"))
		return 0;

	/*
	 * glue commands together until next
	 * WAIT_FOR_ME
	 */
	cmds += _wait_reg(adreno_dev, cmds,
			adreno_getreg(adreno_dev, ADRENO_REG_CP_WFI_PEND_CTR),
			1, 0xFFFFFFFF, 0xF);

	/* set the iommu lock bit */
	*cmds++ = cp_packet(adreno_dev, CP_REG_RMW, 3);
	*cmds++ = iommu->micro_mmu_ctrl >> 2;
	/* AND to unmask the lock bit */
	*cmds++ = ~(KGSL_IOMMU_IMPLDEF_MICRO_MMU_CTRL_HALT);
	/* OR to set the IOMMU lock bit */
	*cmds++ = KGSL_IOMMU_IMPLDEF_MICRO_MMU_CTRL_HALT;

	/* wait for smmu to lock */
	cmds += _wait_reg(adreno_dev, cmds, iommu->micro_mmu_ctrl >> 2,
			KGSL_IOMMU_IMPLDEF_MICRO_MMU_CTRL_IDLE,
			KGSL_IOMMU_IMPLDEF_MICRO_MMU_CTRL_IDLE, 0xF);

	return cmds - start;
}

static unsigned int _iommu_unlock(struct adreno_device *adreno_dev,
				  unsigned int *cmds)
{
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	struct kgsl_iommu *iommu = KGSL_IOMMU_PRIV(device);
	unsigned int *start = cmds;

	/*
	 * If we don't have this register, probe should have forced
	 * global pagetables and we shouldn't get here.
	 */
	if (WARN_ONCE(iommu->micro_mmu_ctrl == UINT_MAX,
		"invalid GPU IOMMU unlock sequence\n"))
		return 0;

	/* unlock the IOMMU lock */
	*cmds++ = cp_packet(adreno_dev, CP_REG_RMW, 3);
	*cmds++ = iommu->micro_mmu_ctrl >> 2;
	/* AND to unmask the lock bit */
	*cmds++ = ~(KGSL_IOMMU_IMPLDEF_MICRO_MMU_CTRL_HALT);
	/* OR with 0 so lock bit is unset */
	*cmds++ = 0;

	/* release all commands since _iommu_lock() with wait_for_me */
	cmds += cp_wait_for_me(adreno_dev, cmds);

	return cmds - start;
}

static unsigned int _vbif_lock(struct adreno_device *adreno_dev,
			unsigned int *cmds)
{
	unsigned int *start = cmds;
	/*
	 * glue commands together until next
	 * WAIT_FOR_ME
	 */
	cmds += _wait_reg(adreno_dev, cmds,
			adreno_getreg(adreno_dev, ADRENO_REG_CP_WFI_PEND_CTR),
			1, 0xFFFFFFFF, 0xF);

	/* MMU-500 VBIF stall */
	*cmds++ = cp_packet(adreno_dev, CP_REG_RMW, 3);
	*cmds++ = A3XX_VBIF_DDR_OUTPUT_RECOVERABLE_HALT_CTRL0;
	/* AND to unmask the HALT bit */
	*cmds++ = ~(VBIF_RECOVERABLE_HALT_CTRL);
	/* OR to set the HALT bit */
	*cmds++ = 0x1;

	/* Wait for acknowledgment */
	cmds += _wait_reg(adreno_dev, cmds,
			A3XX_VBIF_DDR_OUTPUT_RECOVERABLE_HALT_CTRL1,
			1, 0xFFFFFFFF, 0xF);

	return cmds - start;
}

static unsigned int _vbif_unlock(struct adreno_device *adreno_dev,
				unsigned int *cmds)
{
	unsigned int *start = cmds;

	/* MMU-500 VBIF unstall */
	*cmds++ = cp_packet(adreno_dev, CP_REG_RMW, 3);
	*cmds++ = A3XX_VBIF_DDR_OUTPUT_RECOVERABLE_HALT_CTRL0;
	/* AND to unmask the HALT bit */
	*cmds++ = ~(VBIF_RECOVERABLE_HALT_CTRL);
	/* OR to reset the HALT bit */
	*cmds++ = 0;

