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author | Marc Zyngier <marc.zyngier@arm.com> | 2015-11-23 08:26:02 (GMT) |
---|---|---|
committer | Marc Zyngier <marc.zyngier@arm.com> | 2015-12-16 15:29:44 (GMT) |
commit | ab6484ee84c17a948c4235c20928f6aee295ced7 (patch) | |
tree | 0c9e1040ddeb9e6c397e660579c0bc7d7e80570a /drivers/base | |
parent | 9f9499ae8e6415cefc4fe0a96ad0e27864353c89 (diff) | |
download | linux-ab6484ee84c17a948c4235c20928f6aee295ced7.tar.xz |
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>
Diffstat (limited to 'drivers/base')
-rw-r--r-- | drivers/base/platform-msi.c | 32 |
1 files changed, 20 insertions, 12 deletions
diff --git a/drivers/base/platform-msi.c b/drivers/base/platform-msi.c index 5df4575..6148c78 100644 --- a/drivers/base/platform-msi.c +++ b/drivers/base/platform-msi.c @@ -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; - for (i = 0; i < nvec; i++) { - struct msi_desc *desc; + 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); } |