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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: Marc Zyngier <marc.zyngier@arm.com>
hifive-unleashed-5.1
Marc Zyngier 2015-11-23 08:26:02 +00:00
parent 9f9499ae8e
commit ab6484ee84
1 changed files with 20 additions and 12 deletions
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32
drivers/base/platform-msi.c
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@ -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
@ -110,13 +111,16 @@ 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) {
list_del(&desc->list);
free_msi_entry(desc);
if (desc->platform.msi_index >= base &&
desc->platform.msi_index < (base + nvec)) {
list_del(&desc->list);
free_msi_entry(desc);
}
}
}
@ -124,17 +128,22 @@ static int platform_msi_alloc_descs(struct device *dev, int nvec,
struct platform_msi_priv_data *data)
{
int 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++) {
struct msi_desc *desc;
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);
}