	/* release all commands since _vbif_lock() with wait_for_me */
	cmds += cp_wait_for_me(adreno_dev, cmds);
	return cmds - start;
}

static unsigned int _cp_smmu_reg(struct adreno_device *adreno_dev,
				unsigned int *cmds,
				enum kgsl_iommu_reg_map reg,
				unsigned int num)
{
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	struct kgsl_iommu *iommu = KGSL_IOMMU_PRIV(device);
	unsigned int *start = cmds;
	unsigned int offset;

	offset = kgsl_mmu_get_reg_ahbaddr(KGSL_MMU(adreno_dev),
					  KGSL_IOMMU_CONTEXT_USER, reg) >> 2;

	/* Required for a3x, a4x, a5x families */
	if (adreno_is_a5xx(adreno_dev) || iommu->version == 1) {
		*cmds++ = cp_register(adreno_dev, offset, num);
	} else if (adreno_is_a3xx(adreno_dev)) {
		*cmds++ = cp_packet(adreno_dev, CP_REG_WR_NO_CTXT, num + 1);
		*cmds++ = offset;
	} else if (adreno_is_a4xx(adreno_dev)) {
		*cmds++ = cp_packet(adreno_dev, CP_WIDE_REG_WRITE, num + 1);
		*cmds++ = offset;
	}
	return cmds - start;
}

static unsigned int _tlbiall(struct adreno_device *adreno_dev,
				unsigned int *cmds)
{
	unsigned int *start = cmds;
	unsigned int tlbstatus;

	tlbstatus = kgsl_mmu_get_reg_ahbaddr(KGSL_MMU(adreno_dev),
			KGSL_IOMMU_CONTEXT_USER,
			KGSL_IOMMU_CTX_TLBSTATUS) >> 2;

	cmds += _cp_smmu_reg(adreno_dev, cmds, KGSL_IOMMU_CTX_TLBIALL, 1);
	*cmds++ = 1;

	cmds += _cp_smmu_reg(adreno_dev, cmds, KGSL_IOMMU_CTX_TLBSYNC, 1);
	*cmds++ = 0;

	cmds += _wait_reg(adreno_dev, cmds, tlbstatus, 0,
			KGSL_IOMMU_CTX_TLBSTATUS_SACTIVE, 0xF);

	return cmds - start;
}


/**
 * _adreno_iommu_add_idle_cmds - Add pm4 packets for GPU idle
 * @adreno_dev - Pointer to device structure
 * @cmds - Pointer to memory where idle commands need to be added
 */
static inline int _adreno_iommu_add_idle_cmds(struct adreno_device *adreno_dev,
							unsigned int *cmds)
{
	unsigned int *start = cmds;

	cmds += cp_wait_for_idle(adreno_dev, cmds);

	if (adreno_is_a3xx(adreno_dev))
		cmds += cp_wait_for_me(adreno_dev, cmds);

	return cmds - start;
}

/*
 * _invalidate_uche_cpu() - Invalidate UCHE using CPU
 * @adreno_dev: the device
 */
static void _invalidate_uche_cpu(struct adreno_device *adreno_dev)
{
	/* Invalidate UCHE using CPU */
	if (adreno_is_a5xx(adreno_dev))
		adreno_writereg(adreno_dev,
			ADRENO_REG_UCHE_INVALIDATE0, 0x12);
	else if (adreno_is_a4xx(adreno_dev)) {
		adreno_writereg(adreno_dev,
			ADRENO_REG_UCHE_INVALIDATE0, 0);
		adreno_writereg(adreno_dev,
			ADRENO_REG_UCHE_INVALIDATE1, 0x12);
	} else if (adreno_is_a3xx(adreno_dev)) {
		adreno_writereg(adreno_dev,
			ADRENO_REG_UCHE_INVALIDATE0, 0);
		adreno_writereg(adreno_dev,
			ADRENO_REG_UCHE_INVALIDATE1,
			0x90000000);
	} else {
		WARN_ONCE(1, "GPU UCHE invalidate sequence not defined\n");
	}
}

