Commit d601ea91 authored by Frederic Barrat's avatar Frederic Barrat Committed by Michael Ellerman
Browse files

cxl: Support the cxl kernel API from a guest 



Like on bare-metal, the cxl driver creates a virtual PHB and a pci
device for the AFU. The configuration space of the device is mapped to
the configuration record of the AFU.

Reuse the code defined in afu_cr_read8|16|32() when reading the
configuration space of the AFU device.

Even though the (virtual) AFU device is a pci device, the adapter is
not. So a driver using the cxl kernel API cannot read the VPD of the
adapter through the usual PCI interface. Therefore, we add a call to
the cxl kernel API:
ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count);

Co-authored-by: default avatarChristophe Lombard <clombard@linux.vnet.ibm.com>
Signed-off-by: default avatarFrederic Barrat <fbarrat@linux.vnet.ibm.com>
Signed-off-by: default avatarChristophe Lombard <clombard@linux.vnet.ibm.com>
Reviewed-by: default avatarManoj Kumar <manoj@linux.vnet.ibm.com>
Acked-by: default avatarIan Munsie <imunsie@au1.ibm.com>
Signed-off-by: default avatarMichael Ellerman <mpe@ellerman.id.au>
parent b40844aa

drivers/misc/cxl/api.c

+46 −17
Original line number Diff line number Diff line
@@ -89,28 +89,11 @@ int cxl_release_context(struct cxl_context *ctx) 
}

EXPORT_SYMBOL_GPL(cxl_release_context);



int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)

{

	if (num == 0)

		num = ctx->afu->pp_irqs;

	return afu_allocate_irqs(ctx, num);

}

EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);



void cxl_free_afu_irqs(struct cxl_context *ctx)

{

	afu_irq_name_free(ctx);

	cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);

}

EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);



static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num)

{

	__u16 range;

	int r;



	WARN_ON(num == 0);



	for (r = 0; r < CXL_IRQ_RANGES; r++) {

		range = ctx->irqs.range[r];

		if (num < range) {
@@ -121,6 +104,44 @@ static irq_hw_number_t cxl_find_afu_irq(struct cxl_context *ctx, int num) 
	return 0;

}



int cxl_allocate_afu_irqs(struct cxl_context *ctx, int num)

{

	int res;

	irq_hw_number_t hwirq;



	if (num == 0)

		num = ctx->afu->pp_irqs;

	res = afu_allocate_irqs(ctx, num);

	if (!res && !cpu_has_feature(CPU_FTR_HVMODE)) {

		/* In a guest, the PSL interrupt is not multiplexed. It was

		 * allocated above, and we need to set its handler

		 */

		hwirq = cxl_find_afu_irq(ctx, 0);

		if (hwirq)

			cxl_map_irq(ctx->afu->adapter, hwirq, cxl_ops->psl_interrupt, ctx, "psl");

	}

	return res;

}

EXPORT_SYMBOL_GPL(cxl_allocate_afu_irqs);



void cxl_free_afu_irqs(struct cxl_context *ctx)

{

	irq_hw_number_t hwirq;

	unsigned int virq;



	if (!cpu_has_feature(CPU_FTR_HVMODE)) {

		hwirq = cxl_find_afu_irq(ctx, 0);

		if (hwirq) {

			virq = irq_find_mapping(NULL, hwirq);

			if (virq)

				cxl_unmap_irq(virq, ctx);

		}

	}

	afu_irq_name_free(ctx);

	cxl_ops->release_irq_ranges(&ctx->irqs, ctx->afu->adapter);

}

EXPORT_SYMBOL_GPL(cxl_free_afu_irqs);



int cxl_map_afu_irq(struct cxl_context *ctx, int num,

		    irq_handler_t handler, void *cookie, char *name)

{
@@ -356,3 +377,11 @@ void cxl_perst_reloads_same_image(struct cxl_afu *afu, 
	afu->adapter->perst_same_image = perst_reloads_same_image;

}

EXPORT_SYMBOL_GPL(cxl_perst_reloads_same_image);



ssize_t cxl_read_adapter_vpd(struct pci_dev *dev, void *buf, size_t count)

{

	struct cxl_afu *afu = cxl_pci_to_afu(dev);



	return cxl_ops->read_adapter_vpd(afu->adapter, buf, count);

