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Commit ab6484ee authored by Marc Zyngier's avatar Marc Zyngier
Browse files

platform-msi: Allow MSIs to be allocated in chunks 



MSIs for a given device are normally all allocated in one go.
Make sure the internal code can allocate them one at a time
if required.

Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 9f9499ae

drivers/base/platform-msi.c

+20 −12
Original line number Diff line number Diff line
@@ -25,6 +25,7 @@ 
#include <linux/slab.h>



#define DEV_ID_SHIFT	24

#define MAX_DEV_MSIS	(1 << (32 - DEV_ID_SHIFT))



/*

 * Internal data structure containing a (made up, but unique) devid
@@ -110,31 +111,39 @@ static void platform_msi_update_chip_ops(struct msi_domain_info *info) 
		chip->irq_write_msi_msg = platform_msi_write_msg;

}



static void platform_msi_free_descs(struct device *dev)

static void platform_msi_free_descs(struct device *dev, int base, int nvec)

{

	struct msi_desc *desc, *tmp;



	list_for_each_entry_safe(desc, tmp, dev_to_msi_list(dev), list) {

		if (desc->platform.msi_index >= base &&

		    desc->platform.msi_index < (base + nvec)) {

			list_del(&desc->list);

			free_msi_entry(desc);

		}

	}

}



static int platform_msi_alloc_descs(struct device *dev, int nvec,

				    struct platform_msi_priv_data *data)



{

	int i;



	for (i = 0; i < nvec; i++) {

	struct msi_desc *desc;

	int i, base = 0;



	if (!list_empty(dev_to_msi_list(dev))) {

		desc = list_last_entry(dev_to_msi_list(dev),

				       struct msi_desc, list);

		base = desc->platform.msi_index + 1;

	}



	for (i = 0; i < nvec; i++) {

		desc = alloc_msi_entry(dev);

		if (!desc)

			break;



		desc->platform.msi_priv_data = data;

		desc->platform.msi_index = i;

		desc->platform.msi_index = base + i;

		desc->nvec_used = 1;



		list_add_tail(&desc->list, dev_to_msi_list(dev));
@@ -142,7 +151,7 @@ static int platform_msi_alloc_descs(struct device *dev, int nvec, 


	if (i != nvec) {

		/* Clean up the mess */

		platform_msi_free_descs(dev);

		platform_msi_free_descs(dev, base, nvec);



		return -ENOMEM;

	}
@@ -201,8 +210,7 @@ int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec, 
	 * accordingly (which would impact the max number of MSI

	 * capable devices).

	 */

	if (!dev->msi_domain || !write_msi_msg || !nvec ||

	    nvec > (1 << (32 - DEV_ID_SHIFT)))

	if (!dev->msi_domain || !write_msi_msg || !nvec || nvec > MAX_DEV_MSIS)

		return -EINVAL;



	if (dev->msi_domain->bus_token != DOMAIN_BUS_PLATFORM_MSI) {
@@ -238,7 +246,7 @@ int platform_msi_domain_alloc_irqs(struct device *dev, unsigned int nvec, 
	return 0;



out_free_desc:

	platform_msi_free_descs(dev);

	platform_msi_free_descs(dev, 0, nvec);

out_free_id:

	ida_simple_remove(&platform_msi_devid_ida, priv_data->devid);

out_free_data:
@@ -266,5 +274,5 @@ void platform_msi_domain_free_irqs(struct device *dev) 
	}



	msi_domain_free_irqs(dev->msi_domain, dev);

	platform_msi_free_descs(dev);

	platform_msi_free_descs(dev, 0, MAX_DEV_MSIS);

}