/*
 * _ctx_switch_use_cpu_path() - Decide whether to use cpu path
 * @adreno_dev: the device
 * @new_pt: pagetable to switch
 * @rb: ringbuffer for ctx switch
 *
 * If we are idle and switching to default pagetable it is
 * preferable to poke the iommu directly rather than using the
 * GPU command stream.
 */
static bool _ctx_switch_use_cpu_path(
				struct adreno_device *adreno_dev,
				struct kgsl_pagetable *new_pt,
				struct adreno_ringbuffer *rb)
{
	struct kgsl_mmu *mmu = KGSL_MMU(adreno_dev);

	/*
	 * If rb is current, we can use cpu path when GPU is
	 * idle and we are switching to default pt.
	 * If rb is not current, we can use cpu path when rb has no
	 * pending commands (rptr = wptr) and we are switching to default pt.
	 */
	if (adreno_dev->cur_rb == rb)
		return adreno_isidle(KGSL_DEVICE(adreno_dev)) &&
			(new_pt == mmu->defaultpagetable);
	else if (adreno_rb_empty(rb) &&
			(new_pt == mmu->defaultpagetable))
		return true;

	return false;
}

/**
 * adreno_iommu_set_apriv() - Generate commands to set/reset the APRIV
 * @adreno_dev: Device on which the commands will execute
 * @cmds: The memory pointer where commands are generated
 * @set: If set then APRIV is set else reset
 *
 * Returns the number of commands generated
 */
static unsigned int adreno_iommu_set_apriv(struct adreno_device *adreno_dev,
				unsigned int *cmds, int set)
{
	unsigned int *cmds_orig = cmds;

	/* adreno 3xx doesn't have the CP_CNTL.APRIV field */
	if (adreno_is_a3xx(adreno_dev))
		return 0;

	cmds += cp_wait_for_idle(adreno_dev, cmds);
	cmds += cp_wait_for_me(adreno_dev, cmds);
	*cmds++ = cp_register(adreno_dev, adreno_getreg(adreno_dev,
				ADRENO_REG_CP_CNTL), 1);
	if (set)
		*cmds++ = 1;
	else
		*cmds++ = 0;

	return cmds - cmds_orig;
}

static inline int _adreno_iommu_add_idle_indirect_cmds(
			struct adreno_device *adreno_dev,
			unsigned int *cmds, uint64_t nop_gpuaddr)
{
	unsigned int *start = cmds;
	/*
	 * Adding an indirect buffer ensures that the prefetch stalls until
	 * the commands in indirect buffer have completed. We need to stall
	 * prefetch with a nop indirect buffer when updating pagetables
	 * because it provides stabler synchronization.
	 */
	cmds += cp_wait_for_me(adreno_dev, cmds);
	*cmds++ = cp_mem_packet(adreno_dev, CP_INDIRECT_BUFFER_PFE, 2, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds, nop_gpuaddr);
	*cmds++ = 2;
	cmds += cp_wait_for_idle(adreno_dev, cmds);
	return cmds - start;
}

/**
 * _adreno_mmu_set_pt_update_condition() - Generate commands to setup a
 * flag to indicate whether pt switch is required or not by comparing
 * current pt id and incoming pt id
 * @rb: The RB on which the commands will execute
 * @cmds: The pointer to memory where the commands are placed.
 * @ptname: Incoming pt id to set to
 *
 * Returns number of commands added.
 */
static unsigned int _adreno_mmu_set_pt_update_condition(
			struct adreno_ringbuffer *rb,
			unsigned int *cmds, unsigned int ptname)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	unsigned int *cmds_orig = cmds;
	/*
	 * write 1 to switch pt flag indicating that we need to execute the
	 * pt switch commands
	 */
	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 2, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(switch_pt_enable)));
	*cmds++ = 1;
	*cmds++ = cp_packet(adreno_dev, CP_WAIT_MEM_WRITES, 1);
	*cmds++ = 0;
	cmds += cp_wait_for_me(adreno_dev, cmds);
	/*
	 * The current ptname is
	 * directly compared to the incoming pt id
	 */
	*cmds++ = cp_mem_packet(adreno_dev, CP_COND_WRITE, 6, 2);
	/* write to mem space, when a mem space is equal to ref val */
	*cmds++ = (1 << 8) | (1 << 4) | 3;
	cmds += cp_gpuaddr(adreno_dev, cmds,
	   (adreno_dev->ringbuffers[0].pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(current_global_ptname)));
	*cmds++ = ptname;
	*cmds++ = 0xFFFFFFFF;
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(switch_pt_enable)));
	*cmds++ = 0;
	*cmds++ = cp_packet(adreno_dev, CP_WAIT_MEM_WRITES, 1);
	*cmds++ = 0;
	cmds += cp_wait_for_me(adreno_dev, cmds);