}

EXPORT_SYMBOL_GPL(cxl_read_adapter_vpd);

drivers/misc/cxl/cxl.h

+5 −1
Original line number Diff line number Diff line
@@ -587,6 +587,7 @@ int cxl_pci_setup_irq(struct cxl *adapter, unsigned int hwirq, unsigned int virq 
int cxl_update_image_control(struct cxl *adapter);

int cxl_pci_reset(struct cxl *adapter);

void cxl_pci_release_afu(struct device *dev);

ssize_t cxl_pci_read_adapter_vpd(struct cxl *adapter, void *buf, size_t len);



/* common == phyp + powernv */

struct cxl_process_element_common {
@@ -808,7 +809,6 @@ int cxl_psl_purge(struct cxl_afu *afu); 


void cxl_stop_trace(struct cxl *cxl);

int cxl_pci_vphb_add(struct cxl_afu *afu);

void cxl_pci_vphb_reconfigure(struct cxl_afu *afu);

void cxl_pci_vphb_remove(struct cxl_afu *afu);



extern struct pci_driver cxl_pci_driver;
@@ -869,6 +869,10 @@ struct cxl_backend_ops { 
	int (*afu_cr_read16)(struct cxl_afu *afu, int cr_idx, u64 offset, u16 *val);

	int (*afu_cr_read32)(struct cxl_afu *afu, int cr_idx, u64 offset, u32 *val);

	int (*afu_cr_read64)(struct cxl_afu *afu, int cr_idx, u64 offset, u64 *val);

	int (*afu_cr_write8)(struct cxl_afu *afu, int cr_idx, u64 offset, u8 val);

	int (*afu_cr_write16)(struct cxl_afu *afu, int cr_idx, u64 offset, u16 val);

	int (*afu_cr_write32)(struct cxl_afu *afu, int cr_idx, u64 offset, u32 val);

	ssize_t (*read_adapter_vpd)(struct cxl *adapter, void *buf, size_t count);

};

extern const struct cxl_backend_ops cxl_native_ops;

extern const struct cxl_backend_ops cxl_guest_ops;

drivers/misc/cxl/guest.c

+26 −0
Original line number Diff line number Diff line
@@ -418,6 +418,24 @@ static int guest_afu_cr_read64(struct cxl_afu *afu, int cr_idx, u64 offset, 
	return _guest_afu_cr_readXX(8, afu, cr_idx, offset, out);

}



static int guest_afu_cr_write32(struct cxl_afu *afu, int cr, u64 off, u32 in)

{

	/* config record is not writable from guest */

	return -EPERM;

}



static int guest_afu_cr_write16(struct cxl_afu *afu, int cr, u64 off, u16 in)

{

	/* config record is not writable from guest */

	return -EPERM;

}



static int guest_afu_cr_write8(struct cxl_afu *afu, int cr, u64 off, u8 in)

{

	/* config record is not writable from guest */

	return -EPERM;

}



static int attach_afu_directed(struct cxl_context *ctx, u64 wed, u64 amr)

{

	struct cxl_process_element_hcall *elem;
@@ -807,6 +825,9 @@ int cxl_guest_init_afu(struct cxl *adapter, int slice, struct device_node *afu_n 


	afu->enabled = true;



	if ((rc = cxl_pci_vphb_add(afu)))

		dev_info(&afu->dev, "Can't register vPHB\n");



	return 0;



err_put2:
@@ -832,6 +853,7 @@ void cxl_guest_remove_afu(struct cxl_afu *afu) 
	if (!afu)

		return;



	cxl_pci_vphb_remove(afu);

	cxl_sysfs_afu_remove(afu);



	spin_lock(&afu->adapter->afu_list_lock);
@@ -987,4 +1009,8 @@ const struct cxl_backend_ops cxl_guest_ops = { 
	.afu_cr_read16 = guest_afu_cr_read16,

	.afu_cr_read32 = guest_afu_cr_read32,

	.afu_cr_read64 = guest_afu_cr_read64,

	.afu_cr_write8 = guest_afu_cr_write8,

	.afu_cr_write16 = guest_afu_cr_write16,

	.afu_cr_write32 = guest_afu_cr_write32,

	.read_adapter_vpd = cxl_guest_read_adapter_vpd,

};

drivers/misc/cxl/native.c

+50 −0
Original line number Diff line number Diff line
@@ -1019,6 +1019,52 @@ static int native_afu_cr_read8(struct cxl_afu *afu, int cr, u64 off, u8 *out) 
	return rc;