	return cmds - cmds_orig;
}

/**
 * _adreno_iommu_pt_update_pid_to_mem() - Add commands to write to memory the
 * pagetable id.
 * @rb: The ringbuffer on which these commands will execute
 * @cmds: Pointer to memory where the commands are copied
 * @ptname: The pagetable id
 */
static unsigned int _adreno_iommu_pt_update_pid_to_mem(
				struct adreno_ringbuffer *rb,
				unsigned int *cmds, int ptname)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	unsigned int *cmds_orig = cmds;

	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 2, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(current_rb_ptname)));
	*cmds++ = ptname;
	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 2, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds,
		(adreno_dev->ringbuffers[0].pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(current_global_ptname)));
	*cmds++ = ptname;
	/* pagetable switch done, Housekeeping: set the switch_pt_enable to 0 */
	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 2, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(switch_pt_enable)));
	*cmds++ = 0;
	*cmds++ = cp_packet(adreno_dev, CP_WAIT_MEM_WRITES, 1);
	*cmds++ = 0;
	cmds += cp_wait_for_me(adreno_dev, cmds);

	return cmds - cmds_orig;
}

static unsigned int _adreno_iommu_set_pt_v1(struct adreno_ringbuffer *rb,
					unsigned int *cmds_orig,
					u64 ttbr0, u32 contextidr, u32 ptname)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	unsigned int *cmds = cmds_orig;
	unsigned int *cond_exec_ptr;

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);

	/* set flag that indicates whether pt switch is required*/
	cmds += _adreno_mmu_set_pt_update_condition(rb, cmds, ptname);
	*cmds++ = cp_mem_packet(adreno_dev, CP_COND_EXEC, 4, 2);
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(switch_pt_enable)));
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(switch_pt_enable)));
	*cmds++ = 1;
	/* Exec count to be filled later */
	cond_exec_ptr = cmds;
	cmds++;

	cmds += cp_wait_for_idle(adreno_dev, cmds);

	cmds += _iommu_lock(adreno_dev, cmds);

	cmds += _cp_smmu_reg(adreno_dev, cmds, KGSL_IOMMU_CTX_TTBR0, 2);
	*cmds++ = lower_32_bits(ttbr0);
	*cmds++ = upper_32_bits(ttbr0);
	cmds += _cp_smmu_reg(adreno_dev, cmds,
			KGSL_IOMMU_CTX_CONTEXTIDR, 1);
	*cmds++ = contextidr;

	/* a3xx doesn't have MEQ space to hold the TLBI commands */
	if (adreno_is_a3xx(adreno_dev))
		cmds += _iommu_unlock(adreno_dev, cmds);

	cmds += _tlbiall(adreno_dev, cmds);

	/* unlock or wait for me to finish the TLBI */
	if (!adreno_is_a3xx(adreno_dev))
		cmds += _iommu_unlock(adreno_dev, cmds);
	else
		cmds += cp_wait_for_me(adreno_dev, cmds);

	/* Exec count ordinal of CP_COND_EXEC packet */
	*cond_exec_ptr = (cmds - cond_exec_ptr - 1);
	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);
	cmds += _adreno_iommu_pt_update_pid_to_mem(rb, cmds, ptname);

	return cmds - cmds_orig;
}


static unsigned int _adreno_iommu_set_pt_v2_a3xx(struct kgsl_device *device,
					unsigned int *cmds_orig,
					u64 ttbr0, u32 contextidr)
{
	struct adreno_device *adreno_dev = ADRENO_DEVICE(device);
	unsigned int *cmds = cmds_orig;

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);

	cmds += _vbif_lock(adreno_dev, cmds);

	cmds += _cp_smmu_reg(adreno_dev, cmds, KGSL_IOMMU_CTX_TTBR0, 2);
	*cmds++ = lower_32_bits(ttbr0);
	*cmds++ = upper_32_bits(ttbr0);
	cmds += _cp_smmu_reg(adreno_dev, cmds, KGSL_IOMMU_CTX_CONTEXTIDR, 1);
	*cmds++ = contextidr;

	cmds += _vbif_unlock(adreno_dev, cmds);

	cmds += _tlbiall(adreno_dev, cmds);

	/* wait for me to finish the TLBI */
	cmds += cp_wait_for_me(adreno_dev, cmds);

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);

	return cmds - cmds_orig;
}

static unsigned int _adreno_iommu_set_pt_v2_a4xx(struct kgsl_device *device,
					unsigned int *cmds_orig,
					u64 ttbr0, u32 contextidr)
{
	struct adreno_device *adreno_dev = ADRENO_DEVICE(device);
	unsigned int *cmds = cmds_orig;

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);

	cmds += _vbif_lock(adreno_dev, cmds);

	cmds += _cp_smmu_reg(adreno_dev, cmds, KGSL_IOMMU_CTX_TTBR0, 2);
	*cmds++ = lower_32_bits(ttbr0);
	*cmds++ = upper_32_bits(ttbr0);
	cmds += _cp_smmu_reg(adreno_dev, cmds, KGSL_IOMMU_CTX_CONTEXTIDR, 1);
	*cmds++ = contextidr;

	cmds += _vbif_unlock(adreno_dev, cmds);

	cmds += _tlbiall(adreno_dev, cmds);

	/* wait for me to finish the TLBI */
	cmds += cp_wait_for_me(adreno_dev, cmds);

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);

	return cmds - cmds_orig;
}

static unsigned int _adreno_iommu_set_pt_v2_a5xx(struct kgsl_device *device,
					unsigned int *cmds_orig,
					u64 ttbr0, u32 contextidr,
					struct adreno_ringbuffer *rb)
{
	struct adreno_device *adreno_dev = ADRENO_DEVICE(device);
	unsigned int *cmds = cmds_orig;

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);
	cmds += cp_wait_for_me(adreno_dev, cmds);

	/* CP switches the pagetable and flushes the Caches */
	*cmds++ = cp_packet(adreno_dev, CP_SMMU_TABLE_UPDATE, 3);
	*cmds++ = lower_32_bits(ttbr0);
	*cmds++ = upper_32_bits(ttbr0);
	*cmds++ = contextidr;

	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 4, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(ttbr0)));
	*cmds++ = lower_32_bits(ttbr0);
	*cmds++ = upper_32_bits(ttbr0);
	*cmds++ = contextidr;

	/* release all commands with wait_for_me */
	cmds += cp_wait_for_me(adreno_dev, cmds);

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);

	return cmds - cmds_orig;
}

static unsigned int _adreno_iommu_set_pt_v2_a6xx(struct kgsl_device *device,
					unsigned int *cmds_orig,
					u64 ttbr0, u32 contextidr,
					struct adreno_ringbuffer *rb,
					unsigned int cb_num)
{
	struct adreno_device *adreno_dev = ADRENO_DEVICE(device);
	unsigned int *cmds = cmds_orig;

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);
	cmds += cp_wait_for_me(adreno_dev, cmds);

	/* CP switches the pagetable and flushes the Caches */
	*cmds++ = cp_packet(adreno_dev, CP_SMMU_TABLE_UPDATE, 4);
	*cmds++ = lower_32_bits(ttbr0);
	*cmds++ = upper_32_bits(ttbr0);
	*cmds++ = contextidr;
	*cmds++ = cb_num;

	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 4, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds, (rb->pagetable_desc.gpuaddr +
		PT_INFO_OFFSET(ttbr0)));
	*cmds++ = lower_32_bits(ttbr0);
	*cmds++ = upper_32_bits(ttbr0);
	*cmds++ = contextidr;