}



static int native_afu_cr_write32(struct cxl_afu *afu, int cr, u64 off, u32 in)

{

	if (unlikely(!cxl_ops->link_ok(afu->adapter)))

		return -EIO;

	if (unlikely(off >= afu->crs_len))

		return -ERANGE;

	out_le32(afu->native->afu_desc_mmio + afu->crs_offset +

		(cr * afu->crs_len) + off, in);

	return 0;

}



static int native_afu_cr_write16(struct cxl_afu *afu, int cr, u64 off, u16 in)

{

	u64 aligned_off = off & ~0x3L;

	u32 val32, mask, shift;

	int rc;



	rc = native_afu_cr_read32(afu, cr, aligned_off, &val32);

	if (rc)

		return rc;

	shift = (off & 0x3) * 8;

	WARN_ON(shift == 24);

	mask = 0xffff << shift;

	val32 = (val32 & ~mask) | (in << shift);



	rc = native_afu_cr_write32(afu, cr, aligned_off, val32);

	return rc;

}



static int native_afu_cr_write8(struct cxl_afu *afu, int cr, u64 off, u8 in)

{

	u64 aligned_off = off & ~0x3L;

	u32 val32, mask, shift;

	int rc;



	rc = native_afu_cr_read32(afu, cr, aligned_off, &val32);

	if (rc)

		return rc;

	shift = (off & 0x3) * 8;

	mask = 0xff << shift;

	val32 = (val32 & ~mask) | (in << shift);



	rc = native_afu_cr_write32(afu, cr, aligned_off, val32);

	return rc;

}



const struct cxl_backend_ops cxl_native_ops = {

	.module = THIS_MODULE,

	.adapter_reset = cxl_pci_reset,
@@ -1044,4 +1090,8 @@ const struct cxl_backend_ops cxl_native_ops = { 
	.afu_cr_read16 = native_afu_cr_read16,

	.afu_cr_read32 = native_afu_cr_read32,

	.afu_cr_read64 = native_afu_cr_read64,

	.afu_cr_write8 = native_afu_cr_write8,

	.afu_cr_write16 = native_afu_cr_write16,

	.afu_cr_write32 = native_afu_cr_write32,

	.read_adapter_vpd = cxl_pci_read_adapter_vpd,

};

drivers/misc/cxl/pci.c

+6 −3
Original line number Diff line number Diff line
@@ -881,6 +881,7 @@ static void cxl_pci_remove_afu(struct cxl_afu *afu) 
	if (!afu)

		return;



	cxl_pci_vphb_remove(afu);

	cxl_sysfs_afu_remove(afu);

	cxl_debugfs_afu_remove(afu);
@@ -1067,6 +1068,11 @@ static int cxl_vsec_looks_ok(struct cxl *adapter, struct pci_dev *dev) 
	return 0;

}



ssize_t cxl_pci_read_adapter_vpd(struct cxl *adapter, void *buf, size_t len)

{

	return pci_read_vpd(to_pci_dev(adapter->dev.parent), 0, len, buf);

}



static void cxl_release_adapter(struct device *dev)

{

	struct cxl *adapter = to_cxl_adapter(dev);
@@ -1272,7 +1278,6 @@ static void cxl_remove(struct pci_dev *dev) 
	 */

	for (i = 0; i < adapter->slices; i++) {

		afu = adapter->afu[i];

		cxl_pci_vphb_remove(afu);

		cxl_pci_remove_afu(afu);

	}

	cxl_pci_remove_adapter(adapter);
@@ -1451,8 +1456,6 @@ static pci_ers_result_t cxl_pci_slot_reset(struct pci_dev *pdev) 
		if (cxl_afu_select_best_mode(afu))

			goto err;



		cxl_pci_vphb_reconfigure(afu);



		list_for_each_entry(afu_dev, &afu->phb->bus->devices, bus_list) {

			/* Reset the device context.

			 * TODO: make this less disruptive

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