	/* release all commands with wait_for_me */
	cmds += cp_wait_for_me(adreno_dev, cmds);

	cmds += _adreno_iommu_add_idle_cmds(adreno_dev, cmds);

	return cmds - cmds_orig;
}

/**
 * adreno_iommu_set_pt_generate_cmds() - Generate commands to change pagetable
 * @rb: The RB pointer in which these commaands are to be submitted
 * @cmds: The pointer where the commands are placed
 * @pt: The pagetable to switch to
 */
unsigned int adreno_iommu_set_pt_generate_cmds(
					struct adreno_ringbuffer *rb,
					unsigned int *cmds,
					struct kgsl_pagetable *pt)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	struct kgsl_iommu *iommu = KGSL_IOMMU_PRIV(device);
	struct kgsl_iommu_context *ctx = &iommu->ctx[KGSL_IOMMU_CONTEXT_USER];
	u64 ttbr0;
	u32 contextidr;
	unsigned int *cmds_orig = cmds;

	ttbr0 = kgsl_mmu_pagetable_get_ttbr0(pt);
	contextidr = kgsl_mmu_pagetable_get_contextidr(pt);

	cmds += adreno_iommu_set_apriv(adreno_dev, cmds, 1);

	cmds += _adreno_iommu_add_idle_indirect_cmds(adreno_dev, cmds,
		iommu->setstate.gpuaddr + KGSL_IOMMU_SETSTATE_NOP_OFFSET);

	if (iommu->version >= 2) {
		if (adreno_is_a6xx(adreno_dev))
			cmds += _adreno_iommu_set_pt_v2_a6xx(device, cmds,
						ttbr0, contextidr, rb,
						ctx->cb_num);
		else if (adreno_is_a5xx(adreno_dev))
			cmds += _adreno_iommu_set_pt_v2_a5xx(device, cmds,
						ttbr0, contextidr, rb);
		else if (adreno_is_a4xx(adreno_dev))
			cmds += _adreno_iommu_set_pt_v2_a4xx(device, cmds,
						ttbr0, contextidr);
		else if (adreno_is_a3xx(adreno_dev))
			cmds += _adreno_iommu_set_pt_v2_a3xx(device, cmds,
						ttbr0, contextidr);
		else
			WARN_ONCE(1,
			"GPU IOMMU set pagetable sequence not defined\n");
	} else {
		cmds += _adreno_iommu_set_pt_v1(rb, cmds, ttbr0, contextidr,
						pt->name);
	}

	/* invalidate all base pointers */
	cmds += cp_invalidate_state(adreno_dev, cmds);

	cmds += adreno_iommu_set_apriv(adreno_dev, cmds, 0);

	return cmds - cmds_orig;
}

/**
 * __add_curr_ctxt_cmds() - Add commands to set a context id in memstore
 * @rb: The RB in which the commands will be added for execution
 * @cmds: Pointer to memory where commands are added
 * @drawctxt: The context whose id is being set in memstore
 *
 * Returns the number of dwords
 */
static unsigned int __add_curr_ctxt_cmds(struct adreno_ringbuffer *rb,
			unsigned int *cmds,
			struct adreno_context *drawctxt)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	unsigned int *cmds_orig = cmds;

	/* write the context identifier to memstore memory */
	*cmds++ = cp_packet(adreno_dev, CP_NOP, 1);
	*cmds++ = KGSL_CONTEXT_TO_MEM_IDENTIFIER;

	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 2, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds,
			MEMSTORE_RB_GPU_ADDR(device, rb, current_context));
	*cmds++ = (drawctxt ? drawctxt->base.id : 0);

	*cmds++ = cp_mem_packet(adreno_dev, CP_MEM_WRITE, 2, 1);
	cmds += cp_gpuaddr(adreno_dev, cmds,
			MEMSTORE_ID_GPU_ADDR(device,
				KGSL_MEMSTORE_GLOBAL, current_context));
	*cmds++ = (drawctxt ? drawctxt->base.id : 0);

	/* Invalidate UCHE for new context */
	if (adreno_is_a6xx(adreno_dev)) {
		*cmds++ = cp_packet(adreno_dev, CP_EVENT_WRITE, 1);
		*cmds++ = 0x31; /* CACHE_INVALIDATE */
	} else if (adreno_is_a5xx(adreno_dev)) {
		*cmds++ = cp_register(adreno_dev,
			adreno_getreg(adreno_dev,
		ADRENO_REG_UCHE_INVALIDATE0), 1);
		*cmds++ = 0x12;
	} else if (adreno_is_a4xx(adreno_dev)) {
		*cmds++ = cp_register(adreno_dev,
			adreno_getreg(adreno_dev,
			ADRENO_REG_UCHE_INVALIDATE0), 2);
		*cmds++ = 0;
		*cmds++ = 0x12;
	} else if (adreno_is_a3xx(adreno_dev)) {
		*cmds++ = cp_register(adreno_dev,
			adreno_getreg(adreno_dev,
			ADRENO_REG_UCHE_INVALIDATE0), 2);
		*cmds++ = 0;
		*cmds++ = 0x90000000;
	} else
		WARN_ONCE(1, "GPU UCHE invalidate sequence not defined\n");

	return cmds - cmds_orig;
}

/*
 * _set_ctxt_cpu() - Set the current context in memstore
 * @rb: The ringbuffer memstore to set curr context
 * @drawctxt: The context whose id is being set in memstore
 */
static void _set_ctxt_cpu(struct adreno_ringbuffer *rb,
			struct adreno_context *drawctxt)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);

	if (rb == adreno_dev->cur_rb) {
		_invalidate_uche_cpu(adreno_dev);
		/* Update global memstore with current context */
		kgsl_sharedmem_writel(device, &device->memstore,
			KGSL_MEMSTORE_OFFSET(KGSL_MEMSTORE_GLOBAL,
						current_context),
			drawctxt ? drawctxt->base.id : 0);
	}
	/* Update rb memstore with current context */
	kgsl_sharedmem_writel(device, &device->memstore,
		MEMSTORE_RB_OFFSET(rb, current_context),
		drawctxt ? drawctxt->base.id : 0);
}

/**
 * _set_ctxt_gpu() - Add commands to set the current context in memstore
 * @rb: The ringbuffer in which commands to set memstore are added
 * @drawctxt: The context whose id is being set in memstore
 */
static int _set_ctxt_gpu(struct adreno_ringbuffer *rb,
			struct adreno_context *drawctxt)
{
	unsigned int link[15], *cmds;
	int result;

	cmds = &link[0];
	cmds += __add_curr_ctxt_cmds(rb, cmds, drawctxt);
	result = adreno_ringbuffer_issuecmds(rb, 0, link,
			(unsigned int)(cmds - link));
	return result;
}

/**
 * _set_pagetable_cpu() - Use CPU to switch the pagetable
 * @rb: The rb for which pagetable needs to be switched
 * @new_pt: The pagetable to switch to
 */
static int _set_pagetable_cpu(struct adreno_ringbuffer *rb,
			struct kgsl_pagetable *new_pt)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	int result;

	/* update TTBR0 only if we are updating current RB */
	if (adreno_dev->cur_rb == rb) {
		result = kgsl_mmu_set_pt(&device->mmu, new_pt);
		if (result)
			return result;
		/* write the new pt set to memory var */
		adreno_ringbuffer_set_global(adreno_dev, new_pt->name);
	}

	/* Update the RB pagetable info here */
	adreno_ringbuffer_set_pagetable(rb, new_pt);

	return 0;
}

/**
 * _set_pagetable_gpu() - Use GPU to switch the pagetable
 * @rb: The rb in which commands to switch pagetable are to be
 *    submitted
 * @new_pt: The pagetable to switch to
 */
static int _set_pagetable_gpu(struct adreno_ringbuffer *rb,
			struct kgsl_pagetable *new_pt)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	unsigned int *link = NULL, *cmds;
	int result;

	link = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (link == NULL)
		return -ENOMEM;

	cmds = link;

	/* If we are in a fault the MMU will be reset soon */
	if (test_bit(ADRENO_DEVICE_FAULT, &adreno_dev->priv)) {
		kfree(link);
		return 0;
	}

	cmds += adreno_iommu_set_pt_generate_cmds(rb, cmds, new_pt);

	if ((unsigned int) (cmds - link) > (PAGE_SIZE / sizeof(unsigned int))) {
		KGSL_DRV_ERR(KGSL_DEVICE(adreno_dev),
			"Temp command buffer overflow\n");

		/*
		 * Temp buffer not large enough for pagetable switch commands.
		 * Increase the size allocated above.
		 */
		BUG();
	}
	/*
	 * This returns the per context timestamp but we need to
	 * use the global timestamp for iommu clock disablement
	 */
	result = adreno_ringbuffer_issuecmds(rb,
			KGSL_CMD_FLAGS_PMODE, link,
			(unsigned int)(cmds - link));

	kfree(link);
	return result;
}

/**
 * adreno_iommu_init() - Adreno iommu init
 * @adreno_dev: Adreno device
 */
int adreno_iommu_init(struct adreno_device *adreno_dev)
{
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	struct kgsl_iommu *iommu = KGSL_IOMMU_PRIV(device);

	if (kgsl_mmu_get_mmutype(device) == KGSL_MMU_TYPE_NONE)
		return 0;

	/*
	 * A nop is required in an indirect buffer when switching
	 * pagetables in-stream
	 */

	kgsl_sharedmem_writel(device, &iommu->setstate,
				KGSL_IOMMU_SETSTATE_NOP_OFFSET,
				cp_packet(adreno_dev, CP_NOP, 1));

	/* set iommu features here */
	if (adreno_is_a420(adreno_dev))
		device->mmu.features |= KGSL_MMU_FLUSH_TLB_ON_MAP;

	/*
	 * A5XX: per process PT is supported starting PFP 0x5FF064 me 0x5FF052
	 * versions
	 */
	if (adreno_is_a5xx(adreno_dev) &&
		!MMU_FEATURE(&device->mmu, KGSL_MMU_GLOBAL_PAGETABLE)) {
		if ((adreno_compare_pfp_version(adreno_dev,
				A5XX_PFP_PER_PROCESS_UCODE_VER) < 0) ||
		    (adreno_compare_pm4_version(adreno_dev,
				A5XX_PM4_PER_PROCESS_UCODE_VER) < 0)) {
			KGSL_DRV_ERR(device,
				"Invalid ucode for per process pagetables\n");
			return -ENODEV;
		}
	}

	/* Enable guard page MMU feature for A3xx and A4xx targets only */
	if (adreno_is_a3xx(adreno_dev) || adreno_is_a4xx(adreno_dev))
		device->mmu.features |= KGSL_MMU_NEED_GUARD_PAGE;

	return 0;
}

/**
 * adreno_iommu_set_pt_ctx() - Change the pagetable of the current RB
 * @device: Pointer to device to which the rb belongs
 * @rb: The RB pointer on which pagetable is to be changed
 * @new_pt: The new pt the device will change to
 * @drawctxt: The context whose pagetable the ringbuffer is switching to,
 * NULL means KGSL_CONTEXT_GLOBAL
 *
 * Returns 0 on success else error code.
 */
int adreno_iommu_set_pt_ctx(struct adreno_ringbuffer *rb,
			struct kgsl_pagetable *new_pt,
			struct adreno_context *drawctxt,
			unsigned long flags)
{
	struct adreno_device *adreno_dev = ADRENO_RB_DEVICE(rb);
	struct kgsl_device *device = KGSL_DEVICE(adreno_dev);
	struct kgsl_pagetable *cur_pt = device->mmu.defaultpagetable;
	int result = 0;
	int cpu_path = 0;

	/* Just do the context switch incase of NOMMU */
	if (kgsl_mmu_get_mmutype(device) == KGSL_MMU_TYPE_NONE) {
		if ((!(flags & ADRENO_CONTEXT_SWITCH_FORCE_GPU)) &&
			adreno_isidle(device) && !adreno_is_a6xx(adreno_dev))
			_set_ctxt_cpu(rb, drawctxt);
		else
			result = _set_ctxt_gpu(rb, drawctxt);

		return result;
	}

	if (rb->drawctxt_active)
		cur_pt = rb->drawctxt_active->base.proc_priv->pagetable;

	cpu_path = !(flags & ADRENO_CONTEXT_SWITCH_FORCE_GPU) &&
		_ctx_switch_use_cpu_path(adreno_dev, new_pt, rb);

	/* Pagetable switch */
	if (new_pt != cur_pt) {
		if (cpu_path)
			result = _set_pagetable_cpu(rb, new_pt);
		else
			result = _set_pagetable_gpu(rb, new_pt);
	}

	if (result)
		return result;

	/* Context switch */
	if (cpu_path && !adreno_is_a6xx(adreno_dev))
		_set_ctxt_cpu(rb, drawctxt);
	else
		result = _set_ctxt_gpu(rb, drawctxt);

	return result;
}